The planet Neptune has been hiding a secret that NASA's Hubble Space Telescope just discovered -- another moon.
The newly discovered moon, dubbed S/2004 N 1, is the fourteenth known to be orbiting Neptune, which is anywhere from 2.7 billion miles to as much as 2.9 billion miles from Earth, depending on where both planets are in their orbits.
The newly found moon is the smallest of those around Neptune and is no more than 12 miles across. NASA noted that the moon is so small and dim that it is approximately 100 million times fainter than the faintest star that can be seen with the naked eye. In fact, it's so small and dim that even when NASA's Voyager 2 spacecraft flew past Neptune in 1989, surveying its moons and rings, it never spotted S/2004 N 1.
Mark Showalter of the SETI Institute in Mountain View, Calif., found the moon on July 1, while studying Hubble's images of the faint arcs, or segments of rings, around Neptune, according to the space agency. Showalter tracked the movement of what appeared to be a white dot that appeared over and over again in more than 150 images of Neptune that Hubble took between 2004 to 2009.
"The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system," said Showalter in a written statement. "It's the same reason a sports photographer tracks a running athlete -- the athlete stays in focus, but the background blurs."
The newly discovered moon is about 65,400 miles from Neptune, orbiting between the Neptunian moons Larissa and Proteus. It completes one revolution around Neptune every 23 hours.
The Hubble Space Telescope has had some big wins lately.
Earlier this month, NASA announced that Hubble gave scientists information about a blue planet 63 light years away that looks a lot like Earth. However, that's where the similarities end. On this planet, named HD 189733b, the daytime temperature is nearly 2,000 degrees Fahrenheit, and it may rain glass there, although sideways, in what are believed to be "howling 4,500-mph winds."
Last December, scientists announced that Hubble had given them a look at a previously unseen group of seven primitive galaxies that were created more than 13 billion years ago, when the universe was just 4% of its current age.
This article, NASA's Hubble telescope spots Neptune's hidden moon, was originally published at Computerworld.com.
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