NASA Mars rover Curiosity - watch live

Are we alone? Or was there life on another planet? NASA's $2.5 billion dream machine, the Mars Science Laboratory, aims to take the first steps toward finding out when it nears Mars's surface on Monday.

Scientists have found signs of water on Red Planet, which is Earth's neighbor, hinting that some form of life was once likely even though Mars is now a dry place with a thin atmosphere, extreme winters and dust storms.

NASA said it will find out whether its Mars Science Laboratory and rover, Curiosity -- designed to hunt for soil-based signatures of life and send back data to prepare for a future human mission -- landed safely at 1:31 am Eastern time (0531 GMT) on Monday.

That will be about 14 minutes after the touchdown actually happens due to the time it takes for spacecraft signals to travel from Mars to Earth.

Update: NASA's $2.5 billion Mars rover sent back its first signals to mission control as it was about to enter the Red Planet's atmosphere in the final moments of a dramatic touchdown.

"We can confirm that the event is actually happening," said a member of mission control at NASA's Jet Propulsion Laboratory. "We are receiving heartbeat tones at this time, things are looking good."