Hello everybody and welcome back to Seeker Plus,
where we take deep dives into one topic. I’m your host Julian Huguet,
and today we’re going to explore a place that’s been neglected for far too long.
And no, I’m not talking about the office chair in my bedroom that’s covered in laundry that’s not
quite dirty enough to wash. Maybe you can wear it once or twice more. I’m talking about some place a
little more mysterious than that. I’m talking about Venus, our solar system neighbor often
dubbed Earth’s evil twin. And if you think it’s a bit harsh calling Venus evil, well then you just
try living there and you tell me otherwise because it is no picnic. The conditions on the
planet are terrible. Consider this: Its surface temperature is hot enough to melt lead, the
atmospheric pressure would crush you even if you were inside a nuclear-powered submarine, there’s no
liquid water on the planet, it’s got toxic, toxic clouds, and it forgot my birthday last month.
Alright, well other than that last point, the planet is actually a terrible, inhospitable place that scientists have
had a hard time studying. I’d even go so far as to argue that we have an easier time
studying Saturn and Jupiter than Venus, which is a lot closer. In this series, we’re going to unpack
some mysteries, explain how the planet got so unforgiving in the first place, why 127 minutes
is the number to beat for keeping space probes alive on Venus (take that James Franco), and what
plans NASA has for future exploration. That was a 127 Hours reference in case any one remembers
that movie. Anyway, if by the end of this series you still think Venus isn’t so bad,
then maybe you’re the evil twin. But for now, let’s look at how Venus compares to Earth.
As the similarities go: Earth is only about 5% larger than Venus, the two planets weigh
almost the same with Earth again edging Venus out, and they both have iron cores
surrounded by a mantle of silicate rock. The prevailing solar system origin theory
even suggests that Venus and Earth formed roughly about the same time around 4.5 billion years ago,
when a nebula condensed into the Sun and heavy, rocky materials formed the
inner terrestrial planets. These reasons explain why Venus gets the “twin” moniker,
but it’s where the similarities end and the “evil”, unforgiving part begins.
Compared to Earth, Venus has a thick, toxic atmosphere filled with carbon dioxide,
which puts the YouTube comment section to shame. There are clouds of sulfuric acid,
yes clouds of acid, which are so thick and unrelenting that they trap heat in the atmosphere.
This runaway greenhouse effect explains why despite not being the closest planet to the Sun,
it’s actually the hottest in our solar system, clocking in at around 475 degrees Celsius.
If you somehow managed to withstand those temperatures at the surface,
you’d probably have a hard time standing upright. That’s because the atmospheric pressure at the
surface is over 90 times that of Earth. It’s like having over 1,300 pounds of pressure
pressing down on each square inch of your body. Now before you yell at me for my choice of units,
I picked them because you wouldn’t know what I meant if I used metric. If I said that was like
having 9 million newtons per square meter on your body would you have any sense of that? I’ll put it another
way for all you metric heads. According to NASA, you’d get that same pressure if you were about
1.6 kilometers deep under the ocean. There you go, happy? So poisonous atmosphere, check. Scorching
temperatures, check. Crushing pressures, check. It’s like playing in the Super Bowl in Los Angeles.
Do I need to go on? Well, I do and I will, in case I don't know, you stepped away for a second to
really hammer it home. Venus also has no water on its surface, so in a hypothetical scenario
where you’ve flown to Venus, plummeted through the thick, yellowish clouds of sulfuric acid,
withstood grueling temperatures, and survived not getting crushed to death by the atmosphere,
unfortunately, you wouldn’t have any sweet, sweet liquid water to keep you alive either. To some,
Venus may sound like a lost cause, but the planet we know today may not have always been that way.
You remember how I mentioned earlier that Earth and Venus formed around the same time? About
4.5 billion years ago, when both planets were just coming into their own as baby planets do.
Back then, the Sun was much dimmer, placing Venus firmly inside the habitable zone — the region
around a star that would allow for liquid water to exist on a planet’s surface. At that time,
it’s believed that not only liquid water existed on the surface, but the planet had a stable
climate and cooler temperatures, both of which would’ve been more amenable to some form of life.
While no one is sure at what point things changed and why, we do know that something happened.
