The Sciences

A Final Message From Mercury

NASA probe uncovers a lively planet before meeting its demise at 8,800 mph.

By Eric BetzNov 30, 2015 12:00 AM
NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Newsletter

Sign up for our email newsletter for the latest science news
 

Mercury was the “dead” planet when NASA’s MESSENGER mission launched in 2004. But the spacecraft’s 2011 orbital arrival, and more than 250,000 subsequent images, documented an active planet. Running on fumes this year, MESSENGER (short for Mercury Surface, Space Environment, Geochemistry and Ranging) saved the best for last, swooping just miles above the virtually atmosphereless planet. It gathered fresh evidence for frozen water in crater corners, strange rock features called hollows and the evolution of a magnetic field almost 4 billion years old. The craft finally smacked into Mercury at 8,800 mph on April 30. This view of 1,000-mile-wide Caloris basin — among the largest known asteroid impacts in the solar system — shows how lava (orange) filled the blast site before new craters excavated the original basin (purple).

1 free article left
Want More? Get unlimited access for as low as $1.99/month
Already a subscriber? Log In or Register
1 free articleSubscribe
Want unlimited access?

Subscribe today and save 70%

Subscribe

Already a subscriber? Log In or Register
More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 70% off the cover price when you subscribe to Discover magazine.

Copyright © 2021 Kalmbach Media Co.