Mars Rovers Just Keep Going

Oct. 17, 2007 -- NASA announced it was extending for the fifth time the mission of Mars space probes Spirit and Opportunity, in their indefatigable exploration of the Red planet.

The two robots touched down three weeks apart on Mars in January 2004 for an expected 90-day mission that instead could stretch out to 2009, the National Aeronautics and Space Administration said on its website.

In September, Opportunity began a perilous descent into the Victoria crater, in Mars' Meridiani Planum region.

On the opposite side of the dusty planet and in the opposite direction, Spirit in early September began climbing onto the Home Plate volcanic plateau where scientists believe the volcanic rock might contain traces of water.

"After more than three-and-a-half years, Spirit and Opportunity are showing some signs of aging, but they are in good health and capable of conducting great science," said John Callas, rover project manager at NASA's Jet Propulsion Laboratory, Pasadena, California.

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The roving probes carry several sophisticated instruments to examine the geology of Mars for information about past environmental conditions.

Opportunity has returned dramatic evidence that its area of Mars stayed wet for an extended period of time long ago, with conditions that could have been suitable for sustaining microbial life, NASA said.

Spirit has found evidence in the region it is exploring that water in some form has altered the mineral composition of some soils and rocks, the space agency added.

To date, Spirit has driven 7.26 kilometers (4.51 miles) and has sent back to Earth more than 102,000 images. Opportunity has driven 11.57 kilometers (7.19 miles) and has returned more than 94,000 images.

T. Rex's Missing 3rd Finger Found

Oct. 17, 2007 — It's bad enough to misplace a finger, much less have it lost for 65 million years. But after decades of searching, paleontologists at Montana's Hell Creek have found the missing third finger of one of Tyrannosaurus rex's undersized "hands."

The finger suggests that T. rex had a powerful wrist and its hands were probably able to hold onto chunks of flesh while the monster's gnarly jaws did all the killing.

The newfound bone is a right metacarpal, equivalent to one of the long bones in the palm of a human hand, explains T. rex investigator Elizibeth Quinlan of Fort Peck Paleontology, Inc., in Fort Peck, Montana. She plans to present the discovery on Oct. 28 at the annual meeting of the Geological Society of America in Denver.

"It's unquestionably the metacarpal," Quinlan told Discovery News. No previous T. rex remains have ever been found with a third metacarpal, despite the fact that the other bones suggested its presence. "There is a notch in the side of the second metacarpal that was just begging to have something fit into it."

The revised anatomy of the hand suggests there was a very strong tendon that attached to second metacarpal, giving the hand a pretty decent grip, she said. Still, the puny limbs were almost certainly not used by T. rex to grapple with prey or kill.

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"We were thinking that T. rex did use its upper appendages not so much in hunting but in feeding," said Quinlan. That means ripping off pieces of flesh from corpses and clutching the stuff to keep it from other hungry predators. "We don't think their table manners were very good."

"I would strongly support (the hand) being used for carrying a piece of meat away," said paleontologist Scott Hartman, science director of the Wyoming Dinosaur Center in Thermopolis. "There is a reason that carrying meat away would be useful."

One reason is that the T. rex head is already so large and heavy that adding the weight of a large slab of meat between its teeth would make it unable to tip back and stand up, Hartman said. Holding meat with the arms, which are lower, avoids that overloaded teeter-totter effect.

Another possibility is that the hands were parenting tools. They would have made it possible for a T. rex to carry yummy slabs of dino flesh to its carnivorous babies, Hartman said.

That said, the new finger bone is not going to cause much change to reconstructions of T. rex, says Hartman. Throughout the evolution of meat-eating dinosaurs there was a trend towards fewer fingers, with the earliest having five fingers and the T. rex having two. This newfound nubbin of a third finger was already on its way out, and did not stick out much, he said.

"In another 10 million years they would have lost (the third finger) completely," said Hartman. Unfortunately for them, however, the age of dinosaurs ended before that could happen.

Related Links:

Fort Peck Paleontology, Inc.

Discovery's Dino Guide

The Fossils of Hell Creek

Building a T. rex skeleton

NASA Pulls Plug on Ultraviolet Telescope

Oct. 17, 2007 -- A university-operated space telescope that sheds new light on celestial objects both near and far will be shut down on Thursday after an unexpectedly successful eight-year run.

The Far Ultraviolet Spectroscopic Explorer, known by the acronym FUSE, was repeatedly resurrected by innovative ground control teams after its steering system failed in 2001.

The telescope, which was intended to last just three years, was launched in 1999.

More than 1,200 research papers have been published on FUSE's findings, which include detection of a hot bubble of gas surrounding the Milky Way galaxy, locating remnants of exploded stars, and measuring the amount of a special form of hydrogen called deuterium formed in the Big Bang explosion that created the universe.

The last place its ultraviolet eye observed was its home planet. With its long-troubled steering system now gone, scientists used the telescope one last time to study Earth's atmosphere in far ultraviolet light.

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The telescope's control room will be abandoned on Thursday, leaving the 3,000-pound satellite in an orbital grave. In about three decades FUSE will fall into Earth's atmosphere and burn up.

