New discoveries on alien planets reveal the most violent storms and strangest weather in the universe. On some planets, there might be rain of rubies and diamonds, and others could have supersonic winds and extreme temperatures.
Thanks for watching. Follow for more videos.
#cosmosspacescience
#spacedeepestsecrets
#season2
#episode2
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#spacedocumentary
#alienstroms
#alien
Thanks for watching. Follow for more videos.
#cosmosspacescience
#spacedeepestsecrets
#season2
#episode2
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#spacedocumentary
#alienstroms
#alien
Category
📚
LearningTranscript
00:00we all love talking about the weather is it too hot or is it too cold it's a national obsession
00:14but now scientists have also started looking to the heavens and wondering what the weather
00:22might be like on other planets we're witnessing the birth of extraterrestrial meteorology as
00:30technology is allowing astronomers to study the weather on other planets like never before
00:40and our exploration of the universe is revealing alien worlds with weather far stranger and more
00:47extreme than anyone could ever have imagined we thought we had extreme weather on earth but it
00:57turns out that it's nothing compared to what's out there and the search for the weirdest weather in
01:05the universe is only just beginning it's a warm spring morning and astronomers are experiencing a rare event
01:25they're looking through their telescopes in the middle of the day it's a chance to get a unique
01:33perspective of one of our nearest neighbors to take a closer look astronomer Tom Kurz has set up the
01:44Great Equatorial Telescope in London to look at the Sun for the first time since 1927 at exactly 12 minutes
01:55past noon the planet Mercury will pass in front of the Sun
01:59so here is Mercury emerging onto the face of the Sun looking very beautiful indeed over the next seven and a half hours or so Mercury will gradually
02:22slink across the face of the Sun and as it overtakes us on the inside track in the solar system about 52 million miles away from the earth right now
02:29since we've known about the existence of other planets we've wondered what these mysterious alien worlds are like
02:39could they be home to life and is there any way of finding out
02:46so I'm wondering whether other planets might be habitable or not the key questions that we need to ask to begin with is what is the atmosphere actually like what is the climate like what's the weather like whether it'd be very extreme or whether it'd be quite pleasant and stable the kind of weather that we think is necessary for life
03:06so what will the weather be like on Mercury
03:13if we look back at the beginning of the Mercury transit we can see a really clean bite taken out of the Sun and the edge is so clean because Mercury doesn't have any appreciable atmosphere to speak of
03:25with no real atmosphere Mercury is effectively a dead and barren world
03:32because Mercury lacks anything that we would call an atmosphere there's essentially no weather on Mercury at all
03:40it's all
03:47cloudy with a few sunny breaks and not as warm tomorrow with Mercury is unique in our solar system because all the other planets do have atmospheres and therefore also have weather
03:57Death Valley California one of the most extreme and alien environments on Earth
04:04Planetary Explorer Suzanne Smircar has come here because it shares a surprising similarity to our nearest neighbor Venus
04:12Venus Venus is the brightest object in the night sky and the reason it's so bright is because it's covered in thick clouds and when you turn your telescope to it you can see nothing of the surface it's kept it shrouded in mystery
04:31because Venus is similar in size to Earth and also relatively close to us astronomers once believed it would have a climate much like ours
04:38astronomers once believed it would have a climate much like ours
04:42we used to think that Venus was much like the Earth maybe 50 degrees hotter because it's that much closer to the Sun we thought it had an atmosphere like the Earth we thought it would be cool enough to have oceans
04:53we even thought it was covered in steamy hot swamps
04:59probably covered with verdant green life
05:06to discover what Venus was really like we needed to go there
05:14in the late 1960s the Russians succeeded
05:19the one that finally made it to the surface was Venera 7 in 1967
05:24and that probe fell gently through the atmosphere got to the surface and survived for only about two hours
05:37before they died the Venera probes revealed the true nature of Venus's climate
05:46Venus has a surface temperature of 462 Celsius which makes it the hottest place in this solar system
