News from Space: Mars Gets New Crater!

martian_craterThe Mars Reconnaissance Orbiter (MRO) captured this image of a 50-meter wide crater on the Red Planet back on March 28th, 2012. But the impressive thing is that this same crater was not there when the MRO took pictures of the area the day before. In other words, this crater was spotted less than a day after the impact that formed it. This is a record=setting events, since it usually takes a few years before the presence of new craters have been confirmed.

In this case, though, the constant sweep of the Mars weather camera (called the Mars Color Imager, or MARCI) picked up the black smudge that is a telltale sign of a fresh impact. Because the imager is low-resolution, it sees a large area of the surface, and does so all the time. It’s also the largest crater in the solar system ever seen with before and after shots. At 50 meters or so across, it’s half the length of a football field, so the impacting object was probably up to a few meters across.

mars_crater_marcimars_crater_marci2Something that small would burn up in Earth’s atmosphere, but given that Mars has a much thinner atmosphere (about 1 percent as thick of Earth’s) rocks of this size make it to the surface with ease. Once they make it to the ground, they hit hard enough to carve out a hole and blast out ejecta debris – which was how the crater was found. But the atmosphere is thick enough to cause a lot of pressure in front of the incoming meteoroid, which can break it up into smaller pieces.

As you can see from the images above – the top which was taken on March 27th and the bottom on the following day – there was one big crater, one smaller one, and quite a few even smaller ones around the main one. These may have been from pieces of the meteoroid that broke up as it came in. Not only that, but landslides were observed in the area that occurred around the same time, so they may have been caused by the seismic ground wave from the impact as well.

mars_avalanche4Events like this are not only novel, they are also very useful for scientists, since they help them to understand how impacts have shaped the Martian landscape. They also help determine the number of small impacts suffered by Mars (and by extrapolation, Earth), and in some cases reveal what’s underneath the surface of the planet (including ice). This latest impact is many ways a gift, since most craters are very old and the atmosphere have eroded them to the point that there results are no longer fresh.

Kudos to the MRO team for their fine work in spotting this new Martian surface feature. And in the meantime, be sure to enjoy this video that explains this record find, courtesy of the NASA Jet Propulsion Laboratory.


Sources:
slate.com, space.IO9.com, mars.nasa.gov

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 Mars: Updates on Panspermia Theory

PanspermiaFor centuries now, scientists have been toying with the idea that the origins of life may owe a great deal to space borne debris. And with ongoing research in the past few years, the link between Earth and Mars have become increasingly convincing. And a new bit of research out of the University of Hawaii has provided yet another piece of the puzzle by suggesting solar wind plays a major role.

Solar wind – the stream of charged particles consisting mostly of naked protons called H+ ions – permeate our Solar System because they are periodically ejected from the sun. The University paper shows that in an airless environment, typical space rocks will react with impacting protons to create tiny vesicles of water, thus allowing water and organic molecules to travel through space in tandem.

asteroid_earthInterestingly, the paper comes soon after NASA released evidence that Mars once sported a fair amount of water in the past, and that this water is sometimes found in unexpected places. The finding that water can be generated within dry space rocks, coupled with the fact that space rocks are known to deliver organic compounds to the surface of the Earth, is yet another indication that Earth and Mars might be linked.

Other recent papers have suggested that life’s important molecules arrived intact from Mars – a primitive version of RNA is one major proposed molecular stow-away – but these researchers claim only that “complex organic molecules” came from somewhere else in space. Complex organic compounds and liquid water, in conjunction, could theoretically provide the potential for non-living material to come alive.

Comet1One important aspect of this idea is that it focuses on small particles of material, rather than comets. Prior research has looked to such large bodies as the carriers of life and the drivers of the chemistry that created it, due to their energetic impacts. It’s been suggested that the earliest living things were cobbled together from high-energy molecules that couldn’t exist unless their synthesis was driven by massive astronomical impacts.

