Artist's Impression of Kuiper Belt Object (Annotated)
This is an artist's impression of a Kuiper Belt object (KBO), located
on the outer rim of our solar system at a staggering distance of 4
billion miles from the Sun. Unlike asteroids, KBOs have not been
significantly heated by the Sun, and so are thought to represent a
pristine, well preserved, deep-freeze sample of what the outer solar
system was like following its birth 4.6 billion years ago. A Hubble
survey uncovered three KBOs, ranging from 27 to 35 miles across, that
are potentially reachable by NASA's New Horizons spacecraft after it
passes by Pluto in mid-2015.
The Sun appears as a bright star at image center in this graphic,
which represents the view from the KBO. The Earth and other inner
planets are too close to the Sun to be seen in this illustration. The
bright "star" to the left of the Sun is the planet Jupiter, and the
bright object below the Sun is the planet Saturn. Two bright pinpoints
of light to the right of the Sun, midway to the edge of the frame, are
the planets Uranus and Neptune, respectively. The planet positions are
plotted for late 2018 when the New Horizons probe reaches a distance of 4
billion miles from the Sun. The Milky Way appears in the background. . Illustration Credit: NASA, ESA, and G. Bacon (STScI)
Kuiper Belt Object 1110113Y
A Kuiper Belt object (KBO) that is potentially reachable by NASA's
Pluto-bound New Horizons probe is visible in multiple exposures taken
with the Hubble Space Telescope. Hubble tracked the KBO (named 1110113Y
or "PT1") moving against the crowded background field of stars in the
constellation Sagittarius. The object is no bigger than 19 to 28 miles
across, and it is a deep-freeze relic of what the outer solar system
was like 4.6 billion years ago, during the period when the Sun formed.
As the KBO orbits the Sun, its position noticeably shifts between
exposures taken approximately 10 minutes apart. Following an initial
proof of concept of the Hubble pilot observing program in June, the New
Horizons team was awarded telescope time by the Space Telescope
Science Institute for a wider survey in July. When the search was
completed in early September, the team identified this KBO as
"definitely reachable" by the New Horizons spacecraft. Credit: NASA, ESA, SwRI, JHU/APL, and the New Horizons KBO Search Team
Hubble's Search for Kuiper Belt Objects
A Kuiper Belt object (KBO) that is potentially reachable by NASA's
Pluto-bound New Horizons probe is visible in multiple exposures taken
with the Hubble Space Telescope. Hubble tracked the KBO (labeled PT1)
moving against the crowded background field of stars in the summer
constellation Sagittarius. The object is no bigger than 19 to 28 miles
across, and it is a deep-freeze relic of what the outer solar system
was like 4.6 billion years ago, during the period when the Sun formed.
The image at right shows the KBO at an estimated distance of
approximately 4 billion miles from Earth. As the KBO orbits the Sun, its
position noticeably shifts between exposures taken approximately 10
minutes apart. Following an initial proof of concept of the Hubble
pilot observing program in June, the New Horizons team was awarded
telescope time by the Space Telescope Science Institute for a wider
survey in July. When the search was completed in early September, the
team identified this KBO as "definitely reachable" by the New Horizons
spacecraft. Credit: NASA, ESA SwRI, JHU/APL, and the New Horizons KBO Search Team
Peering out to the dim, outer reaches of our solar system, NASA's Hubble Space Telescope has uncovered three Kuiper Belt objects (KBOs) the agency's New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015.
The KBOs were detected through a dedicated Hubble observing program
by a New Horizons search team that was awarded telescope time for this
purpose.
"This has been a very challenging search, and it's great that in the
end Hubble could accomplish a detection — one NASA mission helping
another," said Alan Stern of the Southwest Research Institute (SwRI) in
Boulder, Colorado, principal investigator of the New Horizons mission.
The Kuiper Belt is a vast rim of primordial debris encircling our
solar system. KBOs belong to a unique class of solar system objects
that has never been visited by spacecraft and which contain clues to
the origin of our solar system.
The KBOs that Hubble found are each about 10 times larger than
typical comets, but only about 1-2 percent of the size of Pluto. Unlike
asteroids, KBOs have not been heated by the Sun, and are thought to
represent a pristine, well preserved, deep-freeze sample of what the
outer solar system was like following its birth 4.6 billion years ago.
The KBOs found in the Hubble data are thought to be the building blocks
of dwarf planets such as Pluto.
The New Horizons team started to look for suitable KBOs in 2011 using
some of the largest ground-based telescopes on Earth. They found
several dozen KBOs, but none were reachable within the fuel supply
available aboard the New Horizons spacecraft.
"We started to get worried that we could not find anything suitable,
even with Hubble, but in the end the space telescope came to the
rescue," said New Horizons science team member John Spencer of SwRI.
"There was a huge sigh of relief when we found suitable KBOs; we are
'over the moon' about this detection."
Following an initial proof of concept of the Hubble pilot observing
program in June, the New Horizons team was awarded telescope time by
the Space Telescope Science Institute for a wider survey in July. When
the search was completed in early September, the team identified one
KBO that is "definitely reachable" and two other potentially accessible
KBOs that will require more tracking over several months to know
whether they too are accessible by the New Horizons spacecraft.
This was a needle-in-a-haystack search for the New Horizons team
because the elusive KBOs are extremely small, faint, and difficult to
pick out against myriad background stars in the constellation
Sagittarius, which is in the present direction of Pluto. The three KBOs
identified are each a whopping 1 billion miles beyond Pluto. Two of
the KBOs are estimated to be as large as 34 miles (55 kilometers)
across, and the third is perhaps as small as 15 miles (25 kilometers).
The New Horizons spacecraft, launched in 2006 from Florida, is the
first mission in NASA's New Frontiers Program. Once a NASA mission
completes its prime mission, the agency conducts an extensive science
and technical review to determine whether extended operations are
warranted.
The New Horizons team expects to submit such a proposal to NASA in
late 2016 for an extended mission to fly by one of the newly identified
KBOs. Hurtling across the solar system, the New Horizons spacecraft
would reach the distance of 4 billion miles from the Sun at its
farthest point roughly three to four years after its July 2015 Pluto
encounter. Accomplishing such a KBO flyby would substantially increase
the science return from the New Horizons mission as laid out by the
2003 Planetary Science Decadal Survey.
CONTACT
Dwayne Brown
Headquarters, Washington, D.C.
202-358-0257
dwayne.c.brown@nasa.gov
Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu
Source: HubbleSite