05:51and the atmospheric pressure on Venus is almost 100 times that on the Earth
05:58with surface temperatures of over 860 degrees Fahrenheit
06:02and oppressive atmosphere of carbon dioxide
06:06and belching clouds made of sulfuric acid
06:10Venus is a planetary vision of hell
06:12we knew for the first time that Venus is not a swampy verdant region teeming with life
06:23but instead it's a hellish hot inferno
06:27Venus is the hottest planet in the solar system even though it isn't the closest to the Sun
06:34Sue has come to Death Valley where the unbearable temperatures are created by the same phenomenon at work on Venus
06:44we're here today in Death Valley the hottest place on Earth
06:50the highest temperature ever recorded here was 134 degrees Fahrenheit
06:57but today it's a cool 108
07:00the reason it is so hot here is that we are below sea level
07:04that means that we have additional atmosphere
07:07Death Valley is 282 feet below sea level
07:11so there's that much more atmosphere above the valley floor
07:14and that means it's higher pressure
07:17and that extra bit of pressure is really what's giving us this intense heat that we're experiencing today
07:24it's like adding another layer of insulation or another blanket that's holding the heat in
07:34by simply driving uphill Sue reveals the tremendous insulating power of the atmosphere
07:42it's already looking greener and a bit cooler up here
07:52at Dante's view about a mile above the valley floor the temperature is only 86 degrees compared to the 108 down below
08:04on Earth the temperature typically increases by about 44 degrees Fahrenheit for every half mile you descend
08:15on Venus with its much deeper atmosphere than Earth this insulating effect is taken to its extreme
08:25it is so much hotter on Venus because the pressure is at 92 bars almost a hundred times that on the Earth and the atmosphere is much thicker much denser and it really holds that heat in making Venus the incredible inferno that it is
08:46on top of this Venus's atmosphere is almost entirely made up of the greenhouse gas carbon dioxide
08:56and this combines with the intense pressure to make Venus the hottest planet in the solar system
09:03but in a universe where there are gigantic super storms and ruby rain could this be the mild end of weird weather across the stars
09:12while Venus brings the heat Earth's closest neighbor is its polar opposite
09:19so Mars is the opposite extreme from Venus its atmosphere is one one hundredth the pressure of Earth's
09:26and the effect of having that really low atmospheric pressure on Mars means that it can't trap any of its heat
09:33so Mars is a cold barren desert compared to Earth or to Venus
09:40because of this the danger of the heat has been impacted by the heat of the planet
09:45so Mars is a cold barren desert compared to Earth or to Venus
09:52Earth or to Venus. Because of this thin atmosphere, Mars is home to some
09:58spectacular weather phenomena, like its enormous dust storms which dwarf those
10:04on Earth. In the thin atmosphere of Mars, the dust storms can get to a very high
10:12elevation. They can reach over 12 miles into the atmosphere, and because most of
10:20Mars is a dry, dusty desert, these dust storms can cover vast expanses. In fact, it
10:27seems there's no limit to how far they can spread. Every few years, an enormous dust
10:34storm will grow until the entire planet is engulfed. Incredibly, storms like these have
10:41been shown to envelop the whole planet for as long as two months.
10:50Forecast, plenty of sunshine through today. With seasonal temperatures, we should reach
10:54our normal high of boat. Further out in the solar system, the weather gets even wilder.
11:00It's another fine sunny day in Pasadena, home of NASA's Jet Propulsion Laboratory. Andrew
11:09Ingersoll is the father of extraterrestrial meteorology. He's come to the Deep Space
11:16Operations Center. It's mission control for the small fleet of spacecraft that NASA has sent
11:22to explore the outer reaches of the solar system. Andy has worked on all these missions.
11:29planets. So we've had a whole series of spacecraft visiting the giant planets. The first big
11:37one was Voyager in the 70s, which zoomed past all the giant planets. Then there was Galileo. Then
11:47Cassini, which has been in orbit around Saturn for 10 years. And now we have Juno in orbit around Jupiter.
11:57The spacecraft have given us an unprecedented view of the weather on these planets.
12:03The outer planets are big balls of gas. And that makes a huge difference in the weather.
12:10So there's lots of room for weather. And because you don't have continents, you don't have mountains
12:17for the winds to rub against. And there's nothing to control the weather the way the continents partly control our weather.
