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NASA takes the next step in the search for life on Europa

NASA's Europa mission, which aims to conduct a detailed survey of Jupiter's moon and investigate its habitability, is now entering the development phase. (Video: NASA Jet Propulsion Laboratory)

NASA's mission to the alien world of Europa -- the frozen ocean that may harbor new forms of life -- has moved into the development phase. On Wednesday, the agency announced that the mission has passed its first review, keeping the trip on track for a launch in the 2020s.

[Why NASA’s top scientist is sure that we’ll find signs of alien life in the next decade]

Jupiter's moon Europa is considered the most likely location of life in our solar system. Scientists believe the icy moon is covered by a deep ocean not unlike the subsurface bodies of water found in Earth's Arctic. There's increasing evidence that many strange forms of life thrive in those extreme conditions on Earth, so NASA is hoping that the same could be true on Europa.

It's a world that seems pretty inhabitable to us, but it has enough in common with the most inhospitable -- but ultimately livable, at least for certain microbes -- locations on Earth for scientists to want to take a closer look.

[Scientists want to send a fish-like ‘soft robot’ to swim the oceans of Europa]

As explained in the video above, the proposed spacecraft won't actually orbit Europa. By orbiting Jupiter instead -- and making frequent but quick close passes by Europa -- the spacecraft could avoid the moon's high levels of radiation, giving the mission a longer life. The spacecraft would be able to make close observations of the moon, determining whether or not a subsurface ocean exists. And if Europa erupts geysers of water high up over its ice -- which images from the Hubble suggests it does -- the orbiter could even zip through the water spouts to read the chemical composition of the ocean below.

NASA's 2016 budget included $30 million for the formulation of a Europa mission, and the agency has already selected the instruments that the orbiter will carry. But there's a lot more planning ahead before a launch, and then we'll have several years to wait before the spacecraft reaches its destination.

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