4 Photos - Oct 15, 2015
Photo: Sara Seager is a planetary scientist and astrophysicist. She has been a pioneer in the vast and unknown world of exoplanets, planets that orbit stars other than the sun. Her ground-breaking research ranges from the detection of exoplanet atmospheres to innovative theories about life on other worlds to development of novel space mission concepts. Now, dubbed an "astronomical Indiana Jones", she is on a quest after the field's Holy Grail, the discovery of a true Earth twin. And is a regular cast member of the History channel’s Ancient Aliens.Photo: Directed Panspermia. Did Ancient Astronauts Seed the Planet with Life? Will we?Photo: The geological evidence for the earliest life on Earth is very early, soon after the end of the late bombardment. There is good evidence for life on Earth at 3.5 billion years ago, indirect evidence at 3.8 billion. The end of the late heavy bombardment is 3.8 billion years ago.Photo: Lithospanspermia. An ancient nuclear warfare on Mars or a direct collision with another celestial object could have created a big enough explosion on the planet to have ejected a part of it into space and then resulting in the transportation of an existing life from Mars to Earth and creating life here.