As soon as Galileo first pointed his telescope at Mars and realized that it’s another planet, similar to Earth, people have wondered, is there life on Mars? A few hundred years after the question was first asked, and we’re still wondering. But we’re getting better at asking the right question.
The search for life on Mars got going when Percival Lowell thought he observed canals crisscrossing the surface of Mars. These ended up just being an optical illusion, but Lowell imagined the dying Martian race desperately trying to irrigate their drying planet. The Mariner spacecraft proved once and for all that Lowell was just seeing things.
The next attempt to search for life on Mars was with the Viking landers. They were equipped with a sophisticated biology experiment designed to search for microbial life on Mars. It would take a sample of the Martian soil, and then expose it to chemicals that would feed an microbial life in the soil. Some gases were emitted, but most scientists now think that the results can be explained by purely chemical processes.
Scientists announced evidence for microbial fossils in a meteorite thought to come from Mars, but once again, the skeptics say that the life probably came from Earth, or might not be life at all.
On Earth, wherever there’s water, scientists find life; deep underground, under rocks in Antarctica, or inside nuclear reactor tanks. Life always finds a way. And so, the search for life on Mars will involve the search for water.
NASA’s Mars Phoenix lander has arrived at Mars, with a digging arm that will let it scoop up the icy soil near the Martian north pole. They’re hoping to find evidence of organic molecules in the ice, and further clinch the possibility that the raw ingredients for life are on Mars.
The next big mission be the Mars Science Laboratory, due for launch in 2009. This SUV-sized rover will have all the equipment it needs to find evidence of past and present life on Mars.
But right now, there’s no conclusive evidence of life on Mars, either today, or in the past. Let’s hope that changes in the next few years.
We have many articles on Universe Today about this topic. Here’s an article about a new technique for finding life on Mars. Of course, Martian life could fool us. Or maybe you just want to dig a big hole to search for life.
One of the best resources to learn about the search for life is NASA’s Astrobiology Institute. Here’s more info on the search for Martian life.
Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.