Finding, Tracking and Characterizing Asteroids

Top-down view of the Solar System showing the position on August 9, 2024 UTC of all asteroids and comets detected by NEOWISE during the Reactivation Mission. The blue circles and points indicate the orbits and locations of Mercury, Venus and Mars. The Earth and its orbit are shown in cyan. Filled gray circles are Main Belt asteroids, filled green circles are Near Earth asteroids and the filled yellow squares are comets. The white points indicate the objects NEOWISE detected during the last week of surveying. The tick marks on the x and y axes are in increments of 1 AU. This animation shows how solar system object detections accumulated over the course of the survey. The white points show the new detections from each successive run of the WISE Moving Object Pipeline System, and illustrate how the NEOWISE scan longituded progress around the sky.

The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) and IPAC at the California Institute of Technology announce the NEOWISE Final Data Release.

The Final Data Release includes data acquired during the eleventh year of the NEOWISE Reactivation mission (Mainzer et al. 2014, ApJ, 792, 30), 13 December 2023 to 1 August 2024. These data are combined with data from the first ten years of NEOWISE mission into a single archive that contains ~26.9 million sets of 3.4 and 4.6 micron images and a database of ~199 billion source detections extracted from those images.

NEOWISE scanned the sky over twenty-one complete times during its 10.6 years of survey operations, with approximately six months between survey passes. Twelve or more independent exposures are made on each point of the sky during each survey epoch making the NEOWISE archive a time-domain resource for extracting multiple, independent thermal flux and position measurements of solar system small bodies and background galactic and extragalactic sources.

A guide to the NEOWISE data release, data access instructions, and supporting documentation are available at http://wise2.ipac.caltech.edu/docs/release/neowise. Access to the NEOWISE data products is available via the on-line and API services of the NASA/IPAC Infrared Science Archive (IRSA) at https://irsa.ipac.caltech.edu.

NEOWISE is a joint project of the Jet Propulsion Laboratory/California Institute of Technology and the University of California, Los Angeles, funded by the National Aeronautics and Space Administration Planetary Science Division.

NEOWISE: Mapping the Inner Solar System

This top-down view of the Solar System shows the positions of all asteroids and comets detected by NEOWISE during the Reactivation Mission, which concluded operations on August 8, 2024. The blue circles and points indicate the orbits and locations of Mercury, Venus and Mars. The Earth and its orbit are shown in cyan. Filled gray circles are Main Belt asteroids, filled green circles are Near Earth asteroids and the filled yellow squares are comets. The white points indicate the objects NEOWISE detected during the last week of surveying. The tick marks on the x and y axes are in increments of 1 AU. This animation shows how solar system object detections accumulated over the course of the survey. The white points show the new detections from each successive run of the WISE Moving Object Pipeline System, and illustrate how the NEOWISE scan longituded progress around the sky. Credit: Tommy Grav (Univ. of Arizona)

Source: NEOWISE/News

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Astronomers Release New All-Sky Map of Milky Way's Outer Reaches

Image of the Milky Way and the Large Magellanic Cloud (LMC) are overlaid on a map of the surrounding galactic halo. The smaller structure is a wake created by the LMC’s motion through this region. The larger light-blue feature corresponds to a high density of stars observed in the northern hemisphere of our galaxy. Credit: NASA/ESA/JPL-Caltech/Conroy et. al. 2021

The highlight of the new chart is a wake of stars, stirred up by a small galaxy set to collide with the Milky Way. The map could also offer a new test of dark matter theories. 

Astronomers using data from NASA and ESA (European Space Agency) telescopes have released a new all-sky map of the outermost region of our galaxy. Known as the galactic halo, this area lies outside the swirling spiral arms that form the Milky Way’s recognizable central disk and is sparsely populated with stars. Though the halo may appear mostly empty, it is also predicted to contain a massive reservoir of dark matter, a mysterious and invisible substance thought to make up the bulk of all the mass in the universe.

The data for the new map comes from ESA’s Gaia mission and NASA’s Near Earth Object Wide Field Infrared Survey Explorer, or NEOWISE, which operated from 2009 to 2013 under the moniker WISE. The study makes use of data collected by the spacecraft between 2009 and 2018.

The new map reveals how a small galaxy called the Large Magellanic Cloud (LMC) – so named because it is the larger of two dwarf galaxies orbiting the Milky Way – has sailed through the Milky Way’s galactic halo like a ship through water, its gravity creating a wake in the stars behind it. The LMC is located about 160,000 light-years from Earth and is less than one-quarter the mass of the Milky Way.

Simulation of Dark Matter in the Milky Way Halo

A simulation of dark matter surrounding the Milky Way galaxy (small ring at center) and the Large Magellanic Cloud (LMC) reveals two areas of high density: the smaller of the two light blue areas is a wake created by the LMC’s motion through this region. The larger corresponds to an excess of stars in the Milky Way’s northern hemisphere. Credit: NASA/JPL-Caltech/NSF/R. Hurt/N. Garavito-Camargo & G. Besla

Though the inner portions of the halo have been mapped with a high level of accuracy, this is the first map to provide a similar picture of the halo’s outer regions, where the wake is found – about 200,000 light-years to 325,000 light-years from the galactic center. Previous studies have hinted at the wake’s existence, but the all-sky map confirms its presence and offers a detailed view of its shape, size, and location.

This disturbance in the halo also provides astronomers with an opportunity to study something they can’t observe directly: dark matter. While it doesn’t emit, reflect, or absorb light, the gravitational influence of dark matter has been observed across the universe. It is thought to create a scaffolding on which galaxies are built, such that without it, galaxies would fly apart as they spin. Dark matter is estimated to be five times more common in the universe than all the matter that emits and/or interacts with light, from stars to planets to gas clouds.

Although there are multiple theories about the nature of dark matter, all of them indicate that it should be present in the Milky Way’s halo. If that’s the case, then as the LMC sails through this region, it should leave a wake in the dark matter as well. The wake observed in the new star map is thought to be the outline of this dark matter wake; the stars are like leaves on the surface of this invisible ocean, their position shifting with the dark matter.

The interaction between the dark matter and the Large Magellanic Cloud has big implications for our galaxy. As the LMC orbits the Milky Way, the dark matter’s gravity drags on the LMC and slows it down. This will cause the dwarf galaxy’s orbit to get smaller and smaller, until the galaxy finally collides with the Milky Way in about 2 billion years. These types of mergers might be a key driver in the growth of massive galaxies across the universe. In fact, astronomers think the Milky Way merged with another small galaxy about 10 billion years ago.

