Asteroids may not be as stable as scientists thought. A recent experiment shows that the force from a landing spacecraft might easily cause an avalanche or something resembling an extraterrestrial mudslide, as a result of shifts in the dust on the asteroid’s granular surface.
Researchers compare the force chains to a stack of oranges at the supermarket. Some oranges bear weight while others come away easily, and a small shift in the stack can redistribute the force, moving the weight to different oranges and causing some to topple off the pile. Asteroids work much the same way, with only weak gravity holding together layers of loose rock and dust called regolith. The shock of a spacecraft landing could rearrange the dust in unpredictable ways — and because the gravity is so much weaker than on Earth, the results could be much less stable than the stack of oranges.
via The Verge
Image: NASA JPL