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.
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
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.
Rocket science university students from Puerto Rico pose for photo op with the Terrier-Improved Malemute sounding rocket that will launch their own developed RockSat-X science experiments to space on Aug. 13 at 6 a.m. from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.com
Rocket science university students from Puerto Rico pose for photo op with the Terrier-Improved Malemute sounding rocket that will launch their own developed RockSat-X science experiments to space on Aug. 13 at 6 a.m. from NASA Wallops Flight Facility, VA.
Credit: Ken Kremer/kenkremer.com[/caption]
WALLOPS ISLAND, VA – How many of you have dreamed of flying yourselves or your breakthrough experiments to the High Frontier? Well if you are a talented student, NASA may have a ticket for you.
A diverse group of highly motivated aerospace students from seven universities spread across the United States have descended on NASA’s Wallops Flight Facility along the Eastern Shore of Virginia to fulfill the dream of their lifetimes – launching their very own science experiments aboard a rocket bound for space.
I met the thrilled students and professors today beside their rocket at the Wallops Island launch pad.
On Aug 13, after years of hard work, an impressive array of research experiments developed by more than 40 university students will soar to space on the RockSat-X payload atop a 44-foot tall Terrier-Improved Malemute suborbital sounding rocket at 6 a.m. EDT.
Students from Northwest Nazarene University observe the pre-integration of their experiment into the RockSat-X payload at the NASA Wallops Flight Facility in June. Students from seven universities are participating in the program and will attend the launch on August 13. Credit: NASA/K. Koehler
The two stage rocket will rapidly ascend on a southeasterly trajectory to an altitude of some 97 miles and transmit valuable data in-flight during the 12-minute mission.
The launch will be visible to spectators in parts of Virginia, Maryland and Delaware, and perhaps a bit beyond. Check out the visibility map below.
The RockSat-X flight profile and visibility map. RockSat-X is scheduled to launch from NASA’s Wallops Flight Facility, VA on Aug. 13 at 6.a.m. EDT Credit: NASA
If you’re available, try venturing out to watch it. The available window lasts until 10 a.m. EDT if needed.
The students will put their classroom learning to the test with experiments and instruments built by their own hands and installed on the 20 foot long RockSat-X payload. The integrated payload accounts for nearly half the length of the Terrier Malamute suborbital rocket. It’s an out of this world application of the scientific method.
Terrier-Improved Malemute sounding rocket erected for launch of student experiments on RockSat-X payload on Aug. 13 at 6 a.m. from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.comIncluded among the dozens of custom built student experiments are HD cameras, investigations into crystal growth and ferro fluids in microgravity, measuring the electron density in the E region (90-120km), aerogel dust collection on an exposed telescoping arm from the rockets side, effects of radiation damage on various electrical components, determining the durability of flexible electronics in the cryogenic environment of space and creating a despun video of the flight.
At the conclusion of the flight, the payload will descend to Earth via a parachute and splash down in the Atlantic Ocean approximately 86 miles offshore from Wallops.
Commercial fishing ships under contract to NASA will then recover the RockSat-X payload and return it to the students a few hours later, NASA spokesman Keith Koehler told Universe Today.
They will tear apart the payload, disengage their experiments and begin analyzing the data to see how well their instruments performed compared to the preflight hypotheses’.
RockSat-X is a joint educational activity between NASA and the Colorado Space Grant Consortium. It is the third of three practical STEM educational programs where the students must master increasingly difficult skill level requirements leading to a series of sounding rocket liftoffs.
In mid-June, some 50 new students participated in the successful ‘RockOn’ introductory level payload launch from Wallops using a smaller Terrier-Improved Orion rocket.
“The goal of the RockSat-X program is to provide students a hands-on experience in developing experiments for space flight,” said Chris Koehler, Director of the Colorado Space Grant Consortium.
“This experience allows these students to apply what they have learned in the classroom to a real world hands-on project.”
The students participating in this year’s RockSat-X launch program hail from the University of Colorado at Boulder; the University of Puerto Rico at San Juan; the University of Maryland, College Park; Johns Hopkins University, Baltimore, Md.; West Virginia University, Morgantown; University of Minnesota, Twin Cities; and Northwest Nazarene University, Nampa, Idaho.