“This robbing of a smaller galaxy’s energy is not only why the LMC is merging with the Milky Way, but also why all galaxy mergers happen,” said Rohan Naidu, a doctoral student in astronomy at Harvard University and a co-author of the new paper. “The wake in our map is a really neat confirmation that our basic picture for how galaxies merge is on point!”

 A Rare Opportunity

The authors of the paper also think the new map – along with additional data and theoretical analyses – may provide a test for different theories about the nature of dark matter, such as whether it consists of particles, like regular matter, and what the properties of those particles are.

“You can imagine that the wake behind a boat will be different if the boat is sailing through water or through honey,” said Charlie Conroy, a professor at Harvard University and an astronomer at the Center for Astrophysics | Harvard & Smithsonian, who coauthored the study. “In this case, the properties of the wake are determined by which dark matter theory we apply.”

Conroy led the team that mapped the positions of over 1,300 stars in the halo. The challenge arose in trying to measure the exact distance from Earth to a large portion of those stars: It’s often impossible to figure out whether a star is faint and close by or bright and far away. The team used data from ESA’s Gaia mission, which provides the location of many stars in the sky but cannot measure distances to the stars in the Milky Way’s outer regions.

After identifying stars most likely located in the halo (because they were not obviously inside our galaxy or the LMC), the team looked for stars belonging to a class of giant stars with a specific light “signature” detectable by NEOWISE. Knowing the basic properties of the selected stars enabled the team to figure out their distance from Earth and create the new map. It charts a region starting about 200,000 light-years from the Milky Way’s center, or about where the LMC’s wake was predicted to begin, and extends about 125,000 light-years beyond that.

Conroy and his colleagues were inspired to hunt for LMC’s wake after learning about a team of astrophysicists at the University of Arizona in Tucson that makes computer models predicting what dark matter in the galactic halo should look like. The two groups worked together on the new study.

One model by the Arizona team, included in the new study, predicted the general structure and specific location of the star wake revealed in the new map. Once the data had confirmed that the model was correct, the team could confirm what other investigations have also hinted at: that the LMC is likely on its first orbit around the Milky Way. If the smaller galaxy had already made multiple orbits, the shape and location of the wake would be significantly different from what has been observed. Astronomers think the LMC formed in the same environment as the Milky Way and another nearby galaxy, M31, and that it is close to completing a long first orbit around our galaxy (about 13 billion years). Its next orbit will be much shorter due to its interaction with the Milky Way.

“Confirming our theoretical prediction with observational data tells us that our understanding of the interaction between these two galaxies, including the dark matter, is on the right track,” said University of Arizona doctoral student in astronomy Nicolás Garavito-Camargo, who led work on the model used in the paper.

The new map also provides astronomers with a rare opportunity to test the properties of the dark matter (the notional water or honey) in our own galaxy. In the new study, Garavito-Camargo and colleagues used a popular dark matter theory called cold dark matter that fits the observed star map relatively well. Now the University of Arizona team is running simulations that use different dark matter theories to see which one best matches the wake observed in the stars.

“It’s a really special set of circumstances that came together to create this scenario that lets us test our dark matter theories,” said Gurtina Besla, a co-author of the study and an associate professor at the University of Arizona. “But we can only realize that test with the combination of this new map and the dark matter simulations that we built.”

Launched in 2009, the WISE spacecraft was placed into hibernation in 2011 after completing its primary mission. In September 2013, NASA reactivated the spacecraft with the primary goal of scanning for near-Earth objects, or NEOs, and the mission and spacecraft were renamed NEOWISE. NASA’s Jet Propulsion Laboratory in Southern California managed and operated WISE for NASA’s Science Mission Directorate. The mission was selected competitively under NASA’s Explorers Program managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland. NEOWISE is a project of JPL, a division of Caltech, and the University of Arizona, supported by NASA’s Planetary Defense Coordination Office.

News Media Contact

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

Source: JPL-Caltech/

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Large, Distant Comets More Common Than Previously Thought

This illustration shows how scientists used data from NASA's WISE spacecraft to determine the nucleus sizes of comets. They subtracted a model of how dust and gas behave in comets in order to obtain the core size. Credit: NASA/JPL-Caltech. › Larger view

Comets that take more than 200 years to make one revolution around the Sun are notoriously difficult to study. Because they spend most of their time far from our area of the solar system, many "long-period comets" will never approach the Sun in a person's lifetime. In fact, those that travel inward from the Oort Cloud -- a group of icy bodies beginning roughly 186 billion miles (300 billion kilometers) away from the Sun -- can have periods of thousands or even millions of years.

NASA's WISE spacecraft, scanning the entire sky at infrared wavelengths, has delivered new insights about these distant wanderers. Scientists found that there are about seven times more long-period comets measuring at least 0.6 miles (1 kilometer) across than had been predicted previously. They also found that long-period comets are on average up to twice as large as "Jupiter family comets," whose orbits are shaped by Jupiter's gravity and have periods of less than 20 years. 

Researchers also observed that in eight months, three to five times as many long-period comets passed by the Sun than had been predicted. The findings are published in the Astronomical Journal.

"The number of comets speaks to the amount of material left over from the solar system's formation," said James Bauer, lead author of the study and now a research professor at the University of Maryland, College Park. "We now know that there are more relatively large chunks of ancient material coming from the Oort Cloud than we thought."

The Oort Cloud is too distant to be seen by current telescopes, but is thought to be a spherical distribution of small icy bodies at the outermost edge of the solar system. The density of comets within it is low, so the odds of comets colliding within it are rare. Long-period comets that WISE observed probably got kicked out of the Oort Cloud millions of years ago. The observations were carried out during the spacecraft's primary mission before it was renamed NEOWISE and reactivated to target near-Earth objects (NEOs).

"Our study is a rare look at objects perturbed out of the Oort Cloud," said Amy Mainzer, study co-author based at NASA's Jet Propulsion Laboratory, Pasadena, California, and principal investigator of the NEOWISE mission. "They are the most pristine examples of what the solar system was like when it formed."

Astronomers already had broader estimates of how many long-period and Jupiter family comets are in our solar system, but had no good way of measuring the sizes of long-period comets. That is because a comet has a "coma," a cloud of gas and dust that appears hazy in images and obscures the cometary nucleus. But by using the WISE data showing the infrared glow of this coma, scientists were able to "subtract" the coma from the overall comet and estimate the nucleus sizes of these comets. The data came from 2010 WISE observations of 95 Jupiter family comets and 56 long-period comets.

