Alien beings could be living in the clouds of planet Venus, according to a new NASA-backed study by space scientists.

Researchers say simple microbial lifeforms might exist in the upper atmosphere of the world that has been dubbed Earth’s evil twin – and might even have been detected.

Mysterious dark patches have been observed in the clouds of Venus when viewed in ultraviolet light. They appear to resemble the light-absorbing properties of some bacteria on Earth, say the scientists.

Venus is a rocky world similar in size to our own, but incredibly inhospitable at the surface. The temperature there is twice the maximum setting in a kitchen oven and it rains sulphuric acid.

And if any astronaut avoided getting roasted or poisoned, they would be crushed to death by the pressure of the dense atmosphere.

However, new research by an international team of scientists says extraterrestrial microbes could survive by being blown around by winds in the cooler cloud tops of Venus.

Study co-author David J. Smith, of NASA’s Ames Research Center, says that similar bacteria and other organisms on Earth have been found alive at altitudes of as much as 41 km (about 25 miles).

Microbes have also been found living in the harshest environments on our planet, including, toxic sludge, acidic lakes, hot springs and hydrothermal vents deep in the ocean.

The team’s findings are published in the latest edition of the journal Astrobiology. You can read the original paper here.

Planetary scientist Sanjay Limaye, of the University of Wisconsin-Madison’s Space Science and Engineering Center, led the new research.

Dr Limaye is a NASA scientist working with a Japanese robotic space probe, Akatsuki, that is currently exploring Venus. He said: “Venus has had plenty of time to evolve life on its own.”

Dr Limaye wants to explore the Venusian atmosphere more following a chance meeting with Grzegorz Slowik, of Poland’s University of Zielona Góra, who drew attention to the light-absorbing bacteria.

Spectroscopic studies show the dark patches in Venus’s clouds are made up of concentrated sulphuric acid and other unknown light-absorbing particles.

Professor Rakesh Mogul, a biological chemist at California State Polytechnic University, Pomona, said: “On Earth, we know that life can thrive in very acidic conditions, can feed on carbon dioxide, and produce sulfuric acid.”

Venus, which is closer to the Sun than Earth, may have been habitable, with water on its surface, around two billion years ago.

But scientists believe its climate may have gone out of control due to global warming. Today the dry surface, which can only be mapped by radar through the dense clouds, is covered with active volcanoes.

Related: Smoking gun points to active volcanoes on Venus

Related: Was wet Venus once home to life?

The possibility of life in the clouds of Venus is not a new one, but has been discussed since the late 1960s.

Venus scientists are keen to send balloons or airships to drift in the planet’s atmosphere and find out more about what it is made of.

One advanced concept being prepared in the USA is for a delta-winged aircraft called VAMP (the Venus Atmospheric Maneuverable Platform) to be dropped by an orbiter into the clouds.

It would spend up to a year manoeuvring between the upper and mid cloud layers, gathering data to send back to Earth. During the Venusian day, it would fly in the higher atmosphere, charging its batteries from the sunlight, before dipping to lower regions again at night.

Related: Venus – our neighbour from hell