More evidence of signs of life on Venus

The data, the researchers say, provides strong evidence that phosphine is present in the clouds of Venus, Earth's closest planetary neighbor. Sometimes called Earth's twin, the planet is similar in size to Earth but has surface temperatures hot enough to melt lead. It also has clouds made of corrosive sulfuric acid.

Unexpected discoveries

Some of this data comes from a new receiver installed on one of the instruments used for the observations, the James Clerk Maxwell Telescope in Hawaii, giving the team more confidence in its findings.

"We've collected 140 times more data than the original detection. What we've collected so far shows that we've detected phosphine again," said Dave Clements, a reader in astrophysics at Imperial College London.

The discovery, first presented on July 17 at a meeting of the Royal Astronomical Society, could form the basis for one or more subsequent scientific studies.

Another team, including Mr Clements, has found evidence of another gas, ammonia. “That might be more significant than the discovery of phosphine,” he says.

NASA's Mariner 10 spacecraft photographed Venus in the 1970s, when Venus was covered in a thick layer of clouds. Photo: NASA

Signs of life?

On Earth, phosphine is a foul-smelling toxic gas produced by the decomposition of organic matter or bacteria, while ammonia is a pungent-smelling gas naturally occurring in the environment and also primarily produced by bacteria at the end of the decomposition of plant and animal waste.

"Phosphine has been detected in Saturn's atmosphere, but that's not surprising since Saturn is a gas giant," Clements said.

However, rocky planets like Earth, Venus, and Mars have atmospheres where oxygen is chemically dominant, so finding these gases on Venus was unexpected.

The existence of bacteria?

Ammonia on Venus would make an even more surprising discovery . Jane Greaves, professor of astronomy at Cardiff University in the UK, said the findings would form the basis of a separate scientific paper, using data from the Green Bank Telescope in West Virginia.

Clements says Venus' clouds are made up of droplets, but not water droplets. There is water in them, but there is also a lot of dissolved sulfur dioxide, making them extremely concentrated sulfuric acid – a highly corrosive substance that can be fatal to humans if exposed for long enough.

Venus' northern hemisphere photographed by NASA's Magellan spacecraft in 1996. Photo: NASA/JPL

“It’s so concentrated that it’s incompatible with any life we ​​know of on Earth, including extremophiles, which prefer highly acidic environments,” he said, referring to organisms that can survive in harsh environmental conditions.

However, the ammonia inside these acid droplets can act as a buffer to the acidity and bring it down to levels low enough for some types of bacteria on Earth to survive.

“If there is some kind of bacteria that produces ammonia, it means it has adapted to make its environment much less acidic and is able to survive, to the point where it is only as acidic as some of the most inhospitable places on Earth,” Greaves said.

In other words, the role of ammonia is easier to explain than phosphine. “We understand why ammonia might be useful for life. We don’t understand how ammonia is produced, just as we don’t understand how phosphine is produced, but if ammonia is there, it would have a functional purpose that we could understand,” Clements says.

However, Greaves cautions, the presence of both phosphine and ammonia is not necessarily evidence of microbial life on Venus, as much is still unknown about the planet's conditions.

Ngoc Anh (according to CNN)

Source: https://www.congluan.vn/them-nhieu-bang-chung-ve-dau-hieu-su-song-tren-sao-kim-post305495.html