Is there life on Mars?
Earth is the only place that scientists know for certain supports life. The United States and other countries have been sending spacecraft to orbit or land on Mars since the 1960s, and each mission teaches scientists more about this fascinating planet. Although Mars is more similar to Earth than other planets in the solar system, it is still different from Earth in many ways. In 1976, NASA landed robotic spacecraft named Viking 1 and Viking 2 on Mars. Viking 1 scooped up samples of Martian soil and tested it for signs of life, but none were found. In the future, NASA will be looking for live bacteria and searching for tiny fossils that might indicate life may have existed early in Mars' history butunlike on Earthdid not survive and evolve into larger life forms. In 2008, NASA's Phoenix Mars Lander landed on the planet to search for complex organic molecules in the ice-rich soil of the arctic region. And, in March 2013, NASA's Curiosity rover scooped up powder from drilled rock on Mars that suggested that conditions were once right for life on Mars, though no evidence of actual life was found.