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There's a lot of talk about sending humans to Mars.
But no one talks about Venus.
Why not?
And could Venus actually be the better option
for a human colony?
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Going to Mars has been a fixture in
our collective cultural consciousness
for a very long time.
It's inspired more sci-fi movies and stories than I can count,
a ride at Disney World, and a Twitter following for the Mars
Rover that's almost two million strong.
Meanwhile, Venus has inspired-- what?
Two Ray Bradbury stories, a plant
that eats flies, and a razor?
Basically, Venus has the worst public relations
team in the solar system.
And that hurts our sister planet,
not just in culture and media but in space policy.
Presidents Bush and Obama and the Chinese government
have all outlined goals for manned missions to Mars.
The Dutch nonprofit group Mars One
even held in international competition
to find volunteers for a one-way mission to the Martian surface.
But Venus?
No manned mission love-- at all.
Which is odd since in most respects,
Venus is actually an easier and less costly
colonization target than Mars is.
For starters, Venus is closer to Earth.
That's why we sent probes to Venus long before we sent them
to Mars and why we sent more of them.
Depending on the launch window, the round trip
can be 30% to 50% shorter, which is a major factor
for manned missions.
Shorter trips means less weightlessness and radiation,
less food and water to carry, and thus
less fuel and lower cost.
This would also be a huge advantage
in moving the people and equipment necessary to actually
colonize another world, because bear in mind,
there's no Craigslist in space.
If we ever start a colony, we'll need to bring along
almost everything.
And it's not just the shorter trip.
The planet itself has some significant advantages
over Mars.
It's closer to the sun, which means about four times
more available solar power then you have on Mars.
It also has a thick atmosphere, unlike that wispy layer
on Mars.
That means better protection from space radiation
and meteorites for our enterprising colonizers
and their future cities.
It also means more available carbon dioxide
from which, in principle, you might extract oxygen.
But the real kicker is gravity.
Venus has about 0.9 Earth g's-- pretty close--
while Mars has less than 0.4.
And one thing we do know is that prolonged low gravity
is bad for humans.
How bad?
In Earth orbit, astronauts lose bone mass
at about 10 times the rate of someone
with advanced osteoporosis.
Now no one knows exactly how bad Martian gravity
would be for humans, but it's definitely not
going to be good.
On Venus, that's far less of a concern.
And remember, we're talking about long-term colonization,
not just visits.
Even if we have the technological means
to add water to a planet's surface and oxygen to its air,
changing the planet's surface gravity
is currently not even within the realm of discussion.
So terraforming seems silly, and if people couldn't live there
more than a few months without their bones falling apart.
A theoretical Venutian colony thus
seems to have a lot going for it.
So why then this tunnel vision for Mars?
Surfacism.
OK, I just made that word up, but hear me out.
Ever since the days of seafaring exploration,
we've had an obsession with landing
on the surface of things.
If you don't plant a flag on something,
it's almost like having gotten there doesn't count.
So what's all this have to do with Venus, which
actually has a solid surface?
Well it does, but humans can't land on it.
See, there's a teensy problem with temperature.
There's so much CO2 on Venus that the greenhouse effect
makes the surface hotter than hell-- over 450 degrees
Celsius, well above the melting point of lead.
But the bigger problem is the barometric pressure
on the surface.
It's over 90 Earth's atmospheres.
That means that landing on the Venutian surface
would be like diving one kilometer underwater on Earth--
far beyond the crush depth of most military submarines.
In fact, most probes that NASA and the Soviets
sent to the surface of Venus imploded in midair.
We learned our lesson and a few reinforced probes
did manage to touch down and send images of the Venetian
surface.
But even those only lasted about two hours
before-- [SOUND OF AN IMPLOSION] --you know.
The point is-- I think surfacism is a real bias.
And the fact that we can't live on the Venutian surface
could help explain why Mars gets all the hype.
But maybe that's sensible.
I mean, if a surface will kill us,
there's no point in going there, right?
Not so fast.
See, around 50 kilometers or 30 miles
above the Venutian surface, some interesting things happen.
First, the temperature drops to only about 70 degrees Celsius.
That's still super hot, but firefighting equipment on Earth
can withstand proximity to forest fires with temperatures
that reach over 2,000 degrees Celsius.
The pressure at that altitude also
dropped to almost exactly one Earth atmosphere.
That means humans would need heat-resistant clothing
and oxygen masks, but not spacesuits to walk around
in that environment.
Granted, there's the minor nuisance
of sulfuric acid floating around in the Venutian air,
but that's potentially manageable.
And at that altitude, the atmosphere
is still dense enough for lots of stuff
to floae-- like balloons filled with helium
or maybe filled even with just regular Earth air.
Throw in the favorable gravity, and it
starts to look like the upper atmosphere of Venus
might be the closest thing in the solar system
to an Earth-like environment.
So it might make sense to colonize
Venus with cloud cities.
I am not making this up.
NASA Systems Analysis and Concepts Directorate
has unveiled a conceptual blueprint for this scheme.
They call it the High Altitude Venus Operational
Concept or HAVOC-- interesting branding choice,
but still super awesome.
We've linked the NASA videos in the description.
You should check them out.
Now for the record, this is all still conceptual.
We are very far from sending this guy
to lead our Venutian Cloud City.
But NASA is taking the idea seriously.
Right now, most of the chatter is still
about using Venus as practice for colonies
elsewhere-- like Mars.
So we haven't overcome surfacism just yet.
But this might change.
The gravity issue alone might make Venus the go-to option
for long-term human habitation.
Who know?
Centuries from now, if we learn how
to sequester enough carbon out of its atmosphere,
we might even be able to plant a flag or two.
So what do you guys think?
Is Venus a better colonization option than Mars?
Put your $0.02 in the comments-- or even better, tweet them,
#occupyvenus.
If we start a grassroots movement,
I'll let you know on the next episode of "Space Time".
Last week, we asked how you measure
the size of the universe?
Here are some of your questions.
awtizme asked, how can space be expanding faster
than light if the speed of light is the ultimate speed limit?
I'm going to answer you in two parts.
First, the speed of light speed limit
is for things moving through space, not about expansion
of space itself.
The second, you're right.
I shouldn't be talking about space
expanding at a given speed.
I should be talking about the size of the enlarge setting
on a photocopier button.
If I hit enlarge once every second,
then there will always be two points on the page
that-- if they're far enough apart to begin with--
will end up more than one extra light second apart after I
hit that photocopier button.
lingwingzing commented that this was a pretty intuitive way
to understand inflation.
Thanks for the compliment, but be careful.
We're talking about expansion of space in general.
Inflation refers to a very specific expansion
of space that occurred in just the first few instances
after The Big Bang.
The Mattman1313 says that the Hubble Bubble
is a possible alternative to the idea
that space is expanding at all.
That's not correct.
Space is expanding-- period.
What the Hubble Bubble offers is a potential alternative
to the currently observed, accelerated expansion of space.
Look it up.
And to Brandon Spears, sure, we could always
use help here at "Space Time".
Like the Hubble Space Telescope, we've
got schmutz on our lens too, so give it a wipe and help us out.
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