Spirit has surveyed rocks at Gusev exploration site that are solidified from lava as shown in this approximate true color image. Image Credit: NASA/JPL-Caltech/Cornell
Posted on 02/10/2006 11:38:56 PM PST by NormsRevenge
NASA's Spirit Mars rover has arrived at a site dubbed "Home Plate" within Gusev crater. But what the robot found has left scientists puzzled.
As the Mars machinery relays images of the area, the sightseeing has sparked healthy debate within the team running the mission.
"Well, so far it has been great," said Steve Squyres, lead Mars Rover Exploration scientist at Cornell University. "It's the most spectacular layered rock we've ever seen at Gusev," he told SPACE.com.
The images relayed so far by Spirit of Home Plate "really are stunning," Squyres added. "Many of us were pretty much reduced to incoherent babble...like 'WOW!!', 'Holy Toledo!' ... in our emails to one another as the first good pictures were coming down."
But, excitement aside, the real task ahead is attempting to figure out the true nature of Home Plate. "And that's going to take a little while yet," Squyres pointed out.
Picturesque, but a puzzle
"I think it is one of the most picturesque views that we have encountered in either mission thus far," said Jim Rice, a Mars Exploration Rover Project science team member at Arizona State University in Tempe.
The drive was well worth the effort, Rice told SPACE.com. The outcrop now being studied is layered, but "we're not sure what it is yet."
Tasking Spirit's robot arm to being intensive scrutiny of the area is underway, Rice said. "It is a spectacular scene with Home Plate and all the ridges and buttes."
"Is Home Plate cool or what?", said Larry Crumpler, Research Curator, Volcanology and Space Sciences at the New Mexico Museum of Natural History and Science in Albuquerque, New Mexico.
As a Mars rover science team member, Crumpler said deliberations within the team about what they are viewing "have been the closest thing to passionate debate that I have seen yet."
For his part, Crumpler said that he refuses to accept one spectacular interpretation: "Namely, that it is a volcanic vent structure."
Crumpler said more detailed rover images are needed.
Home Plate has been a target for Spirit since shortly after the robot landed on the red planet in January 2004. The feature stood out in overhead images taken by Mars Global Surveyor's Mars Orbiter Camera. It stood out as a bright, nearly circular spot in the Columbia Hills region, Crumpler explained.
"It has a shape when seen from above that is reminiscent of a playa or evaporite basin...so that has made it a point of possible interest in a mission seeking evidence for past water on Mars," he said.
Diverse hypotheses
As Spirit has wheeled ever closer to Home Plate, and as the rover science team have learned more about what is likely and unlikely in this part of Mars, "I think the hypotheses for Home Plate have gotten more diverse."
Currently these include such possibilities as playa, exhumed crater floor filled with typical Columbia Hills layered deposits, a tuff cone or maar, and a hydrothermal vent area, Crumpler noted. "In fact, it is a healthy debate within the team right now."
But based on previous experience with Mars so far, Crumpler told SPACE.com, it's not wise to place any bets on initial interpretations. The debate is never fully over until Spirit makes use of its science instrument-tipped robot arm, he said.
As for helping pin down what the rover is seeing at Home Plate, there are a bunch of possibilities, Squyres said: Impact deposits, volcanic deposits, maybe wind- or water-lain sediments.
Given Spirit's navigation camera images now in hand, many of the Mars rover science team sense that the rocks are possibly explosive volcanic deposits.
"But that's purely conjecture at this point ... a working hypothesis," Squyres said. "Everything is on the table until we've gotten more data down."
Spirit has surveyed rocks at Gusev exploration site that are solidified from lava as shown in this approximate true color image. Image Credit: NASA/JPL-Caltech/Cornell
Hardened Lava Meets Wind on Mars
NASA's Mars Exploration Rover Spirit used its microscopic imager to capture this spectacular, jagged mini-landscape on a rock called "GongGong." Measuring only 3 centimeters (1.2 inches) across, this surface records two of the most important and violent forces in the history of Mars -- volcanoes and wind.
GongGong formed billions of years ago in a seething, stirring mass of molten rock. It captured bubbles of gases that were trapped at great depth but had separated from the main body of lava as it rose to the surface. Like taffy being stretched and tumbled, the molten rock was deformed as it moved across an ancient Martian landscape. The tiny bubbles of gas were deformed as well, becoming elongated. When the molten lava solidified, the rock looked like a frozen sponge.
Far from finished with its life, the rock then withstood billions of years of pelting by small sand grains carried by Martian dust storms that sometimes blanketed the planet. The sand wore away the surface until, little by little, the delicate strands that enclosed the bubbles of gas were breached and the spiny texture we see today emerged.
Even now, wind continues to deposit sand and dust in the holes and crevices of the rock.
Similar rocks can be found on Earth where the same complex interplay of volcanoes and weathering occur, whether it be the pelting of rocks by sand grains in the Mojave desert or by ice crystals in the frigid Antarctic.
GongGong is one of a group of rocks studied by Spirit and informally named by the Athena Science Team to honor the Chinese New Year (the Year of the Dog). In Chinese mythology, GongGong was the god-king of water in the North Land. When he sacrificed his life to knock down Mount BuZhou, he defeated the bad Emperor in Heaven, freed the sun, moon and stars to go from east to west, and caused all the rivers in China to flow from west to east.
Spirit's microscopic imager took this image during on the rover's 736th day, or sol, of exploring Mars (Jan. 28, 2006). The rock lies in the "Inner Basin" between "Husband Hill" and "McCool Hill" in Gusev Crater. Spirit acquired the image while the rock was fully shadowed, with diffuse illumination mostly from the top in this view.
Image credit: NASA/JPL-Caltech/Cornell/USGS
And...
Home Plate has been a target for Spirit since shortly after the robot landed on the red planet in January 2004. The feature stood out in overhead images taken by Mars Global Surveyor's Mars Orbiter Camera. It stood out as a bright, nearly circular spot in the Columbia Hills region, Crumpler explained.
I think it is amazing that for over 700 Martian days the rover has been in operation, when it was originally designed for 90 days of use, after which it was expected to be useless.
"But that's purely conjecture at this point ... a working hypothesis," Squyres said. "Everything is on the table until we've gotten more data down."
It's been a while since I studied geology, but those rocks definitely look extrusive. They look a lot like aa. I like the high resolution image because you can almost imagine that when it wasn't as weathered that you could see where volcanic gasses were trapped before expanding and escaping at the surface. It should be interesting to see how lava with a high quantity of trapped gases develops on Mars as compared to the Earth. With the lower atmospheric pressure I would expect that gas bubbles in rocks would be much larger and the jaggedness that starts on the surface of a rock would extend much deeper.
Latest panoramic camera pictures from Spirit at Homeplate are here: http://marsrovers.jpl.nasa.gov/gallery/all/spirit_p748.html
And here in color.
Do you have a working link for this article?
I guess the money spent on that Best Buy extended warranty was a waste.
Looks like sedimentary rock. Why does that puzzle them?
Mark
Mark
STOP posting pictures of the Prophet Mohamed!!!
I'm going to RIOT!!
:-)
The picture in post 13 looks like Marvin has already blasted the rocks.
That third rock in the upper left corner looks like the baseball cap I lost when I was a kid and I could swear one of those "rocks" is my missing sock.
I think we now know where missing socks and hats go.
You have incoming.
This is the yahoo link, cabojoe sent the space.com link
http://news.yahoo.com/s/space/20060210/sc_space/spiritmarsroverreacheshomeplateformationhasresearcherspuzzled
Thanks!
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