00:00Ah, Saturn. Incredible with its majestic rings and swirling clouds.
00:12But what would it be like to dive into it?
00:16NASA's Cassini tried that, and it turned out to be a wild trip.
00:21NASA's Cassini spacecraft was a probe that spent 13 years orbiting Saturn and gathering some incredible data.
00:27One of its major goals was to help us understand how come Saturn's atmosphere is so hot.
00:33The upper atmospheres of planets are always heated, duh. They're directly under the Sun.
00:38The strange thing about Saturn is that gas giants are too far from the Sun to get that kind of warmth.
00:44So Cassini didn't just observe the planet from outside.
00:48On September 15, 2017, it dove deep to the journey that would become the spacecraft's grand finale.
00:55Its last moments were spent inside Saturn's upper atmosphere, sending back priceless data as it slowly disintegrated.
01:04Now, these upper layers are no joke.
01:07The planet's horrifying magnetic field hums with energy, and powerful winds whip around at thousands of miles per hour.
01:14Cassini would pass through thick layers of clouds, hazy, pale gold and muted, reflecting the Sun's faint light.
01:21And these aren't cute, fluffy, Earth-like clouds made of water vapor.
01:25This is a nightmare cocktail of hydrogen and helium.
01:29The probe ventured deeper, passing through the region where Saturn's iconic rings rain material onto the planet.
01:36Cassini discovered that this rain was more intense than anyone expected – more than 22,000 pounds of material per second.
01:44That's at a rate that Saturn's rings might not last forever.
01:48The planet's own gravity could eat them away completely someday, unless the rings get a sudden update.
01:55These are all tiny grains of ice and dust, caught in the planet's gravity, falling into the atmosphere like a relentless storm.
02:02The grains, mixed with water, methane, and even chemicals like propane and butane, slowly alter Saturn's atmospheric chemistry.
02:11It mixes with the particles in the planet's upper atmosphere, making them heavier and warming Saturn up.
02:18Unfortunately, this was too much for poor little Cassini.
02:22It was designed to be tough enough for the outer layers, but it burned up before it could descend into the terrifying deeper regions.
02:29In the more intense layers of Saturn's atmosphere, winds reach extreme speeds of over 1,100 miles per hour.
02:38The pressure becomes crushing, and the deeper you go, the more overwhelming it becomes.
02:43It would feel like entering an ocean of gas, one with no clear surface, where the sky gets darker, thicker, and more hostile as you descend.
02:52And at a certain point, complete darkness.
02:55Just you and the overwhelming mass of hydrogen gas pressing in from all sides.
03:01But Cassini's sacrifice was invaluable to scientists.
03:04The key data it sent us before the grand finale allowed scientists to map Saturn's upper atmosphere more completely than ever before.
03:13Cassini tracked bright stars, like those in Orion and Canis Major, as they passed behind the planet, measuring how their starlight shifted.
03:21This helped scientists to understand how dense and hot the atmosphere was.
03:27It left us some final pictures as well, though they're not as impressive as you might think.
03:32It was a monochrome shot taken from about 394,000 miles away, showing a dark portion of Saturn's night side, softly illuminated by the reflection of its own rings.
03:44NASA also posted a picture made by their own artists of what Cassini could have seen in its last moments.
03:50And, of course, it gave us the answer to the big mystery of Saturn's heat.
03:55It's because of auroras.
03:57It turns out that, due to the crazy magnetic field, the planet's cloud layers are sparked up by sudden bursts of auroras at the poles.
04:06They're like the northern lights on Earth, but far more intense.
04:09The gas giant skies occasionally light up with radiant greens and blues.
04:13They're sparked by the interaction between solar winds and the charged particles from Saturn's moons.
04:19The hottest areas of Saturn were near these auroras.
04:23These light shows are powerful enough to heat the upper atmosphere, spreading warmth across the planet.
04:29Thanks to this added information, we discovered something important, not just about Saturn, but about all gas giants across our solar system and beyond.
04:40Meanwhile, the photos we have of Venus are much more dramatic.
04:44Venus is a bit closer to the Sun than Earth.
