For thousands of generations humans have looked up at the Moon and imagined a face in its features: the Man in the Moon, smiling gently upon us from his perch high in the heavens. A pleasant thought, right? But maybe also a warning—a warning of a threat from space that we on Earth have no way to stop.

Japanese scientists announced last week in the journal Nature Geoscience that they had used spectral analysis to measure the composition of minerals in the 3000-kilometre-wide Procellarum Basin, the giant flat space that makes up the largest part of the Man in the Moon’s face. Then they’d compared those results with rock samples brought back from the Moon by Apollo astronauts. Their conclusion? The Procellarum basin is a newer feature than most of the Moon’s craters, and was most likely caused by the strike of one giant asteroid that ripped off a huge portion of the crust and produced a new one, about 3.9 billion years ago.

That’s not just an interesting factoid (and a serious romantic buzzkill) but also a reminder that a huge chunk of space rock like that might one day have Earth in its sights.

You can get two fairly similar versions of that scenario in the movies Armageddon and Deep Impact, both released in 1998. The newer movie Seeking a Friend for the End of the World, a quirky but often sweet romantic comedy starring Steve Carell and Kiera Knightley, has just come out on video and is worth a look (but note that Bruce Willis isn’t in the cast, and adjust your expectations accordingly). I’ve explored the killer asteroid idea in some old blog posts and in my short story “Saviour” which you can read by following this link. In “Saviour” the man in charge of the mission to save humankind from the approaching cosmic doom takes a rather unorthodox approach.

“Saviour” was significantly inspired by another movie called Sharkwater in which filmmaker Rob Stewart showed that sharks are on the path to extinction, thanks to the inexplicable human taste for shark fin soup (among other things). Stewart has now produced a follow-up to Sharkwater due in movie theatres next spring that’s even more disturbing. Ocean scientists pointed out to him that by the 2040’s not only will sharks be gone, virtually every other species of fish and sea mammal will also be wiped out, due to indiscriminate overfishing, pollution, and global warming. The movie goes on to show the forecast consequences of climate change on the rest of the planet. Revolution expresses a message of hope, but its premise is certainly dire. And it’s not fiction.

So what’s the connection between climate change extinctions and a killer asteroid? For that you’ll have to read “Saviour”. But consider: if a giant space rock ever is found to be on a collision course with Earth, will it be a terrible twist of fate?

Or the universe protecting itself from us?