Seeding Life in the Oceans of Moons

Plumes of salty water ice emerge from Enceladus's cracked ice shell
Credit: NASA/JPL/Space Science Institute

Title: Impacts on Ocean Worlds Are Sufficiently Frequent and Energetic to Be of Astrobiological Importance

Authors: Shannon M. MacKenzie et al.
First Author’s Institution: Johns Hopkins University Applied Physics Laboratory
Status: Published in PSJ

A steroids and meteorites are usually associated with doom and destruction (rest easy, dinosaurs), but they may have also been essential for the emergence of life on Earth. It is popularly theorized that some of the base building blocks of life, like volatiles and organics, were delivered here by meteorites and that the energy of these impacts synthesized even more, like HCN and amino acids. Expectedly, the same should be true for other planets. Today’s article explores this possibility using nearby analogies for potentially habitable exoplanets: our solar system’s ocean worlds.

Why Do Meteorites Carry Organics?

The solar system formed from one massive cloud of gas and dust, so the composition everywhere is approximately the same. However, early Earth was an extremely hot ball of magma that destroyed its organic matter. Luckily, organics were able to survive in objects like meteorites in the cold outskirts of the solar system.

Figure 1: Saturn’s moon Enceladus with a liquid water ocean beneath the icy crust. Jets on the surface are strong indicators of hydrothermal vents on the ocean floor.Credit: JPL

Today’s authors studied typical impact events on Jupiter’s moon Europa and Saturn’s moons Enceladus and Titan to determine 1) if organics could survive the impacts, and 2) what processes could occur in the resulting melted material in the impact craters before it refreezes.

Ocean Worlds in Our Neighborhood

In the search for extraterrestrial life, we start by looking for the basic necessities — and water is a big one. Though Earth is the only planet in our solar system with liquid water, several moons of Jupiter and Saturn have it as well. These moons are beyond the balmy habitable zone, so their surfaces are covered in icy crusts, but beneath those crusts are subsurface oceans of liquid water, making these moons “ocean worlds” (see Figure 1). On their own, the presence of water makes these moons astrobiologically interesting, and they will also elucidate ocean worlds that are further away.

Today’s authors studied typical impact events on Jupiter’s moon Europa and Saturn’s moons Enceladus and Titan to determine 1) if organics could survive the impacts, and 2) what processes could occur in the resulting melted material in the impact craters before it refreezes.

Figure 2: The modeled impact velocities and maximum pressures for icy (black) and rocky (gray) impactors. Survivable pressures of various organics (green and gray colored bars on the y-axis) are within the range of observed velocities and pressures from craters on each ocean world moon (colored boxes). Credit: MacKenzie et al. 2024

Surviving the Impact

To evaluate survivability, the authors modeled the maximum pressure of an impact on an ocean world’s ice crust for a range of impact velocities and angles. Around Jupiter and Saturn, most impactors are either icy or rocky objects that originate from the Kuiper Belt or Oort cloud, so the authors modeled both types of impactors. Rocky impactors create higher pressures (shown in gray in Figure 2) than icy impactors (shown in black in Figure 2). From the sizes of observed craters on the ocean world moons, previous works determined the velocities and pressures of impacts, which are shown by the colored boxes in Figure 2. Finally, a number of other works have estimated the ranges of survivable pressures for biota and biologically important molecules, which are shown by the green and black bars on the right of Figure 2. Impressively, the survivable pressure ranges are within the observed and modeled pressures of impacts! So these life building blocks can be, and likely have been, deposited on the ocean world moons.

Crater Melt Pools

When an impactor hits the icy crust, some of the ice will melt. The deposited organics will end up in a pool of liquid water in the crater, which is an ample environment for prebiotic chemistry until the pool freezes. From the observed crater sizes and modeled velocities, the authors estimated how much liquid water could remain in a crater and how long it would take to freeze. Freeze times ranged from a few Earth years for the smallest craters (<4 a="" acids="" amino="" as="" been="" br="" conditions="" crater="" craters="" diameter="" earth="" few="" for="" have="" hundreds="" in="" is="" kilometers="" labs="" largest="" melt="" mimicking="" months="" of="" on="" pools.="" possible="" short="" so="" synthesis="" synthesized="" the="" thousands="" to="" years="">
The pools eventually freeze, trapping any deposited or synthesized material on the icy surface. Other processes, like future impacts, are required to break through the icy crust and transport material to the subsurface oceans where theorized hydrothermal vents could allow more complex development.

Tangible Evidence

In summary, survivable impacts on the ocean world moons are common, and each provides an opportunity for prebiotic chemistry to arise. Unlike most objects astronomers study, the proximity of these ocean worlds means that we can thoroughly understand them through physical samples. NASA’s Cassini detected organic compounds in the plumes that burst off the surface of Enceladus, and the Dragonfly mission is set to head for Titan in 2028 to collect and analyze samples once it arrives in 2034. In the coming decades, we may witness the discovery of more precursors to life or microbial life itself in the subsurface oceans of moons in our solar system, and gain radical insight into the ocean worlds beyond.

Original astrobite edited by Sonja Panjkov

Source: Astronomical Society/AAS-Nova

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About the author, Annelia Anderson:

I’m an Astrophysics PhD candidate at the University of Alabama, using simulations to study the circumgalactic medium. Beyond research, I’m interested in historical astronomy, and hope to someday write astronomy children’s books. Beyond astronomy, I enjoy making music, cooking, and my cat.

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Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.

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Another First: NASA Webb Identifies Frozen Water in Young Star System

Debris Disk Around Star HD 181327 (Artist's Concept)

For the first time, researchers confirmed the presence of crystalline water ice in a dusty debris disk that orbits a Sun-like star, using NASA’s James Webb Space Telescope. All the frozen water detected by Webb is paired with fine dust particles throughout the disk. The majority of the water ice observed is found where it’s coldest and farthest from the star. The closer to the star the researchers looked, the less water ice they found. Credits/Artwork: NASA, ESA, CSA, STScI, Ralf Crawford (STScI)

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Is frozen water scattered in systems around other stars? Astronomers have long expected it is, partially based on previous detections of its gaseous form, water vapor, and its presence in our own solar system.

Now there is definitive evidence: Researchers confirmed the presence of crystalline water ice in a dusty debris disk that orbits a Sun-like star 155 light-years away using detailed data known as spectra from NASA’s James Webb Space Telescope. (The term water ice specifies its makeup, since many other frozen molecules are also observed in space, such as carbon dioxide ice, or “dry ice.”) In 2008, data from NASA’s retired Spitzer Space Telescope hinted at the possibility of frozen water in this system.

