NASA Opens Doors For Asteroid Capture Ideas, Offering $6M For Possible Future Missions

An astronaut retrieves a sample from an asteroid in this artist's conception. Credit: NASA

Got some ideas about how to snag an asteroid? NASA has just announced $6 million in opportunities for its asteroid retrieval initiative, which would see astronauts explore one of these space rocks in the 2020s if the agency receives budgetary approval to go through with the idea.

First proposed in the 2014 fiscal year budget (which has yet to be approved by Congress), the agency is moving forward with the idea by getting ideas from industry about the best way to approach the asteroid, capture it, and other priority areas. Up to 25 proposals will be selected.

The announcement comes just ahead of a one-day conference to (in part) gather public ideas for the mission. For those who weren’t able to snag one of the sold-out seats, NASA is offering virtual attendance at the forum. Follow the instructions at this page and then make a note of the program schedule on Wednesday.

In NASA’s words, these are the topics that are priority areas for solicitation:

  • Asteroid capture system concepts including using deployable structures and autonomous robotic manipulators;
  • Rendezvous sensors that can be used for a wide range of mission applications including automated rendezvous and docking and asteroid characterization and proximity operations;
  • Commercial spacecraft design, manufacture, and test capabilities that could be adapted for development of the Asteroid Redirect Vehicle (ARV);
  • Studies of potential future partnership opportunities for secondary payloads on either the ARV or the SLS;
  • Studies of potential future partnership opportunities for the Asteroid Redirect Crewed Mission, or other future missions, in areas such as advancing science and in-situ resource utilization, enabling commercial activities, and enhancing U.S. exploration activities in cis-lunar space after the first crewed mission to an asteroid.

“NASA is developing two mission concepts for the Asteroid Redirect Mission (ARM): one concept uses a robotic spacecraft to capture a whole small near-Earth asteroid, and the second concept uses largely the same robotic spacecraft to capture a cohesive mass from a larger asteroid,” the agency added in the solicitation documents.

Artist's conception of NASA's asteroid retrieval mission. Credit: NASA
Artist’s conception of NASA’s asteroid retrieval mission. Credit: NASA

“In both mission concepts, the asteroid mass would be redirected into a stable orbit around the Moon. Astronauts aboard the Orion spacecraft launched on the Space Launch System (SLS) would rendezvous with the captured asteroid mass in lunar orbit and collect samples for return to Earth.”

The agency is framing this initiative as a way to prepare for longer-duration missions (such as going to Mars) as well as better characterizing the threat from asteroids — which is certainly on many people’s minds after a meteor broke up over Chelyabinsk, Russia just over a year ago.

More information on the initiative is available at this NASA webpage, and you can read the solicitation documents at this link.

NASA Offers $35,000 In Prizes For Citizen Scientists To Help Find Asteroids

Hypothetical astronaut mission to an asteroid. Credit: NASA Human Exploration Framework Team

Fancy yourself an asteroid hunter? There’s $35,000 available in prizes for NASA’s new Asteroid Data Hunter contest series, which will be awarded to citizen scientists who develop algorithms that could be used to search for asteroids.

Here’s where you can apply for the contest, which opens March 17 and runs through August. And we have a few more details about this joint venture with Planetary Resources Inc. below.

“The Asteroid Data Hunter contest series challenges participants to develop significantly improved algorithms to identify asteroids in images captured by ground-based telescopes,” NASA stated. “The winning solution must increase the detection sensitivity, minimize the number of false positives, ignore imperfections in the data, and run effectively on all computer systems.”

We got a sharp reminder of the danger of asteroids to Earth in February 2013 when a meteor slammed into the atmosphere above Chelyabinsk, Russia, causing damage and hundreds of injuries. Meanwhile, NASA is working on a project to redirect an asteroid closer to Earth for astronauts to explore, a concept that has funding allocated in their 2015 budget request to Congress.

In November, NASA announced that Planetary Resources (the company best known for the “selfie” space telescope) is going to work on “crowdsourced software solutions” with NASA-funded data to make it easier to find asteroids and other near-Earth objects.

