A meteorite found in Antarctica could lend weight to the argument that life on Earth was aided by an extraterrestrial body, scientists claim. Chemical analysis of the meteorite shows it to be rich in the gas ammonia, which contains the element nitrogen - found in the amino and nucleic acids which form the basis of life. Read more
We came from outer space. Well, at least a key ingredient of our proteins - the meat and sinew of our bodies - did, a new study suggests. The paper analysed dust ground up from an Antarctic meteorite, which crashed to Earth billions of years ago, and found it contained a type of nitrogen that could form the basic building blocks of proteins. Read more
'Life chemicals' may have formed around far-flung star
There is now even more evidence that life on Earth may have been seeded by material from asteroids or comets. Prior research has shown how amino acids - the building blocks of life - could form elsewhere in the cosmos. These molecules can form in two versions, but life on Earth exclusively uses just one of them. Now an Astrophysical Journal Letters paper shows how conditions around a far-flung star could favour the formation of one type over another. Read more
A wider range of asteroids were capable of creating the kind of amino acids used by life on Earth, according to new NASA research. Amino acids are used to build proteins, which are used by life to make structures like hair and nails, and to speed up or regulate chemical reactions. Amino acids come in two varieties that are mirror images of each other, like your hands. Life on Earth uses the left-handed kind exclusively. Since life based on right-handed amino acids would presumably work fine, scientists are trying to find out why Earth-based life favoured left-handed amino acids. Read more
In sci-fi movies, the first stirrings of life happen in a gooey pool of primordial ooze. But new research suggests the action started instead in the stormy skies above. The idea sprang from research led by University of Arizona's Sarah Hörst. Her team recreated, in the lab, chemical reactions transpiring above Saturn's largest moon, Titan. Read more
Building Blocks of Life Created in "Impossible" Place
NASA-funded scientists have discovered amino acids, a fundamental building block of life, in a meteorite where none were expected.
"This meteorite formed when two asteroids collided. The shock of the collision heated it to more than 2,000 degrees Fahrenheit, hot enough that all complex organic molecules like amino acids should have been destroyed, but we found them anyway. Finding them in this type of meteorite suggests that there is more than one way to make amino acids in space, which increases the chance for finding life elsewhere in the Universe" - Dr. Daniel Glavin of NASA's Goddard Space Flight Centre, Greenbelt, Md.
Glavin is lead author of a paper on this discovery appearing December 15 in Meteoritics and Planetary Science.
PSI Research Points to Better Understanding of Carbon in Comets
Using a comet as a far-flung laboratory, a Planetary Science Institute researcher has shown that the ionisation lifetime of carbon is much shorter than what is currently used in calculations by comet scientists. An accurate ionisation lifetime is critical to understanding the amount of carbon released from comets, said Jeff Morgenthaler, senior scientist at PSI. A shorter lifetime suggests that the carbon content of some comets may be lower than previously estimated. This work could affect current ideas about where comets formed in the early solar system and the role they may have played in bringing the seeds of life to Earth. Read more
Many molecules are chiral, which means they have two possible forms that are non-superimposable mirror images of each other, just like your left and right hand. But in the amino acids and sugars that make up living things, we find only one of these forms--and young chemist Abigail Hubbard wants to know why. She's keen to pick Jack Szostak's brain on the source of this "homochirality," a subject close to Jack's own research into the origin of life on Earth. Read more
A mysterious bias in the way the building blocks of proteins twist could be due to supernovae, researchers now suggest. If correct, this could be evidence that the molecules of life weren't created on Earth, but came from elsewhere in the cosmos. Organic molecules are often chiral, meaning they come in two versions that are mirror images of each other, much as right and left hands appear identical but possess reversed features. Read more
The Secret of Life May Be As Simple As What Happens Between Mica Sheets
That age-old question, "where did life on Earth start?" now has a new answer. If the life between the mica sheets hypothesis is correct, life would have originated between sheets of mica that were layered like the pages in a book. The so-called "life between the sheets" mica hypothesis was developed by Helen Hansma of the University of California, Santa Barbara, with funding from the National Science Foundation (NSF). This hypothesis was originally introduced by Hansma at the 2007 annual meeting of the American Society for Cell Biology, and is now fully described by Hansma in the September 7, 2010 issue of Journal of Theoretical Biology. Read more