News From Space: Ancient Meteorite Crater Found

meteorIn southern Alberta, scientists have found a vast, ancient crater that they claim dates back some 50 to 70 million years. Discovered entirely by accident in near the hamlet of Bow City, some 20 km south-west of Brooks, and 100 km south-east of Calgary. According to assessments of the impact zone, researchers estimate that the space rock would have been the size of an apartment block, and would have left a crater 8 kilometers wide and roughly 2 and half km deep.

All told, this explosive force of this impact would have been 200 times stronger than the most powerful thermonuclear bomb ever built. That’s basically a force of 1000 megatons, a detonation so powerful that anything within 200 km of the impact would have received 1st-degree burns. To put that in perspective, this means that the city of Calgary would have been decimated by the blast, and in Edmonton, some 400 km away, every window would shattered.

alta-meteorite-crater-20140507But even more awe inspiring was the long-term effects of the damage, which would have thrown enough dust and debris into the atmosphere to mess with the Earth’s climate for the next few years. As Schmitt put it:

Something of that size, throwing that much debris in the air, potentially would have global consequences; there could have been ramifications for decades.

But after eons of erosion, very little of the crater is left. In fact, the discovery happened entirely by accident when a geologist – who was doing some routine mapping of the underground layers a few meters beneath the surface – apparently noticed a circular disturbance that was covered. Schmitt and his lab were called in to inspecting the feature and used seismic data to create a complete image of it. They quickly realized that it was most likely an impact crater, complete with a central peak where the meteorite would have struck.

Alberta_craterThe size of the object can only be estimated, but assuming the meteor was composed mostly of iron, it would have had to have been between 300 and 500 meters in diameter to create a crater of this size. If the meteorite was rock, it would have had to have been a kilometre across. Schmitt said the crater is a rare opportunity to study the floor of an impact crater. His team is now looking for certain types of minerals that form only under certain conditions so as to confirm the crater is from a meteor impact.

But he doesn’t have much doubt. As he put in a recent interview with CBC news:

We’re able to get at the lower parts of (a crater) and see how rocks have been moved around… We’re pretty confident it can only be a meteorite impact. It’s pretty clear.

Once they’ve had a chance to uncover and examine the area in greater detail, a clear picture of the meteorite’s size, composition, and what lasting marks its impact left beyond the crater. This information will only contribute to our understanding of our Solar System, but of the history of our planet as well.

Sources: cbc.ca, calgarysun.com

News From Space: “Rosetta Stone” Meteorite Lands in Ontario

meteorite_st.thomasA search is underway in the small community St. Thomas, Ontario for a rare meteorite that may prove to be a major scientific find. That’s what the Canadian and NASA researchers believe, and they are urging local residents to comb their fields and neighborhoods for one or more of the rock’s fragments. It all began on Tuesday, March 18th at 10:45 p.m., when a fireball streaked across the sky some 75 kilometres above Port Dover, Ont.

The fireball then headed in a westerly direction before vanishing at an altitude of 32 kilometres between Aylmer and St. Thomas. It was widely seen in Toronto, Hamilton, London and other parts of southern Ontario, where skies were clear. Peter Brown, the director of Western University’s Center for Planetary Science and Exploration, estimated the space rock was originally the size of a basketball, which then broke up upon entry.

????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????His colleague, Western University meteorite curator Phil McCausland, said one or more fragments “about the size of a golf ball or baseball” likely landed about five kilometers north or northwest of St. Thomas. The meteorite from this event is particularly rare and valuable because the fireball was captured by seven all-sky cameras of Western University’s Southern Ontario Meteor Network, allowing researchers to calculate its orbit.

Not only were they able to obtain solid data on the space rock’s orbit, but that orbit itself was special. Before entering Earth’s atmosphere, the object spent most of time circling closer to the sun than the Earth, having left its original orbit in the asteroid belt between Mars and Jupiter long ago. Bill Cooke, head of NASA’s meteoroid environment office, said only one other meteorite known to have come from that kind of orbit has ever been recorded.

asteroids1As Cooke said during a recent press conference:

This is not your run-of-the-mill meteor fall. This is a very unusual orbit. We’re really interested in knowing what type of object was in this … We won’t know that until we find a piece of it.

According to Brown, this makes each of the meteorite’s fragments something of a “Rosetta Stone”, referring to the famous Egyptian artifact that was the key to translating ancient hieroglyphics. The comparison is not an exaggeration, as the meteor is likely to tell scientists quite a bit about the history of the early Solar System. As he described it:

This is like a poor man’s space probe. It comes to us. It’s going to tell us … what made the Earth, what made the other planets.

st.thomas_meteor1Hence why Brown is asking for the public to help look for the meteorite, which has been described as a rock that looks like it was painted black, and contact the researchers if they find it. The researchers are also interested in hearing accounts from anyone who may have heard a whistling sound “like artillery coming in” or a thud after witnessing the fireball, indicating that it may have landed within a few hundred metres. That may help narrow down the area for the search.

