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The London fog might be bad — but at least the country isn’t being eaten away by an acidic vapour that is spewing out of its volcanoes.
That is what is happening on Mars, where a fog is gradually eating away the rocks that cover its surface.
Nasa’s Spirit Rover has spotted strange rock formations on Mars’s Gusev Crater that seem to indicate that an acidic vapour is gradually wearing them down.
On the planet’s Cumberland Ridge, rocky outcrops have been seen with small bumps or agglomerations, which are thought to be a consequence of minerals inside of them losing their structure.
Instruments on the rover also revealed that something had reacted with iron in the rocks to varying degrees.
In other respects, the composition of the rocks was identical.
Planetary scientist Dr Shoshanna Cole, from Ithaca College, New York, said: "That makes us think that they were made of the same stuff when they started out. Then something happened to make them different from each other."
Dr Cole believes the rocks were exposed to acidic water vapour from volcanic eruptions similar to the corrosive "vog" in Hawaii.
When the Martian vog touched the surface of the rocks, it dissolved away some of the minerals, forming a gel, according to the theory. Then the water evaporated leaving the agglomerations behind.
"Nothing is being added or taken away, but it was changed," Dr Cole added. "This would have happened in tiny amounts over a very long time."
The more altered rocks, with larger agglomerations, were found in shadier spots on steep slopes facing away from the sun.
Show all 20 1 /20Science news in pictures Science news in pictures Pluto has 'beating heart' of frozen nitrogen Pluto has a 'beating heart' of frozen nitrogen that is doing strange things to its surface, Nasa has found. The mysterious core seems to be the cause of features on its surface that have fascinated scientists since they were spotted by Nasa's New Horizons mission. "Before New Horizons, everyone thought Pluto was going to be a netball - completely flat, almost no diversity," said Tanguy Bertrand, an astrophysicist and planetary scientist at NASA's Ames Research Center and the lead author on the new study. "But it's completely different. It has a lot of different landscapes and we are trying to understand what's going on there."
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Science news in pictures Over 400 species discovered this year by Natural History Museum The ancient invertabrate worm-like species rhenopyrgus viviani (pictured) is one of over 400 species previously unknown to science that were discovered by experts at the Natural History Museum this year
PA
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Ye et al/Current Biology
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Reuters
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A. Gennari
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Steven G Johnson
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Clay Bolt
Science news in pictures New mammal species found inside crocodile Fossilised bones digested by crocodiles have revealed the existence of three new mammal species that roamed the Cayman Islands 300 years ago. The bones belonged to two large rodent species and a small shrew-like animal
New Mexico Museum of Natural History
Science news in pictures Fabric that changes according to temperature created Scientists at the University of Maryland have created a fabric that adapts to heat, expanding to allow more heat to escape the body when warm and compacting to retain more heat when cold
Faye Levine, University of Maryland
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Science news in pictures Final warning to limit "climate catastrophe" The Intergovernmental Panel on Climate Change has issued a report which projects the impact of a rise in global temperatures of 1.5 degrees Celsius and warns against a higher increase
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Science news in pictures Nobel prize for evolution chemists The nobel prize for chemistry has been awarded to three chemists working with evolution. Frances Smith is being awarded the prize for her work on directing the evolution of enzymes, while Gregory Winter and George Smith take the prize for their work on phage display of peptides and antibodies
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Reuters/AP
Science news in pictures Discovery of a new species of dinosaur The Ledumahadi Mafube roamed around 200 million years ago in what is now South Africa. Recently discovered by a team of international scientists, it was the largest land animal of its time, weighing 12 tons and standing at 13 feet. In Sesotho, the South African language of the region in which the dinosaur was discovered, its name means "a giant thunderclap at dawn"
Viktor Radermacher / SWNS
Science news in pictures Birth of a planet Scientists have witnessed the birth of a planet for the first time ever. This spectacular image from the SPHERE instrument on ESO's Very Large Telescope is the first clear image of a planet caught in the very act of formation around the dwarf star PDS 70. The planet stands clearly out, visible as a bright point to the right of the center of the image, which is blacked out by the coronagraph mask used to block the blinding light of the central star.
ESO/A. Müller et al
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Science news in pictures Previously unknown society lived in Amazon rainforest before Europeans arrived, say archaeologists Working in the Brazilian state of Mato Grosso, a team led by archaeologists at the University of Exeter unearthed hundreds of villages hidden in the depths of the rainforest. These excavations included evidence of fortifications and mysterious earthworks called geoglyphs
José Iriarte
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Science news in pictures Nasa releases stunning images of Jupiter's great red spot The storm bigger than the Earth, has been swhirling for 350 years. The image's colours have been enhanced after it was sent back to Earth.
Pictures by: Tom Momary
Previous laboratory experiments had shown that when Martian basalt rocks are exposed to sulphuric and hydrochloric acids, they lose their crystalline structure in just the same way.
The findings were presented at the Geological Society of America's annual meeting in Baltimore.
Additional reporting by Press Association
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