Avez-vous déjà pensé à installer des horloges sur la Lune ? Cela semble fou, n'est-ce pas ? Mais les scientifiques disent que c'est un impératif pour les futures missions lunaires. Le temps fonctionne un peu différemment sur la Lune en raison de sa gravité plus faible et de sa distance avec la Terre. Des horloges précises aideraient les astronautes à naviguer, à coordonner leurs tâches et même à mieux communiquer avec la Terre. De plus, avec des projets de bases lunaires et d'exploration, synchroniser le temps lunaire pourrait changer la donne. C'est comme établir les bases d'un tout nouveau fuseau horaire—sur la Lune ! 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
----------------------------------------------------------------------------------------
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
Category
😹
FunTranscript
00:00Time can be distanced or contracted depending on where you are.
00:05If you climb to the top of a very high mountain,
00:08time will flow a little bit faster than if you were in a valley.
00:12This phenomenon is due to gravity and the way it affects time.
00:16We hardly notice it in our daily life.
00:18But for scientists and space agencies preparing missions on the Moon,
00:23these tiny differences in time have a real importance.
00:26We will answer the question why a little later.
00:31At the moment, a new space race is underway.
00:36Many countries want to establish long-term bases on our satellite.
00:40With human beings on the Moon,
00:42it becomes crucial to have a reliable time measurement system.
00:46However, the Moon does not rotate at Earth time.
00:48A day on the Moon is slightly faster than a day on Earth.
00:52The difference is about 56 microseconds, and it seems insignificant.
00:56But over time, this slight difference can lead to an accumulation and considerable problems.
01:02That is why, in order to ensure the good progress of lunar missions
01:06and to avoid any desynchronization,
01:08NASA and scientists around the world are now facing a major challenge.
01:12Create a brand new lunar time scale.
01:18NASA should start using it by 2026.
01:21It is this same year that it hopes to send astronauts back to the Moon for the first time in 50 years.
01:26But this new time scale is not just a time-lunar fuselage.
01:30In fact, it is a complete system that will adapt to the faster time of the Moon
01:35and will ensure synchronization with the Earth's time systems.
01:39It is only on this condition that missions will be able to take place without trouble.
01:43On Earth, the time measurement is already surprisingly complicated.
01:47One might think that time is a simple concept.
01:50But measuring time with precision is in fact an exact science.
01:54Especially if we consider how much it affects our everyday life.
01:58Thus, to ensure the coordination of time on a global scale,
02:02scientists rely on what is called the Coordinated Universal Time, or UTC.
02:07This global time standard is based on ultra-precise atomic clocks
02:12that scientists have installed in various places around the world.
02:16Atomic clocks are interesting because they measure time
02:20based on the constant vibrations of atoms, which makes them extremely stable and precise.
02:25They allow scientists to ensure that their UTC is the same for everyone, everywhere.
02:31These atomic clocks also take into account the fact that time moves slightly slower
02:36as we get closer to the center of our planet.
02:39Thus, atomic clocks placed closer to the surface of the Earth
02:43rotate a little slower due to the stronger gravitational attraction.
02:47This effect, explained by Einstein's theory of relativity,
02:51is due to the fact that gravity affects time.
02:54By distributing atomic clocks at different altitudes,
02:57scientists establish an average of all the tiny temporal shifts caused by gravity.
03:03In addition, for a precise measurement of time,
03:05scientists occasionally add intercalar seconds
03:10to take into account small natural variations in the Earth's rotation speed.
03:14This seems very complex,
03:16but this synchronization process allows the modern world to function.
03:20After all, a well-defined time is essential for world trade,
03:23GPS navigation and Internet communications.
03:27But on the Moon, time works differently.
03:30The gravitational field of our natural satellite is weaker than that of the Earth.
03:34As a result, clocks rotate a little faster on the Moon.
03:37This difference means that, without correction,
03:40these clocks are likely to shift slowly from terrestrial clocks.
03:44This can cause big problems
03:46when astronauts have to stay in close contact with the Earth
03:50or navigate on the lunar surface.
03:52The solution proposed by NASA?
03:54A lunar time scale.
03:56Scientists will not adjust the lunar clocks
03:59so that they correspond exactly to those of the Earth.
04:02They want, rather, to establish a unique system
04:05that measures lunar time with precision,
04:07but which is also easy to convert to terrestrial time.