"It is a sad and ignominious end to such an outstandingly successful mission," said FUSE operations chief Bill Blair. "But a tremendous scientific legacy is left behind."

Scientists will spend about a year archiving FUSE's observations and writing final reports.

The telescope leaves an engineering legacy as well as a scientific one. Six months after reaching orbit, one of FUSE's four flywheels, needed for aiming the telescope, was showing troubling signs.

FUSE was designed to use three of its four wheels to properly orient itself and hold steady on a target with at least a 0.5-arcsecond degree of accuracy. With a one-arcsecond alignment, you could count pine needles on a tree from a mile away.

By December 2001, two of the wheels were dead. But in a week, engineers devised a way to use Earth's magnetic field to fix and hold the satellite, thus compensating for the third axis' loss of control.

The procedure turned FUSE's passive magnetic torque bars into an active spacecraft control system. The bars, which are 3-foot long, 1 1/2-foot diameter steel rods with a ferrite core, were used to push or pull against Earth's magnetic field so the momentum wheels would have an outside force to transfer their excess energy to.

With new software, the telescope was resurrected. Then engineers began planning for the next failure: the loss of FUSE's gyroscopes, which let the telescope know what position it is in. For that fix, engineers made use of a camera on the telescope that finds guide stars for positioning information.

FUSE's troubles and triumphs continued until July 12 when the last flywheel suddenly failed. Ground controllers worked for a month trying to restart the system, to no avail.

"Once we lost that last wheel, basically we could hold it steady in a safe mode, but we couldn't do any science," Blair said.

On Aug. 14, the lead scientist sent a note to NASA recommending the termination of FUSE science operations.

"It is a sad day for the FUSE project," Blair wrote that day in his Weblog.

"It has been a wild ride, but it looks like we are pulling into the station," he said. "It will soon be time to step off this roller coaster and find a new one to climb onto."

Scientists interested in the far ultraviolet view of the universe will have to content themselves with FUSE archive data for the foreseeable future. NASA has no similar replacement telescope in the works.

NASA's partners in FUSE are the Canadian Space Agency and the Centre National d'Etudes Spatiales in Toulouse, France.

Related Links:

FUSE findings

Blog: The End Is Near

The FUSE Telescope homepage

Early Humans Wore Makeup, Ate Mussels

Oct. 17, 2007 -- In one of the earliest hints of "modern" living, humans 164,000 years ago put on primitive makeup and hit the seashore for steaming mussels, new archaeological finds show.

Call it a beach party for early man.

But it's a beach party thrown by people who weren't supposed to be advanced enough for this type of behavior. What was found in a cave in South Africa may change how scientists believe Homo sapiens marched into modernity.

Instead of undergoing a revolution into modern living about 40,000 to 70,000 years ago, as commonly thought, man may have become modern in stuttering fits and starts, or through a long slow march that began even earlier. At least that's the case being made in a study appearing in the journal Nature on Thursday.

Researchers found three hallmarks of modern life at Pinnacle Point overlooking the Indian Ocean near South Africa's Mossel Bay: harvested and cooked seafood, reddish pigment from ground rocks, and early tiny blade technology. Scientific optical dating techniques show that these hallmarks were from 164,000 years ago, plus or minus 12,000 years.

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"Together as a package this looks like the archaeological record of a much later time period," said study author Curtis Marean, professor of anthropology at the Institute of Human Origins at Arizona State University.

This means humans were eating seafood about 40,000 years earlier than previously thought. And this is the earliest record of humans eating something other than what they caught or gathered on the land, Marean said. Most of what Marean found were the remnants of brown mussels, but he also found black mussels, small saltwater clams, sea snails and even a barnacle that indicates whale blubber or skin was brought into the cave.

Marean figured the early people, probably women, had to trudge two to three miles to where the mussels, clams and snails were harvested and to bring them back to the cave. Then they put them over hot rocks to cook. When the food was done, the shells popped open in a process similar to modern-day mussel-steaming, but without the pot.

Marean and colleagues tried out that ancient cooking technique in a kind of archaeological test kitchen.

"We've prepped them the same way," Marean said in telephone interview from South Africa. "They're a little less moist (than modern steamed mussels). They definitely lose some moisture."

Marean also found 57 pieces of ground-up rock that would have been reddish- or pinkish-brown. That would be used for self-decoration and sending social signals to other people, much the way makeup is used now, he said.

There have been reports of earlier but sporadic pigment use in Africa. The same goes with rocks that were fashioned into small pointy tools.

But having all three together shows a grouping of people that is almost modern, Marean said. Seafood harvesting, unlike other hunter-gatherer activities, encourages people to stay put, and that leads to more social interactions, he said.

Yet 110,000 years later, no such modern activity, except for seafood dining, could be found in that part of South Africa, said Alison Brooks, a George Washington University anthropology professor who was not associated with Marean's study. That shows that the dip into modern life was not built upon, said Brooks, who called Marean's work "a fantastic find."

Similar "blips of rather precocious kinds of behaviors seem to be emerging at certain sites," said Kathy Schick, an Indiana University anthropologist and co-director of the Stone Age Institute. Schick and Brooks said Marean's work shows that anthropologists have to revise their previous belief in a steady "human revolution" about 40,000 to 70,000 years ago.