00:00What if I told you that humans could have evolved on a planet other than Earth?
00:03And we're not talking about Mars here.
00:06This planet is Venus, one of the most toxic and dangerous places in our solar system.
00:11But imagine this.
00:13Once upon a time, Venus was a happening place for potential life.
00:18And maybe, just maybe, life was there.
00:22How is that possible?
00:24And what happened?
00:25Let's figure it out.
00:27Picture this, a planet swathed in clouds and named after a deity of love and beauty, Aphrodite.
00:33Sounds enchanting, right?
00:35But don't be fooled.
00:36Venus, our neighbor, is the second planet from the sun, and it's no picnic.
00:41Its surface is hot enough to melt lead, and the atmosphere is so thick that the sun is just a blurry smudge.
00:46As you get closer to it, things turn from dreamy to downright hellish.
00:51About 30 miles up in the atmosphere, temperatures range from 86 to 158 degrees Fahrenheit.
00:57And this is just the beginning.
00:59To survive on Venus, you'd need super-duper insulation, because temperatures can reach a sizzling 900 degrees Fahrenheit.
01:07Plus, the weight of the atmosphere would bear down on you like being submerged deep in the ocean.
01:13The atmosphere is mostly made of carbon dioxide, and down at the surface, it behaves in a corrosive way due to the intense heat and pressure.
01:20The sky is sulfur-yellow, and the clouds are composed of sulfuric acid.
01:25The surface is filled with active volcanoes and craters.
01:28Yikes!
01:29It's like the environment itself turns against you.
01:32Venus is often referred to as the Earth's twin.
01:35That's because Venus is almost as big as Earth, just a tad smaller, and these two planets look quite similar on the inside.
01:42But in reality, Venus is more like Earth's opposite than its twin.
01:46It spins in the opposite direction, has longer days than years, and has no seasons to speak of, not even mentioning its crazy weather conditions.
01:55But believe it or not, it wasn't always this way.
01:58A long time ago, around 3 billion years after it was born, Venus might have been a watery wonderland like our beloved Earth.
02:06It had a cozy climate, and researchers think there was even enough time for life to emerge.
02:12But how do we know that?
02:14Back in 1978, NASA's Pioneer Venus spacecraft discovered hints that Venus might have had oceans on its surface.
02:21Since then, scientists have sent more missions to explore the planet, and they've learned some fascinating things about its past.
02:29NASA researchers have come up with five cool simulations to show what Venus was like with different amounts of water covering its surface.
02:36To create these simulations, scientists used a fancy 3D model that takes into account the gases in Venus's atmosphere billions of years ago and how they are now.
02:45They also considered how the sun's radiation has changed over time, getting warmer as it ages.
02:51And it turns out that Venus used to be a lot like Earth.
02:54All simulations suggest that Venus could have had stable temperatures, ranging from a comfy 68 degrees Fahrenheit to a toasty 122 degrees Fahrenheit.
03:03In some of the simulations, Venus had a similar landscape to what it has now, with a shallow ocean and some water trapped in the soil.
03:11In others, they imagined Venus having a deep ocean or even the entire surface covered in water.
03:16Surprisingly, in all these scenarios, Venus could have maintained temperatures suitable for liquid water.
03:22Now, imagine a parallel universe where Venus stayed this way.
03:26What if things turned out differently and it was still as cozy as Earth?
03:29It could have been the perfect place for humans.
03:33Its oceans would have provided a nurturing environment for life to flourish and evolve.
03:38The temperatures would have been like a perpetual springtime picnic.
03:42Can you imagine lounging under a Venusian palm tree, sipping Venusian lemonade?
03:47Ah, the good life.
03:48Also, Venus had a slow rotation compared to Earth.
03:52Days would have stretched out, giving us more time to enjoy life's simple pleasures.
03:56Instead of 24 hours, a Venusian day might have lasted for months.
04:01You could have taken an extended vacation and still had time for a full makeover.
04:05And what about the higher atmospheric pressure?