“Webb unambiguously detected not just water ice, but crystalline water ice, which is also found in locations like Saturn’s rings and icy bodies in our solar system’s Kuiper Belt,” said Chen Xie, the lead author of the new paper and an assistant research scientist at Johns Hopkins University in Baltimore, Maryland.

All the frozen water Webb detected is paired with fine dust particles throughout the disk — like itsy-bitsy “dirty snowballs.” The results published Wednesday in the journal Nature.

Astronomers have been waiting for this definitive data for decades. “When I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but prior to Webb, we didn’t have instruments sensitive enough to make these observations,” said Christine Chen, a co-author and an astronomer at the Space Telescope Science Institute in Baltimore. “What’s most striking is that this data looks similar to the telescope’s other recent observations of Kuiper Belt objects in our own solar system.”

Water ice is a vital ingredient in disks around young stars — it heavily influences the formation of giant planets and may also be delivered by small bodies like comets and asteroids to fully formed rocky planets. Now that researchers have detected water ice with Webb, they have opened the door for all researchers to study how these processes play out in new ways in many other planetary systems.

Rocks, Dust, Ice Rushing Around

The star, cataloged HD 181327, is significantly younger than our Sun. It’s estimated to be 23 million years old, compared to the Sun’s more mature 4.6 billion years. The star is slightly more massive than the Sun, and it’s hotter, which led to the formation of a slightly larger system around it.

Webb’s observations confirm a significant gap between the star and its debris disk — a wide area that is free of dust. Farther out, its debris disk is similar to our solar system’s Kuiper Belt, where dwarf planets, comets, and other bits of ice and rock are found (and sometimes collide with one another). Billions of years ago, our Kuiper Belt was likely similar to this star’s debris disk.

“HD 181327 is a very active system,” Chen said. “There are regular, ongoing collisions in its debris disk. When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect.”

Frozen Water — Almost Everywhere

Water ice isn’t spread evenly throughout this system. The majority is found where it’s coldest and farthest from the star. “The outer area of the debris disk consists of over 20% water ice,” Xie said.

The closer in the researchers looked, the less water ice they found. Toward the middle of the debris disk, Webb detected about 8% water ice. Here, it’s likely that frozen water particles are produced slightly faster than they are destroyed. In the area of the debris disk closest to the star, Webb detected almost none. It’s likely that the star’s ultraviolet light vaporizes the closest specks of water ice. It’s also possible that rocks known as planetesimals have “locked up” frozen water in their interiors, which Webb can’t detect.

This team and many more researchers will continue to search for — and study — water ice in debris disks and actively forming planetary systems throughout our Milky Way galaxy. “The presence of water ice helps facilitate planet formation,” Xie said. “Icy materials may also ultimately be ‘delivered’ to terrestrial planets that may form over a couple hundred million years in systems like this.”

The researchers observed HD 181327 with Webb’s NIRSpec (Near-Infrared Spectrograph), which is super-sensitive to extremely faint dust particles that can only be detected from space.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

To learn more about Webb, visit: https://science.nasa.gov/webb

Source: NASA's James Webb Space Telescope/News

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About This Release

Credits:

Media Contact:

Claire Blome
Space Telescope Science Institute, Baltimore

Christine Pulliam
Space Telescope Science Institute, Baltimore

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• The science paper by C. Xie et al.
• NASA’s Webb Reveals the Ancient Surfaces of Trans-Neptunian Objects

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Another First: NASA Webb Identifies Frozen Water in Young Star System

Debris Disk Around Star HD 181327 (Artist's Concept)

For the first time, researchers confirmed the presence of crystalline water ice in a dusty debris disk that orbits a Sun-like star, using NASA’s James Webb Space Telescope. All the frozen water detected by Webb is paired with fine dust particles throughout the disk. The majority of the water ice observed is found where it’s coldest and farthest from the star. The closer to the star the researchers looked, the less water ice they found. Credits/Artwork: NASA, ESA, CSA, STScI, Ralf Crawford (STScI)

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Is frozen water scattered in systems around other stars? Astronomers have long expected it is, partially based on previous detections of its gaseous form, water vapor, and its presence in our own solar system.

Now there is definitive evidence: Researchers confirmed the presence of crystalline water ice in a dusty debris disk that orbits a Sun-like star 155 light-years away using detailed data known as spectra from NASA’s James Webb Space Telescope. (The term water ice specifies its makeup, since many other frozen molecules are also observed in space, such as carbon dioxide ice, or “dry ice.”) In 2008, data from NASA’s retired Spitzer Space Telescope hinted at the possibility of frozen water in this system.

“Webb unambiguously detected not just water ice, but crystalline water ice, which is also found in locations like Saturn’s rings and icy bodies in our solar system’s Kuiper Belt,” said Chen Xie, the lead author of the new paper and an assistant research scientist at Johns Hopkins University in Baltimore, Maryland.

All the frozen water Webb detected is paired with fine dust particles throughout the disk — like itsy-bitsy “dirty snowballs.” The results published Wednesday in the journal Nature.

Astronomers have been waiting for this definitive data for decades. “When I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but prior to Webb, we didn’t have instruments sensitive enough to make these observations,” said Christine Chen, a co-author and associate astronomer at the Space Telescope Science Institute in Baltimore. “What’s most striking is that this data looks similar to the telescope’s other recent observations of Kuiper Belt objects in our own solar system.”

Water ice is a vital ingredient in disks around young stars — it heavily influences the formation of giant planets and may also be delivered by small bodies like comets and asteroids to fully formed rocky planets. Now that researchers have detected water ice with Webb, they have opened the door for all researchers to study how these processes play out in new ways in many other planetary systems.

Rocks, Dust, Ice Rushing Around

The star, cataloged HD 181327, is significantly younger than our Sun. It’s estimated to be 23 million years old, compared to the Sun’s more mature 4.6 billion years. The star is slightly more massive than the Sun, and it’s hotter, which led to the formation of a slightly larger system around it.

Webb’s observations confirm a significant gap between the star and its debris disk — a wide area that is free of dust. Farther out, its debris disk is similar to our solar system’s Kuiper Belt, where dwarf planets, comets, and other bits of ice and rock are found (and sometimes collide with one another). Billions of years ago, our Kuiper Belt was likely similar to this star’s debris disk.

“HD 181327 is a very active system,” Chen said. “There are regular, ongoing collisions in its debris disk. When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect.”