Chelyabinsk ‘Was A Pretty Nasty Event’ And Is Spurring Asteroid Action

Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.
Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.

Looking at the power of the Chelyabinsk meteor (which struck a year ago and is visible starting around 1:15 in the video above) is still terrifying all these months later. Happily for those of on Earth worried about these big space rocks, the world’s space agencies are taking the threat seriously and are starting to implement new tracking systems to look out for more threatening space rocks.

“It was a pretty nasty event. Luckily, no one was killed but it just shows the sort of force that these things have,” said Alan Harris, senior scientist of the DLR Institute of Planetary Research in Berlin, in this new European Space Agency video.

An asteroid that is only about 100 meters (328 feet) in diameter, for example, “could actually completely destroy an urban area in the worst case. So those are the things we’re really looking out for and trying to find ways to tackle.”

Check out the video for some examples of how the Europeans are talking about dealing with this problem, including a fun comparison to cosmic billiards and a more serious discussion on how to shove these rocks aside if they were on a collision course with our planet.

For more information on tracking down killer asteroids, check out this past video with Universe Today founder Fraser Cain.

Happy 1st Anniversary Chelyabinsk! The Fireball that Woke Up the World

Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.
Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.

Wonder and terror. Every time I watch the dashcam videos of the Chelyabinsk fireball it sends chills down my spine. One year ago today, February 15, 2013, the good citizens of Chelyabinsk, Russia and surrounding towns collectively experienced these two powerful emotions as they witnessed the largest meteorite fall in over 100 years. 


Incredible compilation of dashcam and security camera videos of the fireball

The Chelyabinsk fall, the largest witnessed meteorite fall since the Tunguska event in 1908, exploded with 20-30 times the force of the atomic bomb over Hiroshima at an altitude of just 14.5 miles (23 km). Before it detonated into thousands of mostly gravel-sized meteorites and dust,  it’s estimate the incoming meteoroid was some 66 feet (20-meters) end to end, as tall as a five-story building. The shock wave from the explosion shattered windows up and down the city, injuring nearly 1,500 people.

Friction and enormous pressures placed upon the Chelyabinsk meteoroid by the atmosphere caused it to explode to pieces and send a shock wave across the cities below. This is a selection of typical small, fusion-crust covered Chelyabinsk meteorites. The U.S. penny is 9mm in diameter. Credit: Bob King
Atmospheric friction pressure on the Chelyabinsk meteoroid caused it to explode to pieces and send a shock wave across the land below. Pictured is a selection of typical small, fusion-crust covered Chelyabinsk meteorites recovered shortly after the fall. The U.S. penny is 9mm in diameter. Credit: Bob King

For nearby observers it briefly appeared brighter than the sun.  NASA Meteorite researcher Peter Jenniskens conducted an Internet survey of eyewitnesses and found that eye pain and temporary blindness were the most common complaints from those who looked directly at the fireball.  20 people also reported sunburns including one person burned so badly that his skin peeled:

Trajectory projection and strewnfield map showing the main fireball (and two additional explosions) at top and the elliptical shaped area where the densest concentration of meteorites were found. Credit: Svend  Buhl and K. Wimmer
Map showing the trajectory of the main fireball in yellow (and two additional explosions at top left). The pink oval, called the strewnfield, is where the densest concentration of meteorites were found. Click to see additional maps. Credit: Svend Buhl and K. Wimmer

“We calculated how much UV light came down and we think it’s possible,” Jenniskens said. Perhaps surprisingly, most of the meteoroid’s mass – an estimated 76% – burned up and was converted to dust during atmospheric entry. It’s estimated that only 0.05% of the original meteoroid or 9,000 to 13,000 pounds of meteorites fell to the ground.


No video I’ve seen better captures the both the explosion of the fireball and ensuring confusion and chaos better than this one.

The largest fragment, weighing 1,442 lbs. (654 kg), punched a hole in the ice of Lake Chebarkul. Divers raised it from the bottom muck on Oct. 16 last year and rafted it ashore, where scientists and excited onlookers watched as the massive space rock was hoisted onto a scale and promptly broke into three pieces. Moments later the scale itself broke from the weight.

