Scientists have proposed that the primitive life forms on terrestrial planets can be ejected into space from where they would be carried to the other planets, and moons of the Jupiter and Saturn to generate life. This report is supporting the concept of lithopanspermia.
[sociallocker]arXiv – accepted for publication in Astrobiology
In the present study, scientists performed simulations to find the places where the rocks and other small celestial bodies would have gone and the transfer of materials including some forms of life would have taken place from Earth and Mars. They found significant re-impact of the materials in the first million years after ejection.
“We expect that such transfer is most likely during the Late Heavy Bombardment or during the next one or two billion years. At this time, the icy moons were warmer and likely had little or no icy shell to prevent meteorites from reaching their liquid interiors,” Astronomers wrote in the paper.
This same concept can help in re-seeding life on those planets and moons by large impact, i.e. utilizing the hypothesis of panspermia, according to which life can be spread between planets and other celestial bodies. One form of panspermia is lithopanspermia in which pieces of rock can help in the dispersal of life to other celestial bodies.
Scientists found that the moons of Jupiter and Saturn are among the rare places in space where the transfer of materials might take place in the early life of Universe.
“It is known that rock can be exchanged between planets; therefore, if life can survive the transfer, it is probable that life from Earth has already been brought to other planets.” Researchers wrote.
Following table shows the probability of transfer of material and the mass transferred between the celestial bodies over the last 3.5 billion years.
“Any planned missions to search for life on Titan or the moons of Jupiter will have to consider whether any biological material found represents an independent origin, rather than another branch in the family tree populated by Earth life,” Researchers wrote.
R. J. Worth, Steinn Sigurdsson, & Christopher H. House (2013). Seeding Life on the Moons of the Outer Planets via Lithopanspermia arXiv arXiv: 1311.2558v1