Scientists got a little surprise this week when they began analyzing photos and data sent back by the Messenger spacecraft who made a pass of Mercury earlier this month. Turns out Mercury isn’t quite what they expected.
Messenger’s Pictures From Mercury Surprise Scientists – washingtonpost.com: “The Messenger spacecraft that sped past Mercury on Jan. 14 sent back pictures of a geological formation never seen before in the solar system: a central depression with more than 100 narrow troughs radiating out from it.
Called ‘The Spider’ by scientists analyzing the trove of images and data coming back from Messenger, the puzzling feature is the kind of surprise that researchers live for.
‘Messenger has sent back data near perfectly, and some of it confirms earlier understandings, and some of it tells us something brand-new,’ said principal investigator Sean C. Solomon. ‘The Spider is definitely in the category of something we never imagined we’d find.’
Scientists were also surprised by evidence of ancient volcanoes on many parts of the planet’s surface and how different it looks compared with the moon, which is about the same size. Unlike the moon, Mercury has huge cliffs, as well as formations snaking hundreds of miles that indicate patterns of fault activity from Mercury’s earliest days, more than 4 billion years ago.
‘It was not the planet we expected,’ said Solomon, of the Carnegie Institution of Washington. ‘It’s a very dynamic planet with an awful lot going on.’
Messenger passed by Mercury after a journey of more than 2 billion miles. It will swing by the planet twice more before settling into orbit around it in 2011. “