The Hubble Space Telescope has spotted two previously-unknown objects beyond the orbit of Pluto. A spacecraft to visit one of these distant bodies may already be well on the way.
Astronomers looking for targets for the New Horizons Spacecraft spent two years using ground-based telescopes, without success. That spacecraft, launched in 2006, will be the first vehicle to visit Pluto, when it performs a flyby in July 2015.
New Horizons was launched without a target to visit after what was then considered the most distant planet in the solar system. Beyond the icy dwarf planet of Pluto lies the Kuiper belt. Here, rocky and icy bodies of all sizes orbit the distant reaches of the solar system.
Mission planners are now searching for a candidate target among these bodies for the far-flung aircraft. After a preliminary study period lasting just 10 days using the Hubble Space Telescope, astronomers found two candidate Kuiper Belt Objects (KBO's). The team examined 20 regions of the sky, trying to discover potential targets for the spacecraft.
This early success has convinced Hubble managers to allow additional viewing time on the telescope for the New Horizons team. Additional observations will begin in July and run through August. Any candidate for a visit would require additional observations and approval by the space agency.
"Once again the Hubble Space Telescope has demonstrated the ability to explore the Universe in new and unexpected ways," John Grunsfeld, NASA associate administrator, said.
The preliminary survey took place from 16 to 26 June, and examined around 200 bodies. The Hubble Time Allocation Committee set a minimum goal for the pilot program of two candidates. With that requirement met, New Horizons investigators were awarded 160 additional orbits using the world's best-known orbiting observatory.
"I am delighted that our initial investment of Hubble time paid off. We are looking forward to see if the team can find a suitable KBO that New Horizons might be able to visit after its fly-by of Pluto," Matt Mountain, Space Telescope Science Institute director, said.
The Kuiper Belt is named after astronomer Gerard Kuiper, who first developed the idea of such a feature in a work of science fiction, published in 1951. The first of these bodies was discovered two decades ago, and more than 1,000 such objects are currently known. They are remnants of the formation of our solar system.
New Horizons will make its closest approach to Earth on 14 July, 2015.