Shergotty (meteorite)

Fragment of the meteorite

Shergotty is a Mars meteorite , which in 1865 Shergotty ( India struck). He is the prototype for the Shergottite . Its geological age is dated to around 4.1 billion years.

history

The meteorite struck Shergotty (today Sherghati in the Indian state of Bihar ) on the morning of August 25, 1865 and was recovered by eyewitnesses shortly afterwards. Its original total mass should have been around 5 kilograms. Radiometric dating suggests that it formed from volcanic magma about 4.1 billion years ago . It consists largely of pyroxenes , which do not occur in this special composition on earth.

Determining its crystallization age is extremely difficult. Previous analyzes have shown different ages between 147 and 600 million years. The impact on Mars, which hurled the meteorite from the Martian soil into space, is likely to have occurred around 2.2 to 2.8 million years ago. What is certain is that it was the same impact event that hurled the meteorites QUE 94201 and Zagami to earth.

Today the main piece of the meteorite (≈3.6 kg) is in the Geological Survey of India ( Calcutta ). It is not known what happened to the second of the two original fragments.

Classification

It is the prototype of the Shergottite in the classification of Martian meteorites.

Signs of water

As previously demonstrated in the Nakhla meteorite, traces can also be found on Shergotty, which can only have been created over centuries by the presence of liquid water.

Signs of life

Signs of fossilized biofilms as they also occur on earth have been found. However, neither earthly contamination can be ruled out, nor do these traces prove a microbiological origin.

literature

Gustav Tschermak : The meteorites of Shergotty and Gopalpur , Imperial Academy of Sciences , Vienna 1872 ( online )

Individual evidence

↑ ^a ^b Audrey Bouviera, Janne Blichert-Tofta, Francis Albarèdea: Martian meteorite chronology and the evolution of the interior of Mars . In: ScienceDirect . April 15, 2009, doi : 10.1016 / j.epsl.2009.01.042 (English, sciencedirect.com ).
↑ ^a ^b V. Shergotty. In: Mars Meteorite Compendium 2003. NASA , January 1, 2003, accessed October 22, 2014 .
^ ^A ^b Evidence for ancient martian life. NASA / JPL , accessed October 21, 2014 .

[:0-1] Audrey Bouviera, Janne Blichert-Tofta, Francis Albarèdea: Martian meteorite chronology and the evolution of the interior of Mars . In: ScienceDirect . April 15, 2009, doi : 10.1016 / j.epsl.2009.01.042 (English, sciencedirect.com ).

[:2-2] V. Shergotty. In: Mars Meteorite Compendium 2003. NASA , January 1, 2003, accessed October 22, 2014 .

[:1-3] A ^b Evidence for ancient martian life. NASA / JPL , accessed October 21, 2014 .