This more passive, dust-based explanation seems to fit well with the known history of the Earth, which predicts there was a high level of dust flux in the period before life began to flourish. In addition, the theory could help explain how in the predominantly shadowy areas of the Moon – another airless silicate body – unexpectedly high levels of water have been detected.

resolve_roverNASA has plans to launch RESOLVE (Regolith and Environment Science and Oxygen & Lunar Volatile Extraction) in 2018 to collect and analyze ice samples and use them to look back into just that sort of astronomical history. Large quantities of water are thought to have arrived on the Moon via impacting comets, but this research suggests that at least some of it could have been created on the Moon itself.

All of this is of extreme importance to discovering how life began on Earth, mainly because scientists are still unsure of what makes the process complete. For instance, evolutionary theory can adequately explain how a bacterium becomes a protist that becomes an animal, but it cannot explain how a pile of non-living molecules ever became a living cell.

panspermia2Evidence seems to be mounting that, whether it was seeded with dust or fused into existence by huge asteroid impacts, life on Earth needed a kickstart in its earliest days. Interestingly, Earth’s atmosphere and the abundance of messy lifeforms on its surface could mean that Earth is the single worst place to search for such evidence.

The Moon or Mars, by contrast, are perfect environments for preserving evidence of the past given their dry and airless nature. And with ongoing research into both planets and our scientific knowledge of them expanding apace, whatever role they may have played in kickstarting life on Earth may finally be learned. This could come in handy if ever we need to do a little kickstarting of our own…

Source: extremetech.com

News from Space: Biggest Lunar Explosion Ever Seen!

moon-asteroid-impact-1600Back in September of 2013, something truly amazing happened on the surface of the Moon. Granted, small objects impact with Earth’s only satellite all the time, hence its cratered surface. But this time around, Earth-based instruments observed an impact that was caused by an object the size of a small car, ten times bigger than any previously-recorded impacts.

The burst occurred on Sept. 11, 2013, at about 20:07 GMT in a area on the moon known as Mare Nubium, producing a flash that would have been visible from Earth. It was caused by a meteor that is believed to measure between 0.6- and 1.4-meters wide, weighed some 400 kg (880 pounds) and generated a crater with a diameter of about 40 meters.

Mars_impact_craterJudging from the explosion and the crater it left behind, scientists estimate that the rock hit Mare Nubium at a speed of 61,000 kph (38,000 mph), generating an explosion equivalent to roughly 15 tons of TNT. This beats the previous record, which occurred in March 2013 when a 40 kg meteoroid 0.3 or 0.4 meters wide struck the moon at about 90,000 km/hr (56,000 mph) and caused an explosion equivalent to 5 tons of TNT.

These findings appeared in the February issue of Monthly Notices of the Royal Astronomical Society (MNRAS), in a paper entitled “A large lunar impact blast on 2013 September 11”. According to the paper’s authors – Jose M. Madiedo, from the University of Huelva and Jose L. Ortiz, from the Institute of Astrophysics of Andalusia – the impact was the longest and brightest impact ever observed, as the “afterglow” remained visible for 8 seconds.

moonIn a subsequent press release, Madiedo and Ortiz said that:

Our telescopes will continue observing the Moon as our meteor cameras monitor the Earth’s atmosphere. In this way we expect to identify clusters of rocks that could give rise to common impact events on both planetary bodies. We also want to find out where the impacting bodies come from.

Knowing how often such collisions happen on the moon could be important for future lunar explorers, one reason why NASA has set up a specific program – Lunar Impacts, working out of the Marshall Space Flight Center – to study them. This campaign started in 2005 and has already proved that lunar impacts happen about 10 times more frequently than scientists previously expected.

Russian_meteorBecause the moon is our next-door neighbor, and a place where human beings may someday live in large numbers, knowing the frequency and severity of meteoric impacts is certainly important. These latest findings also suggests that the Earth might get hit more often than we previously thought by objects of a similar size. And given the damage associated with such impacts, knowing all we can is certainly prudent.