12:27This means that these planets have storms on an entirely different scale to ours.
12:33And the most famous storm of all is Jupiter's Great Red Spot.
12:39The Great Red Spot is a huge storm in Jupiter's atmosphere. You could put two Earths inside the Red Spot. And the winds going around the periphery of the Red Spot are about three times the speed of the Earth's jet streams.
12:55With winds whipping around at about 400 miles per hour and releasing so much energy that it heats the atmosphere above it to over 2500 degrees Fahrenheit, the Red Spot has been raging for as long as we on Earth have been able to observe Jupiter.
13:14Shortly after Galileo built the first telescope, people were using these primitive telescopes to look at Jupiter and they saw this storm.
13:26And it's apparently been there ever since, which is remarkable compared with Earth storms.
13:35The Red Spot has been there for over 350 years and that makes it the longest living storm that we know of.
13:45Jupiter may have the longest lasting storm, but it's Saturn, the next gas giant, that is home to the largest and most powerful storm ever seen in the solar system.
13:58And in 2010, the Cassini spacecraft is there to see it.
14:03Saturn, of course, is a spectacular sight because of the rings.
14:09And it's also rather boring as far as the weather is concerned.
14:13It's a bland thing.
14:16But every now and then, 20, 30 years, Saturn erupts with a giant storm.
14:23And Cassini was fortunate to be orbiting Saturn at the time of one of these eruptions.
14:31What happened was on December 5th, 2010, the radio receiver on Cassini started picking up the radio signal of lightning.
14:45And on the same day, the camera saw a little storm up in the northern hemisphere of Saturn.
14:52By January, it had developed into a fair sized thing.
14:58And then we watched it for six months.
15:03During that time, the huge storm grew and wrapped itself around the entire planet, covering over one and a half billion square miles until its head caught up with its tail.
15:14Driven by winds going around 1100 miles per hour, with huge lightning flashes, 10,000 times stronger than those we get on Earth.
15:29It's very funny. Jupiter has these very long lived storms, but Saturn has these very violent storms.
15:36We don't fully understand why there's this difference in the weather between Jupiter and Saturn.
15:42Whether it's duration or size, the storms on both these planets dwarf those on Earth.
15:51However, because they receive far less heat from the Sun than the Earth does, something else is also powering their weather.
15:59The weather on Jupiter and Saturn comes from two sources. One is the Sun, as on Earth, and the other is the internal heat left over from when the planets formed.
16:11It's this internal heat trying to escape through their deep atmospheres that makes the gas planets so tumultuous.
16:21The storms on the gas planets are certainly weirder and wilder than anything we have on Earth.
16:27But when it comes to the clouds and the rain, things get even stranger.
16:52It's a typical June morning in Southern California.
16:54And a local weather phenomenon known as the June Gloom makes it the perfect day for taking a closer look at the clouds.
17:03Dr. Kevin Baines has a passion for the skies on Earth and beyond, and he's been studying the clouds on the gas planets.
17:16Dr. Kevin Baines, Sirius 599, I've got Mike's coming out of SoCal. We're going to make a left turn on Alpha and taxi over the runway runway one.
17:31So on a planet, you'll get clouds at different levels depending on the local temperature and the local pressure.
17:35On Earth, all clouds are made of water.
17:36So in Southern California, we have this marine layer. What happens is it actually forms over the water.
17:46The Pacific Ocean, of course, has a lot of water. So during the day, it heats up and releases water into the air as water vapor.
17:52And as this water vapor rises, it cools, and then it condenses out as water droplets in the air. And when you get millions and millions of water droplets, it forms a cloud.
18:05Clouds will form wherever it gets too cold for water to stay as a vapor in the air.
18:10And if there's enough moisture, the cloud droplets grow in size until they're big and heavy enough to fall as rain.
18:21Jupiter and Saturn also have a layer of water clouds.
18:29If we were to transport ourselves magically to Jupiter or Saturn, we could find a water layer like this.
18:35But other substances form clouds at colder temperatures. So above the layer of water clouds, higher up in the atmospheres of Jupiter and Saturn, there are two more cloud layers.
