Life in Space?

Venus is the second planet from the sun. Its rocky surface reaches temperatures nearly 900°F! That’s too hot for any living thing on Earth. For that reason, Venus has always seemed like an unlikely place for life.

But in 2020, scientists made an exciting discovery. Researchers used powerful telescopes to look at Venus’s atmosphere. They found a chemical called phosphine surrounding the planet. On Earth, phosphine is made only by microbes.

Could tiny alien microbes have made the phosphine in Venus’s clouds? The clouds are 86° to 158°F. That’s cool enough for life to exist. “If there is life there, it’s hard to imagine what it might be like,” says Clara Sousa-Silva. She’s a scientist who helped make the discovery. She works at Harvard University in Massachusetts.

Other research groups tried to find phosphine in Venus’s atmosphere. Some could find the chemical in Venus’s clouds, but others could not. Now, Sousa-Silva and her team are looking for phosphine again to make sure their findings are correct. “This is exactly how science works,” says Sousa-Silva.

Our solar system’s largest planet is Jupiter. It has 79 moons. Its fourth-largest moon is Europa. It is covered in a thick layer of ice. Under the ice is an ocean of liquid water. Scientists think that alien life could live there.

Openings on the moon’s ocean floor gush hot water full of minerals. These openings are like hydrothermal vents found on Earth’s seafloor. Heat from the vents could make water warm enough for life. Microbes could eat the minerals.

NASA hopes to send a spacecraft to Europa. The spacecraft would orbit around the moon. It would catch spray from the vents that might reach space. Scientists hope the water might hold chemicals made by lifeforms. Another mission could drill through Europa’s ice. Then a robot could travel into the ocean to look for signs of life.

Today, the surface of Mars looks like a desert. But scientists think it was once covered in oceans. These bodies of water could have held life. Over time, Mars lost its atmosphere. Without that protetcive layer around the planet, its liquid water evaporated , changing into gas. Mars turned cold and dry.

Scientists think that microbes once lived in Mars’s ancient oceans. They also think microbes could still be buried below the planet’s surface. That’s where there may still be liquid water, says Sarah Hörst. She’s a planetary scientist at Johns Hopkins University in Maryland.

A NASA rover named Perseverance landed on Mars in February 2021. One of its missions is to search for signs of life. The robot is collecting dirt and rock. The samples will be left on the planet’s surface. They will be picked up during a later mission. Scientists on Earth will then study the bits of dirt and rock. They hope to find clues that life once did or still does exist on Mars.