Frozen Water — Almost Everywhere

Water ice isn’t spread evenly throughout this system. The majority is found where it’s coldest and farthest from the star. “The outer area of the debris disk consists of over 20% water ice,” Xie said.

The closer in the researchers looked, the less water ice they found. Toward the middle of the debris disk, Webb detected about 8% water ice. Here, it’s likely that frozen water particles are produced slightly faster than they are destroyed. In the area of the debris disk closest to the star, Webb detected almost none. It’s likely that the star’s ultraviolet light vaporizes the closest specks of water ice. It’s also possible that rocks known as planetesimals have “locked up” frozen water in their interiors, which Webb can’t detect.

This team and many more researchers will continue to search for — and study — water ice in debris disks and actively forming planetary systems throughout our Milky Way galaxy. “The presence of water ice helps facilitate planet formation,” Xie said. “Icy materials may also ultimately be ‘delivered’ to terrestrial planets that may form over a couple hundred million years in systems like this.”

The researchers observed HD 181327 with Webb’s NIRSpec (Near-Infrared Spectrograph), which is super-sensitive to extremely faint dust particles that can only be detected from space.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

To learn more about Webb, visit: https://science.nasa.gov/webb

Source: NASA's James Webb Space Telescope/News

---

About This Release

Credits:

Media Contact Claire Blome
Space Telescope Science Institute, Baltimore

Christine Pulliam
Space Telescope Science Institute, Baltimore

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• The science paper by C. Xie et al.
• NASA’s Webb Reveals the Ancient Surfaces of Trans-Neptunian Objects

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Earth-bound asteroids ‘could be tracked more precisely’ with new equation

Light bending - Credit: NASA, ESA, and Goddard Space Flight Center/K. Jackson

Identifying asteroids on a potential collision course with Earth could be made easier thanks to an advancement in how to track their orbits more precisely.

Taking into account a phenomenon first identified by Sir Isaac Newton and later confirmed by Albert Einstein, researchers have come up with a way to pinpoint the precise positions of minor objects in the solar system.

They include those in the Kuiper Belt – a region of icy objects including Pluto and other dwarf planets beyond the orbit of Neptune – and a vast, frozen, spherical shell called the Oort Cloud, which is the most distant region in our solar system and home to many long-period comets.

In a new paper published today in Monthly Notices of the Royal Astronomical Society, researchers have put forward an accurate calculation of the gravitational bending of light (GBL) angle by a static massive object, such as the Sun or slowly-moving planets.

Newton was the first to propose the bending of light by gravity, although it was Einstein who went further and deeper when he published his theory of general relativity in 1915. This successfully predicted the deflection angle for distant starlight grazing the solar limb.

Now, Professor Oscar del Barco Novillo, of the University of Murcia in Spain, has proposed an exact equation for the GBL angle when both source and observer are placed at any distance from the static gravitational mass.

This is significant because it could allow astronomers to establish the exact locations of asteroids and minor objects in the solar system – thereby enabling a more accurate calculation of their orbits around the Sun and making it easier to spot objects potentially hazardous to Earth.

Schematic diagram for the calculation of the GBL angle, due to the Sun, for a light beam coming from planet Mercury (Ma) and reaching the Earth (Ea). The deflected beam is illustrated as the solid red curve, where r0 stands for the closest approach to the Sun. Due to this relativistic phenomenon, a virtual position of each planet occurs (represented by MV and EV, respectively) which are shifted with respect to their actual positions. The GBL angle is computed as the difference between the actual angle αa and the virtual angle αV. Credit: Oscar del Barco Novillo

Licence type: Attribution (CC BY 4.0)

The hope is that it could even give a more precise location of the nearest star to our planet after the Sun, called Proxima Centauri, which is 4.25 light-years away and is thought to have three exoplanets orbiting around it. If its exact whereabouts can be determined, this would also help to accurately estimate the orbits of its planets.

“Our study, which is based on a geometric optics model, provides an exact equation for the most accurate calculation to date of the GBL angle by a static massive object – such as the Sun or solar system planets,” Professor Novillo said.

“This could have implications on the precise positioning of distant stars, as well as the correct location of solar system minor objects like asteroids, to a better estimation of their exact orbits.

“As a consequence, different branches of astronomy and astrophysics, such as celestial mechanics or stellar dynamics, might benefit from this new result.”

The calculation may also help to more precisely locate distant galaxies which are distorted and magnified by large amounts of intervening mass, such as galaxy clusters, due to weak gravitational lensing. Such a breakthrough is important in the field of astrometry – a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.

Contour plot showing the differences between the new equation for the GBL angle and previous approximate equations. It is assumed that the main reflector is the Sun. Non-negligible discrepancies (in reddish shades) are found for Asteroid belt bodies (left panel), leading to a plausible delocalisation of such minor objects. On the other hand, significant deviations are also reported for Proxima Centauri (right panel), in comparison with the angular size of this star. Credit: Oscar del Barco Novillo

Licence type: Attribution (CC BY 4.0)

It could even spark more precise maps of mass distribution in galaxy clusters, particularly in the era of the European Space Agency’s Euclid mission, which revealed its first images last year. The spacecraft is tasked with investigating how dark matter and dark energy have made our Universe look like it does today.

Over the next six years, Euclid will observe the shapes, distances and motions of billions of galaxies out to 10 billion light-years – with the goal of creating the largest cosmic 3D map ever made.

Professor Novillo said: “The fundamental significance of our new equation is its high accurateness for the GBL angle calculation due to a static gravitational mass, in comparison with previous approximate equations based on the post-Newtonian formalism.

“As a result, it might be instrumental in finding a precise location of minor celestial objects in our solar system and, consequently, a better determination of their orbits around the Sun.

“The new research should therefore be important for astronomers and astrophysicists working on ultra-precise astrometry measurements, particularly in gravitational lensing studies.”

The paper ‘An accurate equation for the gravitational bending of light by a static massive object’ has been published in Monthly Notices of the Royal Astronomical Society.

Submitted by Sam Tonkin

Keep up with the RAS on X, Facebook, LinkedIn and YouTube.

Source: Royal Astronomical Society (RAS)/News

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Media contacts:

Sam Tonkin
Royal Astronomical Society
Mob: +44 (0)7802 877700
press@ras.ac.uk

Robert Massey
Royal Astronomical Society
Mob: +44 (0)7802 877699
press@ras.ac.uk

Science contacts:

Professor Oscar del Barco Novillo
University of Murcia
obn@um.es

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Further information

The paper ‘An accurate equation for the gravitational bending of light by a static massive object’, by Professor Oscar del Barco, has been published in Monthly Notices of the Royal Astronomical Society.

