Discovery of DNA components in meteorites

In this update are talking about the carbonaceous chondrites and ureilite.

• Carbonaceous chondrites or C chondrites are meterorites of 7 known and many unknown groups. Ureilite is a rare type of stony meteorite that has a unique mineralogical composition very different from that of other stony meteorites.

Both of them are rich on organic material.

• The notable carbonaceous chondrites are: Allende, Murchison, Orgueil, Ivuna, Murray, and Tagish Lake, while notable ureilites are the Novo Urei and the Goalpara.

• You must note that Goalpara is an Ureilite landed in town Goalpara of Assam in India.

Similarly, in 2008, a tiny asteroid 2008 TC3 entered Earth’s atmosphere and exploded an estimated 37 kilometres above the Nubian Desert in Sudan. Fragments of this asteroid were recovered the following December and were found to be ureilite.

• It was reported that the scientists have discovered amino acids, the building blocks of life in this meteorite 2008 TC3 where none were expected taking into account the high temperatures reached in the explosion about 1000 °C.

  Recently, a NASA-funded study was published in the Proceedings of the National Academy of Sciences.

As per this study, the scientists used advanced mass spectrometry instruments to scan 11 organic-rich meteorites called carbonaceous chondrites and one ureilite. The study found three nucleobases — purine, 6,8-diaminopurine and 2,6-diaminopurine — that are widely distributed in carbonaceous chondrites.

• These nucleobases are rare or absent in terrestrial biology.
• These components of DNA, the building blocks of life on Earth, in meteorites, is a discovery that, as per these scientists, confirms the theory that at least some of the materials needed to make early life forms came to our planet from space.

  Allan Hills 84001 Please note that the most news making meteorite was Allan Hills 84001, which was found in Allan Hills of Antarctica in 1984. It consisted of fossiled nanobacteria of 20-100 nanometres in diameter, similar in size to the theoretical nanobacteria, but smaller than any known cellular life at the time of their discovery.

Month: Current Affairs - October, 2011