This site may earn affiliate commissions from the links on this page. Terms of apply.

Comets, it turns out, are rather more active places than we thought. Comet 67P, where we left Rosetta and Philae not too long agone, is one such happenin' spot. Scientists poring over photos by Rosetta and Philae have unearthed evidence of a spectacular landslide on 67P — and we caught it in activeness. This is the showtime time anyone has e'er caught direct testify of a landslide on a comet.

The landslide, which took identify in July of 2022, would non have looked like any landslide on Earth when it was happening. Comet 67P is so small information technology has barely whatever gravity to speak of. In that surround, instead of tumbling downwards like an avalanche, much of the fabric that broke off from the crumbling cliff face created an "outburst." Some 22,000 cubic meters of cloth, plenty to make full nine Olympic-size swimming pools, floated upward above the comet's surface to form a diffuse cloud of grit and gas.

"These images are showing that comets are some of the most geologically active things in the solar system," Pajola said. "We see fractures increasing, dust covering areas that were not dusted before, boulders rolling, cliffs collapsing" — all on an object barely wider than the Washington Mall is long.

Here's the before and after:

What makes comets so agile is their lack of temper. With nothing to shield them from the Sun's direct rays, sometimes the sunlight plays off the landscape in surprising means. It was winter on 67P'southward northern hemisphere, and winter there is about -160°C. Simply with 67P positioned how it was, the angle of the sunlight equally it crested a nearby ridge was such that a focused beam hit the cliffside. Its laser-similar intensity raised the local temperature, merely in that location, to 50°C, which was plenty of a thermal differential to stress the cliffside until its weakest points merely gave out.

Because the patch exposed by the landslide had such a loftier albedo — that is, it reflected most of the light that struck it — scientists believe the landslide must accept revealed h2o ice from below 67P's surface. Later on it was exposed, the ice sublimated from a solid straight into a gas, and the brilliant spot faded away. Looking at Comet 67P today, the but inkling that there always was such a landslide is a little pile of rubble at the bottom of the cliff.

Philae was a decorated piddling spacecraft, even though it spent its whole tenure on 67P wedged in a crevice. As presently as it landed, scientists started snapping every picture they could go with the lander's cameras, just they only spied it downwards in its hidey-hole about a month before the finish of the mission.

Amongst the things Philae was sent to explore were the geological dynamics and composition of prophylactic-duck-shaped 67P. Scientists take adamant that information technology's likely that comets like 67P seeded Earth with organic materials relevant to the formation of life on our planet. Water, though, is another story. It's unlikely that World's h2o came from comets like 67P.