Talampaya

March's Meteorite of the Month is Talampaya, an achondrite that fell in Argentina, in 1995.

According to the Meteoritical Bulletin (MB 83): 

Stories circulating among meteorite dealers tell of a meteorite that fell in Argentina, producing a sonic boom that scared a mountain climber. The climber eventually found the meteorite somewhere down range. The location of the fall may have been in San Juan or La Rioja province.  One 1421 gram stone was recovered, and sold in the United States.

Talampaya is a cumulate eucrite, and part of the HED (Howardite-Eucrite-Diogenite) meteorite group, believed to have formed on the surface of asteroid 4-Vesta.
Talampaya

Photo © ASU/CMS/Garvie.

Eucrites are the most common type of achondrite meteorite falls (vs. finds) and are believed to have formed from the cooling of magma on the surface of the Asteroid 4-Vesta; the number 4 refers to Vesta being the fourth asteroid ever discovered, in March of 1807, by German astronomer Heinrich Wilhelm Olbers.

In September 2007, NASA launched the Dawn mission to study Vesta and the dwarf planet Ceres to provide insight into the formation and evolution of solid bodies in the early solar system, using a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer.

Dawn stayed in orbit around Vesta for a year, thoroughly studying the asteroid's geology, chemistry and more; insights gained there helped build the link between Vesta and the howardite-eucrite-diogenite (HED) class of meteorites. 

Thika

Thika is an ordinary (L6) chondrite that fell in central Kenya the morning of July 16, 2011.

According to the Meteoritical Bulletin (MB 100):

A bright fireball in multiple pieces was observed from southern Kenya traveling to the northwest around 10 am on the July 16, 2011. Residents around Kiambu County in the Thika District reported multiple loud explosions and loud screaming noises, with ground shaking. The first piece (~2.5 kg) landed within 1 m of a woman tilling her field in the village of Kihum Wiri (also spelled Kiumwiri). This meteorite was subsequently removed by the military and taken to the University of Nairobi. Multiple pieces were then found in the nearby village of Mwana Wikio. Two meteorites smashed through greenhouses in Mwana Wikio and one through a house in nearby Muguga village. Stones were recovered from a 7.7 × 1.6 km strewnfield bearing N30°W. The main mass, 3.575 kg, was found outside Rose Kamande’s house in Kihum Wiri the day after the fall. Total known mass is currently 14.2 kg totaling 14 individuals, distributed primarily as large stones, e.g., 3575 g, ~2.5 kg, 1.75 kg and 1.3 kg. Only a few small stones have so far been recovered. All stones were recovered before rainfall.

Classification of Thika, which is an L6 chondrite, was performed by Laurence Garvie at the ASU Center for Meteorite Studies.

Thika

Nakhla

Nakhla is a martian achondrite that fell June 28th, 1911, in Al Buhayrah, Egypt.  Nakhla is one of only 5 martian meteorites to be witnessed as it fell to Earth.

At the time of the fall, a newspaper article was published claiming the meteorite had hit a dog on entry.  This was never proven, but did inspire a Peanuts cartoon strip, in which Linus and Charlie Brown discuss the meteorite striking a dog, to Snoopy’s dismay.

Members of the Center for Meteorite Studies are interested in deciphering the geologic history and evolution of Mars through trace element and isotopic studies of the martian meteorites, and Nakhla has been actively studied by Center researchers, including:

  • Determining redox conditions in the mantle and crust on Mars through studies of rare earth element abundances, as well as the early differentiation history of Mars through investigations of the 146Sm-142Nd and 182Hf-182W short-lived isotope systems in the martian meteorites.
  • Constraining the composition of aqueous crystal fluids on Mars through analysis of the boron isotope composition of the Nakhla meteorite.
  • Utilizing the hydrogen isotope composition of the martian meteorites, determined using secondary ion mass spectrometry, to provide unique insights into the history of water on Mars and alteration of the martian crust.

Nakhla is the namesake for the nakhlite meteorite type group, made up of 14 distinct meteorites, and defined by the Meteoritical Society as clinopyroxenites or wehrlites formed as cumulate rocks.

Currently,  Ph.D. candidate Curtis Williams is analyzing the lithium isotope composition of the martian meteorites, while Ph.D. candidate Prajkta Mane and M.S. student Kera Tucker are

Photo by L. Garvie, © ASU/CMS.

Nakhla

Krähenberg

Krähenberg is an ordinary (LL5) chondrite that fell May 5, 1868, in the Rheinland-Pfalz region of Germany.  The meteorite’s fall to Earth was well-witnessed, and described by English chemist Walter Flight in his 1875 publication History of Meteorites:

"A single stone was seen to fall, the sky being clear and bright.  The noise of the explosion is described as having been louder than that of a cannon; this was followed by one resembling a roll of musketry, terminating with a sound as of the rushing steam from a locomotive; the tone of the last sound increased in pitch, and abruptly ended with another loud noise."

He goes on to say that the 33-lb Krähenberg meteorite hit the ground within a few feet of a little girl, making a “perfectly vertical” hole almost 4 feet deep.

Image from http://commons.wikimedia.org/wiki/File:Meteorit_von_Kr%C3%A4henberg.jpg
Image from http://commons.wikimedia.org/wiki/File:Meteorit_von_Kr%C3%A4henberg.jpg

Camel Donga

Camel Donga is an achondrite found on the Nullarbor Plain of Western Australia in 1984.  The word "donga" is a term for "campsite" in Australia.

Camel Donga is a eucrite (monomict breccia), part of the HED group of meteorites (Howardites-Eucrites-Diogenites).  These meteorites are believed to originate from the cooling of magma on the surface of asteroid 4-Vesta. 

Photo © ASU/CMS.

Camel Donga