View Full Version : Pictures Reveal Mercury’s Tumultuous Past


Ball Lightning
Feb 04, 2008, 02:28 AM
Your thoughts?

Link (http://www.nytimes.com/2008/01/31/science/31mercury.html?em&ex=1202101200&en=51445739faae71c0&ei=5087%0A)

WASHINGTON — The Messenger spacecraft that zipped past Mercury two weeks ago found more evidence of the innermost planet’s turbulent past, including ridges that run hundreds of miles and a unique feature made up of more than 100 troughs radiating in all directions, scientists said Wednesday.

Closer Look at Mercury A preliminary look at data from the flyby, including 1,213 images, shows a small, cratered planet that superficially looks like Earth’s moon but is very different in reality, they said.

The robot spacecraft, the first to visit the planet in more than three decades, passed 124 miles above Mercury’s surface on Jan. 14 before continuing on a path that is to bring it back three more times in the next three years before settling into orbit.

During the encounter, the Messenger’s seven scientific instruments scanned the planet, its magnetic field and its wispy atmosphere in great detail.

“Our little craft has returned a gold mine of exciting data,” said Dr. Sean C. Solomon of the Carnegie Institution of Washington, the mission’s lead investigator.

“We were continually surprised,” Dr. Solomon said at a NASA news conference. “It was not the planet we expected. It was not the moon.”

Mercury remains a very dynamic planet and is a key to understanding the evolution of the inner solar system and its four rocky planets, including Earth, he said.

NASA’s Mariner 10 spacecraft, which made three flybys of Mercury in 1974 and 1975, mapped about 45 percent of the planet’s surface. The Messenger craft took pictures of another 30 percent during its first visit and should complete the portrait when it returns on its next flyby in October, scientists said.

After that visit and another in September 2009 to slow the craft, the Messenger is to settle into orbit around Mercury on March 18, 2011, for at least a year of studies.

Among the features spotted by the Messenger — short for the $446 million mission’s formal name, Mercury Surface, Space Environment, Geochemistry and Ranging — is one informally called “the spider.” It appears to be an impact crater 25 miles in diameter from which more than 100 flat-bottomed troughs shoot out in all directions, said Louise Prockter, an imaging instrument scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., which built and operates the spacecraft.

“It’s a real mystery, a very unexpected find,” Dr. Prockter said, unlike anything ever observed in the solar system. It is unclear if the impact crater caused the shattered-looking feature or came later, after the troughs formed for another reason, she said.

stickciv
Feb 04, 2008, 05:12 PM
Its a planet pretty close to the sun going really fast around it. Anything that gets relatively close gets pulled in, and from time to time stuff will hit mercury. Plus those gravitational forces have got to be massive.

its interesting that we're finally studying the inner solar system.

Falcon02
Feb 04, 2008, 05:39 PM
its interesting that we're finally studying the inner solar system.

We've been studying Venus and Mars for a long time. Mercury has just been neglected as a "Hot cratered rock"

stickciv
Feb 04, 2008, 05:47 PM
Venus has also been pretty neglected I think. Mars though has been the subject of much study lately yes.

Falcon02
Feb 04, 2008, 06:03 PM
True Mars has gotten more attention then Venus, for various reasons.

Venus has probobly gotten about a half a dozen missions I think.

Mars is probobly closer to a dozen.


and outer planets... a handful

Serutan
Feb 04, 2008, 06:15 PM
We've been studying Venus and Mars for a long time. Mercury has just been neglected as a "Hot cratered rock"

Also, it isn't easy to do anything besides a flyby to Mercury due to its proximity to the Sun (for both gravity and radiation protection reasons).

One of the problems with Venus is that we can only see its surface with radar, and have yet to come up with with anything that can survive on
the surface for any period of time (at least that is light and cheap enough
to put in a lander). There is currently a remote sensing mission at Venus
(ESA Venus Express).

Falcon02
Feb 04, 2008, 06:24 PM
Yeah... the Heat Shield on the Messenger spacecraft is fairly impressive, it's basically this big sheet the area of the main spacecraft held about a foot away from it.

EDIT: a foot maybe an exaggeration, but regardless the need for such a Heat Shield in of itself is rather impressive. Even if somewhat expected so close to the sun.

taillesskangaru
Feb 08, 2008, 06:06 PM
Venus has also been pretty neglected I think. Mars though has been the subject of much study lately yes.

Well, Venus is toxic and therefore irrelevant in any near-future space colonisation initiatives.