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?
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Content: 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. Living well past all expectations, Opportunity not only transmits landscape photos and the occasional tweet, but also collects and analyzes soil and atmosphere samples. It's been an invaluable research tool, but has found no direct evidence that life ever existed on Mars, and has revealed that the planet's atmosphere is too thin to protect it from the sun's radiation. The discovery of thousands of planets orbiting nearby stars has nevertheless greatly increased speculation that there may be some kind of life on a planet outside our solar system. In the past 20 years, we have confirmed the discovery of almost 2,000 planets, called exoplanets, beyond our solar system. Four thousand other exoplanet candidates await confirmation.