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Notes for editors

About the Royal Astronomical Society

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.

The RAS organises scientific meetings, publishes international research and review journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.

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NASA's Webb Reveals Unusual Jets of Volatile Gas from Icy Centaur 29P

Centaur 29P Outgassing (Artist's Concept)
Credits: Artwork: NASA, ESA, CSA, Leah Hustak (STScI)

Centaur 29P Outgassing (NIRSpec)
Credits: Illustration: NASA, ESA, CSA, Leah Hustak (STScI), Sara Faggi (NASA-GSFC, American University)

Centaur 29P Outgassing (Artist's Concept)

This is an animation portraying the outgassing activity of Centaur 29P/Schwassmann-Wachmann 1 based on data gathered by NASA’s James Webb Space Telescope’s NIRSpec (Near-Infrared Spectrograph) instrument. Centaur 29P is one of the most active objects in the outer solar system, undergoing quasi-periodic outbursts in brightness.

The video begins by zooming in for a closer view of an artist’s concept of Centaur 29P. The scene is overlaid with graphics that help define the four different jets of gas before the centaur is rotated so the object can be examined from different angles. Credits: Video: NASA, ESA, CSA, Leah Hustak (STScI). Video Youtube

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Inspired by the half-human, half-horse creatures that are part of Ancient Greek mythology, the field of astronomy has its own kind of centaurs: distant objects orbiting the Sun between Jupiter and Neptune. NASA’s James Webb Space Telescope has mapped the gases spewing from one of these objects, suggesting a varied composition and providing new insights into the formation and evolution of the solar system.

Centaurs are former trans-Neptunian objects that have been moved inside Neptune’s orbit by subtle gravitational influences of the planets in the last few million years, and may eventually become short-period comets. They are “hybrid” in the sense that they are in a transitional stage of their orbital evolution: Many share characteristics with both trans-Neptunian objects (from the cold Kuiper Belt reservoir), and short-period comets, which are objects highly altered by repeated close passages around the Sun.

Since these small icy bodies are in an orbital transitional phase, they have been the subject of various studies as scientists seek to understand their composition, the reasons behind their outgassing activity — the loss of their ices that lie underneath the surface — and how they serve as a link between primordial icy bodies in the outer solar system and evolved comets.

A team of scientists recently used Webb’s NIRSpec (Near-Infrared Spectrograph) instrument to obtain data on Centaur 29P/Schwassmann-Wachmann 1 (29P for short), an object that is known for its highly active and quasi-periodic outbursts. It varies in intensity every six to eight weeks, making it one of the most active objects in the outer solar system. They discovered a new jet of carbon monoxide (CO) and previously unseen jets of carbon dioxide (CO2) gas, which give new clues to the nature of the centaur’s nucleus. “Centaurs can be considered as some of the leftovers of our planetary system’s formation. Because they are stored at very cold temperatures, they preserve information about volatiles in the early stages of the solar system,” said Sara Faggi of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and American University in Washington, DC, lead author of the study. “Webb really opened the door to a resolution and sensitivity that was impressive to us — when we saw the data for the first time, we were excited. We had never seen anything like this.”

Webb and the Jets

Centaurs’ distant orbits and consequent faintness have inhibited detailed observations in the past. Data from prior radio wavelength observations of Centaur 29P showed a jet pointed generally toward the Sun (and Earth) composed of CO. Webb detected this face-on jet and, thanks to its large mirror and infrared capabilities, also sensitively searched for many other chemicals, including water (H2O) and CO2. The latter is one of the main forms in which carbon is stored across the solar system. No clear indication of water vapor was detected in the atmosphere of 29P, which could be related to the extremely cold temperatures present in this body.

The telescope’s unique imaging and spectral data revealed never-before-seen features: two jets of CO2 emanating in the north and south directions, and another jet of CO pointing toward the north. This was the first definitive detection of CO2 in Centaur 29P.

Based on the data gathered by Webb, the team created a 3D model of the jets to understand their orientation and origin. They found through their modeling efforts that the jets were emitted from different regions on the centaur’s nucleus, even though the nucleus itself cannot be resolved by Webb. The jets’ angles suggest the possibility that the nucleus may be an aggregate of distinct objects with different compositions; however, other scenarios can’t yet be excluded.

“The fact that Centaur 29P has such dramatic differences in the abundance of CO and CO2 across its surface suggests that 29P may be made of several pieces,” said Geronimo Villanueva, co-author of the study at NASA Goddard. “Maybe two pieces coalesced together and made this centaur, which is a mixture between very different bodies that underwent separate formation pathways. It challenges our ideas about how primordial objects are created and stored in the Kuiper Belt.”

Persisting Unanswered Questions (For Now)

The reasons for Centaur 29P’s bursts in brightness, and the mechanisms behind its outgassing activity through the CO and CO2 jets, continue to be two major areas of interest that require further investigation. In the case of comets, scientists know that their jets are often driven by the outgassing of water. However, because of the centaurs’ location, they are too cold for water ice to sublimate, meaning that the nature of their outgassing activity differs from comets. “We only had time to look at this object once, like a snapshot in time,” said Adam McKay, a co-author of the study at Appalachian State University in Boone, North Carolina. “I’d like to go back and look at Centaur 29P over a much longer period of time. Do the jets always have that orientation? Is there perhaps another carbon monoxide jet that turns on at a different point in the rotation period? Looking at these jets over time would give us much better insights into what is driving these outbursts.” The team is hopeful that as they increase their understanding of Centaur 29P, they can apply the same techniques to other centaurs. By improving the astronomical community’s collective knowledge of centaurs, we can simultaneously better our understanding on the formation and evolution of our solar system.

These findings have been published in Nature.

The observations were taken as part of General Observer program 2416.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

Source: NASA's James Webb Space Telescope/News

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About This Release

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Media Contact:

Abigail Major
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• The science paper by S. Faggi et al.

