In January 2006, New Horizons was launched for its long journey to explore Pluto and its five known moons. This will be NASA’s first opportunity to explore the distant planet of which little is known since its 1930 discovery.
Pluto is the most famous resident of the Kuiper Belt, an area of space beyond Neptune that is filled with innumerable objects that are believed to be remnants of the formation of the solar system. A Dutch astronomer, Jan Oort, theorized that comets might originate from this distant region. Gerard Kuiper first envisioned the existence of icy objects beyond Neptune in 1951.
The Kuiper Belt is about 3 billion miles from Earth and is similar to the asteroids that orbit the sun between Mars and Jupiter. The asteroid belt is filled with rocky objects whereas the Kuiper Belt’s objects are icy. Several dwarf planets, of which Pluto is one, exist in these far reaches of space. Dwarf planets are not only smaller than regular planets, but their lack of size does not give them the ability to clear space around them.
Currently in a hibernation state, New Horizons will awake and begin preparing for its encounter with Pluto on Dec. 6. The actual flyby will begin in January with the spacecraft’s closest encounter occurring on July 15, 2015. A scheduled trajectory adjustment burn was not deemed necessary and has left the craft with additional fuel.
The additional fuel has NASA officials searching for additional Kuiper Belt objects for New Horizons to explore. To identify potential targets, officials used the Hubble telescope to locate objects of interest. These targets had to be in line with Pluto so that additional use of fuel would not be required. The Hubble data identified three additional objects that will be tracked to ascertain their orbital path.
New Horizons crossed Neptune’s orbital path on Aug. 25. On Sept. 12 NASA, using the Long Range Reconnaissance Imager, began its initial preparatory testing of the approaching Pluto system. Hydra, a small moon of Pluto, was detected. It was not anticipated to view the moon until early in 2015. Locating Hydra this early in the process bodes well for the team’s ability to locate potential unknown moons or planetary rings.
New Horizons took 48 images, each lasting 10 seconds, of Pluto on two separate occurrences in July. While these images revealed Hydra, officials were unable to see Nix, another of Pluto’s moons. New Horizons was still 267 million miles from Pluto when these images were taken. Those images also revealed its largest moon, Charon. Some astronomers consider Pluto-Charon as a binary planet.
NASA has completed its detailed engineering review of the mission and has begun the process of planning for the approach science. By next month sequences for planetary approach will be developed. Each sequence serves as a two-week flight plan for the spacecraft and takes about eight weeks to develop, test and certify.
New Horizon’s exploration of Pluto and the Kuiper Belt is NASA’s first extensive look at this distant part of the solar system. Pluto was still classified as a planet when the mission initially launched. It has since been downgraded to a dwarf planet.
By Hans Benes
Image courtesy of NASA