[meteorite-list] NASA's Hubble Telescope Finds Potential Kuiper Belt Targets for New Horizons Pluto Mission

[Ron Baalke]

October 15, 2014
     
NASA's Hubble Telescope Finds Potential Kuiper Belt Targets for New Horizons Pluto Mission

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 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 was 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 considered 
"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-haystack search for the New Horizons team because the 
elusive KBOs are extremely small, faint, and difficult to pick out against a 
myriad background of stars in the constellation Sagittarius, which is in the 
present direction of Pluto. The three KBOs identified each are 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.

The Hubble Space Telescope is a project of international cooperation between 
NASA and the European Space Agency. NASA's Goddard Space Flight Center in 
Greenbelt, Maryland, manages the telescope. The Space Telescope Science 
Institute (STScI) in Baltimore conducts Hubble science operations. STScI is 
operated for NASA by the Association of Universities for Research in 
Astronomy, Inc., in Washington.

The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, 
Maryland, manages the New Horizons mission for NASA's Science Mission 
Directorate. APL also built and operates the New Horizons spacecraft.

For images of the KBOs and more information about Hubble, visit:

http://www.nasa.gov/hubble 

For information about the New Horizons mission, visit:

http://www.nasa.gov/newhorizons 

-end-

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
Villard at stsci.edu