00:00It looks like an ordinary beach, but something wreaks your fear.
00:05The sable is too red, the sun is too intense, the wind falls out of a strange way,
00:11we breathe well, and there is no water in the ocean.
00:15Don't worry, it's normal, you are on Mars.
00:18During very long time, we considered Mars as a cold and without vie,
00:23a desert where the water exists only in form of glass or smoke.
00:27But new research suggests that it was hundreds of years ago, it was a completely different place.
00:32And instead of this rain at perte of view, there was perhaps something that was much more familiar,
00:38the clouds of sable sun.
00:40The scientists of Penn State, the University of Berkeley and the University of Guangzhou
00:45studied the radar data of the Chinese rover Zhurong.
00:48It started to race on Mars in 2021.
00:51In exploring the surface of the red planet,
00:54he discovered the formations rocheuses inclinées
00:57which looks like the earth as we found on the Earth.
01:00We call them the sable littorals.
01:02They form the effect of waves, which push the sable towards the river.
01:06But Zhurong didn't make a beautiful picture of taking pictures.
01:09He was also equipped with a radar capable of penetrating the soil,
01:13and this tool allowed to scan the depths of the Martian surface
01:17on 2 km between May 2021 and May 2022.
01:20He made a pretty incredible discovery.
01:23There are layers of sediment forming a pente of about 15 degrees,
01:26so a configuration identical to the one that we found on Earth.
01:30And no, it does not come from the wind,
01:32from the volcanoes or other natural phenomena.
01:34It really looked like a beach.
01:36And it's in fact very important.
01:39Because if there were waves and waves,
01:41it was supposed to be a big étendue of water.
01:44Even after 3,5 milliards of years,
01:51these formations are still still similar to our planet.
01:55There is a time where Mars was quite more than a simple rocher poussiéreux
01:59floating in space.
02:01After revealing this surprise,
02:03the radar of Zhurong has scanned the soil
02:06to 79 mètres of profondeur
02:08and discovered the sedimentary clouds.
02:10They formed the along a perpendicular
02:13to an ancient littoral
02:14which probably existed there 4 billion years ago.
02:17From the other side,
02:18this is perhaps not so surprising.
02:20Jadis,
02:21Mars was not the desert arid and gelé
02:23that we know today.
02:25Her atmosphere was more dense,
02:27her climate was more hot,
02:28and the liquid water was abundant.
02:30And I don't talk about some small waves.
02:32The waves are not formed without a massive mass of water.
02:35For the waves to feed the terrain
02:37in such a way,
02:38it was necessary to get the rivers into a vast ocean.
02:41It was necessary to be able to move the water
02:43to move the sable.
02:44And all this water is still a long time
02:46at the same place.
02:47It was not a simple period
02:49a little humid,
02:50but a few millions of years
02:51during which Mars was active
02:53on the planet hydrologic,
02:55offering the ideal conditions
02:57for the rise of life.
02:58This discovery reinforces
03:00even a theory
03:01which intrigue the scientists
03:02since the years 1970.
03:04It is at this time
03:05that the Viking sonde
03:07of the NASA
03:08took photos of what seemed to be
03:09a littoral
03:10around the north of Mars.
03:12However,
03:13there was a problem.
03:14The littoral
03:15was very irregular,
03:16with a dénivelé
03:17to reach 10 km.
03:19It had nothing to do
03:20with the plates
03:21and relatively uniform
03:22that we observe on Earth.
03:24This difference
03:25has led
03:26the scientists
03:27a doubt
03:28of the existence
03:29of a Martian océan.
03:30Pendant years,
03:31scientists
03:32tried to
03:33this mystery.
03:34In 2007,
03:35they suggested that
03:36the rotation of Mars
03:37was modified
03:38there hundreds of years.
03:39As soon as
03:40the gigantic
03:41region volcanic
03:42of Tarsis
03:43developed,
03:44the axis of rotation
03:45of the planet
03:46was inclined,
03:47deforming the surface.
03:48This could explain
03:49why the river
03:50is so irregular
03:51today.
