Venus isn't the only world beyond Earth where scientists have gotten a possible whiff of life.
Researchers announced today (Sept. 14) that they've spotted in Venus' air the fingerprint of phosphine, a stinky gas that here on Earth is produced only by microbes and humans, as far as we can tell.
The new find is not a detection of alien life. But it does suggest that something intriguing and mysterious may be occurring in Venus' clouds, an environment that astrobiologists have flagged as potentially habitable for microbial life.
Related: Strange chemical Venus clouds defies explanation. A sign of life?
More: 6 most likely places for alien life in the solar system
Intriguing and mysterious things are happening on other potentially life-supporting worlds as well. For example, NASA's Mars rover Curiosity has rolled through several plumes of methane inside the Red Planet's Gale Crater and determined that background concentrations of the gas vary on a seasonal basis.
This is potentially exciting stuff, given that the vast majority of the methane in Earth's atmosphere is generated by living organisms. In addition, ultraviolet radiation from the sun breaks methane down in Mars' air within a few hundred years, so the stuff Curiosity is sniffing must have been emitted relatively recently.
But methane can be produced abiotically as well — for instance, by chemical reactions involving hot water and certain kinds of rock. And it's possible that the Gale Crater surges were caused by "burps" of methane that has been locked underground for millions or billions of years, scientists say. In short, Mars methane is far from a convincing biosignature at the moment; we don't know nearly enough to make such a monumental call.
There's also astrobiological action farther out in the solar system. Take the Saturn moon Enceladus, which harbors an ocean of liquid water beneath its icy shell. NASA's Cassini spacecraft identified complex organic compounds — the carbon-containing building blocks of life as we know it — in the plume of water vapor wafting from Enceladus' south polar region.
Organics are not proof of life by themselves. The molecules are widespread throughout the solar system; they've been found in meteorites and in the tails of comets. But Enceladus' plume is generated by geysers blasting material from the moon's subsurface sea into space.
So, Cassini's observations show that potential chemical precursors to life — and perhaps even signs of life itself — are floating in this possibly habitable environment, which also likely features an energy source that organisms could tap into.
Cassini also spotted complex organics in the air of another Saturn satellite: Titan, the second-largest moon in the solar system. Scientists think Titan hosts two potentially life-supporting environments — a buried ocean of liquid water, and frigid surface seas of liquid methane and ethane. (If life does swim in Titan's hydrocarbon seas, it would be very different than that of Earth, which requires liquid water.)
These hints and clues may be building toward some very big discoveries in the not-too-distant future. NASA's recently launched Mars 2020 rover Perseverance, for example, will hunt for signs of ancient life after touching down inside the Red Planet's Jezero Crater in February 2021. Perseverance will also collect and cache several dozen samples that NASA and the European Space Agency will bring to Earth, possibly as early as 2031.
NASA is also developing a Titan mission called Dragonfly, which will land a rotorcraft on the big moon in 2034. Dragonfly will study Titan's complex chemistry, assess the moon's habitability and search for possible biosignatures, among other tasks.
We could see a Venus life hunt in the next few years as well. California-based company Rocket Lab aims to launch a private mission to Earth's hellishly hot sister planet in 2023. The plan involves dropping small, instrument-laden probes through the Venusian atmosphere to look for signs of life inthe planet's sulfuric-acid clouds.
So it's not crazy to think that we could soon get an answer to that biggest of queries: Are we alone?
"We're the first generation that could actually address this question, other than in a philosophical way," Seth Shostak, a senior astronomer at the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California, told Space.com. "And that is special."
Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.
My observation. While the search for life in the universe continues, including here in our solar system, *verified* life is yet to be shown in science (other than on Earth). Wait and see. Yet if life can only be shown here on Earth, including a fossil record, the answer to the question is - we are it, at least for biological life :)
Certainly agree with your point. In fact, it is too huge to deduce any such conclusions, in my view.
Strangely, it's a hydride covalently bonded with a pnictogen (in this case, obviously, phosphorus). Rather nasty little chemical. Certainly in aerobic settings, so any adventurous would-be explorers might think twice if they want to take their chances with a particle, 20 parts per billion, that might spontaneously explode and would certainly inhibit breathing and which in Venus' atmosphere would probably be about the most hospitable substance there (not even to mention the ground, which is even less friendly).Colonization certainly seems far-fetched.
And yet, still, that it is there. Phosphine would not last very long in the acidic soup that is Venus' sky. Sulfuric acid and sunlight--both fairly ample things, clearly, would not allow it to exist long at all. So for there to be a presence enough to detect, continuously, it must have some source.
The amount the team has detected, though it seems small, is orders of magnitude more than conventional other sources could be leaving. I share your skepticism of jumping to "biological processes" (as I have no idea how... or more importantly where---anything biological might sustain itself in such a hostile environment. But that leaves us with: what process is causing it, and continuously?
It is such a stumping question that, aside from the question of life on Venus, is an extraordinary discovery.
So, it is inevitable that the remains of Earth life have been transported to Venus’s upper atmosphere by natural means.
Earth was hostile enough 3.83 billion years ago to, against incredible odds, to have life emerge. Elsewhere, we can just starting with habitable zones: water, UV, planetary electric field, planet rotation rate/tidal locking, planet rotation axis tilt, astrosphere stellar magnetic wind, then the galactic habitable zones inc. co-rotation zone (just inside of), far from super novae, staying near plane of rotation, far from any large galaxy, and much more. The math is insanely against it.
So, sorry, just color me as a skeptic.
The astronomers who did the measurements are just as skeptical as any of us are - they explicitly say that it's the result of a previously unknown process, which could be organic or inorganic. The latter, of course, is far more likely.
Given the critical role of metalloenzymes in life as we know it - even in the simplest forms of life - I find it especially hard to imagine life in the clouds, where metals are surely scarce.
No it doesn't.... it suggests that there was once life there.
I wonder if Mars and Venus had evolved life at the same time.
I'm fairly certain venus can't support it above ground anymore. No matter what gases you find.
We all want to find the kinda life we can relate to, the visible, breeding kind.
something that isn't simply a tree, or a planet.
But getting all excited and expecting actual living organisms.. I'd say the Galilean moons are a better bet.
Or, as i've been saying for decades.. goto mars and dig very deep.
I'm more concerned with how we can terraform Venus and get some use out of it before the Sun grows too hot for mankind to make use of it. If there is something already living there, well , should have evolved faster.
There's got to be some kind of baking soda asteroids out there we can strap an engine on and slam them into Venus to help neutralize the acidic atmosphere. Send some bacteria that eats acid and poops oxygen. Maybe people wanting to test their solar sails could park several in orbit around Venus and create a constant eclipse, help cool things down. It's a big lab we can practice climate control on and end up with prime real estate :-), Well, our great great great great....... great grand kids anyway.
Also the thinking facility is very essential for Life. Each organ in our body functions because of its latent Intelligence.
The observation reveals that looking from Earth the Sun and our Moon appear almost the same Angular size.
The reason for this is the ratio of the distance from Earth to the diameter of the object (Sun and Moon respectively) is almost 107 to 110.
Our search in the Space for this unique coincidence can be a factor to determine life in a planet.
This may be a wild guess based on observation and perspective...