Pourquoi Vénus est Devenue la Jumelle Maléfique de la Terre

Sympa

Vénus, le plus proche semblable de la Terre, possédait autrefois des océans et des lacs semblables à ceux de la Terre, mais c'est maintenant un lieu extrêmement chaud et pressurisé. La raison principale en est que Vénus est plus proche du soleil, recevant plus d'énergie, ce qui a rendu son atmosphère beaucoup plus harsh au fil des milliards d'années. Contrairement à la Terre, Mars a perdu son atmosphère primitive car sa taille plus petite ne pouvait pas la retenir, notamment après que l'activité volcanique se soit ralentie et arrêtée. Vénus, étant si proche du soleil, a vu ses océans s'évaporer, et les volcans ont continué à émettre du dioxyde de carbone, un puissant gaz à effet de serre. Les océans de la Terre aident à contrôler le dioxyde de carbone en l'absorbant et en le transformant en roche, raison pour laquelle il est si important de les protéger.  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

Transcript

00:00Venus and Earth are so different, that a question as absurd as

00:05What is the longest?

00:07A day or a year?

00:09Which would have no meaning on Earth

00:11takes all its meaning on our neighbor

00:13Indeed, a day on Venus is longer than a year

00:17To put this in perspective

00:19a Venusian day is equivalent to 243 Earth days

00:23while a Venusian year lasts only 225 Earth days

00:27It's as if you were celebrating your birthday every day

00:30Venus is often nicknamed the malefic twin of Earth

00:34Their differences are so striking

00:36that one could think they come from totally different galaxies

00:40To give you an idea of their divergence

00:42if the year-day ratio was not enough

00:45the sun rises to the west on Venus and sets to the east

00:48One of the rare similarities between these two planets is their size

00:52However, there was a time when Venus and Earth were knitted like ass and shirt

00:56the best friends since the beginning of the solar system

01:00Venus was once the center of all attention

01:03NASA scientists think it could have sheltered a liquid water ocean

01:07and surface temperatures suitable for life for up to 2 billion years

01:12But the current Venus is quite different

01:14with its extreme temperatures and a dense atmosphere of carbon dioxide

01:19So, what led to this cosmic relooking?

01:22The size, location and latitude

01:25In other words, the distance from the sun and the internal heat of the planet

01:29which played a crucial role in the destinies of Venus and Earth

01:33By the way, it was a time when three planets could potentially shelter life

01:38Venus, Earth and Mars

01:41Imagine three cakes in an oven

01:43Once cooked, it would be time to take them out

01:46One would have been placed in front of an open window in the middle of winter

01:49another carefully placed on a table and covered with a nice clean torch

01:54and the last one would have simply been forgotten in the oven

01:57Mars, Earth and Venus are like these three cakes

02:01Mars has become too cold and inhospitable

02:04Earth has remained pleasant and tempered

02:06well protected from most of the unpleasantness

02:09just like the lucky cake protected by its torch

02:12and Venus has become hot and clean and edible

02:15In terms of development, Earth has followed a slow and regular path

02:20Preserving its oceans, its stable atmosphere and its biodiversity

02:24Venus, on the other hand, has increased its temperature

02:27seen its oceans evaporate

02:29and did not lean on greenhouse gases

02:32As a result, we have a planet where you melt faster than a snowman in July

02:37Mars, on the contrary, would turn you into ice in a few seconds

02:41However, it could have been quite welcoming

02:45Some scientists think that Mars was once covered with rivers and lakes in abundance

02:50and that it certainly did not lack water

02:53Even today, Mars still has the remains of an ocean called Oceanus Borealis

02:59This ocean has lost almost all its water over time

03:02Now, the Martian water sources include the ice caps of the poles

03:06and the minerals present in the rock

03:09According to estimates, only 1% of all this water has evaporated

03:13while 99% are still prisoners of the red planet

03:17The polar ice caps are easy to apprehend since we have the same on Earth

03:22But rocks containing water?

