Life on Venus? Karl Sagan predicted this in 1967. He may be right.


Millions of people reacted with joy on Monday in a study showing the Venusian atmosphere, which contains phosphine, a chemical by-product of biological life. But no one would have been more thrilled or less surprised by the discovery of the late, great Carl Sagan – who said that the day may have arrived more than 50 years earlier.

Now best remembered as the presenter of the most watched PBS series Kasmos universeThe author of the book behind the film Contact, And the man who put gold discs of Earth music on NASA’s Voyager missions, Sagan actually began to study the two planets closest to us. He became an astronomer after being inspired as a child by the space imaginations of Edgar Rice Burrows, founded on Mars and Venus.

but as Kasmos universe Fans know, Sagan’s brown-eyed sci-fi hopes never beat his hard-sciences. He shot an early “proof” of life on Mars. He speculated that before the first Venus probe of NASA in 1962, Venus’s surface would be insanely hot, which he worked on, confirmed this. And he was the first scientist who saw the Hellscape of Venus as the result of a fugitive greenhouse effect – one he knew could guide the Earth’s climate-changing future.

So it’s all the more surprising when Sagan co-authored a paper in which we may still one day find microbial life above our sister planet. He said, “If small amounts of the mineral are dispersed from the surface to the clouds, it is not difficult to imagine an indigenous biology in Venus’s clouds.” Nature In 1967 – two years before NASA landed on the moon. “While the position of Venus’s surface embodies the life there, the Venus clouds are a different story altogether.”

As Sagan pointed out, a high carbon-dioxide atmosphere was no barrier. Conditions on the 50 km (31-mi) layer at the top of Venus’ clouds, are indeed hospitable and almost earth-like. Organisms can thrive overhead, in the same way that bacteria thrive around superheat, CO2-rich vents in Yellowstone. Add sunlight and water vapor to CO2, he said, and you have a recipe for that building block of life, photosynthesis.

Derby Dyer, chairman of NASA’s Venus Exploration Advisory Group, says, “Sagan’s work on Venus was formal, though few today remember his influence.” “His idea was presenter, and still makes sense today: presently there must be a temperate zone between the surface position on Venus and the near-vacuum of outer space where life can live.”

Exactly 11 years after Sagan made his prediction, another Venus probe discovered methane in the atmosphere – which could be considered a precursor to the presence of organic matter. Scientists like Sagan were cautious about the discovery; No methane could prove that life is meant beyond a reasonable doubt. (We also found it on Mars in 2018, and have yet to explain it). Still, no one has ever given a reasonable choice as to why methane can rotate on Venus.

Sagan died in 1996 amid a prolonged dry spell to discover NASA Venus. But his idea continued. In 2013, we discovered a large amount of microbes alive in the clouds above the earth. More than 300 varieties, much to the surprise of scientists collecting them – microbes are actually atleast Dense at low altitude. In 2016, NASA’s model showed that Venus was once an ocean, for at least 2 billion years. One theory was endorsed by planetary expert David Grinspoon, which suggests that microbial life went into the clouds when it was too hard for life on the surface a billion years ago.

Call them native climate refugees.

Science did not stop even when we used only Earth-based telescopes to do it. We found evidence for volcanoes active on the surface, which would “shake the minerals” in the atmosphere suggested by Sagan. In 2018, another study of the Venus atmosphere replaced the mysterious “dark patch”, which speculated that scientific microorganisms could be evidence of life – vast amounts of it. How much? We will need more study to know this. “I came away disappointed with that paper,” co-author Sanjay Limaye told me last year. “We are not looking for creatures [on Venus]. Why not?”

Why not really. As I wrote earlier this year, NASA’s budgetary priorities wrongly shook Venus to Mars. Although Venus is closer to Earth and more Earth-like, Mars has a surface on which we can stand, which was an easy sell for our 20th-century “space colonization” mentality.

But the more we look at Venus, the more we need to find out what the exploration looks like.

Silently, inside and outside NASA, a “Venus community” grew up wanting to explore its clouds and begging for a budget scrap. Its most exciting moment so far came in 2015, when NASA unveiled a concept mission called HAVOC – a zeppelin, basically, that you didn’t need to fill with helium or hydrogen. The air of the old earth regularly floats in the dense atmosphere of Venus. Tear off the fabric of the balloon, and high pressure can actually prevent air from escaping. Week.

As you might expect, the Venus community was filled with excitement over the discovery of phosphine on Monday. At least not because the NASA administrator gave time to give priority to the magic word: Venus by tweeting.

Of course, caution is exercised in spades. Phosphine is also found in the giant, churning gas giants of Jupiter and Saturn. But to explain why it would exist on a rocky planet as small as Venus if it is not due to life, scientists say, you have to propose some geological process about which we do not yet know.

NASA’s Dyer says, “The exciting discovery of phosphine in Venus’s atmosphere confirms that Venus is likely a growing body of other places in our solar system where life exists now and in the past.” Confirms it. ” “Venus holds the key to our understanding of the development of rocky planets as homes for life.

“The discovery may be the first of many to come as NASA and other countries renew the Venus exploration program.”

Currently the ESA, the Russian Space Agency and NASA all have Venus probe plans that could arrive in this decade; The Phosphine announcement may well extend the launch dates. If and when the next investigation finds more evidence of life above the solar system’s most mysterious planet, we will be one step closer to confirming Carl Sagan’s legacy as a visionary Venutian genius.