This stressed asteroid could give new impetus to NASA's comet destruction plan

The groundbreaking analysis of a distant and fast-moving comet has revealed new details about how asteroids form, highlighting the formation of unusual shapes and, potentially, paving the way for more protection. effective Earth against meteor impacts. The Asteroid Comet 67P / Churyumov – Gerasimenko has a width of about 2.7 miles and travels more than 100,000 kilometers at the time, but scientists have long been fascinated by its unusual shape .

The vaguely dumbbell shape, with two distinct lobes connected by a central part, helped to make the 67P / C-G the target of the Rosetta mission of the European Space Agency. In November 2014, the Philae lander came across the asteroid. Despite failed tests that ended the experiments prematurely, he returned valuable information on the chemical composition.

Now, using data from Rosetta's OSIRIS camera – the optical, spectroscopic and infrared remote imaging system that tracks visible, near-infrared and ultra-violet wavelengths – ESA has mapped the flaws and fractures that threaten the comet. With the help of stress modeling and 3D analysis, discover how different forces have shaped rock and ice have been unblocked.

"These geological features were created by shearing, a mechanical force often observed during earthquakes or glaciers on Earth and other terrestrial planets, when two bodies or blocks grow and move in different directions. Christophe Matonti, Aix-Marseille. University, France, senior author of the research, reported results. "It's extremely exciting: it says a lot about the shape of the comet, its internal structure and its evolution over time."

The unusual form is, according to their theories, up to the two lobes trying to move in different directions, producing strong forces in the "neck" that separates them. "It's as if the material in each hemisphere is separating and moving away, bypassing the central part – the neck – and reducing it as a result of the resulting mechanical erosion," says co-author Olivier Groussin.

Key, nothing that research has discovered can be explained by thermal processes. Instead, it might suggest that the interior of the 67P / C-G is much more fragile than we originally thought. A similar form was observed more recently during Ultima Thule's overflight, with NASA's New Horizons probe returning images of the two-lobed object.

According to scientists, it might be crucial to understand how forms of comets form over time to understand the evolution of the universe. "We have only explored a handful of comets with a spacecraft, and the 67P is by far the one we have the most detailed," said Matt Taylor, chief scientist of the Rosetta Project at 39. ESA, about the results. "Rosetta says a lot about these mysterious icy visitors, and with the latest result, we can study the outer limits and early days of the solar system like never before."

The results could, however, have more destructive consequences. NASA has been working for several years on a project known as an asteroid re-routing test or DART. Its goal is to find a way to move an asteroid on a potentially dangerous path to the Earth, or even destroy it completely.

To do this, DART will use a technique called "kinetic impact": that is to say, breaking an object in another. The project plans to launch a probe in 2022 that will reach Didymos B, an asteroid about 530 feet in width that is expected to be relatively close to the Earth by the end of 2022, and then again by 2024. When it is close enough, the DART probe – which is about the size of a refrigerator – locks on the asteroid, then accelerates into it.

Space agencies say that when it happens, it should travel about 3.7 km per second. It's about nine times faster than the speed of a ball. Even in this case, it's a tiny fraction of the overall speed of Didymos B. The theory behind DART is that a small change, applied early enough to a potentially dangerous asteroid, would be enough to alter its course significantly once he gets closer to the Earth.

A better understanding of the internal geometry and composition of asteroids through the techniques applied to the 67P could well shape the future methods used by planetary defense projects such as DART. After all, if a space rock is riddled with erosion and stress cracks, a DART collision might require less energy to ensure this very important path change. This could also allow you to move the asteroids spotted later, as a DART probe could have a larger effect than expected on the impact.