Photo by: NASA/JPL

NASA/JPL

Is There Life on Venus? Something Smells Fishy…

Does the presence of a stinky gas mean there was once life on Venus?

September 14, 2020

Phosphine is one of the grossest chemicals out there. Not because of what it’s made of–one atoms of phosphorus and three atoms of hydrogen–but because it’s really, really stinky. It’s commonly associated with decaying organic matter, if you need a mental picture. It occurs naturally through a variety of processes, most notably as a byproduct of non-oxygen-using life. But since oxygen-using life is quite common on our planet, thankfully this stinky chemical is relatively rare.

Who Stank?

Phosphine or phosphane is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas and pnictogen hydride. 3d illustration

660674942

Phosphine or phosphane is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas and pnictogen hydride.

Photo by: ollaweila

ollaweila

Phosphine or phosphane is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas and pnictogen hydride.

Recently some astronomers have been raising a big stink (pun very much intended) about Earth’s sister planet, Venus. For those of you new to Venus: don’t go. It’s a nightmarish hellhole of a planet, choking on so much poisonous carbon dioxide that its surface pressure is over 90 times that of sea level. The temperatures at the surface are hot enough to melt lead. It rains sulfuric acid.

It’s nasty. And it just might–might – be a home for life.


A certain subgroup of astronomers known as astrobiologists (and yes, that’s a thing) are hunting for signs of life outside the Earth. One of the most promising ways is to look for (and this is a pretty awesome jargon word) biosignatures. These are signs of life in the form of chemicals that don’t normally come from chemical (i.e., boring unless you’re a chemist) processes.

An example of this is oxygen. The vast majority of the oxygen in our atmosphere comes as a byproduct of photosynthesis (in other words: life). If we were to find a lot of oxygen in another planet’s atmosphere, it just might be teeming with little critters.

Another potential biosignature is stinky molecule phosphine. Sure, it’s possible to create phosphine naturally, but it takes a lot of energy, and is very unstable–the UV radiation from the sun does a really good job at breaking it apart.

I’ll cut to the chase: a group of astronomers recently announced the presence of a load of phosphine in the atmosphere of Venus. A potential sign of life in basically the last place you would expect to find it.

Now we also see a lot of phosphine in the atmospheres of Jupiter and Saturn, and we really don’t think it comes from life on those giant planets–more likely it originates in some super-intense chemical process deep in their interiors.

But Venus?

Venus, computer artwork.

460713161

Venus, computer artwork.

Photo by: SCIEPRO

SCIEPRO

The astronomers argue that they’ve thought of every possible way to make lots of phosphine in Venus without involving life, and keep coming up short.

Where could life exist in that hellscape? Well, a few dozen miles up in the atmosphere is pretty clement: room temperatures and standard air pressures. The air is still full of noxious carbon dioxide and sulfuric acid, but hey life has found footholds in stranger places.

But still, as with all stories of this nature, I urge caution and skepticism. Venus is a strange, strange environment that we barely even pretend to understand. Lots of crazy chemistry could be going on. There have been hints of life on Mars for decades that have been undermined by further study, and the same is likely true for Venus. By the time the news excitement dies down, there is likely to be a dozen hypothetical processes proposed that could explain the strange presence of phosphine on Venus.

Which is exciting if you’re into cool, weird chemistry, but not so exciting if you’re into life.

Paul M. Sutter is an astrophysicist at Stony Brook University and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of How to Die in Space.

Next Up

Do You Want to Go to Space?

Have you always dreamed of going to space? Former NASA astronaut Mike Massimino answers our questions about life at the International Space Station.

Quiz: Test Your Space Exploration Knowledge

Ahead of the historic May 27th NASA and SpaceX crewed space launch, test your space exploration knowledge!

We Have Liftoff: Congratulations to NASA and SpaceX

Here's to NASA, SpaceX, Astronauts Bob Behnken and Doug Hurley, and all of the engineers, scientists, and staff involved with the Saturday, May 30th historical launch.

Top 5 Reasons Why the “UFO Report” Isn’t Interesting to me, a Scientist

Excited by the prospects of the “UFO Report”? As a scientist, I have my doubts. But you can watch UFOS DECLASSIFED: LIVE on Discovery and Science June 30 at 8P where experts discuss what can and can't be explained.

NFL SUPER STADIUMS Follows the Epic Journey of Building SoFi Stadium

In partnership with the NFL, Discovery and Science Channel go behind the scenes and follow the remarkable journey of constructing SoFi Stadium in an all-new, two-hour special, NFL SUPER STADIUMS premiering Wednesday, September 9 at 8P on Science Channel and Saturday, September 12 at 11A on Discovery.

STREET OUTLAWS Returns and the 405 is Back

OKC has been dominating the No Prep Track, but the time has come for the 405 to return to their roots — the streets. STREET OUTLAWS returns on Monday, January 11 at 8p on Discovery followed by Mega Cash Days at 9p on Discovery and streaming on discovery+.

Is Interstellar Travel Really Possible?

Listen folks, I love a good sci-fi movie as much as anyone. Cruising around the galaxy, finding weird stuff, and blowing up aliens--it’s all good. But just because a writer can come up with something, it doesn’t make it possible. I’m sorry to say that we’re going to be bound to our solar system for a really, really long time. As in, probably forever.

Something Funky is Happening to the Earth’s Magnetic Field

Recently a weak spot in the Earth's magnetic field over the southern Atlantic Ocean has been getting weaker, which could signal the beginnings of a global magnetic reversal event. Or not. It’s complicated.

The Milky Way Broke its Arm (But is Totally Okay)

The Milky Way is a giant, magnificent, truly transcendently beautiful spiral arm galaxy. It’s too bad we can’t get a decent picture of it. The problem is that we live inside it, and so astronomers have to work extra-hard to construct an accurate map.

The Great Conjunction is Coming and it's Going to be Epic

On December 21, Jupiter and Saturn will appear closer to each other than they have in nearly 400 years. This once in four lifetimes cosmic event will be visible to many--clear skies permitting--but Lowell Observatory has you covered either way.

Related To: