New Trove of Iron Meteorites

Landsat spacecraft made orbital imagery of Earth readily accessible to the public in the 1970s, and ever since then space-age prospectors have pored over satellite photos in the hope of identifying new impact craters on our planet's surface. Usually these "discoveries" prove to be false alarms — Mother Nature has lots of ways of making circular holes in the ground.

Kamil crater in southern Egypt
The pristine-looking Kamil crater, discovered in February 2009, is about 184 feet across and 50 feet deep (though its floor is thickly blanketed with sand.
Univ. of Siena / Museo Nazionale dell'Antartide
But the search goes on, and in February 2009 Vincenzo De Michele (Istituto Gemmologico Italiano) hit paydirt, both figuratively and literally. He used Google Earth aerial-survey imagery to identify an astrobleme in southern Egypt's East Uweinat Desert, near the Sudan border. (For the curious, the exact coordinates are 22° 1′ 6″ north, 26° 5′ 16″ east.; click here for a Google's-eye view.)

The aerial photography and De Michele's search were part of a year-long cooperative science effort among Italian and Egyptian researchers. Last February a field expedition visited the site, where team members found not only a remarkably fresh impact crater but also a scene littered with tons of meteorites. Score!

Owing to erosion by wind, water, and geologic mayhem, it's a rare to find evidence of cosmic collision on our planet. Only about 175 confirmed craters are known, and most of them retain little of their original character. But the new Kamil crater is so fresh that bright-hued splashes of ejected debris still paint the desert surface. The researchers, led by Luigi Folco (Museo Nazionale dell'Antartide, Siena, Italy), are still analyzing the details they gathered on site; a quick status report appears in July 22nd's edition of Sciencexpress.

The Kamil crater has a classic bowl shape, with a blocky, upraised rim about 10 feet (3 m) high. It's about 50 feet deep, though a thick layer of sand blankets the interior floor. Folco and his team estimate that the cosmic cannonball was an iron mass about 5 feet (1.3 m) across, weighing roughly 10 tons, that struck the desert at 2.2 miles (3.5 km) per second.

Gebel Kamil meteorite
The largest known piece from the Gebel Kamil meteorite field, found 750 feet north of the crater, weighs 183 pounds (83 kg). The characteristic dimples on its exterior, called regmaglypts, are caused by uneven ablation as the iron meteorite raced through the atmosphere.
Univ. of Siena / Museo Nazionale dell'Antartide
The original meteoroid might have been up to four times more massive and traveling five times faster before it crashed through the atmosphere. In any case, when that whittled-down chunk of iron hit, it exploded with the power of 13 tons of TNT, spraying thousands of pieces around the scene. Folco's team identified 5,178 meteoritic fragments totaling 1.7 tons — the biggest single specimen weighs 183 pounds (83 kg) — but undoubtedly far more await discovery.

Officially named Gebel Kamil, the meteorites have already made news among collectors. The shiny, metallic interiors don't show the regular pattern of interlocking crystals typical of many other iron meteorites, likely due to the high nickel content (20%).

Well-connected dealers are already offering Gebel Kamil slices for about $10 per gram — pricey for a common iron meteorite but perhaps understandable given the heady buzz surrounding this new find.

I'm tempted to grab one, but for now I'll just window-shop. All the Kamil Gebel pieces now on the market have been collected illegally, according to expedition member Giancarlo Negro. "In fact, after our February 2010 mission, all the area was declared off limits by military authorities," and since then no one has been given permission to collect meteorites there.

The research team's website showcases many photos from their desert conquest.

9 thoughts on “New Trove of Iron Meteorites

  1. MikeG

    Nobody is exactly sure how old the crater is, but it’s probably quite recent in geological terms. Judging by the level of weathering on the specimens, I’d guess the impact took place in the lasr few thousand years.

    http://www.galactic-stone.com

  2. Alan MacRobert/ Sky & Tel

    Probably within the last 5,000 years, says Folco.

    — Alan MacRobert

  3. A.A.Schaller

    This is a spectacular find. Intriguingly, in the Google-Earth images there appears to be a pattern of secondary craters or pits, especially to the northeast. Another batch appear to be associated with a ray extending toward the east-southeast, where there appears to be a CHAIN of secondaries near the terminus of that ray. The putative secondaries also appear to be associated with light-colored ‘halos’ of their own. The ray pattern with a pronounced zone of avoidance sector with its axis to the east-northeast also suggests the impactor approached at a significantly low angle from the east-northeast. Judging from the fact that the rays and (apparent) secondaries are as well-preserved as they are, it wouldn’t be far fetched to suppose that the impact may have occurred well within the last 1000 years. An age much above a few thousand years would probably by now have obliterated the ray system. Craters are natural sand traps, and this area has probably seen hundreds of major sandstorms in the last several centuries. It seems quite plausible that aeolian transport could have deposited that amount of sand in the main crater over half a dozen centuries or so without having completely erased the ray pattern or secondaries surrounding it.

  4. Mike Boschat

    Well, the meteorite collecting vultures can’t wait to get their greedy hands on these meteorites…these countries
    were meteorites have fallen should put a extreme strict law
    to protect THIER meteorites and place them in a museum
    for the people. The fines should be 2-3 years in prison and $50,000 fine for collectors being greed vultures!

    Mike

  5. robert hunter

    I realize that this is against very, very long odds, but I can not help but notice that the Kamil crater is directly beneath the path of the tiny asteroid that struck Sudan in October 6-7, 2008.

    It’s a different type of meteorite too.

    Is it conceivable that two objects struck the Egypt- Sudan border that night? Many, many times I’ve seen double meteors; close in space or very close in time.

    Surely there must be some aerial photography of this area pre-2007.

    Please forward this comment to Mr. Jenniskens. Thank you.

  6. Phil

    @Robert, it’s definitely not from the same event as the 2008 Sudan impact. First, you can see from the weathering and crater sand-filling that the Egyptian event was more than 2 years old. Second, the Sudan event was a different composition body (stony) that exploded at altitude, leaving no crater, while the Egyptian event (iron-nickel) dug a crater (it’s unlikely that two bodies of very different composition would be traveling together). Third, two separate bodies would have been noticed in the photos of the incoming asteroid (if a near-simultaneous impact). Fourth, the impact would have been big enough to be picked up by seismographs.

    The Kamil event is quite ‘fresh’. In a desert, with a low rate of weathering, it’s difficult to tell how old something like that is, unless there’s the remains of some unfortunate camel (no pun intended) at the bottom of the pit that could provide C14 dating. But, “the last few thousand years” looks like a good guess. Perhaps archeologists and anthropologists could comb inscriptions and tribal histories to see if there’s any record of someone having seen this thing. Perhaps some dating (fission track or optically stimulated luminescence?) can be done on local rock melted by the impact.

  7. MikeG

    First, the Gebel Kamil meteorites on the market are LEGAL. The member of the Italian team who claims otherwise is speaking out of ignorance and sour grapes.

    Second, the comment above by Mike Boschat is uneducated and hostile. He apparently knows NOTHING about meteorites, meteorite collectors, or the meteorite market. Mr. Boschat, before spreading your hateful and ignorant comments, do your homework and know the facts.

    Meteorite collectors have contributed much to science and many scientists will tell you that.

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