04:47It's often been called Earth's twin because of the similarities, like in size, mass, and composition.
04:53But don't be fooled.
04:55Beneath those thick clouds lies one of the most toxic environments in our solar system.
05:00Its surface is a nightmare, where temperatures soar to about 900 degrees Fahrenheit, hot enough to melt lead.
05:08The pressure on the planet is crushing as well, 92 times that of Earth's.
05:13That's like standing 3,000 feet under the ocean.
05:17We just couldn't resist taking some pictures.
05:19So, in the 1970s, scientists managed to land probes on this volcanic, unforgiving surface.
05:26And these missions were successful.
05:28They managed to send back the first photos of Venus and showed us incredible stuff.
05:33The first probe lasted only 23 minutes on the surface and then crushed down under this crazy pressure, winds, and heat.
05:41Both first and second probes captured black-and-white panoramas of a rocky hillside.
05:46On both, the second lens failed to eject.
05:49The horizon was flat, the ground strewn with jagged rocks, and the oppressive atmosphere pressed down like an invisible force.
05:56After lots of hurdles, we finally managed to look at colorful pictures from Venus in the 1980s.
06:03This spacecraft lasted more than two hours after extreme conditions.
06:07It's incredible that they managed to send us anything at all.
06:10Venus is a planet where metals melt, and where the atmosphere itself eats away the spacecraft.
06:16The photos it took showed that, on Venus, the skies aren't blue, but an eerie yellow due to the thick clouds of sulfuric acid.
06:24NASA also has some computer simulations of what Venus's surface could look like.
06:30But these don't really convey the horror of actually being there.
06:34Perhaps it's time we look at Venus once more.
06:37There's so much we don't know about this fiery neighbor.
06:42Finally, we also tried to enter Jupiter's atmosphere in the 90s.
06:46And that's the hardest one on the list.
06:49NASA's Galileo missions probe was designed to dive into Jupiter.
06:53It was launched in 1989 and traveled millions of miles with a small entry probe on board.
07:00This tiny hero would face one of the most intense environments we've ever encountered in space.
07:06It was finally released on July 13, 1995.
07:10At that moment, the spacecraft was still 50 million miles away from Jupiter.
07:15So just to enter the atmosphere, it had to fall for months.
07:19And it finally did fall on December 7th, plunging headfirst into Jupiter's thick, swirling atmosphere.
07:27The probe slammed into Jupiter's skies at a staggering 106,000 miles per hour.
07:33That's fast enough to cross the United States from Los Angeles to New York in 90 seconds.
07:39The intense deceleration caused the probe to experience a horrifying gravity.
07:45228 times stronger than the Earth's, it slowed down from supersonic speeds to just 100 miles per hour in minutes.
07:53The heat generated by its entry was so extreme that the shockwave ahead of it glowed as brightly as the Sun itself.
08:00The temperature soared to 28,000 degrees Fahrenheit.
08:04Then, all this time, somehow, the probe was collecting data every second and sending it all to us.
08:11It gave us some critical information about Jupiter's mysterious atmosphere.
08:17For example, it turned out that Jupiter's upper atmosphere was drier than expected.
08:23Less water vapor and fewer organic compounds than scientists thought.
08:26The probe also measured fierce winds of up to a half a mile per second.
08:32And, surprisingly, it didn't see that much lightning, even though we thought these are never-ending on Jupiter.
08:38One of the probe's biggest surprises was the discovery that Jupiter's atmosphere contained less helium than we thought.
08:46It also revealed a horrifying radiation belt about 30,000 miles above Jupiter's clouds.
08:52It's like intense radiation encircles the planet like a cosmic shield.
08:57The poor little guy managed to survive for 58 minutes.
09:01It eventually succumbed to immense pressure.
09:04Meanwhile, the Galileo orbiter continued its mission, becoming the first spacecraft to orbit Jupiter.
09:10That's it for today.
09:12So, hey, if you pacified your curiosity, then give the video a like and share it with your friends.
09:17Or, if you want more, just click on these videos and stay on the Bright Side!
Comments