Life could have grown between 3.5 billion and 4.2 billion years ago, which precedes the earliest evidence of life on Earth by 500 million years.
Once the planets in our solar system formed, the frequency and size of the meteorites in the solar system diminished. That gradual decline opened a window in which the conditions were right for life to form and stay.
But there are different ideas about when the heavy meteorites ceased. Some scientists believe that the planets endured a later stage of bombardment 3.8 billion years ago.
For the new study, researchers have studied the oldest known mineral grains from meteorites that they originally came from the southern highlands of Mars. By looking at them on an atomic level, the researchers found that the minerals were unchanged since they formed and crystallized near the Martian surface.
The grains were compared to areas on Earth and moon impaired by meteorites. More than 80% of the mineral grains were changed by extreme pressure and temperature. ” data-src-mini=”//cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-small-169.jpg” data-src-xsmall=”//cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-medium-plus-169.jpg” data-src-small=”http://cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-large-169.jpg” data-src-medium=”//cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-exlarge-169.jpg” data-src-large=”//cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-super-169.jpg” data-src-full16x9=”//cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-full-169.jpg” data-src-mini1x1=”//cdn.cnn.com/cnnnext/dam/assets/190624102036-mars-curiosity-methane-small-11.jpg” data-demand-load=”not-loaded” data-eq-pts=”mini: 0, xsmall: 221, small: 308, medium: 461, large: 781″ src=”data:image/gif;base64,R0lGODlhEAAJAJEAAAAAAP///////wAAACH5BAEAAAIALAAAAAAQAAkAAAIKlI+py+0Po5yUFQA7″/>
The researchers believe that the meteorites stopped striking Mars before the mineral grains were formed. This means that the Martian surface could have been habitable around the time when water was abundant