Panoramic view of the NASA Wallops Flight Facility launch range at Virginia’s Eastern Shore during prior launch of two suborbital sounding rockets as part of the Daytime Dynamo mission. RockSat-X payload will launch on a Terrier-Improved Malemute sounding rocket. Credit: Ken Kremer/kenkremer.com
Some of these students today could well become the pioneering aerospace industry leaders of tomorrow!
In the event of a delay forced by weather or technical glitches, August 14 is the backup launch day.
A great place to witness the blastoff is from the NASA Wallops Visitor Center, offering a clear view to the NASA launch range.
It opens at 5 a.m. on launch day and is a wonderful place to learn about NASA missions – especially the pair of exciting and unprecedented upcoming launches of the LADEE lunar science probe to the moon and the Cygnus cargo carrier to the ISS in September.
Both LADEE and Cygnus are historic first of their kind flights from NASA Wallops.
Live coverage of the launch is available via UStream beginning at 5 a.m. on launch day at:
http://www.ustream.tv/channel/nasa-tv-wallops
…………….
Learn more about Suborbital Science, Cygnus, Antares, LADEE, MAVEN and Mars rovers and more at Ken’s upcoming presentations
Aug 12/13: “RockSat-X Suborbital Launch, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM
Sep 5/6/16/17: LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM
Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM
More than 40 University students participating in the Aug. 13 RockSat-X science payload pose for photo op with the Terrier-Improved Malemute sounding rocket that will launch their own experiments to space from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.com
Artist's concept of a GOES spacecraft in orbit. (Credit: NOAA.gov).
It’s sometimes tough being a satellite in Earth orbit these days.
An interesting commentary came our way recently via NASA’s Orbital Debris Program Office’s Orbital Debris Quarterly News. The article, entitled High-Speed Particle Impacts Suspected in Two Spacecraft Anomalies, highlights a growing trend in the local space environment.
The tale begins with GOES 13 located in geostationary orbit over longitude 75° West. Launched on May 24th, 2006 atop a Delta IV rocket, GOES 13 is an integral part of the U.S. National Oceanic and Atmospheric Administration (NOAA’s) Geostationary Operational Environmental Satellite network.
The problems began when GOES-13 began to suffer an “attitude disturbance of unknown origin” on May 22nd of this year, causing it to drift about two degrees per hour off of its required nadir (the opposite of zenith) pointing.
The anomaly was similar to a problem encountered by the NOAA 17 spacecraft on November 20th, 2005. At the time, the anomaly was suspected to be due to a micrometeoroid impact. The Leonid meteors, which peak right around the middle of November, were a chief suspect. However, NOAA 17 suffered a second failure 18 days later, which was later traced down to a hydrazine leak from its errant thrusters.
GOES-13 has weathered hard times before. Back in December of 2006, GOES-13’s Solar X-Ray Imager suffered damage after being struck by a solar flare shortly after initial deployment. GOES-13 also began returning degraded imagery in September 2012, forcing it into backup status for Hurricane Sandy.
GOES-13 was restored to functionality last month. Current thinking is that the satellite was struck by a micrometeorite. No major meteor showers were active at the time.
Loss of a GOES satellite would place a definite strain on our weather monitoring and Earth observing capability. Begun with the launch of GOES-1 in 1975, currently six GOES satellites are in operation, including one used to relay data for PeaceSat (GOES-7) and one used as a communications relay for the South Pole research station (GOES-3).
The GOES program cost NOAA billions in cost overruns to execute. The next GOES launch is GOES-R scheduled in 2015.
But the universe seems to love coincidences.
NEE-01 Pegaso before deployment. (Credit: Wikimedia Commons image in the Public Domain).
Less than 26 hours after the GOES 13 anomaly, Ecuador’s first satellite, NEE-01 Pegaso began to have difficulties keeping a stable attitude. The event happened shortly after passage near an old Soviet rocket booster (NORAD designation 1986-058B) which launched Kosmos 1768 on August 2nd, 1986. The U.S. Joint Space Operations Center had warned the fledgling Ecuadorian Space Agency that conjunction was imminent, but of course, there’s not much that could’ve been done to save the tiny CubeSat.
