New views of Mercury: Simulated and Real

This is some exciting astronomy news I didn’t expect to see on a government computing news site:

From Government Computer News 1/9/2008: Mercury: up close and personal:

The Mercury Flyby Visualization Tool will offer simulated views of what Messenger will see during its approach, flyby and departure from the closest planet to the sun. The site will offer real-time simulations as the spacecraft rendezvous with the planet Jan. 14. Johns Hopkins University’s Applied Physics Laboratory is hosting the service.

The tool will use the best low-resolution imagery and surface maps of Mercury generated on Earth, from such sources as the Arecibo Observatory in Puerto Rico and image mosaics from the Mariner 10 spacecraft Mercury flybys. This imagery will be augmented with material generated on the Messenger by spectrometer and laser altimeter.

Much more information about NASA’s Messenger mission can be found by visiting http://messenger.jhuapl.edu. The January 14th flyby is one of the steps that NASA expects to lead toward Messenger being the first probe to actually orbit Mercury in 2014.

One thing that amazed me when I went to the Messenger site was realizing how FAST the probe is moving. On January 11th, Messenger was about 1.1 million miles away from Mercury. At this distance, Mercury appears as a tiny crescent as shown in this photograph:

By flyby time on January 14th, the probe will be 124 miles above the planet, which is about the same distance as many spy satellites. Just think, a million miles in a little under three days. For perspective, that’s roughly three times faster than it took Apollo astronauts to make it to the moon, which is a quarter of that distance.

Why have the real thing if we got images enough for a simulation? Because 1) Messenger will photograph large areas of the planet missed by earlier probes and inaccessible to earth telescopes and 2) much higher resolution will be available.

Nice to have something to look forward to on a Monday!