Nav: Home

Phosphine on Venus

September 15, 2020

An international team of astronomers detected phosphine (PH3) in the atmosphere of Venus. They studied the origin of phosphine, but no inorganic processes, including supply from volcanos and atmospheric photochemistry can explain the detected amount of phosphine. The phosphine is believed to originate from unknown photochemistry or geochemistry, but the team does not completely reject the possibility of biological origin. This discovery is crucial to examine the validity of phosphine as a biomarker.

"When we got the first hints of phosphine in Venus's spectrum, it was a shock!", says team leader Jane Greaves of Cardiff University in the UK, who first spotted signs of phosphine in observations from the James Clerk Maxwell Telescope (JCMT), operated by the East Asian Observatory, in Hawai?i. Confirming their discovery required the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, a more sensitive telescope. The reason why she was so shocked is that phosphine can be produced by microbes on the Earth [1] , although the research team does not think that they found life on Venus.

How do you find life on a planet from quite far away? One way is to study its atmosphere and find a biomarker that can be evidence of the presence of living forms. If a molecule in the atmosphere is mainly produced by living organisms and the contribution from abiotic origins is negligibly small, it can be a good biomarker.

The international team led by Greaves, including Hideo Sagawa at Kyoto Sangyo University, studied the signal of phosphine in the radio spectra and found that the amount of the molecule is about 20 parts per billion in the atmospheric molecules. This is quite a small amount, but enough to astonish the researchers. This is because researchers have supposed that most of the phosphorus, if it existed in the first place, would bind with oxygen atoms because the Venusian atmosphere has a huge amount of oxygen atoms, although most of them are in the form of carbon dioxide (CO2).

The team carefully examined the possible origins of the phosphine: production by chemical reaction in the atmosphere driven by strong sunlight or lightning, supply from volcanic activity, and delivery by meteorites. The team found that all of these known processes failed to produce the observed amount of phosphine. The amount of phosphine molecules produced by those processes is 10,000 times smaller than the amount detected with the radio telescopes.

The researchers supposed that phosphine is produced by unknown photochemistry or geochemistry, but they also considered the possibility of biological origin. On Earth, some microbes produce and egest phosphine. If similar living organisms were in the Venusian atmosphere, they could produce the detected amount of phosphine.

"Although we concluded that known chemical processes cannot produce enough phosphine, there remains the possibility that some hitherto unknown abiotic process exists on Venus," says Sagawa. "We have a lot of homework to do before reaching an exotic conclusion, including re-observation of Venus to verify the present result itself."

Venus is Earth's twin, in terms of size. However, the atmospheres of the two planets are quite different. Venus has a very think atmosphere and the devastating greenhouse effect raises the surface temperature as high as 460 degrees Celsius. Some researchers argue that the upper atmosphere is much milder and possibly habitable, but the extremely dry and deadly acidic atmosphere would make it difficult for a life form similar to the ones on Earth to survive on Venus.

Further observations with large telescopes on the Earth, including ALMA, and ultimately on-site observations and a sample return of the Venusian atmosphere by space probes will provide crucial information to understand the mysterious origin of the phosphine.
-end-


National Institutes of Natural Sciences

Related Atmosphere Articles:

New study detects ringing of the global atmosphere
A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawai'i at Mānoa, shows that the Earth's entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.
Estuaries are warming at twice the rate of oceans and atmosphere
A 12-year study of 166 estuaries in south-east Australia shows that the waters of lakes, creeks, rivers and lagoons increased 2.16 degrees in temperature and increased acidity.
What makes Saturn's atmosphere so hot
New analysis of data from NASA's Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn's moons, spark the auroras and heat the planet's upper atmosphere.
Galactic cosmic rays affect Titan's atmosphere
Planetary scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) revealed the secrets of the atmosphere of Titan, the largest moon of Saturn.
Physics: An ultrafast glimpse of the photochemistry of the atmosphere
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
Using lasers to visualize molecular mysteries in our atmosphere
Molecular interactions between gases and liquids underpin much of our lives, but difficulties in measuring gas-liquid collisions have so far prevented the fundamental exploration of these processes.
The atmosphere of a new ultra hot Jupiter is analyzed
The combination of observations made with the CARMENES spectrograph on the 3.5m telescope at Calar Alto Observatory (Almería), and the HARPS-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) has enabled a team from the Instituto de Astrofísica de Canarias (IAC) and from the University of La Laguna (ULL) to reveal new details about this extrasolar planet, which has a surface temperature of around 2000 K.
An exoplanet loses its atmosphere in the form of a tail
A new study, led by scientists from the Instituto de Astrofísica de Canarias (IAC), reveals that the giant exoplanet WASP-69b carries a comet-like tail made up of helium particles escaping from its gravitational field propelled by the ultraviolet radiation of its star.
Iron and titanium in the atmosphere of an exoplanet
Exoplanets can orbit close to their host star. When the host star is much hotter than our sun, then the exoplanet becomes as hot as a star.
Astronomers find exoplanet atmosphere free of clouds
Scientists have detected an exoplanet atmosphere that is free of clouds, marking a pivotal breakthrough in the quest for greater understanding of the planets beyond our solar system.
More Atmosphere News and Atmosphere Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.