Although the main mass passed Pegaso at a safe distance, current thinking is that the discarded booster may have left a cloud of debris in its wake. Researchers have tracked small “debris clouds” around objects it orbit before- the collision of Iridium 33 and the defunct Kosmos 2251 on February 10th, 2009 left a ring of debris in its wake, and the Chinese anti-satellite test carried out on January 11th, 2007 showered low-Earth orbit with debris for years to come.
The loss represents a blow to Ecuador and their first bid to become a space-faring nation. Launched less than a month prior atop a Long March 2D rocket, Pegaso was a small 10 centimetre nanosatellite equipped with solar panels and dual infrared and visible Earth imaging systems.
A translation from the Ecuadorian Space Agencies site states that;
“The NEE-01 survived the crash and remains in orbit; however it has entered uncontrolled rotation due to the event.
Due to this rotation, (the satellite) cannot point its antenna correctly and stably to the Earth station and although still transmitting and running, the signal cannot be decoded. The Ecuadorian Civilian Space Agency is working tirelessly to stabilize the NEE-01 and recover the use of their signal.
The PEGASUS aired for 7 days your signal to the world via EarthCam, millions could see the Earth seen from space in real time, many for the first time, the files in those 7 days have been published after transmission.”
Ecuador plans to launch another CubeSat, NEE 02 Krysaor later in 2013. A carrier has not yet been named.
While both events suffered by the GOES-13 and NEE-01 Pegaso satellites were unrelated, they underscore problems with space junk and space environmental hazards that are occurring with a higher frequency.
Gabbard diagram displaying a sample disintegration of a Long March 4 booster in 2000. (Credit: the NASA Orbital Debris Office).
Such is the modern hazardous environment of low Earth orbit that new satellites must face. With a growing amount of debris, impact threats are becoming more common. The International Space Station must perform frequent debris avoidance maneuvers to avoid hazards, and more than once, the crew has waited out a pass in their Soyuz escape modules should immediate evacuation become necessary. Punctures from micro-meteoroids or space junk have even been seen recently on the ISS solar panel arrays.
Plans are on the drawing board to deal with space junk, involving everything from “space nets” to lasers and even more exotic ideas. Probably the most immediate solution that can be implemented is to assure new payloads have a way to “self-terminate” via de-orbit at the end of their life span. Solar sail technologies, such as NanoSailD2 launched in 2010 have already demonstrated this capability.
Expect reentries also pick up as we approach the peak of solar cycle #24 at the end of 2013 and the beginning of 2014. Increased solar activity energizes the upper atmosphere and creates increased drag on low Earth satellites.
It’s a brave new world “up there,” and hazards, both natural and man-made, are something that space faring nations will have to come to terms with.
-Read and subscribe to the latest edition of NASA’s Orbital Debris Quarterly News for free here.
The UNESCO World Heritage Site of Persopolis, Iran (image credit: Oshin D. Zakarian/TWAN).
Citizen scientists have discovered planets beyond our Solar System and established morphological classifications for thousands of galaxies (e.g., the Planet Hunters and Galaxy Zoo projects). At an upcoming meeting of planetary scientists, Hamed Pourkhorsandi from the University of Tehran will present his efforts to mobilize citizens to identify impact craters throughout Persia. Pourkhorsandi said he is recruiting volunteers to identify craters using Google Earth, while continuing to seek sightings of fireballs cited in ancient books and among rural folk. Discovering impact craters is an important endeavour, since it helps astronomers estimate how many asteroids of a particular size strike Earth over a given time (i.e., the impact frequency). Indeed, that is especially relevant in light of the recent meteor explosion over Russia this past February (see the UT article here), which hints at the potentially destructive nature of such occurrences.
Satellite images have facilitated the detection of impact sites such as the Kamil and Puka craters, which were identified by V. de Michele and D. Hamacher using Google Earth, respectively (see the UT article here). Pourkhorsandi noted that, “Free access to satellite images has led to the investigation of earth’s surface by specialists and nonspecialists, attempts that have led to the discovery of new impact craters around the globe. [Yet] few researches on this topic have been done in the Middle East.” Incidentally, citizens are likewise being recruited to classify craters and features on other bodies in the Solar System (e.g., the Moon Zoo project).