The 26-foot-wide (8-meter) hole punched in the ice of Chebarkul Lake by the largest fragment of the Chelyabinsk meteorite. Credit: Eduard Kalinin
The 26-foot-wide (8-meter) hole punched in the ice of Chebarkul Lake by the largest fragment of the Chelyabinsk meteorite. Credit: Eduard Kalinin

There were plenty of meteorite to go around as local residents tracked down thousands of fragments by looking for holes pierced in the snow cover by the hail of space rocks. Working with hands and trowels, they dug out mostly small, rounded rocks covered in fresh black fusion crust, a 1-2 mm thick layer of rock blackened and melted rock from frictional heating by the atmosphere. According to the Meteoritical Bulletin Database entry,  the total mass of the recovered meteorites to date comes to 1,000 kg (2,204 lbs.) with locals finding up to more than half of that total.


Animation of the orbit Chelyabinsk meteoroid via Ferrin and Zuluaga. Meteoroid is the name given a meteor while still orbiting the sun before it enters Earth’s atmosphere.

Thanks to the unprecedented number of observations of the fireball recorded by dashcams, security cameras and eyewitness accounts, astronomers were able to determine an orbit for  Although some uncertainties remain, the object is (was) a member of the Apollo family of asteroids, named for 1862 Apollo, discovered in 1932. Apollos cross Earth’s orbit on a routine basis when they’re nearest the sun. Chelyabink’s most recent crossing was of course its last.

Chelyabinsk meteorites exhibit many signs of  shock created during an asteroid impact long ago. Many specimens show a typical pale white color with small chondrules typical of LL5 chondrite. A closer look shows fine, dark shock veins of melted glass. Other fragments are made of impact melt, rock shocked-heated and blackened by impact. Credit: Bob King
Chelyabinsk meteorites tell the tale of an earlier impact with another asteroid 4.452 billion years ago. Many specimens are pale white with small chondrules typical of LL5 chondrites. A closer look shows fine, dark shock veins of melted glass. Other fragments are made of pure impact melt, rock shocked-heated, melted and blackened by impact. Credit: Bob King

Chelyabinsk belongs to a class of meteorites called ordinary chondrites, a broad category that includes most stony meteorite types. The chondrites formed from dust and metals whirling about the newborn sun some 4.5 billion years ago; they later served as the building blocks for the planets, asteroids and comets that populate our solar system. Chondrites are further subdivided into many categories. Chelyabinsk belongs to the scarce LL5 class — a low iron, low metal stony meteorite composed of silicate materials like olivine and plagioclase along with small amounts of iron-nickel metal.

 

Most of the Chelyabinsk meteorites were shattered and broken during the explosion / shock blast, revealing brecciation, metal and shock veins in their interiors. Credit: Bob King
Most of the Chelyabinsk meteorites were shattered and broken during the explosion / shock blast, revealing brecciation, metal and shock veins in their interiors. Credit: Bob King
A thin slice of Chelyabinsk impact melt breccia. Flows of once-molten rock (gray) surround islands of less altered material. A small iron nickel nodule is seen at lower left. Credit: Bob King
A thin slice of Chelyabinsk impact melt breccia. Flows of once-molten rock (paler gray) surround islands of less altered material. A small iron nickel nodule is seen at lower left. Credit: Bob King

 

A closer look at Chelyabinsk meteorites reveals a fascinating story of ancient impact. Remarkably, the seeds of the meteoroid’s atmospheric destruction were sown 115 million years after the solar system’s formation when ur-Chelyabinsk was struck by another asteroid, suffering a powerful shock event that heated, fragmented and partially melted its interior. Look inside a specimen and the signs are everywhere – flows of melted rock, spider webby shock veins of melted silicates and peculiar, shiny cleavages called “slickensides” where meteorites broke along  pre-existing fracture planes.