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Webb Looks for Fomalhaut's Asteroid Belt and Finds Much More

Fomalhaut Dusty Debris Disk (MIRI Image)
Credits: Image: NASA, ESA, CSA
Image Processing: András Gáspár (University of Arizona), Alyssa Pagan (STScI)
Science: András Gáspár (University of Arizona)

Fomalhaut Dusty Debris Disk (MIRI Compass Image)
Credits: Image: NASA, ESA, CSA
Image Processing: András Gáspár (University of Arizona), Alyssa Pagan (STScI)
Science: András Gáspár (University of Arizona)

Release Images

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Astronomers used NASA’s James Webb Space Telescope to image the warm dust around a nearby young star, Fomalhaut, in order to study the first asteroid belt ever seen outside of our solar system in infrared light. But to their surprise, the dusty structures are much more complex than the asteroid and Kuiper dust belts of our solar system. Overall, there are three nested belts extending out to 14 billion miles (23 billion kilometers) from the star; that’s 150 times the distance of Earth from the Sun. The scale of the outermost belt is roughly twice the scale of our solar system's Kuiper Belt of small bodies and cold dust beyond Neptune. The inner belts – which had never been seen before – were revealed by Webb for the first time.

The belts encircle the young hot star, which can be seen with the naked eye as the brightest star in the southern constellation Piscis Austrinus. The dusty belts are the debris from collisions of larger bodies, analogous to asteroids and comets, and are frequently described as 'debris disks.' “I would describe Fomalhaut as the archetype of debris disks found elsewhere in our galaxy, because it has components similar to those we have in our own planetary system,” said András Gáspár of the University of Arizona in Tucson and lead author of a new paper describing these results. “By looking at the patterns in these rings, we can actually start to make a little sketch of what a planetary system ought to look like — if we could actually take a deep enough picture to see the suspected planets.”

The Hubble Space Telescope and the Herschel Space Observatory, as well as the Atacama Large Millimeter/submillimeter Array (ALMA), have previously taken sharp images of the outermost belt. However, none of them found any structure interior to it. The inner belts have been resolved for the first time by Webb in infrared light. “Where Webb really excels is that we're able to physically resolve the thermal glow from dust in those inner regions. So you can see inner belts that we could never see before,” said Schuyler Wolff, another member of the team at the University of Arizona.

Hubble, ALMA, and Webb are tag-teaming to assemble a holistic view of the debris disks around a number of stars. “With Hubble and ALMA, we were able to image a bunch of Kuiper Belt analogs, and we've learned loads about how outer disks form and evolve,” said Wolff. “But we need Webb to allow us to image a dozen or so asteroid belts elsewhere. We can learn just as much about the inner warm regions of these disks as Hubble and ALMA taught us about the colder outer regions.”

These belts most likely are carved by the gravitational forces produced by unseen planets. Similarly, inside our solar system Jupiter corrals the asteroid belt, the inner edge of the Kuiper Belt is sculpted by Neptune, and the outer edge could be shepherded by as-yet-unseen bodies beyond it. As Webb images more systems, we will learn about the configurations of their planets.

Fomalhaut's dust ring was discovered in 1983 in observations made by NASA's Infrared Astronomical Satellite (IRAS). The existence of the ring has also been inferred from previous and longer-wavelength observations using submillimeter telescopes on Mauna Kea, Hawaii, NASA’s Spitzer Space Telescope, and Caltech's Submillimeter Observatory.

“The belts around Fomalhaut are kind of a mystery novel: Where are the planets?” said George Rieke, another team member and U.S. science lead for Webb's Mid-Infrared Instrument (MIRI), which made these observations. "I think it's not a very big leap to say there's probably a really interesting planetary system around the star.”

“We definitely didn't expect the more complex structure with the second intermediate belt and then the broader asteroid belt,” added Wolff. “That structure is very exciting because any time an astronomer sees a gap and rings in a disk, they say, ‘There could be an embedded planet shaping the rings!’”

Webb also imaged what Gáspár dubs "the great dust cloud" that may be evidence for a collision occurring in the outer ring between two protoplanetary bodies. This is a different feature from a suspected planet first seen inside the outer ring by Hubble in 2008. Subsequent Hubble observations showed that by 2014 the object had vanished. A plausible interpretation is that this newly discovered feature, like the earlier one, is an expanding cloud of very fine dust particles from two icy bodies that smashed into each other.

The idea of a protoplanetary disk around a star goes back to the late 1700s when astronomers Immanuel Kant and Pierre-Simon Laplace independently developed the theory that the Sun and planets formed from a rotating gas cloud that collapsed and flattened due to gravity. Debris disks develop later, following the formation of planets and dispersal of the primordial gas in the systems. They show that small bodies like asteroids are colliding catastrophically and pulverizing their surfaces into huge clouds of dust and other debris. Observations of their dust provide unique clues to the structure of an exoplanetary system, reaching down to earth-sized planets and even asteroids, which are much too small to see individually.

The team's results are being published in the journal Nature Astronomy.

The James Webb Space Telescope is the world's premier space science observatory. The Fomalhaut observations utilized the Mid-Infrared Instrument (MIRI), which was contributed by NASA and ESA (European Space Agency), with the instrument designed and built by a consortium of nationally funded European Institutes (the MIRI European Consortium) and NASA’s Jet Propulsion Laboratory, in partnership with the University of Arizona. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA, and the Canadian Space Agency.

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About This Release

Credits:

Release: NASA, ESA, STScI

Media Contact:

Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the  News Team.

Related Links and Documents:

• The science paper by Gáspár et al.
• The University of Arizona press release

Source: NASA's James Webb Space Telescope/News

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Spotting a hidden exoplanet

AF Leporis
Credit: ESO/Mesa, De Rosa et al.

No, you’re not seeing double: this Picture of the Week shows two images of a Jupiter-like planet that orbits the star AF Leporis. The planet has been imaged by two independent groups of astronomers using the SPHERE instrument on ESO’s Very Large Telescope (VLT) in Chile. But why did they target this particular star?

The two groups, led by Dino Mesa (INAF, Italy) and Robert De Rosa (ESO, Chile), studied star catalogues from the European Space Agency’s Hipparcos and Gaia satellites. Over the years, these two space missions have accurately pinpointed the position and motion of stars in our galaxy using astrometry. Planets exert a gravitational tug on their host stars, perturbing their trajectory on the sky. The two teams found that the star AF Leporis exhibited such a disturbed trajectory, a telltale sign that a planet could be hiding there.

As the two groups took a closer look at this system with the VLT, they managed to directly image the planet that orbits AF Leporis. They both used the SPHERE instrument, which corrects the blurring caused by atmospheric turbulence using adaptive optics, and also blocks the light from the star with a special mask, revealing the planet next to it. They found that the planet is just a few times more massive than Jupiter, making it the lightest exoplanet detected with the combined use of astrometric measurements and direct imaging.

