Mercury’s “Smooth” Plains

Mercury has a vast region of smooth volcanic plains surrounding its northern polar region, wrapping over a third of the way around the planet. But even though the plains are called smooth, they are still characteristically rugged – made obvious in this narrow-angle camera image from MESSEGER acquired December 13. Being an area close to…

Moon Noir

Here’s another intriguing look at Helene, lit by sunlight from the right while some reflected light from its own highlands illuminates the interior of a valley/crater. Its dark side appears pitch black against the slightly brighter region of space behind, possibly lightened by the diffuse reflected light from ice particles in Saturn orbit. This is…

Look Inside a Lunar Crater

The crater shown above is located in the lunar highlands and is filled with and surrounded by boulders of all sizes and shapes. It is approximately 550 meters (1800 feet) wide yet is still considered a small crater, and could have been caused by either a direct impact by a meteorite or by an ejected…

Rocky Shadows

Piles of boulders cast long shadows in the floor of the 18.6-mile (30 km) wide Necho crater on our moon. This dramatically-lit image from the Lunar Reconnaissance Orbiter Camera (LROC) shows the final result of a large impact on the lunar surface, and gives a nice example of some of the rugged terrain that can…

Skimming the Rings

Saturn’s second-largest moon Rhea passes across the face of the ringed planet in this image, color-combined from three raw images taken by Cassini on May 8, 2010. The rings are seen on edge here, a dark horizontal stripe running underneath the cratered 950-mile-wide moon, their wide shadows cast onto Saturn’s atmosphere below. I really love…

Fast Eddy

A huge swirling eddy in Saturn’s northern equatorial bands is visible in this image from Cassini, taken in wavelengths of light sensitive to methane. The planet’s rings are a bright line, illuminated by the sun and casting their shadows onto Saturn’s cloudtops. This image was taken today, April 29. Credit: NASA/JPL/SSI

Rings in Relief

This wide-angle view from Cassini, taken on August 16 (2009), shows an amazing amount of relief across the surface of Saturn’s A ring as well as a long shadow cast by the wake of the shepherd moon Daphnis within the Keeler gap. 4.3-mile-wide Daphnis, almost too small to be seen here, sculpts the edges of…

Out of the Shadows

A stunning image by Cassini, received today, of Daphnis splashing through the Keeler Gap (as seen in my last post). In this photo the sunlight is coming from the opposite direction though. Saturn’s massive shadow falls upon the rings on the right side of this image. Background stars can be seen through the rings. From…