Slickensides on a Chelyabinsk meteorite fragment where the fragment broke along a pre-existing fracture plane. Credit: Bob King
Slickensides on a Chelyabinsk meteorite fragment where the fragment broke along a pre-existing fracture plane. Credit: Bob King

Jenniskens calculated that the object may have come from the Flora family of S-type or stony asteroids in the belt between Mars and Jupiter. Somehow Chelyabinsk held together after the impact until nearly the time it met its fate with Earth’s atmosphere. Researchers at University of Tokyo and Waseda University in Japan discovered that the meteorite had only been exposed to cosmic rays for an unusually brief time for a Flora member – just 1.2 million years. Typical exposures are much longer and indicate that the Chelyabinsk parent asteroid only recently broke apart. Jenniskens speculates it was likely part of a loosely-bound, rubble pile asteroid that may have broken apart during a previous close encounter with Earth in the last 1.2 million years. The rest of the rubble pile might still be orbiting relatively nearby as part of the larger population of near-Earth asteroids.

Rivulets of melted rock line the fusion crust of melted rock on this small Chelyabinsk meteorite. Credit: Bob King
Rivulets of melted rock line the fusion crust of melted rock on this small Chelyabinsk meteorite. Credit: Bob King

Good thing Chelyabinsk arrived pre-fractured. Had it been solid through and through, more of the original asteroid might have survived its fiery descent and wreaked even more havoc in in its wake.

We’re fortunate that Chelyabinsk contains a fantastic diversity of features and that we have so many pieces for study. Surveys have found some 500 near-Earth asteroids. No doubt some are part of the parent body of Chelyabinsk and may grace our skies on some future date. Whatever happens, Feb. 15, 2013 will go down as a very loud “wake-up call” for our species to implement more asteroid-hunting programs both in space and on the ground. Enjoy a few more photos of this incredible gift from space:

This Chelyabinsk "nosecone" or "bullet" weighs just 0.35g. It displays a beautiful streamlined form from its flight through the atmosphere. Credit: Bob King
This Chelyabinsk “nosecone” or “bullet” weighs just 0.35g. It displays a beautiful streamlined form from its flight through the atmosphere. Credit: Bob King
Check out the bubble texture on this one. Heated by friction with the air, this fragment shows bubbly crust from escaping gases. Credit: Bob King
Check out the bubble texture on this one. Heated by friction with the air, this fragment shows bubbly crust from escaping gases. Credit: Bob King
Slice of Chelyabinsk showing relatively unshocked areas (light brown) cut by thick dark veins of shock-darkened material. Credit: Bob King
Slice of Chelyabinsk showing mildy shocked areas (light brown) cut by thick dark veins of shock-darkened material. Credit: Bob King
Some Chelyabinsk individuals show interesting variations in color that have nothing to do with rusting. It's believed that varying amounts of oxygen available to the speeding rocks during the meteorite break up created the brownish-red coloration on some fusion crusts. Credit: Bob King
Some Chelyabinsk individuals show interesting variations in color that have nothing to do with rusting. It’s believed that varying amounts of oxygen available to the speeding rocks during the meteorite break up created the brownish-red coloration on some fusion crusts. Credit: Bob King
OK, I saved the weirdest for last - a smaller Chelyabinsk meteorite appears to have followed closely enough behind the larger for there liquid fusion crusts to have welded them together. Just my speculation. Credit: Bob King
I saved the weirdest for last – a smaller Chelyabinsk meteorite appears to have followed closely enough behind the larger for their still-molten fusion crusts to have welded them together. Just my speculation. Credit: Bob King

How Can We Find Killer Asteroids?

How Can We Find Killer Asteroids?

On the morning of February 15, 2013, people in western Russia were dazzled by an incredibly bright meteor blazing a fiery contrail across the sky. A few minutes later a shockwave struck, shaking the buildings and blowing out windows. 1,500 people went to the hospital with injuries from shattered glass. This was the Chelyabinsk meteor, a chunk of rock that struck the atmosphere going almost 19 kilometers per second. Astronomers estimate that it was 15-20 meters across and weighed around 12,000 metric tonnes.

Here’s the crazy part. It was the largest known object to strike the atmosphere since the Tunguska explosion in 1908. Catastrophic impacts have shaped the evolution of life on Earth. Once every 65 million years or so, there’s an impact so destructive, it wipes out almost all life on Earth. The bad news is the Chelyabinsk event was a surprise. The asteroid came out of nowhere. We need to find all the potential killer asteroids, and understand what risks we face.

