After 442 million miles and a year on the space road, Maven has finally reached its destination. The NASA spacecraft successfully completed a harrowing 30-minute "orbital insertion" into Mars' orbit last night, the AP reports. "I don't have any fingernails any more, but we've made it," says the deputy director for science at Goddard Space Flight Center in Greenbelt, Md. Scientists have big plans for the explorer: It's going to be the first mission to study the Martian upper atmosphere from orbit—it's not meant to land on the surface—in advance of NASA's ambitious plans to send astronauts to Mars in the 2030s. Maven isn't the only new addition to the Martian skies: As Space.com notes, India's Mars Orbiter Mission is set to arrive on the scene tomorrow night.
Researchers believe Mars used to be a "warm and wet" planet billions of years ago and that it may have even sustained microbial life, but they're not sure what sucked all of the water off the planet's surface and eliminated carbon dioxide from its atmosphere (one theory is the sun stripped the planet clean). The school-bus-sized Maven—short for Mars Atmosphere and Volatile Evolution Mission—will spend at least a year hovering as low as 78 miles over the planet's surface, using eight high-tech instruments to gather info and even observe the Siding Spring comet that's set to zip by on Oct. 19. Meanwhile, Curiosity and another rover set to launch in 2020 are designed to bring Mars samples back to Earth and try to make oxygen out of carbon dioxide—a process that would help human explorers survive on Mars, the AP notes. "This really is a quest of humanity," NASA's head of science missions says.