00:00 The emblematic rings of Saturn will disappear in less than two years.
00:04 Soon, we will no longer be able to see the great red spot of Jupiter.
00:08 The atmosphere of Pluto could disappear at any moment.
00:11 And the universe itself could be evaporating slowly.
00:14 But let me start at the beginning.
00:17 The rings of Saturn will not disappear forever, at least not in the near future.
00:21 But they will disappear from our view, that's for sure.
00:24 This phenomenon will cause the inclination of the planet in its orbit around the sun.
00:29 As a result, the spectacular rings that make up this gas giant
00:33 will become invisible to astronomy lovers as early as 2025.
00:37 This scandalous disappearance will occur because the tiny rings of Saturn will move.
00:42 It's like when you hold a sheet of paper horizontally, parallel to the ground.
00:46 You can only see its edge.
00:48 This is what is happening with the rings of this great planet.
00:52 As the seasons progress, instead of the south side of the rings tilting towards us,
00:57 we begin to see their north side.
01:00 After that, the planet tilts again and reveals once again the south side.
01:04 Such a cross of the ring plane occurs every 15 years
01:08 when our planet passes through the ring plane of the gas giant.
01:11 The last time this phenomenon occurred was in 2009.
01:15 Subsequently, the rings gradually became visible again for several months.
01:19 This time, the rings will disappear in March 2025.
01:23 Then they will reappear slowly to disappear again in November of the same year.
01:28 Shortly after, the rings will be visible again,
01:31 first through the largest telescopes, then through the whole world.
01:34 But in the distant future, these rings could cease to exist for good.
01:39 Astronomers have stated that the rings of Saturn,
01:42 which are mainly composed of ice and rocky dust
01:45 coming from pulverized asteroids, are younger than we thought.
01:49 They lose tons and tons of mass every second.
01:53 And it is likely that they will disappear completely
01:56 within a few hundred million years at most.
02:00 Let's now move on to the great red spot of Jupiter.
02:03 This huge storm could stop raging in the next 20 years.
02:07 This storm is larger than our entire planet.
02:10 It was first spotted in 1830.
02:14 But observations dating from the 1600s already mentioned the presence of a giant spot on Jupiter.
02:19 If it is the same great red spot,
02:22 we can say that the storm has been raging for centuries.
02:25 If the storm's whirlwind has remained so powerful,
02:28 it is thanks to Jupiter's jet stream,
02:30 at a speed of 400 to 600 km / h.
02:33 But like any storm, the great red spot cannot continue to blow forever.
02:38 It has been shrinking for a while.
02:40 Within a decade or two, it is expected to turn into GCR, or Great Red Circle.
02:46 And who knows, maybe it will later turn into GSM, or Great Red Memories.
02:52 At the end of the 1980s, the storm was more than 56,000 km in diameter,
02:58 four times the diameter of the Earth.
03:00 But when Voyager 2 flew over Jupiter in 1979,
03:04 the storm had already decreased its initial time by nearly twice.
03:08 And this reduction continues.
03:11 In 2017, the GCR was spreading over a little more than 16,300 km wide,
03:16 less than 1.3 times the diameter of the Earth.
03:19 Let's continue.
03:21 Pluto's atmosphere is undergoing a strange transformation.
03:25 This icy dwarf planet,
03:27 located more than 4 billion km from Earth in the region of the Quipper Belt,
03:31 attracted the attention of astronomers in 2018,
03:34 when it passed in front of a star.
03:37 With a source of such powerful light illuminating Pluto,
03:40 researchers were able to examine the dwarf planet and its atmosphere.
03:44 They came to a shocking conclusion.
03:47 Pluto's atmosphere freezes to its surface.
03:50 The planet is getting colder and colder.
03:52 Astronomers have used several telescopes,
03:55 located in different points in the United States and Mexico,
03:58 to observe Pluto and its fine atmosphere,
04:00 mainly composed of nitrogen.
04:02 This atmosphere is fueled by the pressure of ice vapor at the surface of the dwarf planet.
04:07 For about 25 years, Pluto has been moving away from the Sun.
04:11 The temperature at its surface is gradually decreasing.
