Title: What are the chances of life on another planet?
Headings: What are the chances of life on another planet?
What are the chances of life on another planet?
Explore further

Content: As those particles careen by the edges of Earth's atmosphere, they sometime create the phenomenon we call the Northern Lights.) Without the magnetic field there, the solar wind might destroy all life on Earth. As for Earth's atmosphere, it protects life because the water, carbon dioxide and other gases in it absorb solar radiation in its harmful ultraviolet-light form. The parent stars of other solar systems would emit radiation as well, and the planets orbiting them would need the same kind of protection. Of course, life on Earth also alters the chemical composition of the atmosphere—Earth's atmosphere lacked gaseous oxygen until plants started growing here some million years ago. So molecules like oxygen in the atmosphere of another planet would be one indication—not proof—that there are living things there. Scientists have been studying the planets of our own solar system for more than 50 years, looking for evidence of past or present life, among other things. Launched in 1967, the Soviet Union's Venera 4 was the first probe known to land on and send back data from another planet. The mission revealed that Venus' famously soupy atmosphere is made up almost entirely of carbon dioxide with a surface temperature hot enough to melt lead, making it a very unlikely place to harbor life. Today, NASA's Mars rover, Opportunity, has been sending back reams of data about the red planet since it landed there 12 years ago.