The results reinforce the idea that comets that pass by the Sun more often tend to be smaller than those spending much more time away from the Sun. That is because Jupiter family comets get more heat exposure, which causes volatile substances like water to sublimate and drag away other material from the comet's surface as well. 

"Our results mean there's an evolutionary difference between Jupiter family and long-period comets," Bauer said.

The existence of so many more long-period comets than predicted suggests that more of them have likely impacted planets, delivering icy materials from the outer reaches of the solar system. 

Researchers also found clustering in the orbits of the long-period comets they studied, suggesting there could have been larger bodies that broke apart to form these groups. 

The results will be important for assessing the likelihood of comets impacting our solar system's planets, including Earth. 

"Comets travel much faster than asteroids, and some of them are very big," Mainzer said. "Studies like this will help us define what kind of hazard long-period comets may pose." 

NASA's Jet Propulsion Laboratory in Pasadena, California, managed and operated WISE for NASA's Science Mission Directorate in Washington. The NEOWISE project is funded by the Near Earth Object Observation Program, now part of NASA's Planetary Defense Coordination Office. The spacecraft was put into hibernation mode in 2011 after twice scanned the entire sky, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.

For more information on WISE, visit:  https://www.nasa.gov/wise


News Media Contact

Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
elizabeth.landau@jpl.nasa.gov

Source: JPL-Caltech/News

NASA's NEOWISE Mission Spies One Comet, Maybe Two

An artist's rendition of 2016 WF9 as it passes Jupiter's orbit inbound toward the sun. 

Image credit: NASA/JPL-Caltech.  

Full image and caption

NASA's NEOWISE mission has recently discovered some celestial objects traveling through our neighborhood, including one on the blurry line between asteroid and comet. Another--definitely a comet--might be seen with binoculars through next week.

An object called 2016 WF9 was detected by the NEOWISE project on Nov. 27, 2016. It's in an orbit that takes it on a scenic tour of our solar system. At its farthest distance from the sun, it approaches Jupiter's orbit. Over the course of 4.9 Earth-years, it travels inward, passing under the main asteroid belt and the orbit of Mars until it swings just inside Earth's own orbit. After that, it heads back toward the outer solar system. Objects in these types of orbits have multiple possible origins; it might once have been a comet, or it could have strayed from a population of dark objects in the main asteroid belt.

2016 WF9 will approach Earth's orbit on Feb. 25, 2017. At a distance of nearly 32 million miles (51 million kilometers) from Earth, this pass will not bring it particularly close. The trajectory of 2016 WF9 is well understood, and the object is not a threat to Earth for the foreseeable future.

A different object, discovered by NEOWISE a month earlier, is more clearly a comet, releasing dust as it nears the sun. This comet, C/2016 U1 NEOWISE, "has a good chance of becoming visible through a good pair of binoculars, although we can't be sure because a comet's brightness is notoriously unpredictable," said Paul Chodas, manager of NASA's Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California.

As seen from the northern hemisphere during the first week of 2017, comet C/2016 U1 NEOWISE will be in the southeastern sky shortly before dawn. It is moving farther south each day and it will reach its closest point to the sun, inside the orbit of Mercury, on Jan. 14, before heading back out to the outer reaches of the solar system for an orbit lasting thousands of years. While it will be visible to skywatchers at Earth, it is not considered a threat to our planet either.

NEOWISE is the asteroid-and-comet-hunting portion of the Wide-Field Infrared Survey Explorer (WISE) mission. After discovering more than 34,000 asteroids during its original mission, NEOWISE was brought out of hibernation in December of 2013 to find and learn more about asteroids and comets that could pose an impact hazard to Earth. If 2016 WF9 turns out to be a comet, it would be the 10th discovered since reactivation. If it turns out to be an asteroid, it would be the 100th discovered since reactivation.

What NEOWISE scientists do know is that 2016 WF9 is relatively large: roughly 0.3 to 0.6 mile (0.5 to 1 kilometer) across.

It is also rather dark, reflecting only a few percent of the light that falls on its surface. This body resembles a comet in its reflectivity and orbit, but appears to lack the characteristic dust and gas cloud that defines a comet.

"2016 WF9 could have cometary origins," said Deputy Principal Investigator James "Gerbs" Bauer at JPL. "This object illustrates that the boundary between asteroids and comets is a blurry one; perhaps over time this object has lost the majority of the volatiles that linger on or just under its surface."

Near-Earth objects (NEOs) absorb most of the light that falls on them and re-emit that energy at infrared wavelengths. This enables NEOWISE's infrared detectors to study both dark and light-colored NEOs with nearly equal clarity and sensitivity.

"These are quite dark objects," said NEOWISE team member Joseph Masiero, "Think of new asphalt on streets; these objects would look like charcoal, or in some cases are even darker than that."

NEOWISE data have been used to measure the size of each near-Earth object it observes. Thirty-one asteroids that NEOWISE has discovered pass within about 20 lunar distances from Earth's orbit, and 19 are more than 460 feet (140 meters) in size but reflect less than 10 percent of the sunlight that falls on them.

The Wide-field Infrared Survey Explorer (WISE) has completed its seventh year in space after being launched on Dec. 14, 2009.

Data from the NEOWISE mission are available on a website for the public and scientific community to use. A guide to the NEOWISE data release, data access instructions and supporting documentation are available at:  http://wise2.ipac.caltech.edu/docs/release/neowise/

Access to the NEOWISE data products is available via the on-line and API services of the NASA/IPAC Infrared Science Archive.

A list of peer-reviewed papers using the NEOWISE data is available at:  http://neowise.ipac.caltech.edu/publications.html


News Media Contact

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-5011
agle@jpl.nasa.gov

Laurie Cantillo / Dwayne Brown
NASA Headquarters, Washington
202-358-1077 / 202-358-1726
laura.l.cantillo@nasa.gov / dwayne.c.brown@nasa.gov

Source: JPL-Caltech

NASA's WISE, Fermi Missions Reveal a Surprising Blazar Connection

An analysis of blazar properties observed by the Wide-field Infrared Survey Explorer (WISE) and Fermi's Large Area Telescope (LAT) reveal a correlation in emissions from the mid-infrared to gamma rays, an energy range spanning a factor of 10 billion. When plotted by gamma-ray and mid-infrared colors, confirmed Fermi blazars (gold dots) form a unique band not shared by other sources beyond our galaxy. A blue line marks the best fit of these values. The relationship allows astronomers to identify potential new gamma-ray blazars by studying WISE infrared data.