04:15 Pluto is currently very far from our star.
04:19 But it will eventually get closer.
04:21 Its orbit is incredibly vast.
04:24 In addition to the great red spot of Jupiter,
04:29 the rings of Saturn and Pluto's atmosphere,
04:31 we also lose stars.
04:33 But stars do not disappear, do they?
04:35 For thousands of years,
04:37 scientists have believed that the lights in the sky were fixed and immutable.
04:41 Even after realizing that they were physical objects,
04:44 like our Sun,
04:46 they remained convinced that stars only changed
04:49 over long periods of millions,
04:51 or even billions of years.
04:53 In fact, the most massive stars,
04:56 which can be hundreds of times heavier than the Sun,
04:59 can undergo sudden catastrophic events.
05:02 For example, when they reach the end of their lives,
05:05 they consume themselves in huge explosions,
05:08 the supernovas,
05:09 which shine for months and are visible over hundreds of millions of light years.
05:14 But there are stars that seem to disappear as if by magic.
05:18 This should be impossible.
05:20 In recent years,
05:22 a group of researchers has tried to determine
05:24 if such a phenomenon could really occur.
05:26 They began to compare the data collected
05:29 over decades of observation.
05:31 The project is called VASCO
05:34 and concerns the disappearing and appearing sources
05:37 over a century of observation.
05:39 Scientists are interested in all kinds of disappearing objects.
05:42 But they hope to find a star
05:44 that has been stable and present for a long time,
05:47 then that disappeared without leaving a trace.
05:49 A star that no super-powerful telescope could detect anymore.
05:54 Our current understanding of space and its laws
05:57 suggests that stars change very slowly
06:00 over long periods of time.
06:02 Spectacular disappearances are supposed to leave visible traces.
06:06 Of course,
06:07 this does not mean that all stars must shine constantly.
06:11 The sky is filled with stars whose light changes and pulsates,
06:15 but VASCO's goal is quite different.
06:17 Researchers want to find a star
06:20 that goes from constant brightness to total disappearance.
06:23 Such a phenomenon has not yet been documented,
06:26 and such a discovery could lead to a whole new physics.
06:30 We are now going to talk about something very worrying,
06:33 namely the evaporation of the universe.
06:36 According to a famous theory proposed by Stephen Hawking,
06:39 black holes, the densest objects in the universe,
06:42 evaporate over time.
06:44 They lose their mass in the form of a strange radiation.
06:47 But a new study states that Hawking's radiation,
06:50 or something very similar,
06:52 could not be limited to black holes.
06:55 It is likely that it is present everywhere,
06:57 which could mean that the universe itself evaporates slowly in front of our eyes.
07:02 No one has ever observed Hawking's radiation,
07:06 but theories and experiments suggest that it can exist.
07:11 Let's see how it works.
07:13 It is wrong to believe that black holes are cosmic vacuum cleaners
07:16 that swallow up everything that comes too close
07:19 thanks to their immense gravitational force.
07:22 In reality, black holes have no more gravity
07:25 than any other similar mass body.
07:28 What makes them famous is their density,
07:31 incredible amounts of mass packed into a tiny space.
07:35 From a certain distance,
07:37 their gravitational attraction becomes so powerful
07:40 that it becomes impossible to escape it.
07:43 Even light is not fast enough,
07:45 and it is what we find fastest in the universe.
07:49 At the same time, any object that is massive or dense enough
07:52 can produce a serious curvature of space-time.
07:55 In other words, the immense gravitational field of these objects
07:59 makes space-time literally wrap around them.
08:03 Even if black holes are the most extreme example,
08:06 space-time also wraps around other very dense objects,
08:09 such as white dwarfs, neutron stars, and galaxy clusters.
08:14 This means that any super dense and super massive object
08:18 can produce a kind of radiation similar to Hawking's radiation.
08:22 After a very, very long period,
08:25 the whole universe could evaporate,
08:27 suffering the same fate as the old supermassive black holes.
08:31 If this hypothesis is true,
08:34 it will not only change our understanding of Hawking's radiation,
08:37 but also our vision of the universe,
08:39 of its future, and of ours.
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