One idea involves the Sun. Since this glowing ball of hydrogen and helium is a yellow dwarf star,
it brightens as it ages. So it’s possible that Venus started to warm up and began to move towards
the edge of the habitable zone. As this happened, the oceans on Venus’ surface evaporated and
water vapor moved up into its atmosphere. Once too much water vapor reached the atmosphere,
it kicked off a runaway greenhouse effect, creating clouds that got too thick, trapping heat,
and further increasing the surface temperature, which caused more water to move into the
atmosphere and so on and so forth. I think you get the idea. Basically, the planet
began to suffocate itself over many years. So that’s the slow death version for Venus.
The other suspect worked a lot faster to turn Venus into the hellscape
we know today. This theory suggests that volcanoes — massive world killing, apocalyptic,
multiple extinction-level volcanoes erupted around the same time. It’s like if 2020, 2021, and 2022
were volcanoes and they released so much carbon dioxide into the atmosphere that the planet’s heat
was trapped. This boiled off its oceans, which in turn trapped more heat, creating a feedback cycle
that couldn’t be stopped. Plate tectonics, if Venus had any, would’ve shut down because they use
water as a lubricant, so the plates can slide around. Without it, the system can’t bury carbon
deep in the planet, so CO2 eventually became the dominant gas in the atmosphere. Today, that one
gas makes up about 96% of the planet’s atmosphere, compared to less than .05% of Earth’s.
The jury is still out on which cataclysm did Venus in. Both scenarios are still up for debate at the
moment. You may even be wondering, so what? What does it matter how Venus died? What does the death
of Venus have to do with me? Actually, a lot, Dave. Kidding, it doesn’t pertain specifically to
Daves but can you imagine everyone named Dave who was listening just now? They would’ve been freaked
out. While perfectly habitable Venus was doing not that, its neighbor, our lovely blue planet Earth,
was also going through changes. Oh, those awkward teen years. Earth was forming and
figuring itself out, you know, dealing with what type of planet it wanted to be
in the solar system. Would it follow the same tragic fate as Venus or go down a different
path? After a few bumps in the road, aka nearly planet-killing asteroids and mega volcanoes,
Earth began to stabilize a bit. Its atmosphere kept the planet comfortable enough for life to
start to thrive, and we remained in the habitable zone. Forgive me for completely glossing over the
mega volcanoes and massive space rocks that almost turned Earth into its neighbor, I know it sounds
awesome, but there’s so much to unpack there. We’d need a whole ‘nother series on Earth’s multiple
extinction level events to cover them. Actually, if you do want to learn more about how Earth
kept rebounding, let me know in the comments. Anyway, back to what I was saying about Venus.
Earth was spared Venus’s fate sometimes by luck, sometimes just because of different environmental
conditions. On one level, by studying what happened to Venus, we can learn how
other Earth-like planets evolve, take shape and what conditions cause these exoplanets to either
flourish or die. Studying Venus can even show scientists that the habitable zone can move,
which could mean that an exoplanet may have had life at one point in its history and could harbor
life again, if conditions change. While that opens up tons of questions about terraforming which
no matter what anyone says is still very away (if it will happen at all),
there’s more direct links closer to home.
For instance, studying the sulphuric acid clouds on Venus offers scientists a natural
way to study haze in our own atmosphere. These studies can improve our climate models,
so that we may know what we could be dealing with in the future. That’s not all when it
comes to thinking about greenhouse gases. Venus is a cautionary tale reminding us how much can change
on a planet because of its climate. Of course, Venus is the worst case scenario,
the poster child for the greenhouse effect, but if it can happen on a planet that was potentially
full of liquid water and habitable, well then it can happen almost anywhere.
Now, I don’t want to end on doom and gloom. It’s so incredibly unlikely that what happened to Venus
will happen to Earth today that I don’t even want to leave the impression that that’s in the cards.
It’s not. Instead, what I do want to leave us thinking about is how little we still know
about our neighboring planet. There are so many mysteries and questions about this fascinating,
terrifying and very, very deadly world that keep me up at night.
Like what’s exactly lurking beneath the thick clouds? And why does the
planet keep killing every spacecraft we send there? What are you hiding from us Venus?
We’ll get into all of that and more in the next episode of Seeker Plus. Thanks for watching,
if you like this episode be sure to like and subscribe. As you can tell, Venus is such a weird,
interesting place and there’s so much that I couldn’t cover in this episode. Like did you
know that a day on Venus is longer than a year? Uhmm what? If you know any other fun facts about
Venus or another planet, let us know. And Elon, I know you’re watching. We know you want to talk
about Mars. We’ll talk about Mars, but you got to move on. There are other planets out there,
okay bud? Alright, thanks for tuning in and we’ll see you for the next episode of Seeker+.