04:08It may sound intimidating, but it could have actually worked in our favor.
04:13The higher pressure would have provided a cozy and snug environment,
04:17like being wrapped in a warm, fluffy blanket.
04:20No need to worry about the chilly winds of other planets.
04:23Venus would have had us covered.
04:24Oh, and remember the acidic atmosphere?
04:28It may sound strange, but it would have had its benefits too.
04:31Venus would have been a carbon dioxide-loving paradise.
04:35Plant life would have thrived, creating lush landscapes and filling the air with fresh oxygen.
04:41So in this scenario, Venus could have been our haven among the stars.
04:45So what happened?
04:45What has ruined Venus?
04:47Unfortunately, everything changed about 700 million years ago.
04:51There was a huge event that caused Venus to change completely, turning it into the hostile place it is today.
04:58It experienced a runaway greenhouse effect, which made its atmosphere super thick and scorching hot.
05:04A runaway greenhouse effect sucked all the water into space,
05:07leaving behind a scorching surface of volcanic rock with thick, crushing atmosphere and acid clouds.
05:13Yikes.
05:14So what caused this catastrophic transformation?
05:18Well, our experts believe it may have been due to volcanic activity.
05:22When magma and molten rock reached the surface, they released a bunch of carbon dioxide into the atmosphere.
05:28If the magma cooled before reaching the surface, it created a barrier that prevented the gas from being reabsorbed.
05:35Massive amounts of gas were released into the atmosphere.
05:39Something similar happened on Earth with the Siberian traps, which caused a mass extinction.
05:44Venus had its own mega transformation.
05:46So, unfortunately, this catastrophe changed the history of our solar system once and forever.
05:51But here's the fascinating part.
05:54This little mysterious planet still could teach us a lot about the origins of life.
05:59For example, if Venus was once habitable,
06:02it opens up exciting possibilities for exoplanets in the Venus zone of other star systems.
06:07Maybe they could support life too.
06:09There's also a critical question that scientists ponder.
06:13How do these life-friendly worlds come into existence?
06:16Early on, Venus and Earth were strikingly similar.
06:19They were close in size, had similar structures inside, and even had oceans in their youthful days.
06:26But one planet turned into a scorching inferno, while the other became a thriving hub for abundant life.
06:31Why is that?
06:33And finally, believe it or not, we can't completely rule out the possibility of life on Venus even now.
06:39Up high in the thick yellow clouds where the temperature, air pressure, and chemistry are friendlier,
06:44there might be a chance.
06:45That's a range where Earthly life, like tough extremophile microbes, could potentially survive.
06:51The atmospheric pressure up there is similar to what we experience on Earth's surface.
06:55We've even noticed strange dark patches in its atmosphere that come and go.
06:59Dark streaks persist, defying hurricane-force winds and absorbing ultraviolet radiation.
07:05Scientists are scratching their heads over these persistent streaks.
07:08They suspect they could be made of fine particles or ice crystals.
07:12But here's where it gets wild.
07:15Astrobiologists consider another option.
07:18Could these streaks be made up of Venus-style microbial life?
07:22They theorize that ring-shaped sulfur compounds in Venus's atmosphere could act as a protective coating for the microbes.
07:28Wouldn't that be amazing?
07:29That's why, by studying why Venus went down a different path in terms of habitability,
07:35we can unlock the secrets of what makes other worlds just right for life.
07:39However, there are still mysteries to solve.
07:41We need more missions to study Venus and understand its history better.
07:45For example, learn how quickly it cooled down after its formation.
07:49We also want to figure out if the transformation was a one-time cataclysm or a series of events over billions of years.
07:55Nonetheless, we can still dream of the Venus that could have been.
08:00A paradise where humans and Venusians could have lived side by side.
08:04So keep your eyes on Venus.
08:06It's a wild planet with a captivating history.
08:10Who knows what other surprises it has in store for us.
08:13Let's keep exploring and reaching for the stars.
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