18:48As you climb up out of the water layer, it gets so cold that first you get ammonia hydrosulfide, which is a very exotic cloud made of both ammonia and sulfur put together.
18:58And then as you climb up even higher into the atmosphere, when it gets down to about minus 200 degrees Fahrenheit, there, ammonia gas in the atmosphere condenses out and forms clouds.
19:10So on these planets, it doesn't just rain water. There could also be a light rain of liquid ammonia.
19:17Now if you go out to Uranus and Neptune, it is so cold out there, about minus 300 degrees, that now you even have methane gas come out as clouds.
19:29And so on Uranus and Neptune, liquid methane could fall from the sky.
19:33Bizarre as they are, ammonia and methane aren't the weirdest rains of all.
19:42Because back on Saturn, in the depths of its atmosphere, Kevin believes that an astonishing process is at work that creates what could be the strangest rain in the solar system.
19:54This process can be witnessed on an idyllic summer day in Oxfordshire.
20:05Inside this unremarkable office building, a manufacturing company is replicating the conditions deep in Saturn's atmosphere, not to study it, but for industrial purposes.
20:17Using these massive presses, they're turning carbon graphite into something far more valuable.
20:28And Kevin has come over from California to see how this process can help explain what's happening deep inside Saturn.
20:36We know that on Saturn, there's carbon soot.
20:39We know that by looking at these dark clouds that we saw with our camera on board the Cassini spacecraft in orbit about Saturn, and we see this spectroscopic signature of carbon soot there.
20:50The carbon soot is created by lightning, lightning actually zapping methane in the atmosphere.
20:56Something very strange then happens to the soot as it falls through Saturn's atmosphere.
21:02It is transformed into something remarkable, a process that is actually being replicated here.
21:11What we do, effectively, is we take this carbon graphite, we mix it with several other materials, and we assemble what we call a capsule.
21:20We take that capsule, graphite material inside it, and we place it inside the actual press itself.
21:26The press is then closed up, and the carbon graphite is exposed to extreme temperatures and pressures.
21:35High pressures are generated by these anvils that compress down onto the graphite, pressures of around 50,000 atmospheres.
21:45And the graphite is then going to be heated by large electrical currents.
21:48This heats it to over 3600 degrees Fahrenheit, mimicking what's happening inside Saturn.
21:56We know we have carbon, which is very much like the graphite that we just put into the machine over here.
22:01The carbon precipitates or falls through the atmosphere, and eventually it will encounter the same types of pressures and temperatures that we encounter inside this press over here.
22:09Inside the press, the intense heat and crushing pressure transformed the carbon from graphite into diamond.
22:24All right.
22:26So this may not look like diamonds, but we will then take this rubble, and we'll process it further, and we'll extract the diamond.
22:33Great. So the diamonds are in there somewhere?
22:35Somewhere inside this rubble, Kevin, there are diamonds.
22:37This high temperature, high pressure process can make a variety of diamonds, which are used in industry.
23:00Here we have tiny triangles.
23:02Effectively these are used for wire drawing dyes, and you get square shaped diamonds,
23:06which in this case are used as single crystal cutting tools.
23:11These diamonds are yellow because they contain nitrogen.
23:16So what we were making earlier today, effectively, are these diamond grits.
23:21Tiny little stones are single crystal diamond.
23:24It's nominally about 100 microns in size.
23:27Kevin believes the same thing is happening on Saturn.
23:30So we really think it's very similar conditions, very similar process that's happening in Saturn.
23:37Carbon soot will transform itself into diamonds, creating a diamond ring.
23:42As the carbon soot falls from the clouds, the extreme temperature and pressure deep in the atmosphere turn it into diamonds.
23:49So inside Saturn, we have a huge region of diamond ring.
24:00Our exploration of the other planets in our solar system has revealed weather stranger and more powerful than anything we have here on Earth.
24:11But what about beyond our solar system?
24:17What is the weather like in the rest of the universe?
24:20Rain tapering off tomorrow afternoon, followed by partial clearing and a high of 61.