03:24It's simple

03:25There are at least 4 types of hydrated minerals on Mars

03:29There are hydric clay composed of silicon and oxygen

03:33and what is interesting is that they can also contain magnesium and iron

03:38which decline under the form of hydrated sulfates

03:41Do not be offended if you are told that all this releases a strong smell of rotten eggs

03:46but it is typical of hydrogen sulfide and not just sulfur

03:50These minerals directly integrate water into their chemical formula

03:53We also find hydrated silica, whose formula also contains water

03:58Scientists have experimented with plant culture in conditions similar to those of Mars

04:03and have achieved some success with alfalfa

04:05The culture of alfalfa has also helped to accelerate the growth of other plants

04:09such as turnips and lettuce

04:11Although water can be available on the red planet

04:14the air on Mars is mainly composed of carbon dioxide

04:18However, the in-situ experience of Mars oxygen resources

04:23or simply MOXIE, can produce oxygen on Mars

04:26which could be crucial for future missions

04:29Regarding the Martian energy sources

04:31solar, wind and geothermal energies are among the most promising

04:36Solar energy is less effective on Mars due to lower light and frequent sand storms

04:42but wind and geothermal energies could serve as an alternative

04:46With these resources available, humans could potentially thrive on Mars

04:51But let's go back to the comparison of our sister planets

04:55While Mars and Earth have moons, Mars even having two

04:59Venus has none, just like Mercury

05:02Due to its proximity to the Sun and the gravitational attraction of our star

05:07Mercury cannot retain satellites

05:10The probability that a moon orbiting Mercury will collide with the planet

05:15or be attracted to the orbit of the Sun would be high

05:19All this seems pretty obvious

05:21However, the absence of moons around Venus remains an unsolved enigma

05:26Despite the extremely high temperatures of Venus

05:29scientists think that even today

05:32it could not be as hostile to life as we thought it was before

05:36A recent study by MIT discovered 19 amino acids

05:40that survived a whole month in a solution comparable to what we find on Venus

05:45Yes, some people like it when it's spicy

05:48In addition, Rocket Lab and the Massachusetts Institute of Technology

05:52have teamed up to send a non-inhabited spacecraft

05:55the Venus Lifefinder, on an exploration mission

05:58This spacecraft will search for signs of life in the Venusian atmosphere

06:02using a special instrument called a self-fluorescent nephelometer

06:06And no, we're not inventing anything

06:08Initially planned for launch in 2023

06:11the mission was postponed to December 2024

06:14with an arrival in the orbit of Venus planned for May 2025

06:19The objective of the mission is to discover organic compounds

06:22in the atmosphere of the planet

06:24which could indicate the existence of habitable conditions

06:27in its cloud layer

06:29The spacecraft is equipped with a stage of cruises called Photon Explorer

06:33and a compact atmospheric probe equipped with a nephelometer

06:37The probe will descend through the Venusian atmosphere

06:39collecting data on cloud particles and organic compounds

06:44In 2020, scientists announced the discovery of phosphine on Venus

06:48a compound potentially linked to life

06:51They are still working to confirm this discovery

06:54using data from telescopes or even previous missions

06:58It could be that evidence is hidden in the old data

07:01received from Venus by NASA

07:03which could bring more clarity on this discovery

07:07The possible presence of phosphine on Venus

07:09has aroused both enthusiasm and caution among scientists

07:13To confirm this hypothesis

07:15more data from telescopes or new space missions are necessary

07:20If this gas is actually detected

07:22it could indicate the existence of a form of life

07:25producing phosphine in the clouds of Venus

07:28thus marking a big step towards a better understanding of the planet

07:32Some experts estimate that sending probes to Venus

07:35to detect phosphine directly

07:37would be the most reliable method to confirm its presence

07:41It could even be that a NASA mission from the 80s

07:45has already detected this phosphine

07:47but that this discovery was unnoticed at the time

07:51Today, the data is re-evaluated

07:53to identify any negligible evidence of the presence of this gas

07:57This could also indicate that phosphine

07:59has been present in the atmosphere of Venus for decades

08:02raising questions about its origin

08:05However, this interpretation is not unanimous

08:08and a debate has been engaged among scientists

08:11about the real nature of the gases detected

08:13The old data from other missions

08:15could also provide clues

08:17about the presence of phosphine on Venus

08:20While new space machines are about to explore the planet

08:24the key to solving this mystery

08:26could well be found in archives

08:28that are several decades old

08:30To date, 46 space missions have been sent to Venus

08:34some of them taking advantage of the gravitational assistance of the planet

08:37during its flight

08:39The last time a space machine managed to land on Venus

08:42dates back to June 1985

08:44during the Vega 2 mission

08:46Now, we just have to wait

08:48to see what discoveries Venus LifeFinder has in store for us

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