SOHO offers comet contest
By Robert Roy Britt
(SPACE.com) -- The most prolific comet-hunter in history recently made its 900 discovery of a frozen visitor to the inner solar system, a chunk of ice and rock hurtling precariously close to the Sun.
To celebrate this achievement of the SOHO spacecraft, its operators have begun a contest for the public to pick the timing of the discovery of No. 1,000, officials told SPACE.com.
The winner will receive a SolarMax DVD, a SOHO T-shirt, solar viewing glasses, and more. Prizes will be awarded for second and third place, too. SOHO is a joint project of NASA and the European Space Agency.
Launched in 1995, SOHO (Solar & Heliospheric Observatory) was not designed to find comets. Its main job is to monitor the Sun. It has been near death three times but remains the primary tool for detecting solar eruptions that can threaten satellites and even power grids on Earth.
The craft's instruments block out the Sun's main disk, so that images can be taken of the solar atmosphere and surrounding space -- places that are otherwise largely unobservable.
SOHO pictures are posted to the Internet on an almost-live basis. Comets that otherwise go undetected show up plainly. On such a close approach, frozen water and other chemicals are rapidly boiled off a comet, releasing rocky grains too. All this material forms a tail that arcs gracefully away from the Sun and is brilliantly lit.
Armchair astronomers figured out early on that they could use the images to discover comets. More than 75 percent of the 900 discoveries so far have been made by amateurs. Some of the frozen denizens are swallowed by the Sun shortly after they're spotted. Others arc around the Sun and shoot back out to the outer solar system.
Other comets discovered without SOHO, such as one named Kudo-Fujikawa, have at times been watched in real time by web surfers as they dramatically sliced across SOHO's field of view.
In 2003, a comet named NEAT, whose path in front of the SOHO cameras was well predicted, was smacked by a solar storm, the first such event ever recorded.
The contest winner will be the person who guesses closest to the date and time when comet No. 1,000 reaches its point closest to the Sun. Astronomers call this perihelion, and it will occur within a few days before or after the comet's discovery.
The contest runs now through May 15, 2005. Officials project that the 1,000 discovery will occur sometime between June and October.
The contest entry form and more information are available at: http://soho.nascom.nasa.gov/comet1000/.
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