On Jupiter’s moon Europa, ‘chaos terrains’ could be shuttling oxygen to ocean
Jupiter’s moon Europa is a top contender when looking for alien life because scientists have detected signs of oxygen, water, and chemicals that could be used as nutrients there. However problematically the vast liquid water ocean on its surface is covered by a crust of ice – estimated to be about 15 to 25 kilometres thick – that acts as a barrier between it and oxygen on the surface.
For life as we know it to exist in the ocean it needs oxygen, and it could be hitching a ride on salt water under the ‘chaos terrains’ of the icy shell, according to a new study published in Geophysical Research Letters.
‘Chaos terrains’ are landscapes of cracks, ridges, and ice blocks that cover a quarter of Europa, and which scientists think form when the ice shell partially melts to form brine. This brine can then mix with the oxygen at the surface and drain through the ice into the ocean below.
Researchers built the world’s first physics-based computer simulation of the phenomenon and have shown that the brine drains in a distinctive manner, taking the form of a ‘porosity wave’ that causes pores in the ice to momentarily widen – allowing the brine to pass through – before sealing back up.
The researchers say that the highest estimates of the oxygen brought to Europa’s ocean could be on par with what’s present in Earth’s oceans today.
Birds are laying their eggs earlier due to climate change
Many bird species in Chicago are nesting and laying eggs nearly a month earlier than they did a hundred years ago, according to a new study, which looked at century-old eggs preserved in collections of the Field Museum.
By comparing the dates in which the preserved eggs hatched (collected from roughly 1880-1920) and recent observations (from about 1990 to 2015), scientists were able to determine a third of the 72 bird species nesting in Chicago have moved their egg-laying forward by an average of 25 days.
And as far as the researchers can tell, the culprit in this shift is climate change.
“The majority of the birds we looked at eat insects, and insects’ seasonal behavior is also affected by climate,” says lead author John Bates, curator of birds at the Field Museum, U.S. “The birds have to move their egg-laying dates to adapt.”
The research was published in the Journal of Animal Ecology.
Rescued Victorian period rainfall data smashes former records
When the citizen science Rainfall Rescue project was launched in March 2020, it offered members of the public a distraction from the COVID-19 pandemic by digitally transcribing 130 years’ worth of handwritten rainfall observations from across the UK and Ireland.
Since then, some 16,000 volunteers responded to the challenge with their efforts revealing record-breaking Victorian weather (the driest year on record is now 1855), as well as providing more context around recent changes in rainfall due to human-caused climate change.
The results have been published in a new study in Geoscience Data Journal.
Startling similarities between the ‘teeth’ of grasshoppers and mammals
It likely comes as a surprise that not all grasshoppers eat grass – in fact, some are even carnivorous. But studying grasshopper diets can be difficult, as it requires detailed study of the contents of their guts or painstaking and time-consuming observations of how they feed in the wild.
Now, new research lead by paleobiologists has used sophisticated three-dimensional imaging techniques to precisely map the shape of grasshopper’s mandibles (used for biting and chewing), and comparing them with the topography of mammal teeth.
“Surprisingly, comparing the mandible landscapes of grasshoppers with mammals’ teeth allows grasshopper diet to be predicted with 82% accuracy,” says lead author Chris Stockey, a PhD student at the University of Leicester, UK.
“Pretty amazing when you consider that the mouthparts of mammals and grasshoppers have evolved independently for 400 million years, and were not present in their common ancestor.”
Their findings were presented in Methods in Ecology and Evolution.
Bacterial enzyme makes new type of biodegradable polymer
Strings of sugars, called polysaccharides, are the most abundant biopolymers on Earth. There is significant interest in their potential to replace synthetic polymers – such as plastics derived from fossil fuels – because they are biodegradable. These molecules also show promise as carrier materials for a broad range of therapeutics, because they’re not toxic to living tissue.
Now, researchers have identified a previously unknown bacterial enzyme that can make a new type of polysaccharide – which they’ve named acholetin – described in a new study published in ACS Central Science.
By screening a library of bacterial enzymes for their activities, the researchers found a candidate from a common contaminant of laboratory cell cultures: a bacteria called Acholeplasma laidlawii. They then expressed, purified, and determined the crystal structure of the enzyme, which they suspect could be involved in maintaining the bacteria’s cell membrane.
The new molecule, acholetin, could be useful for drug delivery, tissue engineering and other biomedical applications.
Imma Perfetto is a science journalist at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide.
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