La NASA a récemment découvert une nouvelle planète passionnante appelée "Super-Terre", et elle n'est pas très loin de nous en termes spatiaux ! Cette planète est plus grande que la Terre mais plus petite que Neptune, et les scientifiques pensent qu'elle pourrait même avoir de l'eau, ce qui est extrêmement important pour la vie. Elle est située dans un système stellaire voisin, à seulement 37 années-lumière, ce qui en fait l'une des planètes de ce type les plus proches. Ce qui est cool, c'est qu'elle orbite dans la "zone habitable" de son étoile, où les températures pourraient permettre la présence d'eau liquide. Les scientifiques sont vraiment curieux de savoir à quoi pourrait ressembler l'atmosphère de la planète et si elle pourrait éventuellement abriter la vie. Cette découverte nous rapproche d'un pas de l'exploration de planètes au-delà de notre système solaire ! Animation créée par Sympa. ---------------------------------------------------------------------------------------- Musique par Epidemic Sound https://www.epidemicsound.com Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna ---------------------------------------------------------------------------------------- Nos réseaux sociaux : Facebook: https://www.facebook.com/sympasympacom/ Instagram: https://www.instagram.com/sympa.officiel/ Stock de fichiers (photos, vidéos et autres): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ---------------------------------------------------------------------------------------- Si tu en veux encore plus, fais un tour ici: http://sympa-sympa.com
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00:00A new super-Earth has recently been observed by astronomers, and it arouses great interest.
00:06This planet, designated as TOA-715b, has an equivalent size to one and a half times that of our Earth,
00:14which justifies its name of super-Earth.
00:17In addition, it is relatively close to us, at only 137 light years.
00:22To put this into perspective, the majority of exoplanets are located at several hundred light years,
00:28while fascinating celestial objects such as black holes and nebulae are generally thousands of light years away from us.
00:35Could it therefore be habitable?
00:37The habitable zone represents an estimate of the regions where a planet could present favorable conditions to the existence of liquid water.
00:45This refers to a specific distance from the star, where the temperatures on the planet should be tolerable.
00:51However, this estimate is not very precise, because it depends on various factors such as the type of star,
00:58the ability to reflect the planet, as well as its size, among many others.
01:03In addition, being located in this zone does not guarantee the presence of water.
01:07The planet must also have an appropriate atmosphere as well as other favorable conditions.
01:12To remedy this, a stricter definition was established in 2014, the habitable zone conservative.
01:20This more precise term refers to the best candidates likely to present liquid water.
01:25Otherwise, we would risk meeting too many potentially habitable planets, which, in reality, are not.
01:33The ZHC is determined by the amount of energy a planet receives from its star compared to that of the Earth.
01:39If a telluric planet receives between 40 and 85% of this energy, it is considered to be in the ZHC,
01:46regardless of its distance from its star.
01:49These planets are more likely to be habitable.
01:52And indeed, roof 715 B is located in this zone.
01:56This super-Earth gravitates around a type M star, also known as the red dwarf.
02:02This star is much smaller and less warm than our sun, representing about a quarter of its size and mass.
02:09However, if this planet is located in the habitable zone, it is actually a more suitable option for life,
02:16because red dwarfs live much longer than our sun, which is a yellow dwarf.
02:21This also means that it has more time to allow the emergence of small life forms.
02:26In addition, this red dwarf is older than our star.
02:29Our star is 4.6 billion years old, while this star is 6.6 billion years old.
02:35About a few hundred million years.
02:38This star has little magnetic activity, which puts it at risk.
02:42It does not know of strong eruptions like young red dwarfs.
02:45These eruptions can be extremely powerful and risk damaging the planets by tearing up their atmosphere.
02:51Although some planets in orbit around it have less dense atmospheres,
02:55it seems that this red dwarf has already reached a state of stability.
02:59These red dwarfs are currently privileged targets in the search for planets likely to shelter life.
03:06Our super-Earth is extremely close to its star and completes an orbit in just 19 days.
03:12Given the small size of the star and the proximity of the planet,
03:16the passage of it in front of its star occurs frequently and in a very distinct way.
03:21This facilitates the study of its atmosphere by telescopes such as James Webb,
03:25thus requiring less observation time.
03:28Speaking of the James Webb Space Telescope,
03:30it plunges us into a new era of understanding of distant planets beyond our solar system.
03:35Imagine being able to determine what gases make up the atmosphere of a planet with millions of light years.
03:41James Webb will help us to unravel these potentially habitable worlds.