In the meantime, check out this outreach video provided by J.M. Madiedo (co-author of the MNRAS paper) that discusses this record-breaking lunar impact:


Source:
universetoday.com, wired.com, nasa.gov

Russian Meteorite will be used for 2014 Olympic Medals

Sochi-2014-Olympic-medalsOlympic athletes competing for the gold at the 2014 Sochi Winter Games can expect something truly out of this world if they win. According to media reports, the Russian government is planning on using pieces of the Chelyabinsk meteor that broke up over the remote community in the Urals during February of this year.

Scarcely anyone could forget that incident, where a 17 meter (55 foot) meteor entered the Earth’s atmosphere and caused an airburst that damaged buildings, caused 1600 injuries and frightened every living thing in the region. As astronomers collecting fragments and calculating the orbit of the fireball, the incident directed attention towards the need to monitor space rocks that could threaten the Earth.

Russian_meteorAnd it now seems that the Russian government wants to turn that frightening and eye-opening incident into something positive and celebratory. Alexei Betekhtin, the Minister of Culture of the Chelyabinsk Region, had this to say on the subject:

We will hand out our medals to all the athletes who will win gold on that day, because both the meteorite strike and the Olympic Games are the global events.

Using the shards collected by the various scientific expeditions who’s job it was to recover and study the meteor, they have fashioned seven sets of gold medals. The reported sports that will receive these medals include:

  • Women’s 1,000 meter and men’s 1,500 meter short track
  • Men’s skeleton
  • Women’s cross-country skiing relay
  • Men’s K-125 ski jump
  • Men’s 1,500 meter speed skating
  • Women’s super giant slalom

Each one will feature a small chunk of the meteor contained within the gold frame. And it goes without saying that this is an historic first. To date, no single Olympic games has ever sought to include stellar material in any of their medals. Perhaps this is a sign of the times, where global and interstellar events come together so publicly.

Sochi-2014-Olympic-StadiumNo telling as to whether or not this decision was at all influenced by the negative publicity Russia has been getting for its anti-gay legislation in the lead up to the Olympics. Between people being jailed for joining gay advocacy groups and the government’s refusal to prosecute hate crimes committed against homosexuals, there are those who are arguing for a boycott of the Russian Olympics.

But controversy is hardly a new thing when it comes to the Olympics, especially where the human rights records of host nations are involved. For those old enough to remember, the US boycotted the Moscow Olympics in 1980 to protest the Soviet invasion of Afghanistan. Four years later, the Soviets retaliated in kind by boycotting the Olympics being held in Los Angeles.

And of course, one has to remember that Beijing hosted the Summer Games back in 2008, and if human rights were ever a reason to boycott the games, this would have been a prime opportunity to stand on principle. Personally, I think the Russian government needs to get its head out of its ass and join the post-Medieval era, but I suppose political pressure will have to come from sources other than the Olympic committee.

Source: universetoday.com, en.rian.ru

Alien Matter Found on the Moon!

blue moonYes, it may sound like the setup for a really bad movie. And in truth, it’s more than just a little misleading. But in this case, “alien matter” refers to minerals deposits that were recently discovered on the surface of the Moon which may not belong there. These deposits include Magnesium-rich spinel and olivine found in the central peaks of lunar craters, which scientists previously believed to be indigenous to the surface.

Spinel forms, it should be noted, can be found here on Earth and are the product of high-pressure and temperatures, conditions which do not exist on the Moon’s surface. Hence, scientists were forced to conclude that the presence of such minerals on the surface had to have come from somewhere else. Most likely a meteoric impact, which the Moon – as its pockmarked surface can attest to – get’s no shortage of.

moon-asteroid-impact-1600However, in the past, it was generally accepted that any collision that big would melt or vaporize the impacting material, leaving behind only geochemical traces and tiny fragments. The quantities that were noticed more recently defied this interpretation, consisting or relatively large deposits and not mere fragments.

However, Jay Melosh and his colleagues from Indiana’s Purdue University were able to show through a series of computer simulations that asteroids are capable of still producing these craters at lower impact speeds, giving them greater chance of survival. What’s more, this would leave their mineral compositions unvaporized, allowing for more generous deposits of material.

