Citizen Scientists Hunt for Impact Craters in Persia

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.

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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.”

"Fragments of a H5 chondrite in the field. The scale." from Pour/arXiv.
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).

H. Pourkhorsandi’s findings were shown at the 44th Lunar and Planetary conference in Texas, and will be presented at the upcoming Large Meteorite Impact and Evolution V conference.  That latter conference will feature the latest results concerning the cratering process, and a description of the science program is available here.  Copies of H. Pourkhorsandi and H. Mirnejad’s conference submissions are available via the LPI and arXiv.   Those readers interested in joining H. Pourkhorsandi’s effort, or desiring additional information, may also find the following pertinent: the Earth Impact DatabaseRampino and Haggerty 1996, “Collision Earth! The Threat from Outer Space” by P. Grego, NASA’s projects for Citizen Scientists.

Oldest Impact Crater on Earth Discovered in Greenland

Artistic expression of large meteorite impact
An artistic expression of how a large meteorite impact into the sea might have looked in the first second of the impacting. We do not know if the area that was hit was actually covered by water or if there was just a sea nearby. Source: Carsten Egestal Thuesen, GEUS

With shifting continents, rain, and wind, finding traces of ancient impact craters on Earth has been, literally, astronomically low. Now, an international team of scientists say they have found a massive impact crater in Greenland a billion years older than other known asteroid impact on Earth.

Scientists found the remains of the giant 100-kilometer (62 mile) wide crater near the Maniitsoq region of West Greenland and they believe it’s three billion years old. The largest and previously oldest known crater is the 300 kilometer-wide Vredefort crater in South Africa. Tipped on its side, the edges of the Maniitsoq crater would extend from the surface of the Earth to the edge of space.

“This single discovery means that we can study the effects of cratering on the Earth nearly a billion years further back in time than was possible before,” according to Dr. Iain McDonald of the School of Earth and Ocean Sciences at Cardiff University, who was part of the team.

Finding the crater wasn’t an easy task. Today, the Moon still shows marks of the massive bombardment that took place between three and four billion years ago. The early Earth, with its greater gravitational attraction, would have experienced even more collisions. But the land around Maniitsoq has been eroded over the eons to expose crust that originally was 25 kilometers (16 miles) below the surface. Effects of the immense shockwave produced on impact penetrated deep into the crust and remain visible.

Evidence at that depth had never been observed before, says McDonald. “The process was rather like a Sherlock Holmes story,” said McDonald. “We eliminated the impossible in terms of any conventional terrestrial processes, and were left with a giant impact as the only explanation for all of the facts.”

Only about 180 impact craters have been discovered on Earth. Around 30 percent of them contain important natural resources, including nickel, gold, oil and natural gas. It was during an exploration of natural resources that evidence for the crater was discovered. “It has taken us nearly three years to convince our peers in the scientific community,” said McDonald. “But the mining industry was far more receptive. A Canadian exploration company has been using the impact model to explore for deposits of nickel and platinum metals at Maniitsoq since the autumn of 2011.”

The international team, led by Adam Garde, a senior research scientist at the Geological Survey of Denmark and Greenland, or GEUS, contains members from Cardiff, Lund University in Sweden, and the Institute of Planetary Science in Moscow. Their work was recently published in the jounal Earth and Planetary Science Letters.

Image caption: An artistic expression of how a large meteorite impact into the sea might have looked in the first second of the impacting. We do not know if the area that was hit was actually covered by water or if there was just a sea nearby. Source: Carsten Egestal Thuesen, GEUS

Map caption: Black circle on map shows the location of the meteorite impact structure near the town Maniitsoq in Greenland.

Read more about the Maniitsoq structure.

Impact in Latvia Creates 20-Meter Crater

Latvia crater. Credit: Delfi

A possible meteorite fall near in northern Latvia on Sunday left a crater approximately 20 meters (66 feet) in diameter and 10 meters (33 feet) deep. UPDATE: Many reports now say the impact was a fake; The Bad Astronomer says “shovel” marks were found around the perimeter of the crater; additionally, a burning impactor is highly unlikely (see video below). And here’s an article from the Associated press. , and another from Yahoo news, where a phone company in Latvia admits the “crater” was a publicity stunt.

Our earlier report:
No one was injured, as the impact occurred outside the small town of Mazsalaca, although houses were nearby. Early reports said it was not clear whether it was an asteroid or a space satellite, but later news indicated it was a meteorite strike. Another account said it might be a hoax, as a cover-up of illegal weapons tests. One report said a witness saw the object falling through the sky, leaving a burning trail behind, and said it was making a noise similar to the one of an aircraft flying at a low altitude. See a video of the crater below.

A spokesperson for the Latvian State Fire and Rescue Service said that rescuers and soldiers immediately cordoned off the territory, as they wanted to guard against any radioactive contamination if it was a satellite.

See this link for more images of the crater.

We’ll post more news about the crater as it becomes available.

Sources: RiaNovosti, ITAR-TASS

Hat tip to @cosmos4U on Twitter