The AF Leporis system shares similar features to our Solar System. The star has roughly the same mass, size and temperature as the Sun, and the planet orbits it at a distance similar to that between Saturn and the Sun. The system also has a debris belt with similar characteristics as the Kuiper belt. Since the AF Leporis system is only 24 million years old ––about 200 times younger than the Sun–– further studies of this system can shed light on how our own Solar System was formed.

Links

• Scientific articles, accepted for publication in Astronomy & Astrophysics: Mesa et al. (2023), De Rosa et al. (2023)

• Video showing the atmospheric features in this exoplanet.

Source:  ESO/potw

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NASA’s Webb Indicates Several Stars ‘Stirred Up’ Southern Ring Nebula

Two Views of the Gas in the Southern Ring Nebula (NIRCam and MIRI Composite Images)
Credits Science: NASA, ESA, CSA, STScI, Orsola De Marco (Macquarie University)
Image Processing: Joseph DePasquale (STScI)

Southern Ring Nebula’s Spokes (NIRCam and MIRI Composite Image)
Credits: Science: NASA, ESA, CSA, STScI, Orsola De Marco (Macquarie University)
Image Processing: Joseph DePasquale (STScI)

Illustration of Star Interactions in the Southern Ring Nebula
Credits: Illustration: NASA, ESA, CSA, STScI, Elizabeth Wheatley (STScI)

Southern Ring Nebula’s Gas (NIRCam and MIRI Composite Compass Image)
Credits: Science: NASA, ESA, CSA, STScI, Orsola De Marco (Macquarie University)
Image Processing: Joseph DePasquale (STScI)
Release Images

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Some of the first data from NASA’s James Webb Space Telescope has shown there were at least two, and possibly three, more unseen stars that crafted the oblong, curvy shapes of the Southern Ring Nebula. Plus, for the first time, by pairing Webb’s infrared images with existing data from ESA’s (European Space Agency’s) Gaia observatory, researchers were able to precisely pinpoint the mass of the central star before it created the nebula. A team of almost 70 researchers led by Orsola De Marco of Macquarie University in Sydney, Australia, analyzed Webb’s 10 highly detailed exposures of this dying star to produce these results.

Their calculations show the central star was nearly three times the mass of the Sun before it ejected its layers of gas and dust. After those ejections, it now measures about 60 percent of the mass of the Sun. Knowing the initial mass is a critical piece of evidence that helped the team reconstruct the scene and project how the shapes in this nebula may have been created.

Let’s start with the top-tier celebrity of this particular “party,” the star that sloughed off its layers of gas and dust over thousands of years. It appears red in the image on the left because it is surrounded by an orbiting, dusty disk similar in size to our solar system’s Kuiper Belt. While some stars expel their layers as solo acts “on stage,” researchers propose that there were a few companions with front row seats – and at least one that may have joined the central star before it began to create the Southern Ring Nebula. “With Webb, it’s like we were handed a microscope to examine the universe,” De Marco said. “There is so much detail in its images. We approached our analysis much like forensic scientists to rebuild the scene.”

It’s common for small groups of stars, spanning a range of masses, to form together and continue to orbit one another as they age. The team used this principle to step back in time, by thousands of years, to determine what might explain the shapes of the colorful clouds of gas and dust.

First, they focused on the aging star that cast off its layers and is still surrounded by a dusty red “cloak” of dust. Extensive research about these types of aging stars shows that dusty cloaks like these must take the form of dusty disks that orbit the star. A quick dive into the data revealed the disk. “This star is now smaller and hotter, but is surrounded by cool dust,” said Joel Kastner, another team member, from the Rochester Institute of Technology in New York. “We think all that gas and dust we see thrown all over the place must have come from that one star, but it was tossed in very specific directions by the companion stars.”

Before the dying star shed its layers, the team proposes that it interacted with one or even two smaller companion stars. During this intimate “dance,” the interacting stars may have launched two-sided jets, which appeared later as roughly paired projections that are now observed at the edges of the nebula. “This is much more hypothetical, but if two companions were interacting with the dying star, they would launch toppling jets that could explain these opposing bumps,” De Marco explained. The dusty cloak around the dying star points to these interactions.

Where are those companions now? They are either dim enough to hide, camouflaged by the bright lights of the two central stars, or have merged with the dying star.

The complex shapes of the Southern Ring Nebula are more evidence of additional unseen companions – its ejections are thinner in some areas and thicker in others. A third closely interacting star may have agitated the jets, skewing the evenly balanced ejections like spin art. In addition, a fourth star with a slightly wider orbit might have also “stirred the pot” of ejections, like a spatula running through batter in the same direction each time, generating the enormous set of rings in the outer reaches of the nebula.

What about the very bright blue-white star in Webb’s images? Think of the fifth star like the most responsible party guest that continues to orbit the dying star slowly, predictably, and calmly.

The two images shown here each combine near-infrared and mid-infrared data to isolate different components of the nebula. The image at left highlights the very hot gas that surrounds the central stars. The image at right traces the star’s scattered molecular outflows that have reached farther into the cosmos.

The team's paper, entitled " The messy death of a multiple star system and the resulting planetary nebula as observed by JWST," will be published in Nature Astronomy on December 8.

The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

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About This Release:

Credits:

Media Contact:

Claire Blome
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• The science paper by O. De Marco et al.

Source: NASA's James Webb Space Telescope/News

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Scientists on the Hunt for Planetary Formation Fossils Reveal Unexpected Eccentricities in Nearby Debris Disk

Artist’s impression of the billion-year-old Sun-like star, HD 53143, and its highly eccentric debris disk. The star and a second inner disk are shown near the southern foci of the elliptical debris disk. A planet, which scientists assume is shaping the disk through gravitational force, is shown to the north. Debris disks are the fossils of planetary formation and since we can’t directly study our own disk— also known as the Kuiper Belt— scientists glean information about the formation of our Solar System by studying those we can see from a distance. Credit: ALMA (ESO/NAOJ/NRAO); M. Weiss (NRAO/AUI/NSF). Hi-Res File 

 

While studying HD 53143— a roughly billion-year-old Sun-like star— in millimeter-wavelengths for the first time, scientists discovered that the star’s debris disk is highly eccentric. Unlike ring-shaped debris disks, in which the star sits in the center, HD 53143 is located at one foci of an elliptical-shaped disk, and is shown as the unresolved dot below and left of center. Scientists believe a second unresolved dot in the north of this image to be a planet that is perturbing and shaping the debris disk. Credit: ALMA (ESO/NAOJ/NRAO)/M. MacGregor (U. Colorado Boulder); S. Dagnello (NRAO/AUI/NSF). Hi-Res File 