Credits: NASA's Goddard Space Flight Center/Francesco Massaro, University of Turin

Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope. As matter falls toward the supermassive black hole at the galaxy's center, some of it is accelerated outward at nearly the speed of light along jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, as illustrated here, the galaxy appears especially bright and is classified as a blazar. Credits: M. Weiss/CfA. Hi-res image

Astronomers studying distant galaxies powered by monster black holes have uncovered an unexpected link between two very different wavelengths of the light they emit, the mid-infrared and gamma rays. The discovery, which was accomplished by comparing data from NASA’s Wide-field Infrared Survey Explorer (WISE) and Fermi Gamma-ray Space Telescope, has enabled the researchers to uncover dozens of new blazar candidates.

Francesco Massaro at the University of Turin in Italy and Raffaele D’Abrusco at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, show for the first time that the mid-infrared colors of blazars in WISE data correlate to an equivalent measurement of their gamma-ray output.

"This connection links two vastly different forms of light over an energy range spanning a factor of 10 billion," said Massaro. "Ultimately, it will help us decipher how supermassive black holes in these galaxies manage to convert the matter around them into vast amounts of energy."

Blazars constitute more than half of the discrete gamma-ray sources seen by Fermi's Large Area Telescope (LAT). At the heart of a blazar lies a supersized black hole with millions of times the sun's mass surrounded by a disk of hot gas and dust. As material in the disk falls toward the black hole, some of it forms dual jets that blast subatomic particles straight out of the disk in opposite directions at nearly the speed of light. A blazar appears bright to Fermi for two reasons. Its jets produce many gamma rays, the highest-energy form of light, and we happen to be viewing the galaxy face on, which means one of its jets is pointing in our direction.

From January to August 2010, NASA's WISE mapped the entire sky in four infrared wavelengths, cataloging more than half a billion sources. In 2011, Massaro, D’Abrusco and their colleagues began using WISE data to investigate Fermi blazars.

"WISE made it possible to explore the mid-infrared colors of known gamma-ray blazars," said D’Abrusco. "We found that when we plotted Fermi blazars by their WISE colors in a particular way, they occupied a distinctly different part of the plot than other extragalactic gamma-ray sources."

The scientists detail new aspects of the infrared/gamma-ray connection in a paper published in The Astrophysical Journal on Aug. 9. They say the electrons, protons and other particles accelerated in blazar jets leave a specific "fingerprint" in the infrared light they emit. This same pattern is also clearly evident in their gamma rays. The relationship effectively connects the dots for blazars across an enormous swath of the electromagnetic spectrum.

About a thousand Fermi sources remain unassociated with known objects at any other wavelength. Astronomers suspect many of these are blazars, but there isn't enough information to classify them. The infrared/gamma-ray connection led the authors to search for new blazar candidates among WISE infrared sources located within the positional uncertainties of Fermi's unidentified gamma-ray objects. When the researchers applied this relationship to Fermi's unknown sources, they quickly found 130 potential blazars. Efforts are now under way to confirm the nature of these objects through follow-up studies and to search for additional candidates using the WISE connection.

"About a third of the gamma-ray objects seen by Fermi remained unknown in the most recent catalog, and this result represents an important advance in understanding their natures," said David Thompson, a Fermi deputy project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

NASA's Jet Propulsion Laboratory in Pasadena, California, manages and operates WISE for NASA's Science Mission Directorate in Washington. The spacecraft was put into hibernation mode in 2011 after twice scanning the entire sky, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

For more information on Fermi, visit:  www.nasa.gov/fermi

For more information on WISE, visit:  www.nasa.gov/wise

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For additional information, please contact:

Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
elizabeth.landau@jpl.nasa.gov

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By Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Maryland

Tracking A Mysterious Group of Asteroid Outcasts

The asteroid Euphrosyne glides across a field of background stars in this time-lapse view from NASA's WISE spacecraft.
Image credit: NASA/JPL-Caltech. › Full image and caption

High above the plane of our solar system, near the asteroid-rich abyss between Mars and Jupiter, scientists have found a unique family of space rocks. These interplanetary oddballs are the Euphrosyne (pronounced you-FROH-seh-nee) asteroids, and by any measure they have been distant, dark and mysterious -- until now.

Distributed at the outer edge of the asteroid belt, the Euphrosynes have an unusual orbital path that juts well above the ecliptic, the equator of the solar system. The asteroid after which they are named, Euphrosyne -- for an ancient Greek goddess of mirth -- is about 156 miles (260 kilometers) across and is one of the 10 largest asteroids in the main belt. Current-day Euphrosyne is thought to be a remnant of a massive collision about 700 million years ago that formed the family of smaller asteroids bearing its name. Scientists think this event was one of the last great collisions in the solar system.

A new study conducted by scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, used the agency's orbiting Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) telescope to look at these unusual asteroids to learn more about Near Earth Objects, or NEOs, and their potential threat to Earth.

NEOs are bodies whose orbits around the sun approach the orbit of Earth; this population is short-lived on astronomical timescales and is fed by other reservoirs of bodies in our solar system. As they orbit the sun, NEOs can occasionally have close approaches to Earth. For this reason alone -- the safety of our home planet -- the study of such objects is important.

As a result of their study, the JPL researchers believe the Euphrosynes may be the source of some of the dark NEOs found to be on long, highly inclined orbits. They found that, through gravitational interactions with Saturn, Euphrosyne asteroids can evolve into NEOs over timescales of millions of years.

NEOs can originate in either the asteroid belt or the more distant outer reaches of the solar system. Those from the asteroid belt are thought to evolve toward Earth's orbit through collisions and the gravitational influence of the planets. Originating well above the ecliptic and near the far edge of the asteroid belt, the forces that shape their trajectories toward Earth are far more moderate.

"The Euphrosynes have a gentle resonance with the orbit of Saturn that slowly moves these objects, eventually turning some of them into NEOs," said Joseph Masiero, JPL's lead scientist on the Euphrosynes study. "This particular gravitational resonance tends to push some of the larger fragments of the Euphrosyne family into near-Earth space."

By studying the Euphrosyne family asteroids with NEOWISE, JPL scientists have been able to measure their sizes and the amount of solar energy they reflect. Since NEOWISE operates in the infrared portion of the spectrum, it detects heat. Therefore, it can see dark objects far better than telescopes operating at visible wavelengths, which sense reflected sunlight. Its heat-sensing capability also allows it to measure sizes more accurately.

The 1,400 Euphrosyne asteroids studied by Masiero and his colleagues turned out to be large and dark, with highly inclined and elliptical orbits. These traits make them good candidates for the source of some of the dark NEOs the NEOWISE telescope detects and discovers, particularly those that also have highly inclined orbits.

