Can survive human life on Venus

Possible evidence of life on Venus discovered

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September 14, 2020, 5:41 pm

An international team of astronomers today announced the discovery of a rare molecule - phosphine - in the clouds of Venus. On earth, this gas is only produced industrially or by microbes that thrive in an oxygen-free environment. Astronomers have speculated for decades that high clouds on Venus could provide a home for microbes that hover well above the scorching surface but have to tolerate very high levels of acidity. The evidence of phosphine could indicate such an extraterrestrial "airy" life. A press release from the ESO Science Outreach Network (ESON).

This artist's impression shows our neighbor in the solar system, Venus, where scientists have demonstrated the presence of phosphine molecules. A representation of the molecule can be seen in the overlay. The molecules were detected in the high clouds of Venus in data from the James Clerk Maxwell Telescope and the Atacama Large Millimeter / Submillimeter Array, in which ESO is involved.
(Image: ESO / M. Kornmesser / L. Calçada & NASA / JPL / Caltech)
"When we got the first evidence of phosphine in the spectrum of Venus, it was a shock," says team leader Jane Greaves of Cardiff University in the UK, who saw the first signs of phosphine when observing the James Clerk Maxwell Telescope (JCMT), operated by the East Asian Observatory, discovered in Hawai'i. Confirming their discovery required the use of 45 antennas from the Atacama Large Millimeter / Submillimeter Array (ALMA) in Chile, a more sensitive telescope in which the European Southern Observatory (ESO) is a partner. Both facilities observed Venus at a wavelength of around 1 millimeter, much larger than the human eye can see - only telescopes at great heights can measure them effectively.

The international team, which includes researchers from the UK, USA and Japan, estimates that phosphine is present in the clouds of Venus in a low concentration of only about twenty molecules per billion. As a result of their observations, they performed calculations to determine whether these amounts could have come from natural, non-biological processes on the planet. Some ideas included sunlight, surface-blowing minerals, volcanoes, or lightning, but none of them could produce nearly enough of them. It found that these non-biological sources were no more than a ten-thousandth of the amount of phosphine the telescopes saw.

In order to produce the observed amount of phosphine (which consists of hydrogen and phosphorus) on Venus, the organisms on earth would only have to work at about 10% of their maximum productivity, according to the team. Earth bacteria are known to make phosphine: they take phosphate from minerals or biological material, add hydrogen, and eventually expel phosphine. All organisms on Venus are likely to be very different from their relatives on Earth, but they too should be able to produce the phosphine in the atmosphere.

This new image from ALMA, the Atacama Large Millimeter / Submillimeter Array, in which ESO is a partner, shows the planet Venus. The mottled disk is not a true feature of the planet, but may be due to the interferometer's response to the very bright emission from Venus, making it difficult to accurately map the largest scales.
(Image: ALMA (ESO / NAOJ / NRAO), Greaves et al.)
Although the discovery of phosphine in the clouds of Venus came as a surprise, the researchers are convinced of their discovery. “To our great relief, the conditions at the ALMA were good for follow-up observations when Venus was at a suitable angle to the earth. However, processing the data was difficult because ALMA does not normally look for very subtle effects in very bright objects like Venus, ”says team member Anita Richards from the UK ALMA Regional Center and the University of Manchester. "In the end, we found that both observatories had seen the same thing - weak absorption at the correct wavelength by phosphine gas, with the molecules being illuminated by the warmer clouds below," added Greaves, who wrote the study published today in Nature Astronomy directed.

Another team member, Clara Sousa Silva from the Massachusetts Institute of Technology in the USA, has researched phosphine as a "biosignature" gas for oxygen-free life on planets around other stars because normal chemistry produces so little of it. She comments, “Finding phosphine on Venus was an unexpected success! The discovery raises many questions, such as how any organisms could survive there. On earth, some microbes can tolerate up to about 5% acid in their environment - but the clouds of Venus are almost entirely made up of acid. "

The team believes their discovery is significant because it can rule out many alternative ways to make phosphine, but acknowledges that there is still a lot of work to be done to confirm the presence of "life". Although the high clouds of Venus reach temperatures of up to a pleasant 30 degrees Celsius, they are extremely acidic - around 90% sulfuric acid - and pose major problems for all microbes that try to survive there.

(Image: ESO / M. Kornmesser & NASA / JPL / Caltech)
ESO astronomer and ALMA European Operations Manager Leonardo Testi, who did not take part in the new study, explains: “According to our current understanding of phosphine chemistry in the atmosphere of rocky planets, the abiotic production of phosphine on Venus is excluded. Confirming the existence of life in Venus' atmosphere would be a major breakthrough in astrobiology. It is therefore essential to pursue these exciting results with theoretical and observational studies in order to rule out the possibility that phosphine on rocky planets could also have a different chemical origin than on Earth. "

Further observations of Venus and rocky planets outside our solar system, including with ESO's upcoming Extremely Large Telescope, could help gather clues as to how phosphine can form on them and help find signs of life outside the Earth .

