US researchers study asteroid ‘Vesta‘ with a diameter of 530 km
It is difficult to keep liquid water in space because of the vacuum and extremely low temperatures.
The salty water allows it to flow to the surface for at least an hour.
Image taken by NASA’s unmanned ‘Dawn’ probe in July 2011 from a point 15,000 km away from the asteroid ‘Vesta’. Vesta has a diameter of 530 km, making it a very small celestial body compared to planets in the solar system such as Earth.
Researchers at the Southwest Research Institute in the United States found traces of water flowing (arrows) on the surface of the asteroid ‘Vesta’ and published it in the international academic journal ‘Planetary Science Journal’. Presented by Southwest Research Institute
Traces of liquid water have been found on the surface of Vesta, an asteroid with a diameter of 530 km located between Mars and Jupiter. This finding is unusual because liquid water does not normally exist on the surface of an atmosphereless asteroid. It is expected that such asteroids could serve as supply depots when long-distance flights become common.
The American science magazine Space.com reported on the 29th (local time) that researchers from the Southwest Research Institute and the National Aeronautics and Space Administration (NASA) found traces of water flowing on the surface of the asteroid Vesta in the solar system. The results of the research were published in the latest issue of the international academic journal ‘Planetary Science Journal’.
Vesta is an asteroid that is about 350 million km away from the Sun (about 2.5 times the distance between Earth and the Sun). The diameter is 530 km, slightly longer than the distance between Seoul and Busan (about 400 km). It is a very small celestial body compared to a planet like Earth.
Researchers discovered that water once flowed on Vesta’s surface while closely examining images taken by NASA’s unmanned probe ‘Dawn’ during its flyby through the solar system in the 2010s. It was concluded that several surface patterns, such as wrinkles, were signs of liquid water flowing and changing the soil.
But this is strange. Vesta, which has weak gravity, does not have an atmosphere like Earth. The atmosphere is a shield that blocks the vacuum and cold of space. In general, liquid water exposed to an airless space evaporates immediately upon contact with the vacuum of space. The evaporated water turns to ice when it meets the cold of minus 100 degrees Celsius above the globe. In short, liquid water cannot hold its shape. However, in Vesta, traces of liquid water were found flowing on the surface for a long time, leaving traces.
What is the reason? The researchers believed that this was because the water flowing on the surface of Vesta was salty. Because it contained salt, or sodium chloride, like seawater on Earth, it was able to remain in a liquid state for at least an hour without evaporating or freezing immediately when it was open to space. This happened all over Vesta and changed the earth. The researchers confirmed these properties of salt through experiments carried out on Earth.
Where did the liquid water on Vesta come from? The researchers explained, “A meteoroid (rock floating in space) hit Vesta, causing underground ice to flow into the surface. The ice turned into liquid water due to the energy created during the meteoroid impact.
The researchers said, “There have been cases where water has been found in places where it wouldn’t normally be.” This means that the same thing could happen on other asteroids besides Vesta. There are predictions that when long-distance space travel becomes common, water-bearing asteroids could serve as resting places or supply bases. By reducing the weight of a spacecraft, launch costs can be reduced and travel time can be extended, so future research on asteroids is expected to accelerate.