HST ACS coronagraphic data shows the region surrounding HD 53143. Because coronagraphic masks block out starlight to reveal features of the regions surrounding stars, the eccentric disk, and inner disk, of HD 53143 were originally "hidden" from scientists.Credit: ALMA(ESO/NAOJ/NRAO); NASA/ESA Hubble, P. Kalas (UC Berkeley); S. Dagnello (NRAO/AUI/NSF). Hi-Res File

 

 

Composite image of the HD 53143 star system. Shown in orange/red, millimeter-wavelength data from Atacama Large Millimeter/submillimeter Array (ALMA), reveal a previously unobserved eccentric debris disk orbiting HD 53143 in the form of an ellipse. Am unresolved dot shows the star off-center near the southern foci of the disk, while a second unresolved dot to the north indicates the potential presence of a planet. Optical data from the Hubble Space Telescope’s Advanced Camera for Surveys (ACS) is shown in blue and white; a coronagraphic mask blocks out the starlight, allowing researchers to see what’s happening in the region surrounding HD 53143. Credit: ALMA(ESO/NAOJ/NRAO), M. MacGregor U. Colorado Boulder; NASA/ESA Hubble, P. Kalas (UC Berkeley); S. Dagnello (NRAO/AUI/NSF). Hi-Res File 

 

HD 53143 is located in the Carina constellation, roughly 59.8 light-years from Earth.
Credit: IAU/Sky & Telescope. Hi-Res File

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First radio images of HD 53143 shed new light on the early development of Sun-like systems

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have imaged the debris disk of the nearby star HD 53143 at millimeter wavelengths for the first time, and it looks nothing like they expected. Based on early coronagraphic data, scientists expected ALMA to confirm the debris disk as a face-on ring peppered with clumps of dust. Instead, the observations took a surprise turn, revealing the most complicated and eccentric debris disk observed to date. The observations were presented today in a press conference at the 240th meeting of the American Astronomical Society (AAS) in Pasadena, California, and will be published in an upcoming edition of The Astrophysical Journal Letters (ApJL).

HD 53143— a roughly billion-year-old Sun-like star located 59.8 light-years from Earth in the Carina constellation— was first observed with the coronagraphic Advanced Camera for Surveys on the Hubble Space Telescope (HST) in 2006. It also is surrounded by a debris disk—a belt of comets orbiting a star that are constantly colliding and grinding down into smaller dust and debris— that scientists previously believed to be a face-on ring similar to the debris disk surrounding our Sun, more commonly known as the Kuiper Belt.

The new observations were made of HD 53143 using the highly-sensitive Band 6 receivers on ALMA, an observatory co-operated by the U.S. National Science Foundation’s National Radio Astronomy Observatory (NRAO), and have revealed that the star system’s debris disk is actually highly eccentric. In ring-shaped debris disks, the star is typically located at or near the center of the disk. But in elliptically-shaped eccentric disks, the star resides at one focus of the ellipse, far away from the disk’s center. Such is the case with HD 53143, which wasn’t seen in previous coronagraphic studies because coronagraphs purposely block the light of a star in order to more clearly see nearby objects. The star system may also be harboring a second disk and at least one planet.

“Until now, scientists had never seen a debris disk with such a complicated structure. In addition to being an ellipse with a star at one focus, it also likely has a second inner disk that is misaligned or tilted relative to the outer disk,” said Meredith MacGregor, an assistant professor at the Center for Astrophysics and Space Astronomy (CASA) and Department of Astrophysical and Planetary Sciences (APS) at CU Boulder, and the lead author on the study. “In order to produce this structure, there must be a planet or planets in the system that are gravitationally perturbing the material in the disk.”

This level of eccentricity, MacGregor said, makes HD 53143 the most eccentric debris disk observed to date, being twice as eccentric as the Fomalhaut debris disk, which MacGregor fully imaged at millimeter wavelengths using ALMA in 2017. “So far, we have not found many disks with a significant eccentricity. In general, we don’t expect disks to be very eccentric unless something, like a planet, is sculpting them and forcing them to be eccentric. Without that force, orbits tend to circularize, like what we see in our own Solar System.”

Importantly, MacGregor notes that debris disks aren’t just collections of dust and rocks in space. They are a historical record of planetary formation and how planetary systems evolve over time. and provide a peek into their futures. “We can’t study the formation of Earth and the Solar System directly, but we can study other systems that appear similar to but younger than our own. It’s a bit like looking back in time,” she said. “Debris disks are the fossil record of planet formation, and this new result is confirmation that there is much more to be learned from these systems and that knowledge may provide a glimpse into the complicated dynamics of young star systems similar to our own Solar System.”

Dr. Joe Pesce, NSF program officer for ALMA, added, “We are finding planets everywhere we look, and these fabulous results by ALMA are showing us how planets form – both those around other stars and in our own Solar System. This research demonstrates how astronomy works and how progress is made, informing not only what we know about the field but also about ourselves.”

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Resource

“ALMA Images the Eccentric HD 53143 Debris Disk,” MacGregor et al (2022), The Astrophysical Journal Letters, pre-print

Press conference access and recording:

Tuesday, June 14th, 2022 @ 10:15am PDT — Nearby Disks and Faraway Galaxies

“A New ALMA View of the HD 53143 Debris Disk”

About NRAO

The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

About ALMA

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Media Contact:

Amy C. Oliver
Public Information Officer, ALMA
Public Information & News Manager, NRAO
+1 434 242 9584
aoliver@nrao.edu

Source: National Radio Astronomy Observatory (NRAO)/News

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NASA’s Webb to Explore a Neighboring, Dusty Planetary System

A debris disk, which includes comets, asteroids, rocks of various sizes, and plenty of dust, orbits the star Beta Pictoris, which is blocked at the center of this 2012 image by a coronagraph aboard the Hubble Space Telescope. This is the visible-light view of the system. NASA’s James Webb Space Telescope will view Beta Pictoris in infrared light, both using its coronagraphs and capturing data known as spectra to allow researchers to learn significantly more about the gas and dust in the debris disk, which includes lots of smaller bodies like exocomets. Credits: IMAGE: NASA, ESA, Daniel Apai (University of Arizona), Glenn Schneider (University of Arizona). Release Images

Researchers will take stock of the dust in the debris disk surrounding the nearby star Beta Pictoris

Planetary systems are very busy places. In addition to the planets orbiting their host star, planetary systems are chock full of dust and other fragments left over from planet formation – a debris disk. Our own solar system includes the Kuiper Belt, which begins beyond Neptune. Younger systems, though, are a bit less “organized.” Take Beta Pictoris, a planetary system only 63 light-years away with a mature star, at least two planets, and the first comets discovered outside our solar system. Although researchers have observed it with powerful space- and ground-based telescopes since the 1980s, there’s still a lot we don’t yet know about its overall makeup. That’s why researchers will study the dusty disk of Beta Pictoris with Webb to better map out its dusty contents.