NEOWISE was originally launched as an astrophysics mission in 2009 as the Wide-field Infrared Survey Explorer, or WISE. It operated until 2011 and was then shut down. But the spacecraft, now dubbed NEOWISE, would get a second life. "NEOWISE is a great tool for searching for near-Earth asteroids, particularly high-inclination, dark objects," Masiero said.

There are over 700,000 asteroidal bodies currently known in the main belt that range in size from large boulders to about 60 percent of the diameter of Earth's moon, with many yet to be discovered. This makes finding the specific point of origin of most NEOs extremely difficult.

With the Euphrosynes it's different. "Most near-Earth objects come from a number of sources in the inner region of the main belt, and they are quickly mixed around," Masiero said. "But with objects coming from this family, in such a unique region, we are able to draw a likely path for some of the unusual, dark NEOs we find back to the collision in which they were born."

A better understanding of the origins and behaviors of these mysterious objects will give researchers a clearer picture of asteroids in general, and in particular the NEOs that skirt our home planet's neighborhood. Such studies are important, and potentially critical, to the future of humanity, which is a primary reason JPL and its partners continue to relentlessly track these wanderers within our solar system. To date, U.S. assets have discovered more than 98 percent of the known NEOs.

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the NEOWISE mission for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

NASA's Near-Earth Object Program at NASA Headquarters, Washington, manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. JPL manages the Near-Earth Object Office for NASA's Science Mission Directorate in Washington.

For more information about NEOWISE, visit:  http://www.nasa.gov/neowise

More information about asteroids and near-Earth objects is available at:  http://neo.jpl.nasa.gov - http://www.jpl.nasa.gov/asteroidwatch

Media Contact

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov

Source: JPL-Caltech

Asteroid Named for Nobel Prize Winner Joins Historic Lineup

An asteroid discovered by NASA's NEOWISE spacecraft has been given the formal designation 316201 Malala, in honor of Malala Yousafzai of Pakistan, who received the Nobel Peace Prize in 2014. Image credit: NASA/JPL-Caltech.  › Larger image

An asteroid discovered by NASA's NEOWISE spacecraft has been given the formal designation 316201 Malala, in honor of Malala Yousafzai of Pakistan, who received the Nobel Peace Prize in 2014. The asteroid's previous appellation was 2010 ML48.

The International Astronomical Union (IAU) renamed the asteroid as the request of Amy Mainzer of NASA's Jet Propulsion Laboratory, Pasadena, California. Mainzer is the principal investigator of NASA's NEOWISE space telescope. The IAU is the sole worldwide organization recognized by astronomers everywhere to designate names for astronomical bodies. So far, Mainzer and the NEOWISE team have focused on pioneers in civil rights, science and the arts for the astronomical honor. Among the strong women of history who have already had NEOWISE-discovered asteroids named for them are civil rights activist Rosa Parks, conservationist Wangari Maathai, abolitionists Sojourner Truth and Harriet Tubman, and singer Aretha Franklin.

Asteroid Malala is in the main belt between Mars and Jupiter and orbits the sun every five-and-a-half years. It is about two-and-a-half miles (four kilometers) in diameter, and its surface is very dark, the color of printer toner.

NASA's Jet Propulsion Laboratory manages the NEOWISE mission for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information about NEOWISE, visit: http://www.nasa.gov/neowise

Media Contact

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov

Source:  JPL-Caltech/News

Comet Pan-STARRS Marches Across the Sky

NASA's NEOWISE mission captured a series of infrared images of comet C/2012 K1 -- also referred to as comet Pan-STARRS -- as it swept across our skies in May 2014.  Full image and caption

 

NEOWISE Spies Comet Pan-STARRS Against Galaxy Backdrop

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NASA's NEOWISE mission captured a series of pictures of comet C/2012 K1 -- also known as comet Pan-STARRS -- as it swept across our skies in May 2014.

The comet is named after the astronomical survey project called the Panoramic Survey Telescope and Rapid Response System in Hawaii, which discovered the icy visitor in May 2012. 

Comet Pan-STARRS hails from the outer fringes of our solar system, from a vast and distant reservoir of comets called the Oort cloud. 

The comet is relatively close to us -- it was only about 143 million miles (230 million kilometers) from Earth when this picture was taken. It is seen passing a much more distant spiral galaxy, called NGC 3726, which is about 55 million light-years from Earth, or 2 trillion times farther away than the comet.

Two tails can be seen lagging behind the head of the comet. The bigger tail is easy to see and is comprised of gas and smaller particles. A fainter, more southern tail, which is hard to spot in this image, may be comprised of larger, more dispersed grains of dust.

Comet Pan-STARRS is on its way around the sun, with its closest approach to the sun occurring in late August. It was visible to viewers in the northern hemisphere through most of June. In the fall, after the comet swings back around the sun, it may be visible to southern hemisphere viewers using small telescopes.

The image was made from data collected by the two infrared channels on board the NEOWISE spacecraft, with the longer-wavelength channel (centered at 4.5 microns) mapped to red and the shorter-wavelength channel (3.4 microns) mapped to cyan. The comet appears brighter in the longer wavelength band, suggesting that the comet may be producing significant quantities of carbon monoxide or carbon dioxide.

Originally called the Wide-field Infrared Survey Explorer (WISE), the NEOWISE spacecraft was put into hibernation in 2011 after its primary mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE is also characterizing previously known asteroids and comets to better understand their sizes and compositions.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the NEOWISE mission for NASA's Near-Earth Object Observation Program of its Planetary Science Division in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information on NEOWISE is online at: http://www.nasa.gov/wise and http://www.jpl.nasa.gov/wise/

Whitney Clavin
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-4673
whitney.clavin@jpl.nasa.gov

Source: JPL-Caltech

NASA's WISE Findings Poke Hole in Black Hole 'Doughnut' Theory

Active, supermassive black holes at the hearts of galaxies tend to fall into two categories: those that are hidden by dust, and those that are exposed. Image credit: NASA/JPL-Caltech.   Full image and caption

This infographic explains a popular theory of active supermassive black holes, referred to as the unified model -- and how new data from NASA's Wide-field Infrared Survey Explorer, or WISE, is at conflict with the model. Image credit: NASA/JPL-Caltech/NOAO/AURA/NSF/ESO. Full image and caption -  enlarge image

A survey of more than 170,000 supermassive black holes, using NASA's Wide-field Infrared Survey Explorer (WISE), has astronomers reexamining a decades-old theory about the varying appearances of these interstellar objects.

