Big Impact-Triggered Dust Avalanche seen by the HIRSE camera on the Mars Reconnaissance Orbiter. (ESP_017229_2110) Credit: NASA/JPL/University of Arizona
[/caption]
The HiRISE team from the Mars Reconnaissance Orbiter has captured a few avalanches on Mars, some actually while in progress. But this latest landslide is a little different. Above is a dust avalanche that created a streak on the slopes of Olympus Mons, the solar system’s largest volcano. While scientists believe some of the previous avalanches seen on Mars occur due to the expansion and contraction of ice from seasonal temperature differences, this one was caused by an impact event. This HiRISE image was taken on March 31, 2010 and reveals a small, pristine impact crater (blue arrow). “It shows a fuzzy source area, which resembles the airblast patterns seen at many other recent impact sites,” said Alfred McEwen, Principal Investigator for HiRISE. “The crater is only about 4.5 meters across, meaning the bolide was only about a half a meter wide, so it didn’t take much to trigger this landslide.”
“Sometimes, these dust avalanches are easily triggered,” McEwen told Universe Today. “We’ve seen them caused just by dust devils. The dark area was created by an atmospheric blast associated with the impact event, with the bolide coming in at about 10 km per second that distributes the dust. You can see that the upper most fresh dust on the surface is bright, so this landslide disturbed either bare substrate or compacted, older dust.
Planetary scientists say that landslides or avalanches on Mars can also be caused by small Mars-quakes or the sublimation of carbon dioxide frost which dislodges rocks.
Sources: HiRISE, phone conversation with Alfred McEwen.
When massive stars reach the end of their life cycle, they undergo gravitational collapse and…
Planets are born in swirling disks of gas and dust around young stars. Astronomers are…
Sometimes, things across the vast Universe line up just right for us. The Einstein Ring…
Our Sun is a giant plasma windbag spewing a constant stream of charged particles called…
Humanity will eventually need somewhere to live on the Moon. While aesthetics might not be…
How can a geologic map of a lunar impact crater created billions of years ago…