This is an artist's rendering of the New Horizons spacecraft
encountering a Kuiper Belt object — a city-sized icy relic left over
from the birth of our solar system. The Sun, more than 4.1 billion
miles (6.7 billion kilometers) away, shines as a bright star embedded
in the glow of the zodiacal dust cloud. Jupiter and Neptune are visible
as orange and blue "stars" to the right of the Sun. Credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI). Release Images
After careful consideration and analysis, the Hubble Space Telescope
Time Allocation Committee has recommended using Hubble to search for an
object the Pluto-bound NASA New Horizons mission could visit after its
flyby of Pluto in July 2015.
The planned search will involve targeting a small area of sky in
search of a Kuiper Belt object (KBO) for the outbound spacecraft to
visit. The Kuiper Belt is a vast debris field of icy bodies left over
from the solar system's formation 4.6 billion years ago. A KBO has
never been seen up close because the belt is so far from the Sun,
stretching out to a distance of 5 billion miles into a
never-before-visited frontier of the solar system.
"I am pleased that our science peer-review process arrived at a
consensus as to how to effectively use Hubble's unique capabilities to
support the science goals of the New Horizons mission," said Matt
Mountain, director of the Space Telescope Science Institute (STScI) in
Baltimore, Maryland.
The full execution of the KBO search is contingent upon the results
from a pilot observation using Hubble observations provided by
Mountain's director's discretionary time.
The space telescope will scan an area of sky in the direction of the
constellation Sagittarius to try and identify any objects orbiting
within the Kuiper Belt. To discriminate between a foreground KBO and
the clutter of background stars in Sagittarius, the telescope will turn
at the predicted rate that KBOs are moving against the background
stars. In the resulting images, the stars will be streaked, but any KBOs
should appear as pinpoint objects.
If the test observation identifies at least two KBOs of a specified
brightness, it will demonstrate statistically that Hubble has a chance
of finding an appropriate KBO for New Horizons to visit. At that point,
an additional allotment of observing time will continue the search
across a field of view roughly the angular size of the full Moon.
Astronomers around the world apply for observing time on the Hubble
Space Telescope. Competition for time on the telescope is extremely
intense and the requested observing time significantly exceeds the
observing time available in a given year. Proposals must address
significant astronomical questions that can only be addressed with
Hubble's unique capabilities and are beyond the capabilities of
ground-based telescopes. The proposals are peer reviewed annually by an
expert committee, which looks for the best possible science that can
be conducted by Hubble and recommends to the STScI director a balanced
program of small, medium, and large investigations.
Though Hubble is powerful enough to see galaxies near the horizon of
the universe, finding a KBO is a challenging needle-in-haystack search.
A typical KBO along the New Horizons' trajectory may be no larger than
Manhattan Island and as black as charcoal.
Even before the launch of New Horizons in 2006, Hubble has provided
consistent support for this edge-of-the-solar system mission. Hubble
was used to discover four small moons orbiting Pluto and its binary
companion object Charon, providing new targets to enhance the mission's
scientific return. And Hubble has provided the most sensitive search
yet for potentially hazardous dust rings around Pluto. Hubble also has
made a detailed map of the dwarf planet's surface, which astronomers
are using to plan New Horizons' close-up reconnaissance photos.
In addition to Pluto exploration, recent Hubble solar system
observations have discovered a new satellite around Neptune, probed the
magnetospheres of the gas-giant planets, found circumstantial evidence
for oceans on Europa, and uncovered several bizarre cases of asteroids
disintegrating before our eyes. Hubble has supported numerous NASA Mars
missions by monitoring the Red Planet's seasonal atmospheric changes.
Hubble has made complementary observations in support of the Dawn
asteroid mission, and comet flybys. Nearly 20 years ago, in July 1994,
Hubble documented the never-before-seen string of comet collisions with
Jupiter that resulted from the tidal breakup of comet Shoemaker-Levy
9.
"The planned search for a suitable target for New Horizons further
demonstrates how Hubble is effectively being used to support
humankind's initial reconnaissance of the solar system," said Mountain.
"Likewise, it is also a preview of how the powerful capabilities of
the upcoming James Webb Space Telescope will further bolster planetary
science. We are excited by the potential of both observatories for
ongoing solar system exploration and discovery."
CONTACT
Ray VillardSpace Telescope Science Institute, Baltimore, Maryland
410-338-4514
villard@stsci.edu
J.D. Harrington
NASA Headquarters, Washington, D.C.
202-358-5241
j.d.harrington@nasa.gov
Source: HubbleSite