Brown noted that it’s the first time in five years that such a meteor fall has taken place in southern Ontario. The last time researchers issued a callout like this, the meteorite was recovered days later by a member of the public near Grimsby, Ont., where it had crashed through the windshield of an SUV. The fact that this meteorite did not cause injuries or property damage, unlike the one that exploded in the sky over Russia, is also a plus!

Source: cbc.ca

News From Space: We Come From Mars!

Mars_Earth_Comparison-580x356Men are from Mars, women are… also from Mars? That is the controversial theory that was proposed yesterday at the annual Goldschmidt Conference of geochemists being held in Florence, Italy. The proposal was made by Professor Steven Benner of the Westheimer Institute of Science and Technology in Florida and is the result of new evidence uncovered by his research team.

The theory that life on Earth originated on Mars has been argued before, but has remained contentious amongst the scientific community. However, Benner claims that new evidence supports the conclusion that the Red Planet really is our ancestral home by demonstrating that the elements for life here could only form on Mars, and came here via a Martian meteorite.

Asteroid-Impacts-MarsAccording to the theory, rocks violently flung up from the Red Planet’s surface during mammoth collisions with asteroids or comets then traveled millions of kilometers across interplanetary space to Earth. Once they reached Earth’s atmosphere. they melted, heated and exploded violently before the remnants crashed into the solid or liquid surface.

All that would be needed is for a few of those space born rocks to contain microbes from Mars surface. These building blocks of life would have to survive the journey through space and the impact on Earth to make this happen. But research into Exogenesis – the possibility that life was transplanted on Earth by meteorites – has already shown that this is possible.

curiosity_sol-177-1What’s more, NASA’s Curiosity Rover was expressly created to search for the the environmental conditions that would support life. Less than half a year into its mission it accomplished just that, locating proof of the existence of water and a habitable zone. Between it and the Opportunity Rover, the search to determine if life still exists – in the form of organic molecules – continues and is expected to yield results very soon.

But of course, Benner was quick to point out that there is a difference between habitability (i.e. where can life live) and origins (where might life have originated). The presence organic molecules alone is not enough when it comes to the mystery of life’s creation, and when it comes to making the great leap between having the necessarily elements and the existence of living organisms, scientists remain hung up on two paradoxes.

These are known as the tar paradox and the water paradox, respectively. The former paradox addresses how life as we know it comes down to the presence of organic molecules, which are produced by the chemistry of carbon and its compounds. However, the presence of these compounds does not ensure the creation of life, and laboratory experiments to combine and heat them has only ever produced tar.

mars_lifeAs he puts it, the origin of life involves “deserts” and oxidized forms of the elements Boron (B) and Molybdenum (Mo) – namely borate and molybdate. Essentially, these elements are the difference between the formation of tar and RNA, the very building block of life:

Certain elements seem able to control the propensity of organic materials to turn into tar, particularly boron and molybdenum, so we believe that minerals containing both were fundamental to life first starting. Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there too.

The second paradox relates to water, which is believed to be intrinsic for life to flourish, but can be also hazardous to its formation. According to modern research, RNA forms prebiotically, requiring mineral species like borate to capture organic elements before they devolve into tar and molybdate to arrange the material to give it ribose – organic sugars, also intrinsic to life.

Mars-snow-header-640x353This can only occur in deserts, he claims, because water is detrimental to RNA and inhibits the formation of borates and molybdates. And from a geological standpoint, there was simply too much water covering the early Earth’s surface to allow for this creation process to take place:

[W]ater is corrosive to RNA, which scientists believe was the first genetic molecule to appear. Although there was water on Mars, it covered much smaller areas than on early Earth. Various geologists will not let us have these [borates and molybdates] on early Earth, but they will let us have them on Mars. So IF you believe what the geologists are telling you about the structure of early Earth, AND you think that you need our chemistry to get RNA, AND IF you think that life began with RNA, THEN you place life’s origins on Mars,

All of this has served to throw the previously-held theory – that life came to Earth through water, minerals and organics being transported by comets – into disarray. Based on this new theory, comets are a bad candidate for organic life since they lack the hot, dry conditions for borate and molybdate formation.

Living-Mars.2If the new theory is to be believed, Mars boasted the proper conditions to create the elements for life, while Earth possessed the water to help it flourish. If such a partnership is needed for the creation of organic life, then scientists will need to reevaluate the likelihood of finding it elsewhere in the universe. Between the existence of water and hot dry environments, life would seem to require more specialized conditions than previously though.

But of course, the debate on whether Earthlings are really Martians will continue as scientific research progresses and definitive proof is discovered and accepted by the majority of the scientific community. In the meantime, Curiosity is expected to rendezvous with Mount Sharp sometime next spring or summer, where it will determine if organic molecules and elements like Boron and Molybdenum exist there.

And on Nov. 18th, NASA will launch its next mission to Mars – the MAVEN orbiter – which will begin studying the upper Martian atmosphere for the first time, determining its previous composition, and where all the water went and when was it lost. So we can expect plenty more news to come to us from our neighboring Red Planet. Wait and see!

Source: universetoday.com