The Kamil impact crater in Egypt was discovered by V. de Michele using Google Earth, and H. Pourkhorsandi is recruiting volunteers to discover such structures throughout Persia following a similar approach (image credit: L. Folco).
In his paper, Pourkhorsandi describes examples of two targets investigated thus far: “1. a circular structure with a diameter of 200 m (33°21’57”N 58°14’24”E). [However,] there is no sign of … meteoritic fragments in the region that are primary diagnostic indicators for small size impact craters.” The second target is tied to an old tale, and note that the Puka crater in Australia was identified by following-up on an old Aboriginal story. However, Pourkhorsandi states that a field study of the second target (28°24’52” N 60°34’44” E) revealed that the crater is not associated with an impactor from space.
“Beside these structures, field studies on other craters in Persia are in progress, the outcomes of which will be announced in the near future,” said Pourkhorsandi.
Pourkhorsandi underscores that numerous meteorites have been found in desert regions throughout the world, yet scant attention has been given to Persian deserts (e.g., the Lut desert). The Lut desert in Persia extends over several thousand square kilometres and is one of the hottest places on Earth (featuring land surface temperatures upwards of 70 degrees Celsius). Pourkhorsandi noted that in 2005 a ‘curious stone’ was recovered in the Lut desert and subsequent work revealed its extraterrestrial origin.
He went on to remark that, “Three recent short field trips to the central Lut desert led to the collection of several meteoritic fragments, which points to large concentrations of meteoritic materials in the area.” Some of those fragments are shown in the figure below, and the broader region is likely a pertinent place for citizen scientists to continue the hunt for impact craters in Persia.
Pourkhorsandi concluded by telling the Universe Today, “In the future we aim to expand our efforts with the help of additional people, and will direct individuals to scan other regions of the planet. Simultaneously, we have commenced a comprehensive analysis of meteorites in the Lut desert with fellow European scientists.”
H chondrite fragments found in the Lut desert (in Persia) are argued to be extraterrestrial in origin (image credit: Fig. 3 in Pourkhorsandi 2013/LPI).
NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) is slated to lift off from Wallops Island this September 5th in a spectacular night launch. LADEE will be the first mission departing Wallops to venture beyond low Earth orbit. A joint collaboration between NASA’s Goddard Spaceflight Center & the AMES Research Center, LADEE will study the lunar environment from orbit, including its tenuous exosphere.
Scientists hope to answer some long standing questions about the lunar environment with data provided by LADEE. How substantial is the wispy lunar atmosphere? How common are micro-meteoroid impacts? What was the source of the sky glow recorded by the Surveyor spacecraft and observed by Apollo astronauts before lunar sunrise and after lunar sunset while in orbit?
Glows of the solar corona and crepuscular rays reported by the Apollo 17 astronauts in lunar orbit. (Credit: NASA).
The micro-meteoroid issue is of crucial concern for any future long duration human habitation on the Moon. The Apollo missions were only days in length. No one has ever witnessed a lunar sunrise or sunset from the surface of the Moon, as all six landings occurred on the nearside of the Moon in daylight. (Sunrise to sunset on the Moon takes about two Earth weeks!)
And that’s where amateur astronomers come in. LADEE is teaming up with the Association of Lunar & Planetary Observers (ALPO) and their Lunar Meteoritic Impact Search Program in a call to watch for impacts on the Moon. These are recorded as brief flashes on the nighttime side of the Moon, which presents a favorable illumination after last quarter or leading up into first quarter phase.
We wrote recently about a +4th magnitude flash detected of the Moon on March 17th of this year. That explosion was thought to have been caused by a 35 centimetre impactor which may have been associated with the Eta Virginid meteor shower. The impact released an explosive equivalent of five tons of TNT and has set a possible new challenge for Moon Zoo volunteers to search for the resulting 6 metre crater.
An artist’s illustration of a meteoroid impact on the Moon. (Credit: NASA).
We’ve also written about amateur efforts to document transient lunar phenomena and studies attempting to pinpoint a possible source of these spurious glows and flashes on the Moon observed over the years.
