On Aug. 5, NASA's Curiosity rover will notch its 11th year on Mars by doing what it does best: studying the Red Planet's surface. The intrepid bot recently investigated a location nicknamed "Jau" that is pockmarked with dozens of impact craters. Scientists have rarely gotten a close-up view of so many Martian craters in one place. The largest is estimated to be at least as long as a basketball court, although most are much smaller.

Last week, scientists announced that for the first time on record, Antarctic ice has failed to "substantially recover" over winter, in a "once in 7.5-million-year event." Climate change is the most likely culprit.

Petra Heil, a sea ice physicist from the Australian Antarctic Division, told the ABC it could tip the world into a new state. "That would be quite concerning to the sustainability of human conditions on Earth, I suspect."

And in March, a senior United Nations disarmament official told the Security Council the risk of nuclear weapons being used today is higher than at any time since the end of the Cold War.

Both warnings speak to concerns about Earth's security. Will our planet be able to support human life in the future? And if not, will humanity have another chance at survival in space?

'Billionauts' and how to choose who goes

Over the past few years, we've witnessed the rise of the "billionaut." The ultra-wealthy are engaged in a private space race costing billions of dollars, while regular citizens often condemn the wasted resources and contribution to global carbon emissions.