24:33In their grand search to document weather across the stars,
24:38scientists have figured out how to use infrared light to work out just how hot a planet is.
24:56So the main thing that determines the temperature of a planet is the distance that it is from its host star.
25:00Planets that are really close in are going to be boiling hot. Planets that are further away will be a little bit cooler by comparison.
25:09Most of the exoplanets discovered so far are close to their stars.
25:14So scientists expected them to be hot, but they didn't know how hot.
25:19We can actually go and measure the temperature of these planets by measuring their brightness and infrared light.
25:24Hotter things are going to glow more brightly at infrared wavelengths.
25:27Cooler things are going to be a little bit dimmer and fainter.
25:33So probably the hottest planet that we know of is a planet called Wasp 33b.
25:40Wasp 33b is the hottest planet discovered so far in the entire universe.
25:46It's a gas giant, four and a half times the size of Jupiter.
25:50It's atmosphere is a scorching near 5800 degrees Fahrenheit.
25:56So this planet is hot for two reasons.
25:59One is it's very close to its host star.
26:02The other reason is that it orbits a star which is bigger and hotter than the sun.
26:06Both those things together combine to make this one of the hottest planets that we've discovered.
26:09Planets like Wasp 33b are nicknamed hot Jupiters and they don't just have extreme temperatures.
26:20Because being close to their star has another important fact on the weather.
26:26So all planets spin on their axis just like I am now.
26:32The Earth spins once every 24 hours but not all planets spin at the same speed.
26:37There are some planets which we're discovering which are very very close to their stars.
26:42They're so close that the star tugs on the planet as it spins around on its axis.
26:46And the tugging of that star actually slows the planet's rotation down.
26:52Keeps slowing it down and keeps slowing it down until the planet rotates at exactly the same speed that it orbits.
27:01So the same side of the planet always faces towards the star just like I am always facing the center of this ride here.
27:07So we call this tidal locking.
27:10And it means that the planet has a permanent day side and a permanent night side.
27:14And being tidally locked has a dramatic impact.
27:21So whenever you have one part of a planet that's hot and another part that's cold,
27:26the natural result is that you get a wind moving from one part to another.
27:30Here at the beach during the day the land heats up but the sea stays relatively cold
27:35and so you get this nice wind moving from the ocean towards the land that's trying to even out the temperatures.
27:39So when we first discovered these very close in planets we realized that they were probably close enough to be tidally locked.
27:46And one of the very first things we wanted to know is what that meant for the planet's atmosphere.
27:51So did it mean that these planets had a boiling hot day side and a freezing cold night side?
27:56Or were there winds in the atmosphere that were able to carry some of that heat around to the night side?
27:59To find out, Heather mapped the temperature on a hot Jupiter, which scientists think is blue in color.
28:11The particular planet we decided to look at was a hot Jupiter called HD 189733.
28:19Now that's kind of a mouthful but I can tell you that this is actually my favorite hot Jupiter.
28:23This was one of the very first planets that I looked at when I was a grad student.
28:27By looking at it in infrared, Heather was able to measure its temperature.
28:31So this is the map we made. So the color tells you the temperature of different parts of the atmosphere.
28:38So here on the day side things are relatively hot.
28:42On the day side it's 1600 degrees Fahrenheit.
28:46Here on the edges that's the night side and that's a relatively cool part of the atmosphere.
28:51On the night side it's just 1300 degrees.
28:53That difference is actually much smaller than we expected.
28:56And the fact that it's so small suggested to us that this planet must have strong winds circulating through its atmosphere
29:03and carrying that hot air from the day side around to the night side.
29:10Incredibly, these winds have now been measured directly.
29:13And it turns out that HD 189733b is home to the fastest winds in the universe,
29:20which range around 5500 miles per hour, seven times the speed of sound.
29:27And 20 times faster than the fastest winds ever experienced on Earth.
29:37But could exoplanets be home to even weirder weather, where raining rubies is the norm?
29:50With the winds out of the west at 22 miles per hour, it's currently 80 degrees.
30:05It's a beautiful tropical morning on the big island of Hawaii.
