An entrepreneur developing a mission to study and lay claim to a near-Earth asteroid announced a program to award cash prizes to amateur astronomers who discover these bodies.
     Benson, head of the Space Development Corporation, announced the "Benson Prize for the Amateur Discovery of Near Earth Asteroids" June 10 at a meeting of the American Astronomical Society in Winston-Salem, North Carolina.
     Under the prize guidelines, the next ten discoveries of near-Earth asteroids (NEAs) by amateur astronomers will earn the discoverer a $500 award. Discoveries of NEAs by professional astronomers will not be eligible for the award.
     Benson said that with larger telescopes and more powerful CCD camera available to amateurs today, "the discovery of near-Earth asteroids by amateur astronomers is more attainable than ever."
     Benson's company is developing NEAP, the Near-Earth Asteroid Prospector, a private mission to rendezvous with an asteroid, study its composition, and then land with it for purposes of filing mining claims.
     Benson, who discussed NEAP in greater detail last month at the International Space Development Conference, said the mission is planned for launch in the year 2000.

Further analysis of data returned by the Galileo spacecraft and its atmospheric probe show that while the probe dropped into a warm, dry region of the planet in 1995 other areas of the planet contain much more water.
     "We had suspected that the probe landed in the 'Sahara Desert of Jupiter," Andrew Ingersoll, a Caltech planetary science professor and member of the Galileo science team, said. "But the new data show there is moisture in the surrounding areas. Jupiter is not as dry overall as we thought."
     The data returned by Galileo's probe as it entered Jupiter's dense atmosphere on December 7, 1995, showed far less water than had been expected. Comparison of the data with ground-based infrared images showed that the probe had entered a warm spot in the atmosphere, one of a few such spots that cover less than a percent of the planet.
     Areas around the dry area, though, appear very wet, with up to 100 times as much water as the dry regions, based on new measurements from the Galileo spacecraft in orbit.
     The wet and dry regions appear to be linked with circulation of the Jovian atmosphere, with the dry regions areas where winds converge and create a giant downdraft.
     The downdraft would explain the lack of water visible there, said Dr. Glenn Orton of JPL. "Winds rise from the deep atmosphere and lose water and ammonia," he said. "At the top, when they converge and drop back down, nothing is left to condense back into clouds, and a dry clearing is created."
     Ingersoll also all but ruled out the possibility of life in the Jovian atmosphere, despite the presence of water and warm temperatures. He said it was "highly unlikely" that life could survive and evolve while hovering in the atmosphere, without the support of a solid surface.

Astronomers have discovered the brightest object seen beyond Neptune since the discovery of Pluto and its moon Charon, a giant comet that may be the first in a new class of outer solar system bodies.
     The object, designated 1996TL66, was discovered in late 1996 by astronomers at the Harvard-Smithsonian Center for Astrophysics. A paper on the body was published in the British science journal Nature in early June.
     The object is estimated to be over 490 km (300 mi.) in diameter. It is in a highly elliptical orbit which brings it to within 35 AU of the Sun -- nearly as close as Neptune -- but as far away as 150 AU from the Sun.
     Its orbit is unlike those of recently-discovered Kuiper Belt objects, which are generally found in more circular orbits in the vicinity of Neptune and beyond. This had led discoverer Jane Luu of Harvard to conclude that 1996TL66 "could represent the first of a new class of objects in the outer solar system."
     Luu believes that there may be as many as 6,400 bodies like 1996TL66 in similar orbits. This may mean the solar nebula, from which the Sun, planets, asteroids, and the rest of the solar system formed, may have been much larger than once thought.
     Two other recent asteroid discoveries made headlines recently. Astronomers announced that one asteroid, known simply as number 3753, follows a horseshoe, or kidney-shaped orbit around the Sun. Its orbit is influenced by the Earth's gravitational pull, keeping the 5-km (3-mi.) asteroid in its unusual orbit and also keeping it from colliding with Earth.
     A team at the European Southern Observatory has found evidence for a moon orbiting another asteroid, 3671 Dionysus. The astronomers measured the brightness of the near-Earth asteroid over a 10-day period and found periodic dimming of the light, which that believe is caused by the moon orbiting the asteroid.
     Only one asteroid, 243 Ida, is known to have a moon. It's companion, Dactyl, was discovered by the Galileo spacecraft when it flew by the asteroid in 1993. Astronomers will take another look at Dionysus in the coming weeks, as it passes to within 17.2 million km (10.6 million mi.) on July 6.