Venus is normally seen as a vision of hell.
And it is.
It’s not just hot at the surface, it’s actually so bad that that the crushing atmospheric
pressure and continuous clouds of sulfuric acid are so efficient at redistributing heat
that the entire planet at ground level is more or less the same temperature, about 460
degrees celsius or 860 fahrenheit, no matter if you’re standing at the poles or the equator,
or on the night side.
This is strange for a planet that in other ways is very much like earth.
It’s nearly the same size and density, and is only about 30 percent closer to the sun.
And, long ago, it was very likely much more earth-like than it is now.
For a very long time, and not that long ago, it may have had liquid water oceans on its
surface for as long as two billion years, and may have had hydrothermal vents at that
time, and as such might even have been an abode of life or even conceivable served as
the birthplace for the life that now exists on earth through transferring that life via
panspermia.
Unfortunately, if it existed on venus, evidence of this life is probably long gone.
Venus seems to periodically resurface itself through titanic episodes of volcanism, which
would deeply bury or erase any fossil evidence that might have once existed.
As a stretch, maybe some ancient rocks might be present on the surface, and certain minerals
such as tremolite might preserve evidence of it.
But, it’s a long shot so far as we know.
Unless, of course, that life never went extinct.
Even though Venus’s surface isn’t likely to support life now, even the most hardy extremophile
bacteria on earth can’t survive those temperatures, its upper atmosphere is another question entirely.
At a height of about 50 kilometers, it’s much cooler and far lower in pressure.
In fact, at this level above the surface of Venus, we find what is arguably the most earth-like
conditions in the solar system outside of Earth to the point that if you sprung a leak
in your space suit, it wouldn’t kill you due to equalized atmospheric pressure.
So could life that once arose on the surface of Venus have survived by moving high up into
the atmosphere?
After all, we detect earth live very high in our atmosphere.
And there are a handful of odd hints that this might be going on Venus, and another
was recently added to the list, more on that in a minute.
The first hint comes from probes sent in the past.
A chemical called carbonyl sulfide was detected in the upper atmosphere of Venus.
It’s difficult to produce this chemical without life, but in fairness volcanism can
do it.
So it’s ambiguous, but an eyebrow raiser.
Yet, Venus shows plenty of evidence of volcanism on its surface, but so far we haven’t seen
anything currently active, at least active for the last 2.5 million years.
This could change with a single discovery of course, but does the carbonyl sulfide on
Venus come from life or volcanos?
We don’t know yet.
But there are other hints that something may be going on at Venus.
Venus features something we don’t understand.
Known as unknown absorbers, Venus clouds feature dark patches that absorb solar radiation.
It’s speculated that this may be a chemical phenomenon, such as ferric chloride or something
to do with sulfur compounds.
But it could also be biological.
And there’s been a new development in regards to studying the unknown absorbers, they seem
to be affecting Venus’ atmosphere at large in a big way.
In a paper by Yeon Joo Lee and colleagues, link below, they detail that after studying
data from multiple missions and instruments, that there seems to be a relationship between
the solar driven winds of Venus, and the clouds.
The dark absorbers affect the planet’s albedo, or how much solar energy is reflected back
into space, which then causes temperature changes which affect the winds.
This creates an interesting situation where changes in albedo occur due to changes in
the unknown absorbers.
This makes it a bit difficult to explain abiotically, so the possibility is there that microorganisms
that evolved on Venus are affecting its atmosphere.
This would not be unheard of, Earth’s atmosphere is profoundly affected by its biosphere, in
particular through oxygen and methane production.
Intriguingly, the team discovered that the particles making up the unknown absorbers
were consistent physically, chemically and spectrally with some atmospheric microorganisms
here on earth.
But not a lot, which may suggest that if these are indeed microorganisms in Venus’ atmosphere,
a big if, then they likely evolved independently from earth life.
In which case this would be life entirely indigenous to Venus, rather than anything
related to panspermia between worlds.
It would truly be alien life, simple though it might be.
But to either confirm or deny whether this phenomenon is indeed being caused by microorganisms
is going to take time.
The team notes that they need to monitor the planet over long periods of time, and through
multiple solar cycles to get a better picture of the phenomenon and eliminate internal and
external potential sources for the variations.
The absorption seen in Venus’ atmosphere is particularly interesting in ultraviolet.
It’s not clear why, but dark lines have been observed in ultraviolet frequencies for
some time.
It could be that if all of this is due to life, it could be absorbing UV as an energy
source.
Once again, this would be a different adaptation than most earth life has, which has a tendency
to not deal well with ultraviolet.
But there are organisms on earth that have adapted to at least reradiate ultraviolet,
if not use it for an energy source.
So, tick another box as far as the potential for microbial life in the atmosphere of Venus.
But there is a broader question here.
If life could exist on a hell planet like Venus, this could have implications on life
in the universe in general, especially when dealing with stars that produce a lot of ultra-violet,
such as M type red dwarfs, but also stars like Type F which are usually considered not
ideal candidates for life due to large amounts of ultraviolet light.
If we were to find life at Venus that uses ultraviolet as an energy source, this might
change the landscape of thought about those kinds of stars.
Thanks for listening!
I am futurist and science fiction author John Michael Godier currently eyeing Venus suspiciously.
So much so that I’d be doing a monocle drop, or even a double monocle drop, if I didn’t
wear glasses.
So I’ll drop my glasses.
We always thought Mars was the likely planet other than earth to have spawned life.
And, it hints that it may very well still have it.
But Venus hints as well, as does Europa.
And what of nutrient rich Enceladus and its ocean?
Hints a plenty and part of me loves it, the other parts wonders if it would be infectious.
Gonna be a rough cold and flu season some day and be sure to check out my books at your
favorite online book retailer and subscribe to my channels for regular, in-depth explorations
into the interesting, weird and unknown aspects of this amazing universe in which we live.