When a team of researchers reported that phosphine was found in Venus' atmosphere, how scientists next confirmed or denied the existence of life in the Venus cloud.
Illustration: Venus, NASA's Sailor 10 probe was taken in 1974, source: NASA/JPL-Caltech
Yesterday, we were blown up by a piece of information: a research team reported that phosphine was found in the atmosphere of Venus, which was a potential sign of life. This discovery will rekindle the scientific community’s interest in our planetary neighbors. Here are what will happen next and how scientists can confirm or deny the existence of life in the Venus clouds.
Phosphine is a combustible gas that is usually found in stinky swamps and penguin feces, but astrobiologists often don't tend to focus on this gas in their research in their constant search for alien life. This situation changed in yesterday , due to a new paper announcing the discovery of phosphine in Venus’ atmosphere.
On Earth, this gas (one phosphorus atom accompanied by three hydrogen atoms) is produced mainly by microorganisms that can thrive in an oxygen-deficient environment. It is surprising to find about twenty parts per billion of phosphine on Venus, even though it is much less than on Earth, because there shouldn't be life on this planet, and this gas should be killed by ultraviolet radiation and a large amount of sulfuric acid in Venus' clouds. It seems that something appears on Venus and produces phosphine, but what?
The authors of the new study appear to be very restrained in the analysis of the project led by Cardiff University astronomer Jane Greaves, who said the new study is not evidence of life on Venus. But they also do say that phosphine is likely to be produced by some unknown chemical process or life itself.
Venus has never been a target for astrobiologists, because the surface temperature of this planet is as high as 860 degrees Fahrenheit (450 degrees Celsius), and its air pressure is 90 times that of us on Earth. If life really exists on Venus (and that's a big if) it will force us to seriously rethink the habitability of planets inside and outside the solar system.
For understandable reasons, although Venus is the closest planet to Earth, it is very little known. Historically, it has been an unpopular research target, perhaps because a scientific mission is very expensive, while other planets, namely Mars, have received a lot of attention.
"Over the past 20 years, we have made new discoveries that suggest a significant increase in the likelihood of discovering life elsewhere," a NASA spokesman explained in an emailed statement. "As with more and more planets, Venus is also an exciting planet, although due to its extreme temperatures, atmospheric composition and other factors, Venus has not become an important planet in search of life.
Accordingly, scientists have incomplete knowledge of Venus' surface topography, geology (including its geological history), structure and potential volcanic activity. However, the discovery of phosphine on Venus is "the most important advance in the reasons for the creation of life outside the Earth so far," NASA administrator Jim Bridenstine added in a tweet yesterday: "It's time to prioritize Venus." "
Indeed, it's time to conduct a scientific investigation of Venus. However, before we send the probe to investigate, there is still a lot of work on Earth. First, scientists need to confirm the phosphine wavelength signals collected by Greaves and her colleagues using the Maxwell Telescope
in Hawaii and the Atacama Large Millimeter [/submm] wave array in Chile.
"The first task should be to confirm the detection results by searching for phosphine at other wavelengths, and also try to map the global distribution of phosphine," Stanley Limaya, a scientist at the University of Wisconsin-Madison, explained in an email."This is not easy, because the abundance of ultraviolet and infrared wavelengths is relatively small, so the spectral characteristics of phosphine may be masked by the characteristics of more abundant chemicals such as carbon dioxide, water vapor, sulfuric acid, etc.."
Limayer said that Venus, as an inner planet, will never be too far from the sun in the sky, which makes observations at certain wavelengths difficult. Thankfully, he pointed out that radio observations do not have this problem. In addition to finding biologically specific gases, scientists should also look for discernible contrasting features in Venus’ atmosphere and try to track the evolution and chemical properties of these features, he said.
Two years ago, Limayer led a study to discuss the question of the contrasting characteristics of dark spotted forms that may be a hallmark of life on Venus, whose atmosphere may be able to produce microorganisms. This seemed like a weird idea at the time. But in today, is not that weird.
Finally, we will want to send a probe to Venus. As NASA explained in an email statement, the good news is that two of the four candidate missions of NASA’s future discovery program—VERITAS ( Variable Energy Radiation Imaging Telescope Array ?) and DAVINCI+—were focused on Venus, as is the European Space Agency’s EnVision mission, which is its partner. Because Venus is very close, it can also be explored with smaller flight missions.