NASA’s Meteoroid Environment Office is looking for dedicated amateurs to take part in their Lunar Impact Monitoring campaign. Ideally, such an observing station should utilize a telescope with a minimum aperture of 8 inches (20cm) and be able to continuously monitor and track the Moon while it’s above the local horizon. Most micro-meteoroid flashes are too fast and faint to be seen with the naked eye, and thus video recording will be necessary. A typical video configuration for the project is described here. Note the high frame rate and the ability to embed a precise time stamp is required. I’ve actually run WWV radio signals using an AM short wave radio transmitting in the background to accomplish this during occultations.
Finally, you’ll need a program called LunarScan to analyze those videos for evidence of high speed flashes. LunarScan is pretty intuitive. We used the program to analyze video shot during the 2010 Total Lunar Eclipse for any surreptitious Geminid or Ursid meteors.
Brian Cudnik, coordinator of the Lunar Meteoritic Impact Search section of the ALPO, noted in a recent forum post that we’re approaching another optimal window to accomplish these sorts of observations this weekend, with the Moon headed towards last quarter on June 30th.
An example of an impact flash recorded by the Automated & Lunar Meteor Observatory video cameras based at the Marshall Spaceflight Center in Huntsville, Alabama.
Interestingly, the June Boötids are currently active as well, with historical sporadic rates of anywhere from 10-100 per hour. In 1975, seismometers left by Apollo astronauts detected series of impacts on June 24th thought to have been caused by one of two Taurid meteor swarms the Earth passes through in late June, another reason to be vigilant this time of year.
Don’t have access to a large telescope or sophisticated video gear? You can still participate and make useful observations.
LADEE is also teaming up with JPL and the Lewis Center for Educational Research to allow students track the spacecraft en route to the Moon. Student groups will be able to remotely access the 34-metre radio telescopes based at Goldstone, California that form part of NASA’s Deep Space Communications Network. Students will be able to perform Doppler measurements during key mission milestones to monitor the position and status of the spacecraft during thruster firings.
And backyard observers can participate in another fashion, using nothing more than their eyes and patience. Meteor streams that are impacting the Moon affect the Earth as well. The International Meteor Organization is always looking for information from dedicated observers in the form of meteor counts. The Perseids, an “Old Faithful” of meteor showers, occurs this year around August 12th under optimal conditions, with the Moon only five days past New. This is also three weeks prior to the launch of LADEE.
Whichever way you choose to participate, be sure to follow the progress of LADEE and our next mission to study Earth’s Moon!
-Listen to Universe Today’s Nancy Atkinson and her interview with Brian Day of the NASA Lunar Science Institute.
-Also listen to the 365 Days of Astronomy interview with Brian Day and Andy Shaner from the Lunar Planetary institute on the upcoming LADEE mission.
We love a good space debris mystery. Hey, who doesn’t, right? Regular readers of Universe Today know that it’s a shooting gallery out there, from meteor fireballs caught on dashboard cams to rogue space junk reentries lighting up our skies.
But an unusual story that made its rounds across the internet this past weekend caught our attention. What at first glance was a simple “Man finds space rock” story morphed into an extraordinary claim, which, in the words of the late great Carl Sagan, “demand extraordinary evidence.”
The find was made by Phil Green of Amesbury, Massachusetts. Mr. Green was searching the local riverbed for arrowheads when he came across the unusual find. The black pitted rock immediately struck him as something bizarre. It didn’t register as metallic to his metal detector, but Mr. Green kept it in his backyard for about five years until it was noticed by a friend.
“I didn’t really think much of it, and then a fellow came over, saw it and said that’s a meteor,” Green told local reporters.
From here, the story takes a strange turn. Green told local reporters that the rock was sent off for analysis, only to be returned to him just a few weeks ago. The analysis confirmed that the rock was indeed from space… sort of. It also stated that the vitreous material “shows a composition similar to that used in ballast by the Soviet space program starting in the mid-1980s.”
There are just a few problems with the tale. Mir reentered in 2001, six years before the 2007. A few articles do bother to note this, mentioning that Mir ended its career in the “so-called spacecraft cemetery of the southern Pacific Ocean,” about as far away from Massachusetts as you can get.
A few articles do also mention the possibility of a reentry of a Progress resupply vehicle being a potential source, or perhaps an unrelated Russian space vehicle.
But there seems to be a potential problem of the certification. Several articles state that the piece of debris coming from Mir was “confirmed by NASA.” However, Universe Today contacted NASA Chief Scientist for Orbital Debris Nicholas L. Johnson and NASA Headquarters official Joshua Buck, who both told us that no such NASA validation exists. Mr. Johnson went on to tell Universe Today that, “The NASA Orbital Debris Program Office has not been presented with any claim regarding debris from the Mir space station,” adding “I can tell you that it is not possible for debris from the Mir reentry to have landed in the U.S.”
A name that occasionally turns up in reports online as validating the find (withheld by request) also tells Universe Today that they had nothing to do with the discovery. Mr. Green or the original validation source have thus far been unavailable for comment.
We did uncover two documented reentries that occurred over the general region over the last few decades. One is the reentry of Mir-R 1986-017B (The rocket booster that launched the core module of Mir) seen from a trans-Atlantic airliner on February 24th 1986 about 500 kilometres off of the east coast of Newfoundland. Another possible suspect is the June 26/27th 2004 reentry of a SL-12 auxiliary rocket motor with the NORAD ID 1992-088E, seen to the west from New Jersey to Ontario.
Like the International Space Station, Mir was placed in a 51.6° inclined orbit. This made it accessible from the Baikonur Cosmodrome as well as visits from the U.S. Space Shuttle. Payloads going to and from the station would cover an identical ground track ranging from 51.6° north to south latitude.
The story is also reminiscent of the reentry of debris from Sputnik 4, which struck a small town in Wisconsin in 1962. This was analyzed by mineralogist Ursula Marvin and confirmed to be of Russian origin.
A Progress spacecraft inbound for docking with the International Space Station. (Credit: NASA).
Probably the biggest question in our minds is: what links the object back to an errant Russian spacecraft? What do they use for ballast, anyhow? How did they arrive at the often quoted “85% certainty?” of the object’s origin?
Still, the find does look like something interesting. The pitting and the melted fusion crust are all reminiscent of reentry. We’ll keep researching this story, and for the time being we’ll leave it up to you, the diligent and insightful readers of Universe Today, to make up your own minds on this strange and interesting tale.
A few of the many trees felled by the 1908 Tunguska explosion, photographed in 1929 (Wikipedia Commons)
Last week, Russian researcher Andrei Zlobin announced that stony fragments collected from a riverbed in 1988 are “probably Tunguska meteorites,” and are likely the remains of whatever cosmic object — thought to be either a comet or an asteroid — entered Earth’s atmosphere over the boggy region of Siberia on June 30, 1908, detonating with an estimated force of 5 megatons and leveling over 800 square miles of forest.
So far, definitive pieces of the original object have yet to be found despite numerous expeditions to the remote impact site. In a paper submitted on April 29, Zlobin cites the melted appearance of several stones found at the bottom of the Khushmo River as a good argument to “confirm the discovery” of Tunguska meteorite fragments.
According to Natalya Artemyeva of the Russian Academy of Sciences’ Geosphere Dynamics Institute, however, Zlobin’s claim is “ridiculous.”
In an article published May 4 on RIA Novosti, Artemyeva stated “There are many meteorites on Earth. For 100 plus years since the fall of the Tunguska space body, the weight of meteoric dust and small meteorites that have fallen out in that region has exceeded the mass of Tunguska.”
Stones found by Andrei Zlobin in the Khushmo River (A. Zlobin)
An estimated 100 tons of space debris enters Earth’s atmosphere on a daily basis.
Although Zlobin admits in his submitted paper that “strict confirmation of discovered melted stones as Tunguska meteorites is possible only after attentive chemical analysis of substance,” it seems that he is making rather bold claims based on appearance alone — especially considering the enigmatic and iconic nature of this particular impact event.
“It’s ridiculous,” Artemyeva said. “You can’t say by the appearance of a stone that it’s a meteorite. I don’t think there is ground for scientific discussion here.”
And, according to Artemyeva, even if the stones are found to be actual meteorites, connecting them to the 1908 event will still be a challenge.
Zlobin’s samples, which were in storage until 2008, are still awaiting full chemical analysis.
Read more on RIA Novosti here and on the MIT Technology Review here.
Image of potential meteorite fragments from the Tunguska event, from a paper by Andrei E. Zlobin, 'Discovery of probably Tunguska meteorites
at the bottom of Khushmo river's shoal.'
The 1908 explosion over the Tunguska region in Siberia has always been an enigma. While the leading theories of what caused the mid-air explosion are that an asteroid or comet shattered in an airburst event, no reliable trace of such a body has ever been found. But a newly published paper reveals three different potential meteorite fragments found in the sandbars in a body of water in the area, the Khushmo River. While the fragments have all the earmarks of being meteorites from the event – which could potentially solve the 100-year old mystery — the only oddity is that the researcher actually found the fragments 25 years ago, and only recently has published his findings.
Like the recent Chelyabinsk airburst event, the Tunguska event likely also produced a shower of fragments from the exploding parent body, scientists have thought. But no convincing evidence has ever been found from the June 30, 1908 explosion that occurred over the Tunguska region. The explosion flattened trees in a 2,000 square kilometer area. Luckily, that region was largely uninhabited, but reportedly one person was killed and there were very few people that reported the explosion. Forensic-like research has determined the blast was 1,000 times more powerful than a nuclear bomb explosion, and it registered 5 on the Richter scale.
Previous expeditions to the region turned up empty as far as finding meteorites; however one expedition in 1939 by Russian mineralogist Leonid Kulik found a sample of melted glassy rock containing bubbles, which was considered evidence of an impact event. But the sample was somehow lost and has never undergone modern analysis.
The expedition in 1998 by Andrei Zlobin from the Russian Academy of Sciences was initially unsuccessful in finding meteorites or evidence of impacts. He made several drill holes in the peat bogs in the area and while he found evidence of the explosion, he didn’t find any meteorites. He then decided to look in the nearby river shoal.
Zlobin gathered about 100 samples of rocks that had features of potential meteorites, but further examination produced just three rocks with tell-tale features like melting and regmalypts – the , thumblike impressions found on the surface of meteorites which are caused by ablation as the hot rock falls through the atmosphere at high speed.
Zlobin writes that “After the expedition the author focused his efforts on experimental investigation of thermal processes and mathematical modeling of the Tunguska impact [Zlobin, 2007],” and he used tree ring evidence to estimate the temperatures from the event, and concluded that rocks already on the ground would not have been changed or melted from the blast, and therefore any rocks having evidence of melting should be from the impactor itself.
Zlobin says he has not yet carried out a detailed chemical analysis of the rocks, which would reveal their chemical and isotopic composition. But he does say the stony fragments do not rule out a comet since the nucleus could easily contain rock fragments. However, he has calculated the density of the impactor must have been about 0.6 grams per cubic centimeter, which is about the same as nucleus of Halley’s comet. Zlobin says that initially, the evidence seems “excellent confirmation of cometary origin of the Tunguska impact.”
While there is nothing definitive yet from Zlobin’s new paper – and there is the question of why he waited so long to conduct his study – his work provides hope for a better explanation of the Tunguska event as opposed to some rather off-the-wall ideas that have been proposed, such as a Tesla death-ray or an explosion of methane gas from the bogs.
The Technology Review blog writes that “clearly there is more work to be done here, particularly the chemical analysis perhaps with international cooperation and corroboration.”
A hole from a meteorite in the Space Station's solar array
Canadian astronaut and Expedition 35 commander Chris Hadfield just shared this photo on Twitter, showing a portion of one of the solar array wings on the ISS… with a small but very visible hole made by a passing meteoroid in one of the cells.
In typical poetic fashion, Commander Hadfield referred to the offending object as “a small stone from the universe.”
“Glad it missed the hull,” he added.
Hole in an ISS solar cell made by a meteoroid
While likened to a bullet hole, whatever struck the solar panel was actually traveling much faster when it hit. Most bullets travel at a velocity of around 1,000-2,000 mph (although usually described in feet per second) but meteoroids are traveling through space at speeds of well over 25,000 mph — many times faster than any bullet!
Luckily the ISS has a multi-layered hull consisting of layers of different materials (depending on where the sections were built), providing protection from micrometeorite impacts. If an object were to hit an inhabited section of the Station, it would be slowed down enough by the different layers to either not make it to the main hull or else merely create an audible “ping.”