04:10It is, in a way, to create a brand new frame of reference for the Moon.
04:15To make this lunar time system work,
04:17NASA collaborates with its international counterparts,
04:20such as the European Space Agency.
04:22Together, they have put in place the Lunanet.
04:25This lunar network will be a bit like the Internet of the Moon.
04:28It will ensure that all lunar clocks work in concert
04:31and align on terrestrial time.
04:33Just as atomic clocks coordinate to determine their UTC on Earth,
04:37lunar clocks will coordinate with the Lunanet network.
04:42Scientists have a good experience of time management in space.
04:46Satellites of the Global Positioning System,
04:49orbiting the Earth at an altitude of about 20,000 km,
04:53are equipped with atomic clocks.
04:55These clocks rotate faster than clocks on the surface of the Earth,
04:59because they are very far from the Earth's gravitational attraction.
05:02But then, how can GPS navigation remain precise?
05:06Well, scientists have found a way to slow down these clocks
05:10so that they correspond to Earth's time.
05:12This experience with GPS clocks is an excellent basis
05:15for what scientists are looking to do on the Moon.
05:18In some respects, it could even be easier than managing the GPS.
05:22Scientists can work directly with lunar clocks
05:26instead of having to constantly adjust them so that they correspond to Earth's time.
05:30By setting up a precise lunar time,
05:33scientists hope to avoid some complications related to the management of GPS satellites.
05:39And now, here is the most exciting aspect.
05:41For the measurement of lunar time to become a reality,
05:44NASA and its partners want to install clocks
05:47both on the lunar surface and on satellites orbiting the Moon.
05:52Some will be atomic clocks with a long lifespan,
05:56while others will be crystal clock clocks,
05:59which offer stability over a short period of time.
06:02Together, these clocks will create a network on which scientists can rely.
06:07But atomic clocks intended for space are not cheap.
06:11They can cost several million dollars each.
06:14Crystal clock clocks, on the other hand, are more affordable.
06:17But they do not remain accurate over very long periods.
06:20Once these clocks are installed, they will work together thanks to the Lunanet network,
06:25which will be the framework of NASA for everything related to the time and data networks based on the Moon.
06:30Lunanet will act as an Internet for lunar operations.
06:34Various space agencies will contribute to it,
06:37as do Internet access providers on Earth.
06:40But there is another series of challenges,
06:42this time related to the rotation of the Moon.
06:44First of all, a day on the Moon lasts much longer than a day on our planet.
06:49Because it takes about 28 Earth days to complete a complete rotation on the Moon.
06:54In addition, the equator of the Moon has about 14 days of sunlight followed by 14 days of darkness,
07:00unlike the regular day-night cycle of the Earth.
07:03And at the south pole of the Moon, where NASA will establish its future lunar missions,
07:07some areas remain illuminated, or in the shade, permanently.
07:11This could complicate the task of astronauts, who want to keep the notion of time.
07:16NASA and its partners hope to involve more countries in this project
07:20through international organizations such as the International Astronomical Union.
07:25The idea is to make the Moon's time scale adopted by as many nations as possible,
07:30so that all those who explore the Moon are on the same wavelength.
07:34Another fascinating aspect of this project is that the determination of lunar time
07:38could be useful for other further space missions, such as trips to Mars.
07:44The experience and knowledge we will gain by establishing a lunar time scale
07:48will probably serve as a model for time management on even more distant planets.
07:53This is one of the reasons why scientists take this project very seriously.
07:57For astronauts living on the Moon, a coherent and reliable time system will be essential,
08:03not only for navigation, but also for all scientific experiments and everyday activities.
08:10The NASA project on lunar time is truly revolutionary.
08:14This is a first step when humanity begins to venture into space.
08:19If the project succeeds, future astronauts will not only have terrestrial time to guide them,
08:24they will also have this lunar time, and even, one day, a Martian time.
08:29Measuring time with precision is essential,
08:32both to understand scientifically how time flows on the Moon,
08:35and to set up the infrastructure necessary for the realization of missions.
08:39If scientists are so eager to create a new time scale,
08:43it is also because they are now able to apply everything they have learned on Earth
08:47over the last decades in terms of synchronization and timing.
08:51And now, my time is up. Bye!