Science and Society
The Latest Developments in Science and Technology
Ned Potter is the science correspondent for ABC's "World News with Charles Gibson." He has reported on such topics as space exploration, the human genome and climate change.
RECENT POSTS
MONTHLY ARCHIVES
« An Asteroid With Our Name on It | Main | 'Across the Universe' »
The Mystery of Mercury
January 30, 2008 3:46 PM
"More like the Moon than the Moon." That was the conventional wisdom about Mercury, the planet closest to the Sun, and also the smallest (not counting recently-demoted Pluto).
But now scientists have sent a ship called MESSENGER racing past, and "it was not the planet we expected," says the principal investigator, Sean Solomon. "It was not the Moon."
The Johns Hopkins Applied Physics Lab, which is running the mission for NASA, has been posting material HERE. If you look at most of the pictures, you'll have a hard time telling them apart from Apollo Moon shots.
But Mercury is the only inner planet, other than ours, that has a magnetosphere -- something essential to life on Earth. It's the Earth's magnetic field that protects us from cosmic radiation, stuff that would make life here impossible.
Click HERE for a very large version of the picture above. There are differences the scientists point out. For instance, the Moon has large, dark areas, known as maria, believed to be ancient depressions that were filled in by volcanic material from below. Mercury seems to have the opposite -- there's a large circular feature, called the Caloris Basin, that's actually higher in elevation than what surrounds it.
There were deep furrow-like cuts in various places on the surface, possibly steep cliffs. And one odd spot, nicknamed "The Spider" because it looked like one, had deep troughs radiating out from the center of a large basin called Caloris. Cracks from when magma welled up from beneath? Damage from the formation of a crater? No saying yet.
MESSENGER will settle into orbit around Mercury in 2011, after a long, circuitous journey that trades length for fuel savings. (NASA has wised up over the years about cost; this mission isn't cheap, but it was done on a relatively tight budget.) The mission managers, anticipating the question, have assembled a page labeled "Why Mercury?"
When one thinks of space (or at least when I do), one's tempted to think of the eternal cold that consumes most of it. Mercury is so close to the Sun that MESSENGER's most visible part is a giant sunshade.
January 30, 2008 | Permalink | User Comments (9)
TrackBack URL for this entry:
http://www.typepad.com/t/trackback/433071/25636522
Listed below are links to weblogs that reference The Mystery of Mercury:
Mercury is a neat planet. I don't really know much about it. Kind of has the same allure as Luna. And you're right Ned, kind of does look like the old Apollo photos.
Posted by: Lawrence | Jan 30, 2008 5:19:46 PM
What are the intense white spots that look like cities at night seen from a plane here on Earth?
Posted by: Andy Jozan | Jan 30, 2008 5:52:03 PM
Note from Ned--
Andy Jozan, you raise a good question. Most of those white spots, if I'm explaining this well, are impact craters--but what makes them brighter is that they're relatively new, and the material thrown in all directions has settled on the surface, more rugged and more reflective than surrounding rock. It hasn't been exposed to the Sun's heat, or to Mercury's very minimal atmosphere, for as long as what's around it.
Posted by: Ned Potter | Jan 30, 2008 6:08:07 PM
What is going to happen when it gets closer to the sun more spots? I notice passed few days the moon is really moving or changing in the same distance it's been a few days it seems from my window view.
Posted by: Gloria | Jan 30, 2008 6:10:16 PM
Thanks for the notice. Will there be another great depression and vocanic explosion?
Posted by: Gloria | Jan 30, 2008 6:16:42 PM
I'm a fan of space exploration from since just after dirt was invented. I applaud any step NASA takes to further our knowledge of the Solar System and space in general. After all, we have a vested interest in not only our Solar System, but any nearby planets that may be lurking about. It's time we realized that we are mortal, we are vulnerable and we are lagging behind in our scientific accumen. How long has it been since Galileo's ideas have been accepted, and has the Catholic Church ever acknowledged his ideas and research? We're fighting an uphill battle against ignorance and reluctance, and we'd better get it together before the sky DOES fall.
Posted by: Andy | Jan 30, 2008 10:01:16 PM
Couldn't have said it better myself, Andy. (Incidentally, the Catholic Church under John Paul II did finally recognize Galileo's work in 1992 and, if memory serves, restored him from his heretical status.)
Posted by: chuck | Jan 31, 2008 8:52:23 AM
Thanks, chuck. I hope we don't have to do believable science with 'blank' periods of 500 years. Given the current brouhaha about global warming/climate change, that may still appertain.
Posted by: Andy | Jan 31, 2008 10:22:15 AM
No guys,
If the ID people have their way we are in for a very hot/cold dark age! Maybe humanity has to do this to itself every so often for some unexplained reason!
Posted by: Andy Clark | Jan 31, 2008 3:10:12 PM
Post a comment