“I’m Ned Wright…”

That’s Dr. Ned Wright. He’s a professor of physics and astronomy at UCLA, and the Primary Investigator for the Wide-field Infrared Survey Explorer mission; a space telescope that looks for low temperature objects in the infrared spectrum.

“I think the best way to protect the Earth from asteroids is to get out and look very assiduously to find all the hazardous asteroids. Although astronomers have been finding and cataloging asteroids for decades, we still only have a fraction of the dangerous asteroids tracked. The large continent destroyers have mostly been found, but there’s a whole class of smaller, city killers out there, and they’re almost entirely unknown. There are… these dark asteroids that may not be the most dominant part of the population but they certainly can be a very hazardous subset, it’s important to do the observations in the infrared. So you actually, instead of looking for the ones that reflect the most light, you look for the ones that have the biggest area and therefore the ones that are the heaviest and can do the most damage. And so, I think that an infrared survey is the way to go.”

“In the infrared wavelengths, we can find these objects because they’re large, not because they’re bright. And to really do this right, we need a space-based infrared observatory capable of surveying vast areas of the sky, searching for anything moving.”

The WISE mission has been offline for a few years, but WISE is actually being reactivated right now to look for more Near Earth Objects, so we’re currently cooled down to 93 K, and when we get to 73 K, which is where we were when we turned off in 2011 we’ll probably be able to go out and find more Near Earth Objects.

Note: this interview was recorded in November, 2013. WISE resumed operations in December 23, 2013

Kevin Luhman discovered the brown dwarf pair in data from NASA's Wide-field Infrared Survey Explorer (WISE; artist's impression). Image: NASA/JPL-Caltech
Artist’s impression of the WISE satellite

But to really find the vast majority of dangerous asteroids, you need a specialized mission. One proposal is the Near Earth Asteroid Camera, or NEOCam because it’d be much better to have a telescope that was slightly colder than the 73 K WISE is with coolant, and you can do that by getting away from the Earth. and so the NEOcam telescope is designed to go a million and a half kilometers from the Earth and therefore it would be quite cold, about 35 K and at that temperature, it can operate longer into the infrared and do a very sensitive survey for asteroids.

NEOCam is just one idea. There’s also the Sentinel proposal from B612 Foundation. It’s also an infrared survey and it would go into an orbit like Venus’ orbit, so it would be hundreds of millions of km away from Earth, but not orbiting around Venus, because that would be too hot as well and then with an infrared telescope, it would survey for asteroids.

NEOCam and Sentinel would operate for years, scanning the sky in the infrared to find all of the really hazardous asteroids. You wouldn’t be able to necessarily find the ones the size of the one that hit Chelyabinsk, and so that broke some windows, but it didn’t kill people, didn’t knock buildings down. So that’s definitely a hazard, but not the city destroying hazard that a 100 meter diameter asteroid would be.

We live in a cosmic shooting gallery. Rocks from space impact the Earth all the time, our next dangerous asteroid is out there, somewhere. Let’s build a space-based infrared survey mission so we can find it, before it finds us.

Possible Huge Meteorite Fragment Recovered From Russian Fireball

Frame grab from a video of the Feb. 15, 2013 Russian fireball by Aleksandr Ivanov

A half-ton meteorite — presumably from the Russian fireball that broke up over Chelyabinsk in February — was dragged up from Lake Chebarkul in the Urals, Russian media reports said. Scientists estimate the chunk is about 1,260 pounds (570 kilograms), but couldn’t get a precise measurement in the field because the bulky bolide broke the scale, according to media reports.

“The preliminary examination… shows that this is really a fraction of the Chelyabinsk meteorite,” said Sergey Zamozdra, associate professor of Chelyabinsk State University, in reports from Interfax and RT.

