Hippocamp is one of the smallest, and darkest, moons of Neptune. Known to astronomers as “The Moon that Shouldn’t be There,” it orbits the giant planet at a distance so close to the larger moon of Proteus that it should have already been destroyed. Researchers using the Hubble Space Telescope have now concluded that this tiny satellite, just 20 miles in diameter, broke off of its larger neighbor billions of years ago, following an impact with a comet. When Voyager 2 visited Neptune in 1989, it photographed a massive impact crater on Proteus, which is likely evidence of this ancient collision.Read More Hubble Reveals Origins of Hippocamp — The Tiny Moon of Neptune that Shouldn’t Be There
Titan is the second-largest moon in the solar system, and the only one known to possess a thick atmosphere. Since it was first studied in detail by the Voyager 1 spacecraft in 1980, astronomers have wondered how the atmosphere of the largest moon of Saturn developed. Now, researchers have developed a theory that comets, which are rich in organic materials, may have deposited vast quantities of carbon-based chemicals just beneath the surface of Titan, where they were baked, releasing the nitrogen and methane seen in the atmosphere of Titan today.Read More Is Titan Baking its Own Atmosphere? Origin of Mysterious Gases Revealed
The New Horizons spacecraft made a close encounter with Ultima Thule on New Year’s Day, making this the most distant body ever visited by a robotic explorer. The color images returned by the vehicle show the object resembles a red-colored snowman 31 kilometers (19 miles) in length. Exploration of Ultima Thule could help astronomers answer mysteries about comets and the formation of the Solar System. New Horizons made history in 2015, when it became the first spacecraft to visit Pluto.Read More A Giant Red Snowman in Space? New Horizons Returns First Color Images of Ultima Thule
The Geminid Meteor shower is peaking on the nights of December 13th and 14th, delighting viewers on Earth with between 50 and 120 shooting stars every hour. This annual event is sometimes known as “Nature’s Holiday Light Show,” lighting up the skies with bright green streaks. To view the display, head outside after 10 pm, and look to the east. If you are viewing just before dawn, the shooting stars will be seen in the south. Accompanying this display will be a small green comet, known as 46P/Wirtanen. Both the meteor shower and the comet are visible without telescopes or binoculars.Read More Geminid Meteor Shower Peaking Now – View Nature’s Holiday Light Show (and a Green Comet as Well)!