Mars’ atmosphere consists of a different proportion of elements than Earth’s atmosphere, and it is approximately 100 times less dense than Earth’s. Still, the planet has clouds, and the European Space Agency has been watching a rather mysterious cloud on Mars near a massive volcano. Conspiracy theorists are also wondering what could be hiding underneath the cloud.
ESA scientists described the Martian cloud as curious, and it was first spotted over the Arsia Mons volcano on Sept. 13 by the Mars Express spacecraft. ESA doubts that it is a volcanic cloud since the volcano underneath the mysterious cloud on Mars hasn’t been active on the planet. Instead, the agency believes it’s a water ice cloud.
“In spite of its location, this atmospheric feature is not linked to volcanic activity but is rather a water ice cloud driven by the influence of the volcano’s leeward slope on the air flow — something that scientists call an orographic or lee cloud — and a regular phenomenon in this region,” the ESA said in a statement on its website.
The space agency wrote that the cloud grew and changed its shape throughout the day. It is growing “in length during local morning downwind of the volcano, almost parallel to the equator, and reaching such impressive size that could make it visible even to telescopes on Earth,” ESA said.
The winter solstice on the northern half of Mars took place on Oct. 16, while ESA noted that a “seasonally recurrent water ice cloud” like the mysterious cloud on Mars has formed along the flank of the volcano in the past. Mars Express and other Mars spacecraft observed such clouds in 2009, 2012, and 2015.
Even though ESA described the cloud, conspiracy theorists are still inspired to link the mysterious cloud on Mars with aliens or volcanic activity.
“I don’t understand the conspiracy theory contingent that’s going off re: the clouds over Arsia Mons,” tweeted Dr. Tanya Harrison, research director for Arizona State University’s Space Technology and Science Initiative. “What possible reason would we have to hide volcanic eruptions on Mars? Heck, NASA has shared plenty of pics of volcanoes erupting on Io (shown here) & geysers on Enceladus!”
“Sure, it’s a ‘water ice cloud’ known to occur in this area on #Mars. Definitely NOT a puff of white smoke that indicates that the Martian council has selected a new leader…,” another tweet suggested.
ESA created a Flickr page for those interested in observing the changes in the mysterious cloud on Mars. Perhaps the photos will reveal more about it or inspire more ideas.