Chondrites are rocky meteorites with mysterious spheres known as chondrules. Chondrules, consisting of
Meteorites have bombarded the Earth from the very beginning, andsome of the first objects to fall may have included carbonaceous chondrites, a relatively rare subcategory of chondrites containing significant amounts of water and small molecules, including amino acids.
Under the direction of cosmochemist Yoko Kebukawa fromYokohama National University researchers sought to address the issues of previous laboratory experiments examining the potential formation of amino acids on carbonaceous chondrites.
These experiments showed that simple molecules,such as ammonia and formaldehyde can generate amino acids, but only in the presence of heat and liquid water. In a new study, researchers are investigating a possible heat source from a meteorite: gamma rays.
It is known that early carbonaceous chondritescontained aluminum-26, a radioactive element that can emit gamma radiation when it decays. Kebukawa and her colleagues set out to see if this could provide the heat needed to form amino acids.
The researchers dissolved ammonia and formaldehyde inwater, sealed the resulting solution in glass tubes, and then exposed the tubes to high-energy gamma radiation from decaying cobalt-60.
As the dose of gamma radiation increasesincreased production of α-amino acids such as alanine, α-aminobutyric acid and glutamic acid, as well as β-amino acids such as β-alanine and β-aminoisobutyric acid.
The researchers note that these amino acids may help explain the presence of these amino acids in carbonaceous chondrites that have fallen to Earth, such as Australia's famous Murchison meteorite.
Murchison meteorite filled with "presolar"particles of silicon carbide (meaning they are older than the Sun) exploded in the sky over Murchison, Victoria on September 28, 1969. This event was widely observed; subsequently, people collected many fragments in the area. It has since become one of the most studied space rocks in history.
Among many interesting finds, the Murchison meteorite was filled with amino acids. To date, scientists have identified more than 70 amino acids from the meteorite, only 19 of which are known from Earth.
Read more:
Scientists from the permafrost zone: how they develop smart clothes and a cancer vaccine
Two planets have been found not far from Earth. Perhaps they are inhabited
Scientists have found out who benefited from the death of dinosaurs