Organic matter has been found on Mars in soil samples taken from 3 billion-year-old mudstone in the Gale crater by the Curiosity rover, NASA announced Thursday. The rover has also detected methane in the Martian atmosphere.

The search for life outside Earth focuses on the building blocks of life as we know it, which includes organic compounds and molecules — although these can exist without life. Organic matter can be one of several things: a record detailing ancient life, a food source for life or something that exists in the place of life.
No matter its purpose, these work as “chemical clues” for researchers about Mars.
Methane is considered the simplest organic molecule. It’s present in other places in our solar system that could host life, like Saturn and Jupiter’s moons Enceladus, Europa and Titan. And if life does exist elsewhere, it may be very different or even form differently from how we understand life on Earth.

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