Spirit Finds Evidence of Volcano Explosion on Mars

The Mars robot, Spirit, has returned photographs of the Martian ground that seems to be evidence of a big volcanic explosion at the Home Plate area, a plateau of layered bedrock. Steve Squyres of Cornell University says "there is strong evidence that those layers are from a volcanic explosion. He says that the area near Home Plate is dominated by basaltic rocks. "When basalt erupts, it often does so as very fluid lava, rather than erupting explosively. One way for basaltic lava to cause an explosion is for it to come into contact with water---it's the pressure from the steam that causes it to go boom." This new finding gives more proof that water once flowed on Mars. The arrow in the picture points to a 4cm "bomb sag." Mars is a planet that has been considered to be geologically sterile for a long time.

Arsia Mons Volcano of Mars in 3D

This is a high-resolution picture of the caldera of Arsia Mons, one of the largest volcanos on Mars and in the solar system in terms of volume and challenged only by neighboring Olympus Mons (the tallest at 27 km above the surface plain). The greenish photo below is a 3D-ready image of a section of the volcano. If you have the right stereo specs like the one sometimes used in select 3D movies in theaters, you may also view this picture in depth, so to speak.

It was taken in 2004 by the Mars Express spacecraft using its High Resolution Stereo Camera (HRSC). The other picture below it shows Arsia Mons in relation to Olympus Mons. See how they compare visually in terms of size. Note that Arsia Mons does not have a defined extremity, but it's established diameter is at most 450 km. Olympus Mons, which has a more defined area, is 550 km wide. Still, Arsia Mons is recognized to have the largest caldera known at 120 km wide. Mauna Loa, the largest volcano on Earth, would fit snugly on top like a bottle cap.