The nearly matching thicknesses of the layers suggest the terrain might have been formed by a periodic process, such as natural climate variation linked to the red planet's orbital pattern, according to NASA.
Image courtesy NASA/JPL/University of Arizona
A Shuttle Carrier Aircraft—a modified Boeing 747—arrives at NASA's Kennedy Space Center in Florida to pick up the space shuttle Discovery in a picture taken April 10.
The shuttles were designed as gliders and have no engines of their own, so NASA recruited two of the jumbo jets to ferry the shuttles around the country.
The motions of the galaxies' stars indicate that they are all embedded in massive halos of dark matter. A leading dark-matter candidate is a group known as Weakly Interacting Massive Particles, or WIMPS. Scientists think WIMPS mutually annihilate when pairs of them interact, producing gamma rays.
Paek Chang Ho (center), head of North Korea's General Launch Command Center, briefs journalists April 11 on the upcoming launch of the Unha-3 rocket, intended to carry the Kwangmyongsong-3 satellite into orbit.
A live feed of the launch pad, on the country's west coast, is seen in the background.
As seen by the HiRISE camera on the Mars Reconnaissance Orbiter, the newest plume reached 12 miles (20 kilometers) high and was 230 feet (70 meters) wide.
Because Mars's atmospheric density is so low, anyone theoretically caught in such a dust devil wouldn't get blown over, according to NASA—but they would get badly scratched by sand and dust swirling in the Martian monster.