The unified theory of active, supermassive black holes, first developed in the late 1970s, was created to explain why black holes, though similar in nature, can look completely different. Some appear to be shrouded in dust, while others are exposed and easy to see.

The unified model answers this question by proposing that every black hole is surrounded by a dusty, doughnut-shaped structure called a torus. Depending on how these "doughnuts" are oriented in space, the black holes will take on various appearances. For example, if the doughnut is positioned so that we see it edge-on, the black hole is hidden from view. If the doughnut is observed from above or below, face-on, the black hole is clearly visible.

However, the new WISE results do not corroborate this theory. The researchers found evidence that something other than a doughnut structure may, in some circumstances, determine whether a black hole is visible or hidden. The team has not yet determined what this may be, but the results suggest the unified, or doughnut, model does not have all the answers.

"Our finding revealed a new feature about active black holes we never knew before, yet the details remain a mystery," said Lin Yan of NASA's Infrared Processing and Analysis Center (IPAC), based at the California Institute of Technology in Pasadena. "We hope our work will inspire future studies to better understand these fascinating objects."

Yan is the second author of the research accepted for publication in the Astrophysical Journal. The lead author is a post-doctoral researcher, Emilio Donoso, who worked with Yan at IPAC and has since moved to the Instituto de Ciencias Astronómicas, de la Tierra y del Espacio in Argentina. The research also was co-authored by Daniel Stern at NASA's Jet Propulsion Laboratory in Pasadena, California, and Roberto Assef of Universidad Diego Portales in Chile and formerly of JPL.

Every galaxy has a massive black hole at its heart. The new study focuses on the "feeding" ones, called active, supermassive black holes, or active galactic nuclei. These black holes gorge on surrounding gas material that fuels their growth. 

With the aid of computers, scientists were able to pick out more than 170,000 active supermassive black holes from the WISE data. They then measured the clustering of the galaxies containing both hidden and exposed black holes -- the degree to which the objects clump together across the sky.

If the unified model were true, and the hidden black holes are simply blocked from view by doughnuts in the edge-on configuration, then researchers would expect them to cluster in the same way as the exposed ones. According to theory, since the doughnut structures would take on random orientations, the black holes should also be distributed randomly. It is like tossing a bunch of glazed doughnuts in the air -- roughly the same percentage of doughnuts always will be positioned in the edge-on and face-on positions, regardless of whether they are tightly clumped or spread far apart.

But WISE found something totally unexpected. The results showed the galaxies with hidden black holes are more clumped together than those of the exposed black holes. If these findings are confirmed, scientists will have to adjust the unified model and come up with new ways to explain why some black holes appear hidden. 

"The main purpose of unification was to put a zoo of different kinds of active nuclei under a single umbrella," said Donoso. Now, that has become increasingly complex to do as we dig deeper into the WISE data."

Another way to understand the WISE results involves dark matter. Dark matter is an invisible substance that dominates matter in the universe, outweighing the regular matter that makes up people, planets and stars. Every galaxy sits in the center of a dark matter halo. Bigger halos have more gravity and, therefore, pull other galaxies toward them.

Because WISE found that the obscured black holes are more clustered than the others, the researchers know those hidden black holes reside in galaxies with larger dark matter halos. Though the halos themselves would not be responsible for hiding the black holes, they could be a clue about what is occurring.

"The unified theory was proposed to explain the complexity of what astronomers were seeing," said Stern. "It seems that simple model may have been too simple. As Einstein said, models should be made 'as simple as possible, but not simpler.'"

Scientists still are actively combing public data from WISE, which was put into hibernation in 2011 after scanning Earth's entire sky twice. WISE was reactivated in 2013, renamed NEOWISE, and given a new mission to identify potentially hazardous near-Earth objects.

For more information about NEOWISE, visit: http://neo.jpl.nasa.gov/programs/neowise.html

For more information about WISE, visit: http://www.nasa.gov/wise

J.D. Harrington
NASA Headquarters, Washington
202-358-5241
j.d.harrington@nasa.gov

Whitney Clavin
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-4673
whitney.clavin@jpl.nasa.gov

The Search for Seeds of Black Holes

The galaxy NGC 4395 is shown here in infrared light, captured by NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech.  ›Full image and caption

How do you grow a supermassive black hole that is a million to a billion times the mass of our sun? Astronomers do not know the answer, but a new study using data from NASA's Wide-field Infrared Survey Explorer, or WISE, has turned up what might be the cosmic seeds from which a black hole will sprout. The results are helping scientists piece together the evolution of supermassive black holes -- powerful objects that dominate the hearts of all galaxies.

Growing a black hole is not as easy as planting a seed in soil and adding water. The massive objects are dense collections of matter that are literally bottomless pits; anything that falls in will never come out. They come in a range of sizes. The smallest, only a few times greater in mass than our sun, form from exploding stars. The biggest of these dark beasts, billions of times the mass of our sun, grow together with their host galaxies over time, deep in the interiors. But how this process works is an ongoing mystery.

Researchers using WISE addressed this question by looking for black holes in smaller, "dwarf" galaxies. These galaxies have not undergone much change, so they are more pristine than their heavier counterparts. In some ways, they resemble the types of galaxies that might have existed when the universe was young, and thus they offer a glimpse into the nurseries of supermassive black holes.

In this new study, using data of the entire sky taken by WISE in infrared light, up to hundreds of dwarf galaxies have been discovered in which buried black holes may be lurking. Infrared light, the kind that WISE collects, can see through dust, unlike visible light, so it's better able to find the dusty, hidden black holes. The researchers found that the dwarf galaxies' black holes may be about 1,000 to 10,000 times the mass of our sun -- larger than expected for these small galaxies.

"Our findings suggest the original seeds of supermassive black holes are quite massive themselves," said Shobita Satyapal of George Mason University, Fairfax, Va. Satyapal is lead author of a paper published in the March issue of Astrophysical Journal.

Daniel Stern, an astronomer specializing in black holes at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who was not a part of the new study, says the research demonstrates the power of an all-sky survey like WISE to find the rarest black holes. "Though it will take more research to confirm whether the dwarf galaxies are indeed dominated by actively feeding black holes, this is exactly what WISE was designed to do: find interesting objects that stand out from the pack."

The new observations argue against one popular theory of black hole growth, which holds that the objects bulk up in size through galaxy collisions. When our universe was young, galaxies were more likely to crash into others and merge. It is possible the galaxies' black holes merged too, accumulating more mass. In this scenario, supermassive black holes grow in size through a series of galaxy mergers.

The discovery of dwarf galaxy black holes that are bigger than expected suggests that galaxy mergers are not necessary to create big black holes. Dwarf galaxies don't have a history of galactic smash-ups, and yet their black holes are already relatively big.

