The God of Fear

Quickly, before the opportunity passes, I wanted to share an image from a few days ago. It is of Phobos, the larger of the two moons of Mars, as seen by NASA’s Mars Reconnaissance Orbiter, from a distance of about 4,000 miles.  Phobos is only about 13 miles in diameter, which means its gravity is about a thousandth as strong as Earth’s.  No (I’ve asked), an astronaut would not be able to achieve escape velocity by jumping, but neither is the gravity strong enough to have pulled the little world, when it was young and molten, into a spherical shape.  Deimos, the other known Martian moon, is only about seven miles across, which makes one wonder how the astronomer Asaph Hall spotted them from more than 35 million miles away in 1877. NASA says the reddish colors — and the bluish ejecta from relatively young craters — are realistic, but exaggerated to help separate them.  There’s more HERE, including some images for which you’ll need 3-D glasses. A tiny, cold world.  Makes you grateful that spring has arrived here on Earth’s northern hemisphere.