30:10An exoplanet expert, Hannah Wakeford, is taking to the skies to explore another bizarre effect
30:16the extreme heat on exoplanets has on their weather.
30:23The strangest thing about exoplanets is the clouds and the rain.
30:26They're nothing like we have here on Earth.
30:29Spectroscopy has revealed that exoplanets have clouds, and also what these clouds might be made of.
30:35We know that exoplanets have clouds. If we have a planet that we know should be gaseous because of its density,
30:41but we don't detect any spectral signatures from that gas,
30:45then we think there must be clouds in the way which are blocking that light and obscuring our view.
30:50And sometimes we can detect signatures directly from those clouds by the way that they scatter or reflect the light.
30:55But these aren't clouds we recognize.
31:02A lot of the exoplanets that we've been able to follow up are very hot, over a thousand degrees.
31:10So we know that water can't exist as a liquid at those temperatures,
31:14so they're not going to be clouds like we have here on Earth.
31:16Whoo! We're in a cloud!
31:19So on some exoplanets, the clouds will be made of far more exotic substances.
31:27Temperatures are such that substances that we think of as solids on Earth can actually exist as liquids of gas in exoplanet atmospheres.
31:38We can get a glimpse of this on Earth in volcanoes,
31:42where temperatures can reach over 1,800 degrees Fahrenheit.
31:48Down there is the crater of Pu'u'o'o,
31:52and you can see the lava bubbling away.
31:55The temperature of this lava lake is such that all of the rock has melted.
31:59The metals, the minerals, and the silicates that make up the Earth's crust have all become molten.
32:06It's amazing, you can really feel the temperature from the lava lake all the way up here.
32:11It's really very hot.
32:16It's melting the Earth's crust down there, so it's no surprise.
32:22And it's these substances that are thought to make up the clouds on some exoplanets.
32:27There's a planet called 55 Cancri e that we think is rocky because of its density, but it orbits very close to its parent star and is tidally locked.
32:38So temperatures on the dayside should be high enough to melt the rock, making it a lava planet.
32:44While its night side will be relatively cool and solid rock, its dayside is an ocean of permanently molten lava.
32:57And the temperatures reach over 4500 degrees Fahrenheit.
33:03This is hot enough to vaporize the rock at the surface.
33:08This can then be lifted into the atmosphere and condensed to form clouds of liquid lava droplets.
33:15That then could be transported to colder parts of the planet, while they'll rain down as pebbles on the surface.
33:21So on some planets, it rains rock rather than water, like it does here in Hawaii.
33:33Back on the ground on Kilauea, Hannah has made an example of what rock rain might be like.
33:54Right here was the site of a massive eruption.
33:58All along this fissure, fountains of lava shot into the air.
34:03The liquid lava droplets then cooled and solidified in the air before raining down onto the surface as these tiny pebbles.
34:12And sometimes we get these perfect little droplets called Pele's tears.
34:18This is what we think the rain might be like on planets like 55 Cancri e.
34:33But perhaps the strangest rain in the entire universe has been discovered on a giant gas planet, which orbits a star hundreds of light years away.
34:43We've been able to study the exoplanet wasp 12b and the way that it scatters light suggests that there are clouds high up in the atmosphere.
34:53Here, the temperature is about 3600 degrees Fahrenheit.
34:56So the most likely substance forming these clouds is an aluminium oxide called corundum, which forms the basis of rubies.
35:05So instead of having rain, which is liquid water droplets like here on Earth, it would be raining rubies.
35:17We're only just witnessing the birth of exoplanet meteorology.
35:24But so far, what astronomers have discovered on exoplanets is even more extreme and bizarre than anything anyone had ever imagined.
35:34But in our search, could a second Earth be just around the corner?
35:39Compared to what's out there, the most extreme weather on Earth, our hurricanes and tornadoes, our rain and our snow, all seem pretty mild.
36:07Our climate and weather is actually very hospitable.
36:12The Earth is a nice place, and that's all because of the weather.
36:16We've got warm temperatures, not too hot, not too cold. It's a great place.
36:22Ultimately, the planet hunters of the world are hoping to find one thing, another Earth.
36:29A small, rocky planet with a thin blue line encircling it.