In a paper recently published in Nature Geoscience, the team explains their process and what they were able to determine:

We find that for … impact velocities below about 12 kilometres per second, the projectile may both survive the impact, and be swept back into the central peak of the final crater as it collapses… We focused on a simulation of the 93-kilometre diameter Copernicus crater because of the reports of olivine and magnesium-spinel in its central peak… The olivine observed in the central peaks of Copernicus and other lunar craters may be a remnant of the projectile and thus does not indicate deep excavation of the lunar mantle or lower crust.

Overall, their simulations revealed that roughly a quarter of lunar impacts occur at speeds below 12 kilometres per second, which is slow enough for a significant fraction of the impacting object to remain largely intact. According to astronomer Michael Brown of Melbourne’s Monash University, their conclusions about low-velocity asteroid impacts are entirely plausible.

NASA_moonWhat’s more, Brown indicated that previously-held notions about meteors and asteroids impacting the Moon may be biased by our experience here on Earth, where impacts occur at much higher velocities.

When a large asteroid hits Earth, because of the Earth’s gravity and because of the velocity of the asteroid, you’re looking at impact speeds of 20-30 kilometres per second.

But of course, he also added that there are concentrations of spinel on the Moon’s surface which cannot be explained by impact events. How and why these were brought to the surface is something that future generations of astronauts will have to study, no doubt with the help of interior examinations of the planet and surface digs.

ESA_moonbaseWhich brings up another important aspect of this information. Given that the Moon is prone to meteors and asteroids, something we don’t have to worry nearly as much about on Earth due to our protective atmosphere, any plans to colonize it will have to take surface impacts into account. How exactly are people going to be able to live, work, and enjoy themselves on the surface if they have to contend with periodic massive impacts?

And in the meantime, check out this video from CBC about the March 17th impact, the largest impact in recent history which was visible from Earth:

http://www.cbc.ca/player/News/TV%2BShows/The%2BNational/Technology%2B&%2BScience/ID/2387906092/

Sources: cbc.ca, (2)

 

Origins of Russian Meteor Found!

meteorJust over a week after a meteor exploded across the sky above the Chelyabinsk region of Russia, a group of astronomers published a paper that reconstructs where the rock came from. The men in question were Jorge Zuluaga and Ignacio Ferrin at the University of Antioquia in Medellin, Colombia. And the method they used was quite unconventional, and is perhaps a testament to the age we live in.

Basically, Zuluaga and Ferrin used the many sources of dashboard and security cameras that captured the event on film. Using the trajectories shown in the videos posted on YouTube, the researchers were able to calculate the trajectory of the meteorite as it fell to Earth and use it to reconstruct the orbit of the meteoroid before its fell to Earth and cause the shockwave that damaged buildings and shattered windows.

From their calculations, they were able to determine the height, speed and position of the meteorite as it fell to Earth. According to the team’s paper:

“…the Chelyabinski meteor started to brighten up when it was between 32 and 47 km up in the atmosphere. The velocity of the body predicted by our analysis was between 13 and 19 km/s (relative to the Earth) which encloses the preferred figure of 18 km/s assumed by other researchers.”

They then used software developed by the US Naval Observatory (called NOVAS) and the Naval Observatory Vector Astrometry to calculate the likely orbit. From all this, they came to the preliminary conclusion that the meteorite came from the Apollo class of asteroids, a well-known class of rocks that cross Earth’s orbit.

This conclusion has some worried, since the Apollo group, which orbits the Sun in the vicinity of Venus and Earth, contains over 2000 asteroids that are larger than 1 km in diameter. And considering that this one meteor, which measured between 17 and 20 meters, caused 1491 injuries and damage to over 4000 buildings in the area.

Lucky for us, NASA and every other space agency on the planet has some defensive strategies in mind. And of course, early warning is always the most important aspect of disaster preparedness. In the near future, we can expect some of the proposed observation satellites that will be going up to ensure there will be a better degree of early warning.

Source: universetoday.com