Ever since a chemical called phosphine was announced on Venus last September, the scientific community has been in bad weather. Scientists have published papers back and forth, trying to dispel or reinforce the claim.
With two new papers coming ashore this week, some say the nails are being pushed into the phosphine chest. We suspect, however, that investigation and debate will continue to be discovered for some time to come.
So what’s the matter? Read on for a brief primer.
Phosphine on Venus? Why does it matter?
The discovery itself is very interesting. Using two different instruments at different times – the James Clerk Maxwell Telescope (JCMT) in 2017 and the Atacama Large Millimeter / Submillimeter Array (ALMA) in 2019 – a team led by astrobiologist Jane Greaves from Cardiff University in the UK signed a chemical spectrum called phosphine in the Venusian atmosphere, at 20 parts per billion. The results were published in Astronomy of nature.
As we said at the time, here on Earth, phosphine has been found in abundance in anaerobic (low in oxygen) ecosystems. It is found in bogs and sludges, where anaerobic microbes thrive. It is found in the intestines and, well, farts. Somehow, anaerobic microorganisms produce phosphine. And the clouds of Venus are anaerobic.
Although Greaves and her team uncovered many abiotic Venusian phosphine formation pathways, they were wary of realizing that there could be other ways the chemical could emerge. For one, here on volcanoes on Earth extract phosphine, and we have evidence that Venus is still volcanically active. (Volcanic origins have been found to be plausible in another introduction.)
In every way, the discovery was very interesting, but the mention of microbial origin yielded a great deal of profiteering, and much continued study from other scientists.
What happened now?
Well, it all got kind of complicated. First, a team of scientists looked at Venus’ historical data, and discovered that the Pioneer probe could detect phosphine all the way back in 1978. That paper has not yet been approved for publication. Other, included in the magazine Science and also have not yet been peer-reviewed, claiming to have discovered the amino acid glycine – a protein building block – on Venus.
Other scientists began looking at the data. Three separate papers, one since published in Astronomy & Astronomy on ALMA data, another published in the Monthly notices from the Royal Astronomical Society on JCMT data, with the other repeating both data sets and awaiting peer review – no major trace of phosphine was found in the Venus atmosphere.
It then turned out that there was an error in processing the data from the ALMA comments. Greaves requested that the data be reprocessed; these reprocessing data were made available to the public in November 2020.
Greaves and her team analyzed the new data, and found that they could still find phosphine on Venus, but in lower amounts – a global average of 1 to 4 parts per billion, with local peaks of 5 to 10 parts per billion.
Since sulfur dioxide and phosphine both contain radiation near a frequency of 266.94-gigahertz, some suggested that Greaves and her team may have found sulfur dioxide (also extracted). with volcanic activity) and not phosphine. In their new paper, Greaves et al. regulates sulfur dioxide. The line of absence of a spectrum described as phosphine chemical fingerprints, they said, was too wide to be sulfur dioxide, and there was not enough of it on Venus to observe the observed signal.
A third paper from Greaves and her team followed, defending the strength of the phosphine signal.
Okay, so why is it back in the news now?
Two new papers have fallen out, and one of them has been published in Letters of the Astrophysical Journal, and the other was approved for publication in Letters of the Astrophysical Journal, repeating the data. Both papers contribute to the phosphine resistance.
The first paper repeated the two sets of ALMA data, before and after reprocessing. The team found a celestial line at 266.94 gigahertz in the previous data set, but there was no significant signal after reprocessing. They also found that sulfur dioxide could appear in at least 10 parts per billion and undetected by ALMA, suggesting it may be more abundant than Greaves and her team thought.
The second paper used data from decades of Venus observations to model the conditions in the Venusian atmosphere, and to find out how phosphine and sulfa dioxide behave. They found that the 266.94-gigahertz signal is the most suitable source at about 80 kilometers (50 miles) in height, above the deck of clouds, rather than 50 to 60 kilometers, as suggested by Greaves and her team.
At this height, phosphine would not last long at all, so the best explanation is sulfur dioxide, they concluded.
Is that the end? Is the trace of Venus phosphine dead?
Not even close! For starters, Greaves and her team are likely to respond to the new papers, which will encourage more responses, with more simulations and modeling and number crunching and perhaps even a test to see what the opportunities and similarities are. it is.
Other than that, nothing we’ve seen so far is certain. It is more likely that the only way to calm the controversy is by taking more detailed views with more powerful instruments. We may be waiting a while for that. Several proposed missions to Venus are planned, but there is often a long time between praise and achievement.
However, this is science at best. ‘True’ and ‘false’ are here. Venus either contains phosphine, or not. Scientists will use their creativity to try to solve the problem, which will lead to reconstructed methods and study tools.
Finally, we will learn the truth. And whatever that truth may be, it will teach us something new about our Universe.