03:44At the moment, he is working to verify whether Toa 715 b has an atmosphere.
03:50If this is the case, it could be more easily detectable compared to a drier and denser planet.
03:56This would arouse great enthusiasm, because it would indicate an environment conducive to life.
04:02In addition, there could be another planet in this system, also located in the habitable zone.
04:07Its existence is not yet confirmed.
04:09It is only a candidate for the non-extravagant.
04:12But if it turns out to exist, it would be comparable to Earth in terms of size,
04:16thus becoming the smallest planet observed in the habitable zone by the TESS telescope.
04:22Another fascinating feature of Toa 715 b is that it could not only house water,
04:28but also be a real aquatic world.
04:31An oceanic planet designates a type of planet entirely covered by an ocean
04:35or possessing underground oceans.
04:37These planets can only have very few emerging lands,
04:40and sometimes they can even be submerged by other liquids, such as lava or ammonia.
04:46As for the planets located outside our solar system,
04:50our current technology does not allow us to observe the water directly on their surface.
04:55Scientists focus more on the detection of water vapor in the atmosphere,
05:00which can indicate the presence of liquid water below.
05:03Of course, we are also wondering about the possibility of life on these planets,
05:08hoping that they do not take the form of Leviathan-type monsters.
05:12Our models suggest that oceanic planets could be quite widespread in our galaxy.
05:17This means that there could be many more oceanic worlds to discover.
05:22However, the most captivating part about Toa 715 b
05:26is that it is located in what is designated as the Fulton gap.
05:30If we draw up a list of planets,
05:32we will observe those that are larger or smaller than Earth.
05:36However, a void suddenly appears for the celestial bodies,
05:40measuring once and a half to twice the size of our planet.
05:44Where did they go?
05:45This gap arouses the interest of scientists,
05:48because it reveals information about the way in which planets form and evolve over time.
05:53It is not about a lack of planet formation in this size range.
05:57In reality, they often start larger and then lose part of their mass,
06:01like a balloon that is slowly deflating.
06:04This could be due to the way they orbit around their stars,
06:07which can eliminate part of their mass,
06:09like our sun, which interacts with the gas of comets.
06:13This gap contains many mysteries,
06:15and planets like our new super-Earth could provide precious clues to help us pierce them.
06:21We do not yet know if this phenomenon exists around red dwarfs.
06:25It is possible that it is a difference in density among these planets,
06:29rather than a question of size.
06:31Thus, the study of this newly discovered planet becomes all the more interesting.
06:36It will allow us to learn more about distant stars and their planets.
06:40We mentioned TESS a little earlier.
06:42NASA's TESS satellite, or Transiting Exoplanet Survey Satellite,
06:46was launched six years ago, and has since had remarkable success.
06:50NASA launched TESS because we had already identified more than 5,000 planets in orbit around other stars,
06:57mainly thanks to the Kepler telescope.
06:59However, Kepler has mostly detected large planets that do not necessarily look like Earth.
07:05We have therefore decided to orient TESS towards the search for smaller planets,
07:09of terrestrial size, around bright and close stars,
07:13which will facilitate their study through future telescopes.
07:16Here's how it works.
07:18The camera observes the stars and scrutinizes the variations in their brightness.
07:23If it suddenly decreases for a while before returning to normal,
07:27it can indicate that a planet is passing in front of the star.
07:30However, the stars can also darken for other reasons,
07:34such as eruptions or dark spots on their surface.
07:37This is why it is essential to take these data with tweezers.
07:41TESS provides us with information on the size and orbit of these planets.
07:46Then, the terrestrial telescopes help determine their mass.
07:50Thanks to these three parameters, we can understand the composition of the planets
07:54and know whether they are telluric like Earth or gaseous like Jupiter.
07:58And yes, it is better to avoid Jupiter after a night out.
08:02An example of the discoveries made by TESS is the TOA 700 system.
08:07This is where it launched its first planet similar to Earth, TOA 700s d.
08:12This exoplanet also orbits around a red dwarf
08:16and is even closer to us, about 100 light years away.
08:20Unfortunately, it is unlikely that it is habitable due to the extreme temperatures that reign there.
08:25Another great discovery took place in the HOMICROSCOPY system.
08:30TESS detected a planet about four times larger than Earth,
08:34as well as another almost three times larger.
08:38This system has become a key area for studying the formation
08:42and evolution of stars and planets over time.
08:45TESS has also observed a variety of other exciting discoveries,
08:48such as supernovas and burning worlds.
08:51At the dawn of its sixth year, we can expect even more fascinating discoveries.