A cloud longer than California streaks across Mars‘ ruddy cheek. It looks as though an impressionist painter loaded his palette knife with white and scraped a line across the canvas as far as the oily paint would travel.
This is not what astrophysicist Jorge Hernández Bernal first saw in 2018 when the Mars Express Visual Monitoring Camera(Opens in a new window) — affectionately known by the European Space Agency as the Mars webcam(Opens in a new window) — posted a new picture. To the average eye, it was grainy and inscrutable, with the resolution of a standard computer camera circa 20 years ago. But Bernal, who was studying Martian meteorology at the University of the Basque Country in Spain, immediately recognized the shadow as something else: a mysterious weather phenomenon happening on the Red Planet.
It wasn’t until researchers looked at the cloud with better equipment that Mars revealed the cloud in all its sprawling glory. The team dug deeper into photo archives, and discovered it had frequently been there. It was there through the aughts, and it was even there during NASA‘s Viking 2 mission(Opens in a new window) in the 1970s.