Illustration: Envision Plan Source: envisionvenus
DAVINCI+ is the abbreviation of rare gases, chemical composition and imaging in the deep atmosphere of Venus. It is a detector that will slowly descend to the surface of Venus with a parachute. With one of its on-board instruments, the detector will sniff out various gases and map the surface. VERITAS is the abbreviation for Venus emissivity, radio science, InSAR, topographic maps and spectroscopy, and involves a satellite orbiting Venus. In addition to creating a three-dimensional topographic map of the planet, the probe will measure the temperature of Venus, study the gravitational field of Venus, conduct some remote geological studies, and deploy a detector equipped with a mass spectrometer to detect chemical characteristics. EnVision is a satellite that mainly studies the geology of the planet, but given its impressive array of sensors, the probe can be used for many other tasks.
Illustration: DAVINCI+ concept image, it is descending to the surface of Venus Source: NASA/GSFC
There are also some private sectors that can also consider it, namely, the Venus mission proposed by Rocket Lab founder and millionaire Peter Baker (you may still remember his disco spherical object "Human Star" launched into orbit in 2018). According to Baker's plan, a detector with multiple instruments will be sent into Venus' atmosphere. At a press conference yesterday, Greaves said her team was open to working with the private sector.
Illustration: "Human Star". Source: Rocket Laboratory.
It should be noted that none of these tasks were approved, but Venus became quite sexy and popular overnight.
Once these or other detectors are deployed, scientists should sample clouds, which are about 29 to 43 miles (47 to 70 kilometers) from the surface. Limayer described these investigations as "essential". By taking measurements in clouds, he explained that scientists "should be able to discover any gas present, not only phosphine, but other gases of biological significance, such as methane." Another useful task is to determine the physical, chemical and biological properties of cloud droplets, because microorganisms can survive in it," he said, of course, assuming that microorganisms do exist on Venus.
Limayer said a semi-buoyancy platform like Northrop Grumman's VAMP would be ideal for this task, as it can be equipped with a microscope, spectrometer and other instruments.
Illustration: Conceptual diagram of VAMP, Venus Atmospheric Mobility Platform (VAMP) aircraft (AV) is a semi-buoyancy, maneuverable, solar-powered aircraft flying in the Venus atmosphere, which has no bullet-free hypersonic entry into the aircraft.Source: northropgrumman
Another possibility is a balloon similar to the Soviet Vega mission in the mid-1980s. It's "the kind of thing we want to see happen again," Sarah Sieger, an astrobiologist from MIT and co-author of the new study, said in a press conference yesterday. "Maybe the super version of Vega's balloons, not lasting for a few days, but can last for a week, months, or even years," she said. Sieg describes Vega balloons as "the best way to study Venus' atmosphere" for the same reason as Limayer emphasizes: To be fair, Vega balloons will be much less maneuverable than VAMP or similar aircraft, such as those proposed stingray-shaped gliders called BREEZE.
Illustration: Artist's conceptual diagram of BREEZE. Source: CRASH Laboratory, University of Buffalo,
, Limaye and Sieg both said that airborne spectrometers are crucial to such tasks.
Limayer explained that "spectrometers working at different wavelengths from ultraviolet to millimeter waves can map distributions of phosphine, sulfur dioxide and other gases to determine whether they are related to the contrasting characteristics of clouds seen in Venus images."
As Limayer and his colleagues proposed in a 2018 paper, this could allow scientists to understand the connection between possible forms and contrasting characteristics of life. Other important instruments of the atmospheric detector will include meteorological sensors for collecting environmental data, chemical sensors for studying the composition of planets’ atmospherics, fluorescence imaging microscopes for physical and biometric descriptions, and other sensors that can detect biometric features. For Venus orbiters, Limayer recommends using a multispectral imaging camera, you guessed it, and a spectrometer.
In addition to these projects, scientists need to figure out what interesting non-biological or biochemical reactions may occur in Venus’ atmosphere. Phosphine on Saturn and Jupiter is naturally produced through non-biological processes, but there are no similar conditions on Venus. Maybe there are some things that scientists don't consider, as the new institute suggests. Computer algorithms are able to mix and match atomic combinations may be helpful.
At the same time, biologists should figure out how extreme microorganisms can withstand the harsh conditions in Venus' atmosphere. As Greaves explained in a press conference, "the real challenge is whether there is life that can evolve to adapt to this incredibly acidic environment" because there is nothing like that on Earth. Simply put, this life form is actually impossible to exist in evolution or biologically.
In fact, it is time for scientists to conduct multidisciplinary research, because this work requires astronomers, engineers, astrobiologists, microbiologists, chemists, geologists, computer scientists and planetary scientists, as well as other experts (for example, studying these microorganisms, if they exist, what are the ethical and safety issues? What if we accidentally contaminate Venus with bacteria on our planet in the rush to find life?). ) Of course, all the obtained data must be carefully inspected, confirmed and copied before scientists can make clear conclusions.
No one has ever said we will find alien life very quickly and easily, but with microscopic aliens likely to linger at our doorstep, it's time to seriously improve our gameplay.
Author: George Dvorsky
FY: Qiubai
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