Comets and other celestial travelers carry ingredients that can help kick-start life on planets, according to a team of British and American scientists.
The scientists from Imperial College London
, The University of Kent
and the U.S. Department of Energy’s Lawrence Livermore National Laboratory
say they’ve discovered
a cosmic factory for producing amino acids
, which are considered to be the building blocks of life.
According to the researchers, those potential life-producing amino acids are formed when an icy comet
smashes into a planet or a rocky meteorite
collides with an ice covered planet.
The new findings provide additional clues as to how life began on Earth
some 3.8 to 4.5 billion years ago, when our planet was frequently being blasted with comets and meteorites.
"This process demonstrates a very simple mechanism whereby we can go from a mix of simple molecules
, such as water and carbon dioxide ice, to a more complicated molecule, such as an amino acid,” said co-author Mark Price from the University of Kent
. “This is the first step towards life. The next step is to work out how to go from an amino acid to even more complex molecules such as proteins.”
The researchers found a shock wave
is generated when a comet collides with a planet. That shock wave produces the kind of molecules needed to form amino acids.
Enceladus, one of moons of Saturn, as seen by NASA's Cassini spacecraft. (NASA)
"Our work shows that the basic building blocks of life can be assembled anywhere in the Solar System
and perhaps beyond. However, the catch is that these building blocks need the right conditions in order for life to flourish,” said co-author Zita Martins from Imperial College London. “Excitingly, our study widens the scope for where these important ingredients may be formed in the Solar System and adds another piece to the puzzle of how life on our planet took root."
To make their findings, the scientists recreated a comet’s collision with a planet by firing projectiles into mixtures of ice that were similar to the composition of a comet.
They said the impacts resulted in the production of amino acids like glycine
and D and L-alanine
The research team said that they also thought a couple of distant ice covered moons-- Enceladus
, which orbits Saturn, and Europa
which circles Jupiter--could both provide perfect settings for producing amino acid when meteorites smash into them.
The findings could provide support for future missions to the faraway moons to look for signs of life.