Statistical Signatures of Panspermia in Exoplanet Surveys

A fundamental astrobiological question is whether life arose spontaneously on earth or was transported here from an extrasolar system.

We propose a new strategy to answer this question based on the principle that life which arose via spreading will exhibit more clustering than life which arose spontaneously.

We develop simple statistical models of panspermia to illustrate observable consequences of these excess correlations. Future searches for biosignatures in the atmospheres of exoplanets could test these predictions: panspermia predicts large regions in the Milky Way where life saturates its environment interspersed with voids where life is very uncommon.

In a favorable scenario, detection of as few as ∼25 biologically active exoplanets could yield a 5σ detection of panspermia.

Henry W. Lin, Abraham Loeb
(Submitted on 20 Jul 2015)
Comments: 4 pages, 2 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1507.05614 [astro-ph.EP] (or arXiv:1507.05614v1 [astro-ph.EP] for this version)
Submission history
From: Henry Lin Mr.
[v1] Mon, 20 Jul 2015 20:00:19 GMT (89kb,D)
http://arxiv.org/abs/1507.05614