Latest natural satellite Stories
Lee Rannals for redOrbit.com – Your Universe Online Thirty-three years ago today, astronomers discovered Saturn's moon Telesto using ground-based observations. Astronomers Bradford A. Smith, Harold Reitsema, Stephen M. Larson and John W. Fountain were performing ground observations on April 8, 1980 when they discovered the Saturn moon. The moon was officially named after Telesto of Greek mythology, but was also designated as Saturn XIII or Tethys B. NASA said Telesto is known as...
Lee Rannals for redOrbit.com – Your Universe Online NASA's Cassini spacecraft has unveiled new data about how Saturn's moons and rings are like an antique shop. Gianrico Filacchione, a Cassini participating scientist at Italy's National Institute for Astrophysics, Rome, published a paper online in The Astrophysical Journal about how Saturn's moons and rings are gently worn, vintage goods from around the time of our solar system's birth. He suggests these bodies date back more than...
Lee Rannals for redOrbit.com – Your Universe Online The international Cassini spacecraft, a NASA, European Space Agency (ESA) and Italian Space Agency (ASI) jointly-operated project, has taken some unique pictures of Earth's twin planet from the perspective of Saturn. The Cassini-Huygens mission launched on October 15, 1997, traveling 2.2 billion miles toward Saturn, reaching the distant ringed-planet June 30, 2004. The orbiter includes 18 sophisticated science instruments to help...
Lawrence LeBlond for redOrbit.com - Your Universe Online Star Trek fans everywhere have a reason to rejoice today as a contest to name one of Pluto’s two previously unnamed moons ended with one Spock-tacular name reaching, for lack of a better term, warp speed. William Shatner, the man best known for his role as Captain James Tiberius Kirk on the 1960’s television sci-fi classic, which later spawned a large movie franchise and several spin-offs, proposed Vulcan as the name of one of...
Rayshell Clapper for redOrbit.com – Your Universe Online Earth has one moon, and it is considerably larger than Pluto. In fact, the relative size of Earth’s moon is quite massive compared to the moons of other planets. We have a fascination with our moon on many levels. But what if Earth had two moons as Mars does? According to NASA, unlike Earth’s moon, Mars moons are two of the smallest in the entire solar system. Mars moons also have proper names: Phobos and Deimos. Their...
Lee Rannals for redOrbit.com - Your Universe Online Ever wanted your say in the naming of a cosmic object such as a moon? Well, scientists are opening up that door by asking people to vote for the name of two of Pluto's small moons. Currently, the two moons getting a name change are "P4" and "P5." Astronomers have specified that these small moons are in need of names that coincides with Pluto's theme for names associated with the Greek god Hades, ruler of the underworld. Pluto's other...
Revising and revisiting the Giant Impact Theory Scientists are revisiting the age-old question of how Earth's moon formed with the development of two new models that work out the complicated physics of planetary collisions. The idea of a moon-forming collision is not new: The Giant Impact Theory put forth in the 1970s suggested that the moon resulted from a collision with a protoplanet approximately half the size of ancient Earth. But the physics underlying such a collision implied that...
Lee Rannals for redOrbit.com – Your Universe Online New research based on observations from NASA's Cassini spacecraft show that Titan, Saturn's largest moon, may look younger than it really is. While most moons display their age through their thousands of craters, NASA said that Titan's craters are being erased, giving it a 'Benjamin Button' appearance. "Most of the Saturnian satellites - Titan's siblings - have thousands and thousands of craters on their surface. So far on Titan,...
Lawrence LeBlond for redOrbit.com - Your Universe Online Update: January 19, 2013 On Monday evening, astronomers (both amateurs and pros) across the country will be looking up to the skies to witness the super close dance between Jupiter and the Moon. Slooh Space Camera will also be there broadcasting live feeds of the event, giving everyone a shot at seeing the chance encounter. The waxing gibbous moon will appear about one degree south of Jupiter on Monday night, January 21. This...
April Flowers for redOrbit.com - Your Universe Online Delivered just in time for the holiday season, another glorious, backlit image of the planet Saturn has arrived from NASA's Cassini spacecraft, which has been in orbit around the planet for more than eight years. Cassini was deliberately positioned within Saturn's shadow during its 174th orbit around the gas giant on October 17, 2012. This positioning made for a perfect location from which to look in the direction of the Sun and...
Latest natural satellite Reference Libraries
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...
![Pioneer\](/media/gallery/universe/thumbs/thumbs_iod-universe-040613.jpg "Pioneer\")
