Friday, May 1, 2015
Today's Astronomy Picture of the Day shows a section of Mercury, constructed from image and laser altimeter data, from the Mercury MESSENGER orbiter. That probe, alas, is no more. Having gotten every possible gram of thrust out of the onboard fuel (including using some gas that was not intended as fuel), the vehicle impacted on the surface of Mercury yesterday at around 1526 hours Eastern. A job well done and a fantastic mission!