NASA's Dawn probe left the gigantic asteroid Vesta back in September. While Dawn might not be orbiting Vesta gathering new data, scientists, and researchers are still pouring through the data the probe collected from Vesta. One of the things the scientists have discovered hint that water might have once flowed on the surface of the asteroid.
Scientists say that they have discovered features on Vesta that look as though they could possibly been cut by a fluid, such as liquid water. The scientists say that this is an extraordinary discovery because any free water on the surface of Vesta would ordinarily boil rapidly and vaporize because the asteroid has no atmosphere.
The scientists discovered what are called Type B gullies running down the wall of some craters on the surface of Vesta. The scientist new say that the possibility of liquid erosion on the surface of the asteroid requires more research. Researchers say that at this point they are not suggesting the asteroid once had liquid water and are still looking for input from the community on what could've caused the features discovered.
NASA researchers say that during the months Dawn spent orbiting Vesta it was able to map almost the entire surface from an altitude of 210 km. The high-resolution images have allowed NASA researchers to pick out detailed surface features. Scientist Jennifer Scully from the University of California Los Angeles says that in the majority of cases the researchers were able to determine that the gullies were likely caused by loose rock or soil falling down crater slopes. However in a smaller group the pattern of the gullies are different and interlaced.
"The first group we call Type A. They're very typical of dry-mass wasting; the sort of thing you would get on Earth's Moon and on other, smaller asteroids. But the Type B gullies are the ones we think may have this liquid water origin; they have quite distinct morphologies. They are longer and narrower. They also interconnect, branching off one another."