Instead, supermassive black holes might form very early in the history of the universe. Or, they might grow harmoniously with their host galaxies, feeding off surrounding gas. 

"We still don't know how the monstrous black holes that reside in galaxy centers formed," said Satyapal. "But finding big black holes in tiny galaxies shows us that big black holes must somehow have been created in the early universe, before galaxies collided with other galaxies." 

Other authors of the study include: N.J. Secrest, W. McAlpine and J.L. Rosenberg of George Mason University; S.L. Ellison of the University of Victoria, Canada; and J. Fischer of the Naval Research Laboratory, Washington.

WISE was put into hibernation upon completing its primary mission in 2011. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE will also characterize previously known asteroids and comets to better understand their sizes and compositions.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the NEOWISE mission for NASA's Science Mission Directorate. The WISE mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information on WISE and NEOWISE can be found online at: http://www.nasa.gov/wise, http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

NASA's WISE Survey Finds Thousands of New Stars, But No 'Planet X'

A nearby star stands out in red in this image from the Second Generation Digitized Sky Survey. Image credit: DSS/NASA/JPL-Caltech. Full image and caption

Data from NASA's Wide-field Infrared Survey Explorer, or WISE, has found no evidence for a hypothesized body sometimes referred to as "Planet X." Image credit: Penn State University. Full image and caption - enlarge image

The third closest star system to the sun, called WISE J104915.57-531906, is at the center of the larger image, which was taken by NASA's Wide-field Infrared Survey Explorer (WISE). Image credit: NASA/JPL/Gemini Observatory/AURA/NSF. Full image and caption - enlarge image

After searching hundreds of millions of objects across our sky, NASA's Wide-Field Infrared Survey Explorer (WISE) has turned up no evidence of the hypothesized celestial body in our solar system commonly dubbed "Planet X."

Researchers previously had theorized about the existence of this large, but unseen celestial body, suspected to lie somewhere beyond the orbit of Pluto. In addition to "Planet X," the body had garnered other nicknames, including "Nemesis" and "Tyche."

This recent study, which involved an examination of WISE data covering the entire sky in infrared light, found no object the size of Saturn or larger exists out to a distance of 10,000 astronomical units (au), and no object larger than Jupiter exists out to 26,000 au. One astronomical unit equals 93 million miles. Earth is 1 au, and Pluto about 40 au, from the sun.

"The outer solar system probably does not contain a large gas giant planet, or a small, companion star," said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.

But searches of the WISE catalog are not coming up empty. A second study reveals several thousand new residents in our sun's "backyard," consisting of stars and cool bodies called brown dwarfs.

"Neighboring star systems that have been hiding in plain sight just jump out in the WISE data," said Ned Wright of the University of California, Los Angeles, the principal investigator of the mission.

The second WISE study, which concentrated on objects beyond our solar system, found 3,525 stars and brown dwarfs within 500 light-years of our sun.

"We're finding objects that were totally overlooked before," said Davy Kirkpatrick of NASA's Infrared and Processing Analysis Center at the California Institute of Technology, Pasadena, Calif. Kirkpatrick is lead author of the second paper, also in the Astrophysical Journal. Some of these 3,525 objects also were found in the Luhman study, which catalogued 762 objects.

The WISE mission operated from 2010 through early 2011, during which time it performed two full scans of the sky -- with essentially a six-month gap between scans. The survey captured images of nearly 750 million asteroids, stars and galaxies. In November 2013, NASA released data from the AllWISE program, which now enables astronomers to compare the two full-sky surveys to look for moving objects.

In general, the more an object in the WISE images appears to move over time, the closer it is. This visual clue is the same effect at work when one observes a plane flying low to the ground versus the same plane flying at higher altitude. Though traveling at the same speed, the plane at higher altitude will appear to be moving more slowly.

Searches of the WISE data catalog for these moving objects are uncovering some of the closest stars. The discoveries include a star located about 20 light-years away in the constellation Norma, and as reported last March, a pair of brown dwarfs only 6.5 light-years away -- making it the closest star system to be discovered in nearly a century.

Despite the large number of new solar neighbors found by WISE, "Planet X" did not show up. Previous speculations about this hypothesized body stemmed in part from geological studies that suggested a regular timing associated with mass extinctions on Earth. The idea was that a large planet or small star hidden in the farthest reaches of our solar system might periodically sweep through bands of outer comets, sending them flying toward our planet. The Planet X-based mass extinction theories were largely ruled out even prior to the new WISE study.

Other theories based on irregular comet orbits had also postulated a Planet X-type body. The new WISE study now argues against these theories as well.

Both of the WISE searches were able to find objects the other missed, suggesting many other celestial bodies likely await discovery in the WISE data.

"We think there are even more stars out there left to find with WISE. We don't know our own sun's backyard as well as you might think," said Wright.

WISE was put into hibernation upon completing its primary mission in 2011. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE will also characterize previously known asteroids and comets to better understand their sizes and compositions.

JPL managed and operated WISE for NASA's Science Mission Directorate. The mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information is online at: http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise.

 Contact:

Whitney Clavin
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-4673 
Email: whitney.clavin@jpl.nasa.gov

J.D. Harrington
Headquarters, Washington
202-358-5241
Email: j.d.harrington@nasa.gov

NEOWISE Spies Its First Comet

Comet NEOWISE was first observed by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft on Valentine's Day, 2014.  Full image and caption

NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft has spotted a never-before-seen comet -- its first such discovery since coming out of hibernation late last year. 

"We are so pleased to have discovered this frozen visitor from the outermost reaches of our solar system," said Amy Mainzer, the mission's principal investigator from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This comet is a weirdo - it is in a retrograde orbit, meaning that it orbits the sun in the opposite sense from Earth and the other planets." 

Officially named "C/2014 C3 (NEOWISE)", the first comet discovery of the renewed mission came on Feb. 14 when the comet was about 143 million miles (230 million kilometers) from Earth. Although the comet's orbit is still a bit uncertain, it appears to have arrived from its most distant point in the region of the outer planets. The mission's sophisticated software picked out the moving object against a background of stationary stars. As NEOWISE circled Earth, scanning the sky, it observed the comet six times over half a day before the object moved out of its view. The discovery was confirmed by the Minor Planet Center, Cambridge, Mass., when follow-up observations were received three days later from the Near Earth Object Observation project Spacewatch, Tucson, Ariz. Other follow-up observations were then quickly received. While this is the first comet NEOWISE has discovered since coming out of hibernation, the spacecraft is credited with the discovery of 21 other comets during its primary mission.

