New moon found at Pluto; Neptune turns one
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ntThe Hubble Space Telescope discovered a new moon circling the dwarf planet Pluto. While searching for rings around Pluto scientists discovered the tiny moon, currently called P4, which is estimated between 8 and 21 miles in diameter. This moon was spotted using instruments approximately 3 billion miles away.
ntScientists are studying Pluto in preparation for the New Horizons spacecraft which will fly by the icy dwarf planet in 2015.
ntAlso in space news, Neptune was discovered 165 years ago by German astronomer Johann Galle on September 23, 1846. That’s one year ago in Neptune time as it takes the planet 165 years to circle the sun which is 2.8 billion miles away. Plus, Hubble makes its 1 millionth scientific observation.
ntAbove: Images taken on June 28 and July 3 confirm the existence of Pluto’s new moon, P4.
ntCredit: NASA, ESA, and M. Showalter (SETI institute)
ntHere is a map of the Pluto system. The largest moon Charon was discovered in 1978 while Nix and Hydra were both located by the Hubble telescope in 2005.
ntP4 had not been seen in earlier images of Pluto’s system because the exposure times weren’t long enough to pick up the faint light. For more about Pluto’s new moon read NASA’s report.
ntCredit: NASA, ESA, and A. Feild (STScI)
ntInterest in Pluto peaked after astronomers decided that the body wasn’t large enough to be a “real” planet so demoted it to a “dwarf planet” status. Here’s the New Horizons spacecraft.
ntNew Horizons was launched in 2006 and is expected to arrive at Pluto in 2015. Here’s where it is today, just past the orbit of Uranus – more than halfway there.
ntNew Horizons route to Pluto was given a slingshot boost when it flew by the planet Jupiter to help it gain speed. While flying past Jupiter, New Horizons took this photo of an active volcano’s plume on the moon, Io.
ntTo celebrate Neptune’s birthday, images of the planet were taken by the Hubble Space telescope. These four images taken at four-hour intervals show almost the entire surface of Neptune as it only takes about 16 hours to completely rotate.
ntWhen the Voyager 2 spacecraft visited Neptune in 1989, a giant dark spot, about the same size as Jupiter’s Great Red Spot, was observed. The huge storm petered out and disappeared by 1994.
ntVoyager also visited Neptune’s largest moon, Triton, which proved to have a very interesting surface. Triton is the only large moon that orbits in the opposite direction of its planet’s rotation – or retrograde.
ntHere is a map of Neptune and its moons.
ntThe Hubble Space Telescope’s one millionth observation was of an extrasolar planet HAT-P-7b. It is a gas planet larger than Jupiter orbiting a star hotter than our sun. Here is an artist’s conception of the planet.
ntCredit: NASA, ESA, and G. Bacon (STScI)