Why Venus Could Doom 'Habitable' Exoplanets

There are exoplanets out there that seem very Earth-like, but if you look out and see liquid metal instead of liquid water, you might be in the Venus zone.

Host: Caitlin Hofmeister

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[francoislacombe]

Keep in mind that stars get brighter as they age, so the boundaries of those zones move outward with time. Earth is scheduled to become a new Venus in about one billion years.

[nirvanachile]

Also a big missing piece of this puzzle: the absence of a magnetic field. Venus and Mars are both very weak magnetically, which leaves the planets defenseless against solar radiation and has had a severe effect on their atmospheres.

[RobertKenny]

Plot twist: Venus was home to a sentient species that global warminged themselves out of a habitable planet.

[ClockworkRBLX]

I can't wait for the James Webb Space Telescope to launch in 2056.

[gotcha]

The early studies of Venus were quite funny to me; we thought that because it was a twin-earth, it could be habitable and everyone was super excited. Then we sent the Venera probe to take pics from the surface of Venus and, before it quickly melt, the probe sent us an image of an inferno of hot gasses, that quite honestly doesn't sound so different from hell.

[timsmith]

I love Caitlin's energy about new discoveries.

[wxb]

We should just move Venus to where Mars is and place Mars where Venus is. That's what Brian Boitano would do...

[LeedleLeedleLeo]

Caitlin you're hands down the best sci show host.

[pyalot]

The habitable/inhabitable zones don't really matter all that much. You can't use it as a guide to tell you where you might find life and where you won't. We can't even tell in our own solar system where life could be hiding and where it can't. We can tell there isn't a lot of it, visible from the surface anyway, but there could be a **lot** of life right here in our own solar system, we just haven't looked in the right place with the right equipment.


If you want answers regarding life you need atmospheric spectra, or better yet, direct imaging of the planets in a decent enough resolution in a wide spectrum. Even so you might miss it, but at least you're probably going to see massive incidence of life that way.

[aidanwansbrough]

These videos are always really interesting to watch!

[NathanOkun]

Venus is rotating so slowly that it has only a very weak magnetic field generated by its molten outer iron-alloy core -- I assume that its core would cool off as slowly as Earth unless its core is much different in size and/or composition, in which case all bets are off, of course. Without the strong magnetic field, you end up like MARS with the surface water being stripped of its hydrogen by the solar wind and eventually you get carbon dioxide, but in the Venus case, its gravity is strong enough to hold onto its almost all of its oxygen when combined with the carbon to form the heavier carbon dioxide molecules, so all of the oxygen that was in its water became the oxygen in the carbon dioxide, hence the very thick atmosphere. If Venus was spinning like Earth and, if necessary, had a Moon like Earth does, it would probably still be much like Earth and would remain so for almost as long (until the Sun heats up enough to cook both planets in a billion years or so). I am not sure how important the Moon is, but if it is, then alternate livable Earths are going to be very few and very far between...

[TragoudistrosMPH]

0:38 You even make irony/sarcasm sound cheerful and endearing! :)

I kind of assumed, without thinking, that Venus might have a slightly different composition than Earth... interesting.

[ArtaxNOO]

Thanks for all the videos! So damn interesting. Keep em coming😎

[Nyan_Kitty]

Whoa, such enthusiasm xD
She could be talking about taxes and get me all hyped up =)

[supermotofrak]

So.. life could have started on Venus ? Cool theory

[dvklaveren]

This is actually a good thing. The less habitable the universe is, the more likely it is that we're past what's called the "Great Filter".

The Drake Equation is a formula that predicts how many intelligent species ought to exist. However, we can tell our maths are just not adding up yet, because we have no evidence of intelligent life yet if we make optimistic assumptions about the maths.

That raises the question; where should we be making pessimistic assumptions about the emergence intelligent life in the universe?

There are two directions the maths can take us; something prevents intelligent life arising elsewhere or something prevents intelligent life from surviving long enough to make contact.

The harder it is for life to develop, the more we're pushed to the first conclusion, which means we're breaking galactic ground. The easier it is, however, and the more failed intelligent life has preceded us.

So, bad news for life in the universe is ironically great news for us!

[anarchyantz]

Keep in mind as well that the habitable zone can also include moons further out from it, for instance ones around Jupiter and Saturn which heat up due to tidal flexing. We find loads of Jupiter sized planets, so theoretically they also could contain dozens of moons perhaps with liquid water. Spotting them of course is the issue.

[LandoHitman]

SciShow Space makes me more and more excited for the James Webb telescope.

[tannerrennat]

Perhaps Venus was the garden we were ejected from when we got too smart for our own good

[NewMessage]

Figures the Goddess of love would be a jealous bish, and ruin it for all the other habitable planets.