DESPITE its nickname of 'the Red Planet', mysterious green dots have been discovered in the sand on Mars.
Nasa's Perseverance rover, which has been navigating Mars for nearly four years, stumbled upon the new mystery in a region called "Serpentine Rapids".
After scraping away the top layer of regolith in a red rock outcrop named "Wallace Butte", the rover uncovered a "striking" array of colours within the rock, Nasa wrote.
Colours of white, black and even green were discovered.
"One of the biggest surprises for the rover team was the presence of the drab-green-colored spots within the abrasion patch, which are composed of dark-toned cores with fuzzy, light green rims," Nasa added.
The green patches can also be found on Earth's so-called 'red beds' - areas of sediment where water, carrying iron, has filtered through, and eventually hardens into rock.
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On Earth, microbes are sometimes involved in this reaction.
Green spots can also occur when organic matter, such as microbial life, dies and decays in the area, suggesting Nasa could be in close proximity to ancient alien life.
However, the combination of sulfur and iron can also cause these "fuzzy, light green rims".
And the composition of these green Martian rocks will "remain a mystery", according to Nasa, perhaps until human explorers can reach the planet sometime in the 2030s.
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There was apparently not enough room to safely place the rover arm, containing the tools made for sampling the rock, over the patch of green.
How long does it take to get to Mars?
It's not that short of a trip...
- There’s an immense distance between Earth and Mars, which means any trip to the red planet will take a very long time
- It’s also made more complicated by the fact that the distance is constantly changing as the two planets rotate around the sun
- The closest that the Earth and Mars would ever be is a distance of 33.9million miles – that’s 9,800 times the distance between London and New York
- That’s really rare though: the more useful distance is the average, which is 140million miles
- Scientists on Earth have already launched a whole bunch of spacecraft to (or near) Mars, so we have a rough idea of how long it takes with current technology
- Historically, the trip has taken anywhere from 128 to 333 days – admittedly a huge length of time for humans to be on board a cramped spacecraft.
The rover had been picking up rock samples in a region called "Bright Angel" about 20 sols - Martian days - earlier.
Scientists believe "Bright Angel" is where an ancient river once flowed, feeding the Jezero Crater with fresh water billions of years ago.
The Jezero Crater has been under the spotlight at Nasa for years, as experts believe they have the best chance of finding remnants of ancient alien life.
Perseverance is currently making the steep climb out of the crater, where it has been since 2021.
Nasa said it is always on the lookout for similar interesting and unexpected features in the rocks - like this sedimentary slab that resembled a human face.
Or, this "zebra rock", which is "unlike any [rock] seen on Mars before".
Mars facts
Here's what you need to know about the red planet...
- Mars is the fourth planet from the Sun
- It is named after the Roman god of war
- The landmass of Mars is very similar to Earth but due to the difference in gravity you could jump three times higher there than you can here
- Mars is mountainous and hosts the tallest mountain known in the Solar System called Olympus Mons, which is three times higher than Everest
- Mars is considered to be the second most habitable planet after Earth
- It takes the planet 687 Earth days to orbit the Sun
- The planet has a diameter of 4,212 miles, and has an average distance from Earth of 140 million miles
- Martian temperatures can vary wildly, reaching as high as 70F/20C or as low as -225F/-153C