Life can leave 'fingerprints' of its presence in the atmosphere and on the surface of a planet. These potential signs of life, or biosignatures, can be detected with telescopes. See story at <a rel="nofollow" class="external free" href="https://ucrtoday.ucr.edu/54211">https://ucrtoday.ucr.edu/54211</a>.
NASA/Aaron Gronstal
<p><a rel="nofollow" class="external free" href="https://ucrtoday.ucr.edu/54211/panel1">https://ucrtoday.ucr.edu/54211/panel1</a> (<a rel="nofollow" class="external text" href="https://ucrtoday.ucr.edu/wp-content/uploads/2018/06/Panel1.jpg">image link</a>) 
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(<b>NOTE:</b> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20190205000942/https://ucrtoday.ucr.edu/54211/panel1">WayBackMachine Archive Image Link</a> and <a rel="nofollow" class="external text" href="https://web.archive.org/web/20190205000939/https://ucrtoday.ucr.edu/54211">Original Main Article</a> - <a href="//commons.wikimedia.org/wiki/User:Drbogdan" title="User:Drbogdan">Drbogdan</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Drbogdan" title="User talk:Drbogdan"><span class="signature-talk">talk</span></a>) 12:11, 22 June 2021 (UTC) )