Nothing about 2020 surprises us anymore. It has been the year of pandemics, wildfires, asteroids zooming past Earth and now, aliens.
Scientists said on Monday that they have detected in the harshly acidic clouds of Venus, a gas called phosphine, that indicates microbes may inhabit Earth’s inhospitable neighbour, a tantalizing sign of potential life beyond Earth.
This could be indicative of the presence of alien life on a planet that has always been described as inhospitable.
Here's what we know thus far about the stunning finding.
What have the scientists discovered?
In a study published in Nature Astronomy, the researchers have reported traces of phosphine in small concentration on Venus - of around 20 parts per billion, which is much more than what can be expected. The gas has been detected in the highly toxic atmosphere of Venus, as reported by New York Times. The Indian Express reports that this groundbreaking discovery was apparently made in 2017, but the scientists chose dig deeper and confirm before going public with it this year.
Did the scientists find life on Venus?
No, technically, they did not. No images of alien life form have been captured, nor have the scientists been able to bring back specimens of microbes to examine them.
In short, the team of scientists, from the UK, US and Japan, have not found life form on Venus. Instead, they found a substance, Phosphine, which is usually found on Earth either industrially or when microbes thrive in the absence of oxygen.
According to a report by Reuters, the discovery of phosphine is a major breakthrough and could indicate life on the planet. However, life, as an explanation for the discovery should be the last resort, according to Massachusetts Institute of Technology molecular astrophysicist and study co-author Clara Sousa-Silva.
“I should emphasize that life, as an explanation for our discovery, should be, as always, the last resort,” Sousa-Silva added. “This is important because, if it is phosphine, and if it is life, it means that we are not alone. It also means that life itself must be very common, and there must be many other inhabited planets throughout our galaxy.”
The abstract of the study published in the journal mentions clearly that the presence of phosphine on Venus is unexplained. After detailed and thorough study, the scientists have not been able to determine the source of the gas.
"The presence of PH3 is unexplained after exhaustive study of steady-state chemistry and photochemical pathways, with no currently known abiotic production routes in Venus’s atmosphere, clouds, surface and subsurface, or from lightning, volcanic or meteoritic delivery," says the first part of the study.
What is Phosphine?
Phosphine - a phosphorus atom with three hydrogen atoms attached - is highly toxic to people. It is a colourless but smelly gas which is usually produced when microbes, like bacteria, survive in the absence of oxygen. The researchers examined potential non-biological sources such as volcanism, meteorites, lightning and various types of chemical reactions, but none appeared viable. The research continues to either confirm the presence of life or find an alternative explanation.
On Earth, microorganisms in “anaerobic” environments - ecosystems that do not rely on oxygen - produce phosphine. These include sewage plants, swamps, rice fields, marshlands, lake sediments and the excrements and intestinal tracts of many animals. Phosphine also arises non-biologically in certain industrial settings.
To produce phosphine, Earth bacteria take up phosphate from minerals or biological material and add hydrogen.Ideally, given that Venus is extremely hostile and completely toxic and inhospitable, it should be destroying the phosphine that is in its clouds. Reuters adds that its surface and atmosphere are rich in oxygen compounds that would rapidly react with and destroy phosphine.
Yet, that has not happened.
“Something must be creating the phosphine on Venus as fast as it is being destroyed,” said study co-author Anita Richards, an astrophysicist associated with the University of Manchester in England.
But is Venus able to support life?
Ideally, it should not.
Venus is Earth’s closest planetary neighbour. Similar in structure but slightly smaller than Earth, it is the second planet from the sun. Earth is the third. Venus is wrapped in a thick, toxic atmosphere that traps in heat. Surface temperatures reach a scorching 880 degrees Fahrenheit (471 degrees Celsius), hot enough to melt lead.
The planet has massive concentrations of carbon dioxide and the thick atmosphere of the planet exerts a pressure of 1,300 pounds per square inch on whatever is present on the surface. As NY Times reports, all these factors make it extremely difficult to visit Venus or even examine the supposed life form that exists on it. Apparently, Venus destroys any metal that lands on its surfaces, including spacecraft.
What about Venus exploration missions?
Once reports of alien life on Venus began doing the rounds on social media, several pointed out that it was now time to prioritise Venus over other planets like Mars. For long, scientists have focused on Mars and traces of water on it as the most likely planet to have a life form on it. On the other hand, Venus is considered to be the most "hellish" planet in the solar system.
Despite the aforementioned hostile conditions on Venus, human beings have tried to send up spacecrafts to explore the planet. Here's a chronology of missions to Venus, starting from 1961. However, none have been successful per say. Currently, the Japanese spacecraft Akatsuki is the only one monitoring the planet.
How significant is this discovery?
This is, by far, the most credible evidence of the presence of life outside our planet. In fact, some scientists reportedly believe that this could be more important than finding water traces on Mars.
The administrator of NASA, Jim Bridenstine, also said on Twitter that it is time to prioritise Venus, which has long been ignored owing to its hostile environment. Dr David L Clements, Reader in Astrophysics at Imperial College London, told Express UK that the discovery will shift everyone's attention to Venus. According to him, this will prompt more scientists to find out what exactly is going on on Venus. If it is life that is releasing phosphine, then researchers will have to find out more about it. If not, it will give a better understanding of the planet and the complex chemistry it possesses.
“We have done our very best to explain this discovery without the need for a biological process. With our current knowledge of phosphine, and Venus, and geochemistry, we cannot explain the presence of phosphine in the clouds of Venus. That doesn’t mean it is life. It just means that some exotic process is producing phosphine, and our understanding of Venus needs work,” one of the researchers said.
While previous robotic spacecraft have visited Venus, a new probe may be needed to confirm life.
“Fortunately, Venus is right next door,” Sousa-Silva said. “So we can literally go and check.”(With inputs from Reuters)