Shedding New Light On The Faint Young Sun Paradox

Our Solar System was born within an especially dense blob, hidden within the whirling, billowing depths of a giant, dark, and beautiful molecular cloud composed of gas and dust. These frigid undulating clouds haunt our Milky Way Galaxy in huge numbers, and they serve as the bewitching nurseries of fiery baby stars. Our Solar System is a gravitationally bound system, composed of our Star, the Sun, and all of the objects that orbit it–either directly or indirectly. The faint young Sun paradox refers to a troubling contradiction existing between indications of the presence of liquid water very early in Earth’s 4.6 billion year old history, and the astrophysical prediction that our Star’s output would have been merely 70 percent as intense as it now is–the unresolved question is how a climate suitable for the nurturing of life was maintained on our planet over such an extremely long timescale in spite of the variable solar output and wide range of terrestrial climate conditions. In June 2016, a team of astronomers proposed an answer to this question, saying that during the first billion years of Earth’s history, our planet was showered by a multitude of crashing primordial asteroids that fostered life on Earth.

A Southwest Research Institute (SwRI)-led team of planetary scientists proposes that this chaotic ancient beginning may have ultimately fostered life on Earth–particularly in terms of life-sustaining liquid water.

“The early impacts caused temporary, localized destruction and hostile conditions for life. But at the same time, they had a long-term beneficial effect in stabilizing surface temperatures and delivering key elements for life as we know it,” explained Dr. Simone Marchi in a June 22, 2016 SwRI Press Release. Dr. Marchi is a senior research scientist at SwRI’s Planetary Science Directorate in Boulder, Colorado. He is the lead author of a paper titled Massive Impact-induced Release of Carbon and Sulfur Gases in the Early Earth’s Atmosphere, published in the journal Earth and Planetary Science Letters. This paper addresses the faint young Sun paradox, which is certainly one of the outstanding unsolved mysteries in the history of our Solar System and our Earth.

This issue was first raised by the late Dr. Carl Sagan and his Cornell University c