“I think it’s the strangest find of the whole mission and the most unexpected,” said Ashwin Vasavada, Curiosity project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “I have to say, there’s a lot of luck involved here. Not every rock has something interesting inside.”
Exploration of Gediz Vallis Channel
Curiosity has been investigating the Gediz Vallis channel, a prominent geological feature on Mount Sharp. This channel, which appears to have been shaped 3 billion years ago by a combination of flowing water and debris, has been a focal point of the rover’s mission. The team had observed white rocks from a distance and directed Curiosity to capture detailed images.
On May 30, the team discovered a crushed rock within the rover’s wheel tracks. A closer examination revealed the sulfur crystals, described as “mind-blowing” by Vasavada. This find marks the first time pure sulfur has been detected on Mars.
Background on Previous Discoveries
Curiosity had previously identified sulfates, salts containing sulfur, on Mars. These sulfates are typically formed from the evaporation of water. However, the presence of pure sulfur is unprecedented. “No one had pure sulfur on their bingo card,” Vasavada noted.This discovery is reminiscent of a significant find by NASA’s Spirit rover. Spirit, which operated from 2004 to 2011, discovered nearly pure silica, suggesting the presence of hot springs or steam vents on Mars. This discovery of silica contributed to the understanding of ancient Martian environments and inspired further exploration, including Curiosity’s current mission.Analysis and Implications
The newly found sulfur rocks were initially seen in a flat area with many white stones. The team originally thought these stones were debris transported from higher up the mountain. However, the discovery of the sulfur rock led to the conclusion that the rocks likely formed in place rather than being transported.
“Pure sulfur only forms under certain conditions on Earth, such as volcanic processes or in hot or cold springs,” Vasavada explained. Scientists are now analyzing the sulfur rock and nearby bedrock to determine the formation conditions on Mars.
Curiosity’s Ongoing Mission
Since its landing on August 5, 2012, Curiosity has been ascending Mount Sharp, a central peak within the Gale Crater, exploring its layers and uncovering various aspects of Mars’ history. Each layer of Mount Sharp provides insights into the planet’s past, including periods of water presence and dryness.
Curiosity’s exploration of the Gediz Vallis channel has revealed evidence of both violent water flows and landslides. The debris from these processes has contributed to the formation of the current landscape. Recent analyses of a large rock from the channel, named “Mammoth Lakes,” showed an abundance of minerals, providing further insights into Mars’ geological history.
Despite facing mechanical issues and wear over the years, Curiosity remains in good condition. “I feel very lucky, but also we all feel cautious that the next one may not be only a close call,” Vasavada said. The rover will continue exploring Mount Sharp, seeking new geological features and further surprises.