Bio- inspired ‘ invisibility cloak’ developed
Washington, April 1: The clouds of Venus may possibly host alien life, say scientists who suggest that microbes may have evolved on the planet.
Some models suggest Venus once had a habitable climate with liquid water on its surface for as long as two billion years.
“That’s much longer than is believed to have occurred on Mars,” said Sanjay Limaye of the University of WisconsinMadison in the US.
On Earth, terrestrial microorganisms — mostly bacteria - are capable of being swept into the atmosphere, where they have been found alive at altitudes as high as 41 kilometres by scientists using specially equipped balloons, according to David J Smith of Nasa’s Ames Research Center.
There is also a growing catalogue of microbes known to inhabit incredibly harsh environments on our planet, including the hot springs of Yellowstone, deep ocean hydrothermal vents, the toxic sludge of polluted areas, and in acidic lakes worldwide.
“On Earth, we know that life can thrive in very acidic conditions, can feed on carbon dioxide, and produce sulphuric acid,” said Rakesh Mogul, a professor at California State Polytechnic University in the US.
The cloudy, highly reflective and acidic atmosphere of Venus is composed mostly of carbon dioxide and water droplets containing sulphuric acid, he said.
Supporting that Venus’ atmosphere could be a plausible niche for life, a series of space probes to the planet launched between 1962 and 1978 showed that the temperature and pressure conditions in the lower and middle portions of the Venusian atmosphere — altitudes between 40 and 60 kilometres — would not preclude microbial life.
The surface conditions on the planet, however, are known to be inhospitable, with temperatures soaring above 450 degrees Celsius.
According to Grzegorz Slowik of University of Zielona Gora in Poland, certain bacteria on Earth have light- absorbing properties similar to those of unidentified particles that make up unexplained dark ◗ patches observed clouds of Venus.
Spectroscopic observations, Los Angeles, April 1: Inspired by real- life shy squid, scientists have developed soft ‘ invisibility cloaks’ that can change how they reflect heat, making them undetectable to night vision tools.
The thin swatches can quickly smoothen or wrinkle their surfaces in under a second after being stretched or electrically triggered.
This makes them invisible to infrared night vision tools or lets them modulate their temperatures.
“We’ve invented a soft material that can reflect heat in similar ways to how squid skin can reflect light,” said Alon Gorodetsky, a professor at University of California, Irvine in the US.
“It goes from wrinkled and dull to smooth and shiny, essentially changing the way it reflects the heat,” said Gorodetsky.
Potential uses include better camouflage for troops and insulation for spacecraft, storage containers, particularly in the ultraviolet, show that the dark patches are composed emergency clinical care, building heating cooling systems.
“We were inspired both by science fiction and science fact — seeing dinosaurs disappear and reappear under an infrared camera in ‘ Jurassic World’ and seeing squid filmed underwater do similar things,” said Gorodetsky.
“So we decided to merge those concepts to design a really unique technology,” he said.
Made of sandwiches of aluminium, plastic, and sticky tape, the material transforms from a wrinkled grey to a glossy surface when it is either pulled manually or shelters, and and of concentrated sulphuric acid and other unknown light- absorbing particles.
Those dark patches have been a mystery since they were first observed by ground- based telescopes nearly a century ago, said Limaye, who led the study published in the journal Astrobiology.
They were studied in more detail by subsequent probes to the planet.
“Venus shows some episodic dark, sulphuric rich patches, with contrasts up to 30- 40 per cent in the ultraviolet, and muted in longer wavelengths,” said Limaye of the University of Wisconsin- Madison in the USLimaye.
“These patches persist for days, changing their shape and contrasts continuously and appear to be scale dependent,” he said.
The particles that make up the dark patches have almost the same dimensions as some bacteria on Earth, although the instruments that have sampled Venus’ atmosphere to date are incapable of distinguishing between materials of an organic or inorganic nature.
The patches could be something akin to the algae blooms that occur routinely in the lakes and oceans of Earth, researchers said.
“To really know, we need to go there and sample the clouds. Venus could be an exciting new chapter in astrobiology exploration,” said Mogul, professor at California State Polytechnic University in the US. zapped with voltage.
Products that reflect heat, such as emergency blankets, have existed for decades. However, in the past several years, inventors in Gorodetsky’s lab and others have pushed to create dramatically improved versions.
One focus has been to imitate how squid and other cephalopods can nearly instantaneously change their skin to blend into their surrounding environment.
Researchers have created prototypes that can next be scaled up into large sheets of commercially usable material.
“It was hard, especially the first phase when we were learning how to work with the sticky material,” said Chengyi Xu, lead author of the study published in the journal Science.
After trial- and- error processes involving thousands of attempts, researchers finally saw the mirror- like coating change when they pulled it sideways.