By: Nour Hany
For years, we have been hearing stories about the search for life on Mars, and how wonderful it would be to have our human race inhabiting the red planet. Recently, and quite surprisingly to the public, it has been announced that scientists were able to detect the existence of a gas known as phosphine, which on Earth is produced by microorganisms, in the Venusian atmosphere!
The discovery of phosphine, however, does not necessarily mean that scientists have found proof of alien life on Venus. This is a completely new phenomenon that scientists are trying to understand, and could eventually turn out to be something completely different. It could be produced by some form of life, or simply forged by a type of chemical process that has not been seen before.
The discovery began when Jane Greaves, an astronomer at Cardiff University in Wales, decided to apply the words she read in a scientific paper, stating that phosphine is the bio-signature of our planet Earth, which could be seen from far away. She used a ground-based telescope in Hawaii to observe Venus, as it is similar to Earth in size and mass. She was not really expecting to see or to discover anything unusual, then her eyes noticed a pattern of light coming through Venus’s clouds; the light that the gas emits, creating a biosignature for Venus!
Greaves tested the same idea from another telescope in Chile, and found the same light pattern. Currently, there is a NASA rover on its way to Mars to detect traces of long-dead microbes; however, if the discovery of phosphine turned out to be true, it means that there is life on Venus as we speak!
Up till now, no spacecraft has been to Venus, but scientists are on their way to complete their discovery, the one that might be the most important discovery in the history of mankind.
UPDATE
Scientists have stated that their new data analysis shows fainter signs of phosphine in the Venusian atmosphere. The gas is still there; however, it is fainter than was previously seen.
The study has caused controversy among scientists and was criticized by other researchers in the field. Later on, the same team working on it, reanalyzed their data to find that the average phosphine levels in Venus's atmosphere are one part per billion, which means that it is about one seventh of their earlier findings. Following their new analysis, the team described their phosphine discovery across Venus as “tentative”.
One of the critiques of the main study suggested that it was not phosphine that was seen in the Venusian atmosphere, and that it might be sulfur dioxide, as it is a gas normally seen in Venus's cloud, but the only difference is that it is not produced by life. The team replied to this criticism, saying that phosphine's fingerprint was clear in the data they collected, using the JCMT which is the second telescope they used.
Another important evidence supporting the presence of phosphine on Venus is that NASA's pioneer Venus mission in 1978 measured the chemistry of the clouds in the atmosphere of the planet using a probe, and it traced a phosphorous signal that could be phosphine or any other phosphorous compound.
It is not really known where the phosphine comes from, whether it is due to volcanic eruptions at the surface of the planet or lightning strikes in the atmosphere; a lot is still to be investigated. An Indian spacecraft is expected to go on a mission to Venus by 2025, and could be carrying the instruments needed for the search of phosphine.
References
Update Reference
*Image Credit:
NASA/JPL-Caltech
*Image Addition Date:
2020-06-08