A polished slice of one of Russian meteorite samples. You can see round grains called chondrules and shock veins lined with melted rock. The meteorite is probably non-uniform. The preliminary analysis showed that the meteorite belongs to chemical type L or LL, petrologic type 5.
A polished slice of one of Russian meteorite samples (different samples than what was reportedly recovered on Oct. 16). You can see round grains called chondrules and shock veins lined with melted rock. The meteorite is probably non-uniform. The preliminary analysis showed that the meteorite belongs to chemical type L or LL, petrologic type 5.

“It’s got thick burn-off, the rust is clearly seen and it’s got a big number of indents. This chunk is most probably one of the top ten biggest meteorite fragments ever found.”

The big rock was first spotted in September, but it’s taken several attempts to bring it to the surface. If scientists can confirm this came from the fireball, this would be the biggest piece recovered yet. The chunk is reportedly in a natural history museum, where a portion will be X-rayed to determine its origins.

More than 1,000 people were injured and millions of dollars in damage occurred when the meteor broke up in the atmosphere Feb. 15, shattering glass and causing booms.

Since then, there have been numerous papers concerning the meteor’s origins (from the Apollo class of asteroids — you can read this article if you’re unclear on the difference between an asteroid and a meteorite) and tracking the spread of dust through the atmosphere, among other items.

Russian Meteor Experienced Melting Before Slamming Into Earth: Study

The two main smoke trails left by the Russian meteorite as it passed over the city of Chelyabinsk. Credit: AP Photo/Chelyabinsk.ru

A collision or “near miss” caused melting in the Chelyabinsk meteor before it slammed into Earth’s atmosphere this February, causing damage and injuries to hundreds in the remote Russian region.

A new study, presented at the Goldschmidt Conference in Florence, Italy, says some meteorite fragments’ composition shows strong evidence of heating, which is an indication of interplanetary violence of some sort.

“The meteorite which landed near Chelyabinsk is a type known as an LL5 chondrite, and it’s fairly common for these to have undergone a melting process before they fall to Earth,” stated Victor Sharygin, a researcher from the Sobolev Institute of Geology and Mineralogy in Russia.

“This almost certainly means that there was a collision between the Chelyabinsk meteorite and another body in the solar system, or a near miss with the Sun.”

Chelyabinsk’s size of 59 feet (18 meters) was by no means a very large meteor, but it was enough to cause car alarms to go off and to shatter glass when it exploded over Russia on Feb. 15. Its arrival brought the danger of space rocks once again to public attention.

In just the few short months since its arrival, a number of research studies have begun to sketch out its origins and effects. One recent NASA study showed that the cloud of dust from the explosion spread around the northern hemisphere in days.

Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia. Image Credit: NASA's Goddard Space Flight Center Scientific Visualization
Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia.
Image Credit: NASA’s Goddard Space Flight Center Scientific Visualization

Sharygin’s team analyzed several fragments of the meteorites and put them into three groups: light, dark and intermediate. Lights ones were the most abundant. Dark fragments were most commonly found in the area where the meteorite hit the Earth.

While only three of the dark fragments show there was previous melting, the researchers say it’s quite possible that more samples might be available from the public and most notably, from the main portion that is still at the bottom of Chebarkul Lake.

“The dark fragments include a large proportion of fine-grained material, and their structure, texture and mineral composition shows they were formed by a very intensive melting process,” a press release stated.

“This material is distinct from the ‘fusion crust’ – the thin layer of material on the surface of the meteorite that melts, then solidifies, as it travels through the Earth’s atmosphere.”

A "fusion crust" or melting is visible in this fragment of the Chelyabinsk meteorite. Credit: Victor Sharygin
A “fusion crust” or melting is visible in this fragment of the Chelyabinsk meteorite. Credit: Victor Sharygin

Researchers also spotted “bubbles” in the dark fragments that they consider either “perfect crystals” of oxides, silicates and metal or little spots that are filled up with sulfide or metal.

They also saw platinum-type elements in the crust, which was a surprise as the time it takes for a crust to fuse is too short for platinum to form.

“We think the appearance (formation) of this platinum group mineral in the fusion crust may be linked to compositional changes in metal-sulfide liquid during remelting and oxidation processes as the meteorite came into contact with atmospheric oxygen,” Sharygin stated.