36:33A planet with a nice climate. A climate that could be hospitable to life.
36:43But the search for another Earth is still in its infancy.
36:46Dr. Bree Stemmery is a planet hunter, and he may have found the promised land of planetary exploration.
36:57A planet that could have warm, mild weather. Weather just like a lovely summer evening.
37:02So we're looking for a rocky planet. They're similar to the Earth in size, but they are located at the right distance from its star.
37:12It's a bit like cooking a marshmallow. If the marshmallow is too close to the fire, then it will burn.
37:17If it is too far away, it will never cook. So we want the planet to be at the right distance that is just right for habitable conditions to happen.
37:27We've just found three Earth-sized planets that are orbiting a very cool star called Trappist-1.
37:34And those planets are remarkable. The first one is located here and receives about four times the level of radiation than the Earth does.
37:42The second one, located here, receives twice the level of radiation than the Earth does.
37:49Both planets are probably too hot to be habitable.
37:53The third one is the most interesting one. We're not exactly sure of its location right now, but we believe it's located just here,
38:01where it would receive about the same level of radiation as the Earth does.
38:06So this is our base candidate to date for habitability prospects.
38:10Could this planet really be another Earth? As ever, this will depend on its atmosphere.
38:19The atmosphere dramatically affects the habitability of a planet.
38:24In a solar system, Venus, the Earth, and Mars are all within or very close to the habitable zone.
38:30But the atmosphere of Venus and Mars make them completely inhabitable.
38:33These three planets are totally locked to their star, meaning that they show permanent day-side, that would be too hot for habitability, and permanent night-side, that would be too cool, while still having hospitable temperature between the two.
38:55It's a bit like this marshmallow. If I put it in the fire and I don't rotate it, one side will be completely burnt, while the other will be uncooked.
39:05But in the middle, it would be just right.
39:07These planets could have a barren, frozen wasteland on their night-side, a baking inferno on their day-side, and yet, have a temperate and potentially habitable strip down the middle, where it's permanent twilight.
39:22But if you have a sick atmosphere surrounding this planet, then all the heat coming from the star on the day-side will recirculate to the night-side, making the day-side cooler and the night-side warmer.
39:42To really know if any of these planets could be habitable, we need to study their atmospheres.
39:47But they're too small for even our best telescopes.
39:56So the atmospheres in small planets, actually, are very thin.
40:00So it's very difficult to detect them, even with the state-of-the-art telescopes that we have today.
40:08We've reached the limits of our current technology.
40:10But NASA is building a new space telescope called the James Webb, which will enable us to study the atmospheres of exoplanets in far more detail than is possible today.
40:23With a mirror 21 feet in diameter, it will have greater light-gathering abilities than its predecessor, the Hubble Space Telescope.
40:32James Webb will collect seven times more photons than Hubble does, which means that we'll have more signals to study these planets.
40:42The James Webb will also be able to look at a far greater range of wavelengths.
40:46So James Webb will have the possibility to go much farther in the infrared than what Hubble is able to do today, which means that it will give us the ability to probe for many more compounds, chemical compounds, than what we are able to do with Hubble.
41:02When James Webb launches in 2018, astronomers will be able to study Earth-sized planets and discover if they're potentially habitable.
41:16I am convinced that we'll find an habitable planet maybe in the next five or maybe ten years.
41:21There are so many planets in our galaxy and this is the result from the past 20 years of a planet hunting that, based on sheer probability, we'll definitely find at least another habitable planet.
41:40For thousands of years, we've gazed up at the night sky, wondering what other planets might be like.
41:45Astronomers began by studying our own solar system, and now they're exploring the wider universe, and can even study the weather on planets hundreds of light years away.
41:59They've discovered climates and weather stranger than fiction.
42:05Alien worlds with extreme temperatures, bizarre clouds, and even ruby rain.
42:15But they've yet to find another planet like Earth, with weather that's suitable for life, that's not too hot or too cold.
42:26So for the time being, it looks like a warm and pleasant day on Earth, with a gentle breeze and a slight risk of rain.
42:34Might actually be the weirdest weather of them all.
Comments