Dead Ringer

[Image: Mars's moon, Phobos; courtesy NASA /JPL/University of Arizona].

Oh, to live another 40 million years... "One day," Nature reports, "Mars may have rings like Saturn does":

The martian moon Phobos, which is spiralling inexorably closer towards the red planet, will disintegrate to form a ring system some 20 million to 40 million years from now, according to calculations published on 23 November. Other research suggests that long grooves on Phobos's surface may represent the first stages of that inevitable crack-up.

After that point, a red mineral ring will gradually coalesce from the dust storm, circling the planet in a desert halo.

In terms of human experience, 20-40 million years obviously dwarfs our anatomical and genetic history as modern Homo sapiens, and I am excessively confident that no humans will be around to witness this event. Nonetheless, it's not actually that far off. The Earth itself is 4.5 billion years old; 20-40 million years is the geological blink of an eye. In a sense, we will just miss it.

For what it's worth, Neal Stephenson's most recent novel, Seveneves, is about a similar event—but set on Earth, not Mars.

"What if Earth’s moon suddenly and spontaneously broke apart into seven large pieces?" a review in the New York Times asked. "What would happen to life on Earth? It’s an intriguing premise, one that could conceivably go in any number of interesting directions. What would be the ramifications for every aspect of society, including economics, governance, the rule of law, privacy and security, not to mention even more fundamental matters like reproductive rights, religion and belief?"

In any case, read more over at Nature.