Latest natural satellite Stories
Exactly 85 years after Clyde Tombaugh’s historic discovery of Pluto, the NASA spacecraft set to encounter the icy dwarf planet this summer is providing its first views of the small moons orbiting Pluto.
New images captured by the Hubble Space Telescope depict a rare event known as a tri-moon conjunction, in which three of Jupiter’s largest moons are passing across the banded face of the gas-giant at the same time, NASA officials announced on Thursday.
Known as a "triple shadow transit," three of Jupiter’s moons will simultaneously cast shadows onto the cloudy planet on Saturday (January 24th, 2014). Get ready!
Almost immediately after NASA's twin Voyager spacecraft made their brief visits to Saturn in the early 1980s, scientists were hungry for more.
Saturn’s moon Mimas is known for a resemblance to the Death Star from Star Wars, but that’s not the moon’s most unique attribute: The moon actually wobbles significantly in its orbit around Saturn.
Analysis of a massive rectangular feature buried just below the lunar surface by NASA’s GRAIL spacecraft has revealed that the giant basin on the moon’s near side was likely created by ancient lava flows and not a massive asteroid collision.
A recent study led by Olivier Mousis at the Université de Franche-Comté probed the hydrological cycle of Titan by examining how Titan's methane rainfall would interact with icy materials within underground reservoirs.
In honor of the 25th anniversary of Voyager 2’s first up-close look at Neptune and Triton, NASA has “restored” footage obtained by the probe and used it to construct the highest-quality global color map of the moon to date.
Scientists hunting for life beyond Earth have discovered more than 1,800 planets outside our solar system, or exoplanets, in recent years, but so far, no one has been able to confirm an exomoon.
Last year's single supermoon caused quite a stir. This summer, however, will bring a much greater treat to stargazers as there will be three full moons — July 12, August 10, and September 9 — and they will be supermoons.
Satellite -- A satellite is an object that orbits another object. With sufficient tangential velocity, the object does not collide with the primary object it orbits, but maintains a distance from that object as the rate at which it falls towards that object is similar to the rate that it travels away, thus the object orbits the primary object and becomes a satellite. In other words: gravitational force serves as the centripetal force needed to make the object circle the primary...
Retrograde Motion -- Retrograde motion is the orbital motion of a body in a direction opposite that which is normal to spatial bodies within a given system. 'Retrograde' derives from the Latin words retro, backwards, and gradus, step. In the Solar system, mostly everything rotates in the same sense: all major planets orbit the Sun counterclockwise as seen from the pole star (Polaris). Most planets spin in the same sense, including Earth. The same happens with the orbital motions of the...
Lagrangian Point -- In Lagrangian mechanics, a Lagrangian point (or L-point) is one of five positions in space where the gravitational fields of two bodies of substantial but differing mass combine to form a point at which a third body of negligible mass would be stationary relative to the two bodies. Bodies at the L-point will not move relative to the parent bodies if they are not perturbed by other gravitational forces. They are sometimes also referred to as libration points. The...
Planet -- A planet is a body of considerable mass that orbits a star and that doesn't produce energy through nuclear fusion. Until recently, only nine were known (all of them in our own Solar system). As of the end of 2002 over 100 are known, with all of the new discoveries being extrasolar planets. Astronomers often call asteroids minor planets, and call the larger planetary bodies (those which are commonly called planets) major planets. Planets within the solar system can be...
Lunar Phase -- The lunar phase is an astronomical term referring to the portion of the Moon that is visibly illuminated by the Sun, as seen from Earth. As the Moon orbits the Earth, the relative positions of the Sun, Earth and Moon change. Since the Moon only appears bright due to the Sun's reflected light, only the half of the Moon closest to the Sun is illuminated. Lunar phases are the result of our seeing the illuminated half of the Moon at different angles. The Moon exhibits...
- In medieval musical notation, a sign or neume denoting a shake or trill.