Space twister: Mysterious Mars night streaks finally explained
The streaks, which appear bright when captured in thermal imaging, emanate from a number of large-impact craters on the planet. First discovered a number of years ago, the phenomenon has only now been explained.
Streaks emanating from Mars craters caused by tornadoes - study. Credit NASA pic.twitter.com/sThAIz8x45— Colm McGlinchey (@ColmMcGlinchey) May 12, 2017
Meteorites smashing into the planet created tornado-like wind vortices spinning at 500mph (800kph), claims a study in the journal Icarus.
"This would be like an F8 tornado sweeping across the surface,"said Brown University geologist Peter Schultz, who co-authored the study and who first discovered the streaks.
"These are winds on Mars that will never be seen again unless [there’s] another impact."
The streak caught Schultz’s attention several years ago while studying infrared images of Mars taken by the Thermal Emission Imaging System (THEMIS), which flies aboard the Mars Odyssey orbiter.
Due to the difference in heat retention in the ground affected, compared to that around it, the streaks stood out to Schultz, who noticed they extended beyond the normal ejecta (spray radius) pattern.
"Where these vortices encounter the surface, they sweep away the small particles that sit loose on the surface, exposing the bigger blocky material underneath, and that's what gives us these streaks," he said.
He claimed that as the tornadoes formed at the same time as the craters, whose age is known, it will give them valuable information towards studying erosion on the planet. Why they appear in some craters but not others could also help with detailing the Martian surface at the time of the impact.
"The next step is to really dig into the conditions that cause the streaks," Schultz said. "They may have a lot to tell us, so stay tuned."