The work is ongoing, and no submission date for a study for publication was disclosed.

Source: EurekAlert!

Satellite Watches Dust from Chelyabinsk Meteor Spread Around the Northern Hemisphere

Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia. Image Credit: NASA's Goddard Space Flight Center Scientific Visualization

When a meteor weighing 10,000 metric tons exploded 22.5 km (14 miles) above Chelyabinsk, Russia on Feb. 15, 2013, the news of the event spread quickly around the world. But that’s not all that circulated around the world. The explosion also deposited hundreds of tons of dust in Earth’s stratosphere, and NASA’s Suomi NPP satellite was in the right place to be able to track the meteor plume for several months. What it saw was that the plume from the explosion spread out and wound its way entirely around the northern hemisphere within four days.

The bolide, measuring 59 feet (18 meters) across, slipped quietly into Earth’s atmosphere at 41,600 mph (18.6 kilometers per second). When the meteor hit the atmosphere, the air in front of it compressed quickly, heating up equally as quick so that it began to heat up the surface of the meteor. This created the tail of burning rock that was seen in the many videos that emerged of the event. Eventually, the space rock exploded, releasing more than 30 times the energy from the atom bomb that destroyed Hiroshima. For comparison, the ground-impacting meteor that triggered mass extinctions, including the dinosaurs, measured about 10 km (6 miles) across and released about 1 billion times the energy of the atom bomb.

Atmospheric physicist Nick Gorkavyi from Goddard Space Flight Center, who works with the Suomi satellite, had more than just a scientific interest in the event. His hometown is Chelyabinsk.

“We wanted to know if our satellite could detect the meteor dust,” said Gorkavyi, who led the study, which has been accepted for publication in the journal Geophysical Research Letters. “Indeed, we saw the formation of a new dust belt in Earth’s stratosphere, and achieved the first space-based observation of the long-term evolution of a bolide plume.”

The team said they have now made unprecedented measurements of how the dust from the meteor explosion formed a thin but cohesive and persistent stratospheric dust belt.

About 3.5 hours after the initial explosion, the Ozone Mapping Profiling Suite instrument’s Limb Profiler on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite detected the plume high in the atmosphere at an altitude of about 40 km (25 miles), quickly moving east at about 300 km/h (190 mph).

The day after the explosion, the satellite detected the plume continuing its eastward flow in the jet and reaching the Aleutian Islands. Larger, heavier particles began to lose altitude and speed, while their smaller, lighter counterparts stayed aloft and retained speed – consistent with wind speed variations at the different altitudes.

By Feb. 19, four days after the explosion, the faster, higher portion of the plume had snaked its way entirely around the Northern Hemisphere and back to Chelyabinsk. But the plume’s evolution continued: At least three months later, a detectable belt of bolide dust persisted around the planet.

Gorkavyi and colleagues combined a series of satellite measurements with atmospheric models to simulate how the plume from the bolide explosion evolved as the stratospheric jet stream carried it around the Northern Hemisphere.

“Thirty years ago, we could only state that the plume was embedded in the stratospheric jet stream,” said Paul Newman, chief scientist for Goddard’s Atmospheric Science Lab. “Today, our models allow us to precisely trace the bolide and understand its evolution as it moves around the globe.”

NASA says the full implications of the study remain to be seen. Scientists have estimated that every day, about 30 metric tons of small material from space encounters Earth and is suspended high in the atmosphere. Now with the satellite technology that’s capable of more precisely measuring small atmospheric particles, scientists should be able to provide better estimates of how much cosmic dust enters Earth’s atmosphere and how this debris might influence stratospheric and mesospheric clouds.

It will also provide information on how common bolide events like the Chelyabinsk explosion might be, since many might occur over oceans or unpopulated areas.

“Now in the space age, with all of this technology, we can achieve a very different level of understanding of injection and evolution of meteor dust in atmosphere,” Gorkavyi said. “Of course, the Chelyabinsk bolide is much smaller than the ‘dinosaurs killer,’ and this is good: We have the unique opportunity to safely study a potentially very dangerous type of event.”

Source: NASA