Solar System

The Cassini spacecraft made its closest-yet flyby of Enceladus July 14, skimming just 109 miles above the surface.  This was the closest approach to any object thus far in the four-year mission.  It was nearly three times closer than the earlier record, the March 9 Enceladus flyby (see encounter map).     Enceladus has long […]

Cheers and hugs erupted at JPL again last night when the Deep Impact spacecraft successfully sent its washing-machine size copper probe plunging into Comet Tempel 1.  A somewhat unexpected plume of powdery material was ejected, so opaque it was difficult to image the crater.  Speaking of craters, the camera aboard the probe revealed a surface […]

The little inner moon of Jupiter, Amalthea, isn’t dense enough.  A press release from Jet Propulsion Laboratory says that data from the Galileo spacecraft “shakes up long-held theories of how moons form around giant planets.”  Density of moons is supposed to decrease with radius around Jupiter, meaning that Amalthea should be the most solid.  Instead, […]

Several recent news stories touch on the uniqueness of Earth. Eccentric neighbors:  A story in Science Daily draws attention to the highly eccentric orbits of most extrasolar planets found so far.  The press release from Northwestern University begins, “Except for the fact that we call it home, for centuries astronomers didn’t have any particular reason […]

A press release from Jet Propulsion Laboratory announced the discovery of complex hydrocarbons in Titan’s atmosphere.  Some molecules have up to seven carbon atoms.  The discoveries came from the recent flyby on April 16, the closest yet, at just 638 miles above the surface.  Swooping into the upper layers of the atmosphere, the spacecraft came […]