Unnerving, yes, but at least harmless. Still, it’s a reminder that the Solar System is still very much a shooting gallery and our spacefaring safety relies on the use of technology to protect ourselves.
Image: NASA / Chris Hadfield
Fact: The 110 kilowatts of power for the ISS is supplied by an acre of solar panels!
Composite Spitzer, Hubble, and Chandra image of supernova remnant Cassiopeia A. A new study shows that a supernova as far away as 50 light years could have devastating effects on life on Earth. (NASA/JPL-Caltech/STScI/CXC/SAO)
“The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth,” Carl Sagan famously said in his iconic TV series Cosmos. But when two of those grains are made of a silicon-and-oxygen compound called silica, and they were found hiding deep inside ancient meteorites recovered from Antarctica, they very well may be from a star… possibly even the one whose explosive collapse sparked the formation of the Solar System itself.
Researchers from Washington University in St. Louis with support from the McDonnell Center for the Space Sciences have announced the discovery of two microscopic grains of silica in primitive meteorites originating from two different sources. This discovery is surprising because silica — one of the main components of sand on Earth today — is not one of the minerals thought to have formed within the Sun’s early circumstellar disk of material.
Instead, it’s thought that the two silica grains were created by a single supernova that seeded the early solar system with its cast-off material and helped set into motion the eventual formation of the planets.
According to a news release by Washington University, “it’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”
A 3.5-cm chondrite meteorite found in Antarctica in Nov. 1998. Dark meteorites show up well against the icy terrain of Antarctica. (Carnegie Mellon University)
Until the 1960s most scientists believed the early Solar System got so hot that presolar material could not have survived. But in 1987 scientists at the University of Chicago discovered miniscule diamonds in a primitive meteorite (ones that had not been heated and reworked). Since then they’ve found grains of more than ten other minerals in primitive meteorites.
The scientists can tell these grains came from ancient stars because they have highly unusual isotopic signatures, and different stars produce different proportions of isotopes.
But the material from which our Solar System was fashioned was mixed and homogenized before the planets formed. So all of the planets and the Sun have the pretty much the same “solar” isotopic composition.
Meteorites, most of which are pieces of asteroids, have the solar composition as well, but trapped deep within the primitive ones are pure samples of stars, and the isotopic compositions of these presolar grains can provide clues to their complex nuclear and convective processes.
The layered structure of a star about to go supernova; different layers contain different elements (Wikimedia)
Some models of stellar evolution predict that silica could condense in the cooler outer atmospheres of stars, but others say silicon would be completely consumed by the formation of magnesium- or iron-rich silicates, leaving none to form silica.
“We didn’t know which model was right and which was not, because the models had so many parameters,” said Pierre Haenecour, a graduate student in Earth and Planetary Sciences at Washington University and the first author on a paper to be published in the May 1 issue of Astrophysical Journal Letters.
Under the guidance of physics professor Dr. Christine Floss, who found some of the first silica grains in a meteorite in 2009, Haenecour investigated slices of a primitive meteorite brought back from Antarctica and located a single grain of silica out of 138 presolar grains. The grain he found was rich in oxygen-18, signifying its source as from a core-collapse supernova.
Finding that along with another oxygen-18-enriched silica grain identified within another meteorite by graduate student Xuchao Zhao, Haenecour and his team set about figuring out how such silica grains could form within the collapsing layers of a dying star. They found they could reproduce the oxygen-18 enrichment of the two grains through the mixing of small amounts of material from a star’s oxygen-rich inner zones and the oxygen-18-rich helium/carbon zone with large amounts of material from the outer hydrogen envelope of the supernova.
In fact, Haenecour said, the mixing that produced the composition of the two grains was so similar, the grains might well have come from the same supernova — possibly the very same one that sparked the collapse of the molecular cloud that formed our Solar System.
“It’s a bit like learning the secrets of the family that lived in your house in the 1800s by examining dust particles they left behind in cracks in the floorboards.”
Ancient meteorites, a few microscopic grains of stellar sand, and a lot of lab work… it’s an example of cosmic forensics at its best!