Researchers will use NASA’s upcoming James Webb Space Telescope to study Beta Pictoris, an intriguing young planetary system that sports at least two planets, a jumble of smaller, rocky bodies, and a dusty disk. Their goals include gaining a better understanding of the structures and properties of the dust to better interpret what is happening in the system. Since it’s only about 63 light-years away and chock full of dust, it appears bright in infrared light – and that means there is a lot of information for Webb to gather.

Beta Pictoris is the target of several planned Webb observing programs, including one led by Chris Stark of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and two led by Christine Chen of the Space Telescope Science Institute (STScI) in Baltimore, Maryland. Stark’s program will directly image the system after blocking the light of the star to gather a slew of new details about its dust. Chen’s programs will gather spectra, which spread light out like a rainbow to reveal which elements are present. All three observing programs will add critical details to what’s known about this nearby system.

First, a Review of What We Know

Beta Pictoris has been regularly studied in radio, infrared, and visible light since the 1980s. The star itself is twice as massive as our sun and quite a bit hotter, but also significantly younger. (The Sun is 4.6 billion years old, but Beta Pictoris is approximately 20 million years old.) At this stage, the star is stable and hosts at least two planets, which are both far more massive than Jupiter. But this planetary system is remarkable because it is where the first exocomets (comets in other systems) were discovered. There are quite a lot of bodies zipping around this system!

Like our own solar system, Beta Pictoris has a debris disk, which includes comets, asteroids, rocks of various sizes, and plenty of dust in all shapes that orbit the star. (A debris disk is far younger and can be more massive than our solar system’s Kuiper Belt, which begins near Neptune’s orbit and is where many short-period comets originate.)

This outside ring of dust and debris is also where a lot of activity is happening. Pebbles and boulders could be colliding and breaking into far smaller pieces — sending out plenty of dust.

Scrutinizing This Planetary System

Stark’s team will use Webb’s coronagraphs, which block the light of the star, to observe the faint portions of the debris disk that surround the entire system. “We know there are two massive planets around Beta Pictoris, and farther out there is a belt of small bodies that are colliding and fragmenting,” Stark explained. “But what’s in between? How similar is this system to our solar system? Can dust and water ice from the outer belt eventually make its way into the inner region of the system? Those are details we can help tease out with Webb.”

Webb’s imagery will allow the researchers to study how the small dust grains interact with planets that are present in that system. Plus, Webb will detail all the fine dust that streams off these objects, permitting the researchers to infer the presence of larger rocky bodies and what their distribution is in the system. They’ll also carefully assess how the dust scatters light and reabsorbs and reemits light when it’s warm, allowing them to constrain what the dust is made of. By cataloging the specifics of Beta Pictoris, the researchers will also assess how similar this system is to our solar system, helping us understand if the contents of our solar system are unique.

Isabel Rebollido, a team member and postdoctoral researcher at STScI, is already building complex models of Beta Pictoris. The first model combines existing data about the system, including radio, near-infrared, far-infrared, and visible light from both space- and ground-based observatories. In time, she will add Webb’s imagery to run a fuller analysis.

The second model will feature only Webb’s data – and will be the first they explore. “Is the light Webb will observe symmetrical?” Rebollido asked. “Or are there ‘bumps’ of light here and there because there is an accumulation of dust? Webb is far more sensitive than any other space telescope and gives us a chance to look for this evidence, as well as water vapor where we know there’s gas.”

Dust as a Decoder Ring

Think of the debris disk of Beta Pictoris as a very busy, elliptical highway – except one where there aren’t many traffic rules. Collisions between comets and larger rocks can produce fine dust particles that subsequently scatter throughout the system.

“After planets, most of the mass in the Beta Pictoris system is thought to be in smaller planetesimals that we can’t directly observe,” Chen explained. “Fortunately, we can observe the dust left behind when planetesimals collide.”

This dust is where Chen’s team will focus its research. What do the smallest dust grains look like? Are they compact or fluffy? What are they made of?

“We’ll analyze Webb’s spectra to map the locations of dust and gas – and figure out what their detailed compositions are,” Chen explained. “Dust grains are ‘fingerprints’ of planetesimals we can’t see directly and can tell us about what these planetesimals are made of and how they formed.” For example, are the planetesimals ice-rich like comets in our solar system? Are there signs of high-speed collisions between rocky planetesimals? Clearly analyzing if grains in one region are more solid or fluffy than another will help the researchers understand what is happening to the dust, and map out the subtle differences in the dust in each region.

“I’m looking forward to analyzing Webb’s data since it will provide exquisite detail,” added Cicero X. Lu, a team member and a fourth-year Ph.D. student at Johns Hopkins University in Baltimore. “Webb will allow us to identify more elements and pinpoint their precise structures.”

In particular, there’s a cloud of carbon monoxide at the edge of the disk that greatly interests these researchers. It’s asymmetric and has an irregular, blobby side. One theory is that collisions released dust and gas from larger, icy bodies to form this cloud. Webb’s spectra will help them build scenarios that explain its origin.

The Reach of Infrared

These research programs are only possible because Webb has been designed to provide crisp, high-resolution detail in infrared light. The observatory specializes in collecting infrared light – which travels through gas and dust – both with images and spectra. Webb also has another advantage – its position in space. Webb will not be hindered by Earth’s atmosphere, which filters out some types of light, including several infrared wavelength bands. This observatory will allow researchers to gather a more complete range of infrared light and data about Beta Pictoris for the first time.

These studies will be conducted as part of Webb Guaranteed Time Observations (GTO) and General Observers (GO) programs. The GTO programs are led by scientists who helped develop the key hardware and software components or technical and inter-disciplinary knowledge for the observatory. GO programs are competitively selected using a dual-anonymous review system, the same system that is used to allocate time on the Hubble Space Telescope.

The James Webb Space Telescope will be the world's premier space science observatory when it launches in 2021. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

 

Credits:

Media Contact:

Claire Blome
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Contact Us:
Direct inquiries to the News Team.

Related Links and Documents:

Visualization of a Debris Disk: "How Planets Form"

Source: NASA's James Webb Space Telescope/News

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