- READ MORE: Scientists find organic molecules of 'unprecedented size' on Mars
They look like a dish of lentils, or a mass of spider eggs on a leaf.
But whatever they are, these tiny little brown blobs, newly-found on the surface of Mars, have left scientists baffled.
New images captured by NASA's Perseverance rover this month show an alien-like mass comprised of hundreds of the millimeter-sized spheres.
However, scientists are unsure what 'quirk of geology' could've made the strange shapes, which are unlike anything they've seen before.
Whatever they are, they look totally out of place compared with the surrounding rusty red Martian dust.
They could hint at the rich volcanic and geologic history of the Red Planet, which is about 4.6 billion years old.
Mars was once dotted with thousands of huge volcanoes which saw 'super eruptions', according to NASA – the most powerful type of volcanic blast there is.
It follows stunning images of 'araneiforms' – dark cracks in the Martian soil, completely different to anything on Earth.
NASA's new images were found by Perseverance along the rim of the Jezero Crater, a 28-mile-wide region on Mars that may have once been flooded with water.
Alex Jones, a PhD student from Imperial College London's department of earth science, described the rock as 'strange' and 'shocking'.
'The Perseverance Science Team were astonished by a strange rock comprised of hundreds of millimeter-sized spheres,' he said in a blog post on NASA's website.
'Placing these features in geologic context will be critical for understanding their origin, and determining their significance for the geological history of the Jezero Crater rim and beyond.'
Technically, the mass is made up of 'spherules' – roughly spherical pebbles, ranging 0.01mm to 4mm in diameter (up to 0.15 inches).
Some of these spherules are more elongate, elliptical shapes, while others have angular edges, perhaps representing broken spherule fragments.
Others even have miniscule holes as if they'd been pricked with a pin – but how or why they show such variety is a mystery.
On Earth, spherules are formed by rapid cooling of molten rock droplets during a volcanic eruption, or by the condensation of rock vaporized by a meteorite impact.
'Each of these formation mechanisms would have vastly different implications for the evolution of these rocks, so the team is working hard to determine their context and origin,' Jones said.
Dr Matthew Chojnacki, a planetary geologist at the Planetary Science Institute, said they could be 'frothy lava' that rapidly cooled might lead to such a deposit.
'But it's hard to tell without chemistry or mineralogy, especially given it's a float rock (a piece of rock that is not part of the bedrock),' he told MailOnline.
This isn’t the first time strange spheres have been spotted on Mars, which is an average of 140 million miles (225 million km) away from Earth.
In 2004, the Opportunity rover – active on Mars from 2004-2018 – spotted 'Martian Blueberries' at Meridiani Planum, a large plain straddling the equator of Mars.
These marble-sized objects, named for their similar appearance to the fruit, are remnants of small meteorites that broke up in the Martian atmosphere
Then in 2012, the Curiosity rover, which is still exploring Mars after more than a decade, observed spherules in the rocks of Yellowknife Bay at Gale crater.
Meanwhile, Perseverance spied 'popcorn-like textures' in sedimentary rocks exposed in the Jezero crater inlet channel, Neretva Vallis, last year.
Perseverance acquired the two new images on March 11 and March 13 – on sol (Martian day) 1442 and 1444 of its mission.
A Martian day (a 'sol') is 24 hours, 39 minutes and 35 seconds long – so about 40 minutes longer than a day on Earth.
Perseverance touched down on Mars' Jezero Crater – believed to be the home of a lush lakebed and river delta billions of years ago – in February 2021 after a nearly seven-month journey through space.
It is tasked with seeking traces of fossilised microbial life from Mars' ancient past and to collect rock specimens for return to Earth through future missions to the Red Planet.
Comments