Mars May Have Repeatedly Been a Ringed Planet

(News from SETI) Scientists from the SETI Institute and Purdue University have found that the only way to produce Deimos’s unusually tilted orbit is for Mars to have had a ring billions of years ago. While some of the more massive planets in our solar system have giant rings and numerous big moons, Mars only…

Phobos Will Eventually Become a Ring Around Mars

Phobos, Mars’ largest moon — although at just 16 miles wide still quite small — is slowly but steadily being torn apart by the gravitational pull of Mars… and it bears the scars to prove it. Long parallel grooves seen wrapping around the surface of Phobos are most likely stress fractures, visible evidence of the tidal forces…

A Departing View From Cassini After Clearing the Gap

Cassini did it again! On May 2-3, 2017 the spacecraft made its second “ring dive” pass of Saturn, passing through the clear space between the innermost edge of the ring system and the planet itself. The animation above shows a view from Cassini looking back toward Saturn on its outbound flight on May 3, just a…

If You Were Wondering What Earth Looks Like From Saturn, Here You Go

That’s here; that’s home; that’s us. The image above shows what Earth looked like to NASA’s Cassini spacecraft on April 13, 2017 as it flew past Saturn’s night-shadowed A and F rings. At the time the raw images were captured Saturn and Cassini were about 889.6 million miles (1.43 billion kilometers) from Earth. From that distance…

Cassini Pinpoints a Propeller in Saturn’s Rings

NASA’s Cassini spacecraft captured these images of a propeller in Saturn’s A ring on Feb. 21, 2017. These are the sharpest images ever taken of a propeller and reveal an unprecedented level of detail. This propeller is nicknamed “Santos-Dumont” after the Brazilian-French aviator who is hailed as the father of aviation in Brazil. The February 2017 imaging…

Intricate Details of Saturn’s Rings Are Revealed in Latest Cassini Images

Like those fractal designs that were so popular in the ’90s Saturn’s rings reveal finer and finer structures the nearer Cassini gets, now in the final year of its mission. Recent images from the spacecraft, captured in December 2016, show groove-like density waves and skyscraper-sized clumps within the planet’s icy rings—and it’s just a hint at what…

Cassini Has Just Taken the Best Picture of Daphnis Yet!

Hello, Daphnis! On January 16, 2017, the Cassini spacecraft captured the best photo yet of Daphnis, a 5-mile-wide shepherd moon that orbits Saturn inside the Keeler Gap at the outermost edge of the A ring (and also just so happens to be my personal favorite moon of Saturn!) The raw image arrived on Earth today, and…

It’s the Beginning of the End for Cassini (But the Pictures Will Be Awesome)

After more than twelve years in orbit around Saturn, NASA’s Cassini spacecraft is now in its final year of operation…and newly-positioned in an orbit that will send it soaring high over the planet’s north pole as well as close by the outer edge of its glorious shining rings. Over the course of 20 week-long “ring-grazing orbits” — the…

More Moons For Uranus?

The distant ice giant Uranus may not have been visited by a spacecraft since Voyager 2’s “Grand Tour” flyby in 1986 but the data gathered then is still being used today to make new discoveries. Most recently, researchers think they have found evidence of two previously unknown moons around Uranus, potentially bringing the planet’s count up…

Watch Saturn’s Moons Race Inside the Rings

Round and round they go… the animation above, made from 14 raw images taken by NASA’s Cassini spacecraft on August 23, 2016, shows the moons Prometheus and Atlas orbiting Saturn within the Roche Division gap between its A (top right) and F (center) rings. The gravitational tug of Prometheus (92 miles / 148 km long) is strong…