Scientists’ Search for Alien Life Leads to Venus’ Clouds
Scientists in search for physical extraterrestrial life have shifted their attention to Venus after a recent study proposed that its clouds can potentially harbor alien life. In the past, Mars was looked at as the most likely planet to have life in our solar system. The new research shows that Venus is even more equipped for life than Mars—at least the clouds above Venus.
Besides Mars and Venus, other likely candidates in this solar system are Saturn’s moons Titan and Enceladus, as well as Jupiter’s moons Europa, Ganymede and Callisto. If life on these moons exists, it is likely in the oceans under the ice. However, the clouds of Venus currently hold the most promise in the search for life.
Venus Has More Chances of Life than Mars
An international team of researchers recently published their case that the atmosphere of Venus is a great candidate for extraterrestrial microbial life. The article was published on March 30, 2018, in Astrobiology under “Venus’ Spectral Signatures and the Potential for Life in the Clouds.”
Comparing to Mars, the new findings of Venus are even more promising. The geological features of Mars suggest that the planet once had, and still has, subsurface liquid water which is needed for life to exist. What the researchers discussed is that Venus once had liquid water for at least 2 billion years—much longer than Mars. This makes it a prime candidate for life.
“Venus has had plenty of time to evolve life on its own,” explains planetary scientist Sanjay Limaye of the University of Wisconsin-Madison’s Space Science and Engineering Center.
Venus could have been habitable “for much of solar system history,” adds astrobiologist David Grinspoon.
The planet has now dried up and heated up to above 860 degrees Fahrenheit, which is considered to be inhospitable by current data. If advanced life has existed on Venus, when all water has evaporated, lava has likely destroyed all of the planet’s history. However, some life on Venus may have moved up into the atmosphere to live in the clouds.
Lower and middle parts of Venusian atmosphere at 25 to 27 miles altitudes have temperature and pressure conditions that could allow life—most likely bacteria.
Bacteria are known to be able to survive in a variety of harsh environment as we see on Earth. They can survive in acidic conditions, toxic and polluted areas, and very hot regions. It is likely to be able to survive in the clouds of Venus.
Algae on Earth May Be Similar to Mysterious Spots in the Clouds of Venus
One possible confirmation to the theory about the extraterrestrial microbial life of Venus has already been found.
Light-absorbing bacteria on earth are remarkably similar to unidentified particles observed in the unexplained dark patches in the clouds of Venus.
“Venus shows some episodic dark, sulfuric rich patches, with contrasts up to 30-40 percent in the ultraviolet, and muted in longer wavelengths. These patches persist for days, changing their shape and contrasts continuously and appear to be scale dependent,” says Limaye.
The particles in these patches have the same dimensions as some of the bacteria on Earth. Actually, they are remarkably similar to algae found in the waters on Earth usually found in lakes and oceans. Limaye visited a high-altitude salt lake in northern India called Tso Kar to observe what could be a clue to microbial life on Venus. He observed the residues of sulfur-fixing bacteria that live on dying grass around the lake. The unexplored Venusian atmosphere may have residues of this type of bacteria.
The idea of life on Venus is not new. It was first proposed by famous astronomer Carl Sagan and biophysicist Harold Morowitz in 1967. Later it was expanded by planetary scientists David Grinspoon and Mark Bullock, and now the 2018 study added more life to it prompting further research.
One proposed way of sampling the clouds on Venus is by using a flying craft called VAMP or Venus Atmospheric Maneuverable Platform. It could stay afloat a cloud for a year gathering samples and data.
“To really know, we need to go there and sample the clouds. Venus could be an exciting new chapter in astrobiology exploration,” said Rakesh Mogul, a professor of biological chemistry at California State Polytechnic University and one of the Venus study co-authors.
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