Mars, the red planet, has confused astronomers yet again. NASA's Perseverance rover, which has been investigating Mars' Jezero Crater since early 2021, has uncovered hundreds of white rocks scattered throughout the surface. The rover's recent photographs show nearly 4,000 light-toned, pebble-sized "unusual" rocks scattered throughout the crater floor.

"These rocks are very unusual, and we're trying to understand their origin," said Candice Bedford, a planetary scientist at Purdue University and member of the Mars 2020 scientific team, addressing last month's Lunar and Planetary scientific Conference (LPSC).

Perseverance's equipment determined that the rocks are dehydrated. They lack not only water, but also minerals such as iron, magnesium, calcium, and salt.

"These rocks are pretty depleted in a lot of things," Bedford explained.

She believes that the dehydrated state of the rocks implies that they were heated and metamorphosed by events such as lava flows or asteroid impacts on Mars before being deposited in the crater.

NASA's Mars Sample Return (MSR) programme is leading the effort to return these samples to Earth. Questions concerning the programme persist, notably the timetable and method for returning the samples. Following the discovery of flaws in the current plan by an independent review board (IRB), a reaction team (MIRT) was formed to assess alternate options. NASA's budget for MSR has yet to be finalised, with a new plan and budget due in April.