Originally called the Wide-field Infrared Survey Explorer (WISE), the spacecraft was shut down in 2011 after its primary mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE will also characterize previously known asteroids and comets to better understand their sizes and compositions. 

JPL manages the NEOWISE mission for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. 

More information on NEOWISE is online at: http://www.jpl.nasa.gov/wise/ .

DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov 

 

 

Where the Wild Stars Are

Radiation and winds from massive stars have blown a cavity into the surrounding dust and gas, creating the Trifid nebula, as seen here in infrared light by NASA's Wide-field Infrared Survey Explorer, or WISE. Image credit: NASA/JPL-Caltech/UCLA.  Larger image

A storm of stars is brewing in the Trifid nebula, as seen in this view from NASA's Wide-field Infrared Survey Explorer, or WISE. The stellar nursery, where baby stars are bursting into being, is the yellow-and-orange object dominating the picture. Yellow bars in the nebula appear to cut a cavity into three sections, hence the name Trifid nebula.

Colors in this image represent different wavelengths of infrared light detected by WISE. The main green cloud is made up of hydrogen gas. Within this cloud is the Trifid nebula, where radiation and winds from massive stars have blown a cavity into the surrounding dust and gas, and presumably triggered the birth of new generations of stars. Dust glows in infrared light, so the three lines that make up the Trifid, while appearing dark in visible-light views, are bright when seen by WISE. 

The blue stars scattered around the picture are older, and they lie between Earth and the Trifid nebula. The baby stars in the Trifid will eventually look similar to those foreground stars. The red cloud at upper right is gas heated by a group of very young stars.

The Trifid nebula is located 5,400 light-years away in the constellation Sagittarius.

Blue represents light emitted at 3.4-micron wavelengths, and cyan (blue-green) represents 4.6 microns, both of which come mainly from hot stars. Relatively cooler objects, such as the dust of the nebula, appear green and red. Green represents 12-micron light and red, 22-micron light.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages and operates the recently activated NEOWISE asteroid-hunting mission for NASA's Science Mission Directorate. The results presented here are from the WISE all-sky survey mission, which operated before NEOWISE, using the same spacecraft, in 2010 and 2011. WISE was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology, Pasadena. Caltech manages JPL for NASA.

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

NASA-Sponsored 'Disk Detective' Lets Public Search for New Planetary Nurseries

Herbig-Haro 30 is the prototype of a gas-rich "young stellar object" disk around a star. The dark disk spans 40 billion miles (64 billion kilometers) in this image from NASA's Hubble Space Telescope, cutting the bright nebula in two and blocking the central star from direct view. Image credit NASA/Hubble/STScI.  Full image and caption

 

NASA is inviting the public to help astronomers discover embryonic planetary systems hidden among data from the agency's Wide-field Infrared Survey Explorer (WISE) mission through a new website, DiskDetective.org.

Disk Detective is NASA's largest crowdsourcing project whose primary goal is to produce publishable scientific results. It exemplifies a new commitment to crowdsourcing and open data by the United States government.

"Through Disk Detective, volunteers will help the astronomical community discover new planetary nurseries that will become future targets for NASA's Hubble Space Telescope and its successor, the James Webb Space Telescope," said James Garvin, the chief scientist for NASA Goddard's Sciences and Exploration Directorate.

WISE was designed to survey the entire sky at infrared wavelengths. From a perch in Earth orbit, the spacecraft completed two scans of the entire sky between 2010 and 2011. It took detailed measurements on more than 745 million objects, representing the most comprehensive survey of the sky at mid-infrared wavelengths currently available.

Astronomers have used computers to search this haystack of data for planet-forming environments and narrowed the field to about a half-million sources that shine brightly in infrared, indicating they may be "needles": dust-rich disks that are absorbing their star's light and reradiating it as heat.

"Planets form and grow within disks of gas, dust and icy grains that surround young stars, but many details about the process still elude us," said Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md. "We need more examples of planet-forming habitats to better understand how planets grow and mature."

But galaxies, interstellar dust clouds and asteroids also glow in infrared, which stymies automated efforts to identify planetary habitats. There may be thousands of nascent solar systems in the WISE data, but the only way to know for sure is to inspect each source by eye, which poses a monumental challenge.

Public participation in scientific research is a type of crowdsourcing known as citizen science. It allows the public to make critical contributions to the fields of science, technology, engineering and mathematics by collecting, analyzing and sharing a wide range of data. NASA uses citizen science to engage the public in problem-solving.

Kuchner recognized that spotting planetary nurseries is a perfect opportunity for crowdsourcing. He arranged for NASA to team up with the Zooniverse, a collaboration of scientists, software developers and educators who collectively develop and manage citizen science projects on the Internet. The result of their combined effort is Disk Detective.

Disk Detective incorporates images from WISE and other sky surveys in brief animations the website calls flip books. Volunteers view a flip book and classify the object based on simple criteria, such as whether the image is round or includes multiple objects. By collecting this information, astronomers will be able to assess which sources should be explored in greater detail, for example, to search for planets outside our solar system.

"Disk Detective's simple and engaging interface allows volunteers from all over the world to participate in cutting-edge astronomy research that wouldn't even be possible without their efforts," said Laura Whyte, director of citizen science at Adler Planetarium in Chicago, Ill., a founding partner of the Zooniverse collaboration.

The project aims to find two types of developing planetary environments. The first, known as a young stellar object disk, typically is less than 5 million years old, contains large quantities of gas, and often is found in or near young star clusters. For comparison, our own solar system is 4.6 billion years old. The second planetary environment, known as a debris disk, tends to be older than 5 million years, possesses little or no gas, and contains belts of rocky or icy debris that resemble the asteroid and Kuiper belts found in our own solar system. Vega and Fomalhaut, two of the brightest stars in the sky, host debris disks.

WISE was shut down in 2011 after its primary mission was completed. But in September 2013, it was reactivated, renamed Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), and given a new mission, which is to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects (NEOs). NEOWISE also can assist in characterizing previously detected asteroids that could be considered potential targets for future exploration missions.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages and operates WISE for NASA's Science Mission Directorate. The WISE mission was selected competitively under NASA's Explorers Program managed by the agency's Goddard Space Flight Center. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah. The spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology, which manages JPL for NASA.

For more information about Disk Detective, please visit: http://www.diskdetective.org

For more information about NASA's WISE mission, visit: http://www.nasa.gov/wise


Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

J.D. Harrington 202-358-5241
Headquarters, Washington
j.d.harrington@nasa.gov