Sunday, 27 November, 2022
HomeScientiFixScientists decode how Jupiter's moon got its dune 

Scientists decode how Jupiter’s moon got its dune 

ScientiFix, our weekly feature, offers you a summary of the top global science stories of the week, with links to their sources.

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New Delhi: Scientists have decoded how Jupiter’s innermost moon, Io, has dunes — even though its surface is icy. Current scientific understanding dictates that dunes are hills or ridges of sand piled up by the wind.

The team completed a study of the physical processes controlling grain motion coupled with an analysis of images from the 14-year mission of NASA’s Galileo spacecraft, which allowed the creation of the first detailed maps of Jupiter’s moons.

Previous studies of Io, while describing its surface as containing some dune-like features, concluded the ridges could not be dunes since the forces from winds on Io are weak due to the moon’s low-density atmosphere.

However, the latest findings suggest that volcanoes repeatedly resurface on the moon. As a result, Io’s surface is a mix of black solidified lava flows and sand, flowing lava streams, and “snows” of sulfur dioxide.

The scientists used mathematical equations to simulate the forces on a single grain of basalt or frost and calculate its path. When lava flows into sulfur dioxide beneath the moon’s surface, it is dense and fast-moving enough to move grains on Io and possibly enable the formation of large-scale features like dunes. Read more 


Also Read: Ancient rock shows there was life on Earth 3.75 billion years ago, much earlier than we thought


 

Newly discovered millipede species named after Taylor Swift

Scientists have named a newly discovered millipede species after the US singer Taylor Swift.

The twisted-claw millipede — named Nannaria swiftae — joins 16 other new species described from the Appalachian Mountains of the United States.

These invertebrates play a valuable role as decomposers. They break down leaf litter, release their nutrients into the ecosystem. They live on the forest floor, feeding on decaying leaves and other plant matter.

Scientists have long suspected that the twisted-claw millipedes included many new species. A team from Virginia Tech in the US researchers began a multi-year project to collect new specimens throughout the eastern US. They traveled to 17 US states, checking under leaf litter, rocks, and logs to find species so that they could sequence their DNA and scientifically describe them.

Looking at over 1,800 specimens collected over their field study or taken from university and museum collections, the team described 17 new species.

They discovered that the millipedes prefer to live in forested habitats near streams and are often found buried under the soil, exhibiting more cryptic behaviors than relatives.

The newly-described millipedes range between 18 and 38 mm long, have shiny caramel-brown to black bodies with white, red, or orange spots, and have white legs. The males have small, twisted, and flattened claws on their anterior legs, which is the basis for their common name.

Because the lead author of the study is a fan of Taylor Swift, one of the species was named after her. Read more

NASA’s James Webb instrument cool down to operating temperature

The Mid-Infrared Instrument abroad NASA’s James Webb Space Telescope has managed to cool down to its final operating temperature below 7 kelvin — which is about minus 266 degrees Celsius.

The Webb space telescope aims to capture images of the very first galaxies to form after the Big Bang, but to do that, its instruments first need to get cold.

The low temperature is necessary because all four of Webb’s instruments detect infrared light—wavelengths slightly longer than those that human eyes can see. Distant galaxies, stars hidden in cocoons of dust, and planets outside our solar system all emit infrared light. But so do other warm objects, including Webb’s own electronics and optics hardware. Cooling down the four instruments’ detectors and the surrounding hardware suppresses those infrared emissions. MIRI detects longer infrared wavelengths than the other three instruments, which means it needs to be even colder.

Along with Webb’s three other instruments, MIRI initially cooled off in the shade of Webb’s tennis-court-size sunshield, dropping to about minus 183°C.

But dropping to the optimum temperature required an electrically powered cryocooler. Last week, the team passed a particularly challenging milestone called the “pinch point,” when the instrument goes from minus 258°C to minus 267°C.

Another reason Webb’s detectors need to be cold is to suppress something called dark current, or electric current created by the vibration of atoms in the detectors themselves.

Dark current mimics a true signal in the detectors, giving the false impression that they have been hit by light from an external source. Those false signals can drown out the real signals astronomers want to find. Since temperature is a measurement of how fast the atoms in the detector are vibrating, reducing the temperature means less vibration, which in turn means less dark current.

There are still more challenges that the team will have to face before MIRI can start its scientific mission.

Now that the instrument is at operating temperature, team members will take test images of stars and other known objects that can be used for calibration and to check the instrument’s operations and functionality. The team will conduct these preparations alongside the calibration of the other three instruments, delivering Webb’s first science images later this year. Read more 


Also Read: Why human speech will sound garbled on Mars & lettuce to help astronauts retain bone mass


World’s largest particle accelerator to go back online

The world’s largest and most powerful particle accelerator is about to turn back on.

In December of 2018, the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland, was shut down so that improvements and updates could be made to the facility.

CERN expects the particle accelerator to restart sometime between April 22 and April 24, This will be the third run for the particle accelerator.

The LHC functions by making particles like protons accelerate — such that they approach the speed of light. These particles then collide with one another — allowing scientists to get a glimpse of the subatomic particles and their interactions

At the extremely high energies the LHC can create, scientists are able to explore mysterious phenomena like dark matter and dark energy.

The latest improvements increased the power of the LHC’s injectors, which feed the beams of accelerated particles into the collider.

The increase in energy will allow the LHC to pull off even higher energy collisions than before, potentially revealing new insights into how particles behave. Read more 

Link found between bacteria and aggressive prostate cancer

Researchers at the University of East Anglia have found a link between bacteria and aggressive forms of prostate cancer — a finding that could help pave the way for treatments that could target these particular bacteria and slow or prevent the development of aggressive disease.

The team found five types of bacteria that were common in urine and tissue samples from men with aggressive prostate cancer.

Previous studies have already shown some strong links between infections and cancer. Helicobacter pylori bacteria in the digestive tract can lead to stomach ulcers and is associated with stomach cancer, and some types of the HPV virus can cause cervical cancer.

The team analysed samples from more than 600 patients with or without prostate cancer. They found five types of bacteria associated with aggressive prostate cancer, some of which are new types of bacteria never found before.  All of these are anaerobic, which means they like to grow without oxygen present.

This will now enable further work to determine if there are causal relationships between microbes and cancer. Read more 


Also Read: Fossil leads to discovery of sabre-toothed predator & how fallen meteorites can be found using AI


 

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