Spaceflight Now is reporting that, within the next few days, NASA plans to publicly discuss new research concerning ALH 84001, the Martian meteorite found in Allan Hills, Antarctica. The research is said to strengthen the findings of the team that studied the meteorite over a decade ago and announced in 1996 that the meteorite might contain evidence of bacterial life.

The new research, detailed in a 46-page peer reviewed paper, looks at magnetic bacteria found on Earth. The researchers have closely studied magnetic bacteria and the formations they create in rocks. The bacteria leave distinctive remnants in the rock, uniquely-shaped magnetite crystals that test with a chemical purity that reflects biological, rather than geological, origins. That these remnants are unique to magnetic bacteria on Earth and are also found in the Allan Hills meteorite strongly suggests that the crystals indicate ancient bacterial life on Mars.

Critics of the original NASA report have doubted these features as reliable fossils, claiming that the shape and chemical purity could be achieved by the same thermal shock that separated the material from Mars in the first place. But new research reported in the paper disproves the thermal shock theory.

Spaceflight says that the new research isn't quite a "smoking gun," but it greatly strengthens the case for life on Mars, and could change the conversation about future NASA missions.

Martian meteorite surrenders new secrets of possible life [Spaceflight via Universe Today]

The rock, dubbed "Block Island," is approximately 2 feet long and has a blue tint. The rover took a picture of the formation in passing two weeks back, but the Rover team decided that Opportunity should backtrack and do some more tests on the relatively giant space rock.

The tests revealed that the meteorite is made up of iron and nickle, which makes it very similar to the kinds of rocks that have been found on the surface of the Earth. The big discovery isn't the composition of the meteorite, though. It's the size.

NASA says that any rock of this size would certainly break apart if it were to fall on the surface of Mars today. For such a large meteorite to remain intact, the red planet's atmosphere would have to have been much thicker. The NASA team chalks the existence of Mars's thicker atmosphere up to one of two causes: either Mars has vast stores of carbon dioxide ice that filled the atmosphere in a relatively recent warm period, or the meteorite fell billions of years ago.

Whatever the case, the rock also provides scientists with a way to see how Mars's weather and climate have affected a foreign object, letting them piece together a sort of reverse long-term weather forecast for the planet's surface. And if we ever get that manned flight to Mars we are all hoping for, "Block Island" could become one of Mars's popular roadside attractions, like a Martian Chimney Rock.

Meteorite Found on Mars Yields Clues About Planet's Past [via PhysOrg]

Because Saskachewan is so cold and dry, the mineral composition of the rocks is fairly well-preserved, and scientists say they're fairly certain it's from an asteroid that had a high iron content. Milley located the first fragments of fire-blackened rock on the ice after researchers triangulated its probable location from security cameras and eyewitnesses.

Another Calgary researcher, Alan Hildebrand, is in search of information about the meteor's trajectory - that information could prove invaluable if we're hoping to prevent mega-hits from bigger rocks. According to New Scientist:

For Hildebrand, the real payoff is the likelihood that an accurate orbit can be calculated for the object, allowing researchers to trace its trajectory back to a point of origin somewhere in the asteroid belt. So far, only nine meteorites have known orbits.

"It's a magnificent accomplishment," says Rick Binzel of MIT. "Tracing the orbit of a meteorite tells us where it formed. Combining [the rock's orbit and composition] pins down a specific record of the earliest conditions for planet formation at a precise location."

As for Milley, her main concern as she continues the hunt for fragments is telling bits of meteorite apart from cow patties.

Meteorite Hunters Hit Paydirt on Canadian Prairie [via New Scientist]

Writing on SciFi's How You Can Save the World blog, Schweickart says:

We’ve now got a nascent early warning system — albeit not well coordinated or securely funded. Furthermore, while no world space agency has yet demonstrated the space technology to deflect an asteroid, the techniques are pretty well understood. In fact, JPL just completed a detailed performance analysis on the gravity tractor concept for the B612 Foundation, and it works just fine. On paper.

So while these two essential legs of a protective triad sort-of exist, the third leg — making a decision to act — is basically nowhere. Who is in charge? Who issues warnings? . . . Who orders an evacuation if it’s too late for a deflection?

Sure, we could leave all this to the emergence of a threat and see how it all settles out in real time. That would be typical of bureaucracy at the domestic level, let alone at the international level. But unlike global warming or many other huge socio-political issues, this one is 1) pretty clear science-wise, and 2) cheap to “solve.” In this case solve = prevent an impact . . . [But] action has to be taken 12 or more years prior to a predicted impact and political systems are simply not good at addressing lead times of that magnitude (to understate it!).

At last, however, the U.N. is addressing this issue. Schweickart's group is putting together a report on how to respond to potential meteorite impact, and will present it next year to the UN Committee on the Peaceful Uses of Outer Space. I'm guessing the solution might actually be a scenario similar to the one in the cheesy movie Armageddon, but without Bruce Willis - I'm thinking probably it will be a remotely-operated flight that delivers those bombs to the meteor.

So while we may not be ready to fend off meteors yet, we're on the road to having a real-life international group designed to handle such mega-threats from space. We may need that group sooner than we think.

We Can Prevent Astroid Impacts [via How You Can Save the World]

The meteorite appeared in the sky around 5pm MT, and Alan Hildebrand, a planetary scientist said it was probably the largest to land in Canada in 12 years. And the object’s entry into the Earth’s atmosphere created an impressive display. According to the Globe and Mail:

Hildebrand says the meteor could likely be seen up to 700 kilometres away, into the northern United States. It contained about a tenth of a kiloton of energy when it entered the earth's atmosphere, equal to 100 tons of the chemical explosive TNT.

“It would be something like a billion-watt light bulb.”

Besides sonic boom sounds, he said witnesses also reported hearing hissing or crackling noises like frying bacon. Fireballs can act as radio transmitters, Mr. Hildebrand said, causing odd sounds.

The video below shows the fall as captured by a police dashboard camera in Edmonton, Alberta. The next step is for astronomers to search the region for the meteorite fragments, which are billions of years old and valuable for study.

Pieces of large meteor may have landed in Saskatchewan [Globe and Mail]
[Videos via Metafilter]

Panspermia theories often argue that Martian mircobes hitched a ride on an Earth-bound meteor, then thrived and evolved into the life we see here on Earth. But the new findings from researchers at Imperial College London suggest the building blocks of life rather than life itself arrived from outer space. They figure that since the Murchison meteor fell to Earth bringing the molecules uracial and xanthine — precursors to DNA — there must have been a lot of this stuff pelting the planet billions of years ago.

Early life may have needed the space-born material to get started, or it could've incorporated the meteorite bits because they conferred some kind of evolutionary advantage:

Lead author Dr Zita Martins, of the Department of Earth Science and Engineering at Imperial College London, says that the research may provide another piece of evidence explaining the evolution of early life. She says:

“We believe early life may have adopted nucleobases from meteoritic fragments for use in genetic coding which enabled them to pass on their successful features to subsequent generations.”

Between 3.8 to 4.5 billion years ago large numbers of rocks similar to the Murchison meteorite rained down on Earth at the time when primitive life was forming. The heavy bombardment would have dropped large amounts of meteorite material to the surface on planets like Earth and Mars.

Either way, it looks like we're made of space stuff.

Source: Imperial College London