Additional Information:
This study was published in Nature Astronomy under the title "Phosphine Gas in the Cloud Decks of Venus".

The team consists of Jane S. Greaves (School of Physics & Astronomy, Cardiff University, UK [Cardiff]), Anita MS Richards (Jodrell Bank Center for Astrophysics, The University of Manchester, UK), William Bains (Department of Earth, Atmospheric , and Planetary Sciences, Massachusetts Institute of Technology, USA [MIT]), Paul Rimmer (Department of Earth Sciences and Cavendish Astrophysics, University of Cambridge and MRC Laboratory of Molecular Biology, Cambridge, UK), Hideo Sagawa (Department of Astrophysics and Atmospheric Science, Kyoto Sangyo University, Japan), David L. Clements (Department of Physics, Imperial College London, GB [Imperial]), Sara Seager (MIT), Janusz J. Petkowski (MIT), Clara Sousa-Silva (MIT), Sukrit Ranjan (MIT), Emily Drabek-Maunder (Cardiff and Royal Observatory Greenwich, London, GB), Helen J. Fraser (School of Physical Sciences, The Open University, Milton Keynes, UK), Annabel Cartwright (Cardiff), Ingo Mueller- Wodarg (Imperial), Zhuchang Zhan (MIT), Per Frib erg (EAO / JCMT), Iain Coulson (EAO / JCMT), E'lisa Lee (EAO / JCMT) and Jim Hoge (EAO / JCMT).

This artist's impression shows the surface and atmosphere of Venus as well as phosphine molecules. These molecules float in the windswept clouds of Venus at heights of 55 to 80 km and absorb some of the millimeter waves that are created in lower layers of the air. They were detected in the high clouds of Venus in data from the James Clerk Maxwell Telescope and the Atacama Large Millimeter / Submillimeter Array, in which ESO is involved.
(Image: ESO / M. Kornmesser / L. Calçada)
A companion paper, written by some team members, entitled "The Venusian Lower Atmosphere Haze as a Depot for Desiccated Microbial Life": A Proposed Life Cycle for Persistence of the Venusian Aerial Biosphere, "was published in Astrobiology in August 2020. Another related study by some of these authors, "Phosphine as a Biosignature Gas in Exoplanet Atmospheres", was published in January 2020 in Astrobiology.

The ALMA (Atacama Large Millimeter / Submillimeter Array), an international astronomical facility, is a partnership between ESO, U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in collaboration with the Republic of Chile. ALMA is managed by ESO on behalf of its member states, by NSF in collaboration with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC), and by NINS in collaboration with Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). The construction and operation of ALMA is managed by ESO on behalf of its member states; by the National Radio Astronomy Observatory (NRAO), directed by Associated Universities, Inc. (AUI) on behalf of North America and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) ensures the uniform management and administration of the construction, commissioning and operation of ALMA.

With a diameter of 15 m (50 feet), the James Clerk Maxwell Telescope (JCMT) is the largest single astronomical telescope in the world specially designed to operate in the sub-millimeter wavelength range of the electromagnetic spectrum. The JCMT is used to study our solar system, interstellar and circumstellar dust and gas, evolved stars and distant galaxies. It is located on the Maunakea Science Reserve, Hawai’i, at an elevation of 4,092 m (13,425 feet). The JCMT is operated by the East Asian Observatory on behalf of NAOJ; ASIAA; KASI; CAMS and the National Key R&D Program of China. Additional financial support will be provided by the STFC and participating universities in the UK and Canada.

About the ESO:
The European Southern Observatory (ESO) is the leading European organization for astronomical research and the most scientifically productive observatory in the world. The organization has 16 member countries: Belgium, Denmark, Germany, Finland, France, Great Britain, Ireland, Italy, the Netherlands, Austria, Poland, Portugal, Spain, Sweden, Switzerland and the Czech Republic. In addition, the host country Chile and Australia are strategic partners. ESO is running an ambitious program focused on designing, building and operating high-performance ground-based observation facilities that enable astronomers to make important scientific discoveries. The organization also plays a key role in promoting international cooperation in the field of astronomy.

ESO has three worldwide unique observation sites in Chile: La Silla, Paranal and Chajnantor. On the Paranal, ESO operates the Very Large Telescope (VLT) and the world's leading Very Large Telescope Interferometer as well as two survey telescopes: VISTA in the infrared range and the VLT Survey Telescope (VST) for visible light. At Paranal, ESO will also host and operate the Cherenkov Telescope Array South, the largest and most sensitive gamma-ray observatory in the world. ESO is also one of the main partners in two projects on Chajnantor, APEX and ALMA, the largest astronomical project ever. On Cerro Armazones, not far from Paranal, ESO is currently building the Extremely Large Telescope (ELT) with a diameter of 39 meters, which will one day become the largest optical telescope in the world.

The translations of English-language ESO press releases are a service of the ESO Science Outreach Network (ESON), an international network for astronomical public relations work in which scientists and science communicators from all ESO member countries (and several other countries) are represented. The German node of the network is the House of Astronomy in Heidelberg.

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