This artist's conception shows a young, hypothetical planet around a cool star. A soupy mix of potentially life-forming chemicals can be seen pooling around the base of the jagged rocks. Observations from NASA's Spitzer Space Telescope hint that planets around cool stars—the so-called M-dwarfs and brown dwarfs that are widespread throughout our galaxy—might possess a different mix of life-forming, or prebiotic, chemicals than our young Earth.
Life on our planet is thought to have arisen out of a pond-scum-like mix of chemicals. Some of these chemicals are thought to have come from a planet-forming disk of gas and dust that swirled around our young sun. Meteorites carrying the chemicals might have crash-landed on Earth.
Astronomers don't know if these same life-generating processes are taking place around stars that are cooler than our sun, but the Spitzer observations show their disk chemistry is different. Spitzer detected a prebiotic molecule, called hydrogen cyanide, in the disks around yellow stars like our sun, but found none around cooler, less massive, reddish stars. Hydrogen cyanide is a carbon-containing, or organic compound. Five hydrogen cyanide molecules can join up to make adenine—a chemical element of the DNA molecule found in all living organisms on Earth.
These impermanent waterways are part of Oued Irharrhar, which appear to be carrying sulfur (yellow) and iron (red) deposits. The city of Amguid is located on these waterways, and all lie in the Mouydir Mountains in Algeria.
This artist's conception shows a young, hypothetical planet around a cool star. A soupy mix of potentially life-forming chemicals can be seen pooling around the base of the jagged rocks. Observations from NASA's Spitzer Space Telescope hint that planets around cool stars—the so-called M-dwarfs and brown dwarfs that are widespread throughout our galaxy—might possess a different mix of life-forming, or prebiotic, chemicals than our young Earth.