03:52In other words,
03:53the sea
03:55was transformed
03:56over the time.
03:57Mars
03:58gives us
03:59a few years
04:00of his past
04:01aquatics.
04:02Curiosity
04:03has discovered
04:04the ancient
04:05ondulations
04:06in the crater
04:07Gale.
04:08Perseverance
04:09is currently
04:10a delta
04:11fluvial
04:12fossilized
04:13in the crater
04:14Jezero.
04:15Today,
04:16with the proof
04:17of the existence
04:18of an ancient ocean,
04:19the sea
04:21of the sea
04:22of the sea
04:23of the sea
04:24of the sea
04:25of the sea.
04:26The mission
04:27of Zhurong
04:28was achieved
04:29in May 2022,
04:30when the rain
04:31was coming to
04:32cover its
04:33solar panels.
04:34But it can be
04:35that future missions
04:36could explore
04:37more detail
04:38these ancient
04:39depots
04:40of the sea.
04:41The scientists
04:42could also
04:43use
04:44the radars
04:45more perform
04:46to be
04:47more precisely
04:48in the future.
04:49So,
04:50there is a real hope
04:51that in the future,
04:52we can discover more
04:53of the past
04:54Mars.
04:55In the same time,
04:56the rover Perseverance
04:57of the NASA
04:58is already working
04:59in the crater
05:00J-0
05:01to collect
05:02samples.
05:03The scientists
05:04expect that
05:05he will bring them
05:06in the years
05:072030.
05:08Even if these samples
05:09will not come from
05:10the ancient ocean,
05:11they could help us
05:12to know more
05:13about the liquid
05:14of Mars.
05:15For now,
05:16the discovery of
05:17the rover
05:18is
05:19perhaps
05:20more
05:21with
05:22waves
05:23and
05:24rivers
05:25and
05:26rivers
05:27of
05:28Mars.
05:29It is equipped
05:30with a special
05:31special
05:32which is used to
05:33gratter the
05:34surface
05:35and the
05:36layers
05:37of
05:38the
05:39space
05:40that
05:41was
05:42composed
05:43of
05:44the rover
05:45used
05:46two instruments
05:47to analyze the
05:48chemical composition
05:49of the rock.
05:50The results
05:51confirmed that
05:52the rock,
05:53called the rock,
05:54the rock,
05:55was formed
05:56from lava
05:57or magma
05:58and not
05:59the
06:01ice
06:02of
06:03the
06:04sea
06:05and
06:06the
06:07sea
06:08the
06:09sea
06:10that
06:11the
06:12sea
06:13of
06:14the
06:15sea
06:16of
06:17the
06:18sea
06:19and
06:20the
06:22sea
06:23previous étudiait, principalement les roches. Et le climat martien ? Perseverance recherche
06:28des signes de vie passés. Si les scientifiques ont choisi le cratère G0, c'est qu'ils le
06:33soupçonnent d'avoir autrefois été un lac où de minuscules formes de vie auraient
06:38pu exister. Le rover Fort gratte et collecte des échantillons de roches qu'il étudie
06:43à l'aide de ses instruments scientifiques. Il conserve également certains échantillons
06:47afin de les ramener sur Terre où ils seront étudiés de plus près. Perseverance a fait
06:52des découvertes surprenantes sur Mars. Les scientifiques qui analysent les données qu'il
06:56nous a renvoyées ont découvert que le cratère G0 a beaucoup changé au fil du temps. Il
07:01y a très longtemps, cette région était recouverte de lave en fusion, abritait un lac qui a existé
07:07pendant des milliers d'années, était traversé par des rivières qui transportaient de la boue
07:11et du sable, et a même subi d'énormes inondations qui ont apporté des roches depuis des régions
07:16lointaines. Cela signifie que l'histoire de G0 est plus active et imprévisible que ne
07:21le pensaient les scientifiques. Cela a certainement rendu plus difficile la recherche des roches
07:25sédimentaires qu'ils recherchaient. Mais cela a également révélé de nouveaux endroits
07:29où la vie aurait pu exister par le passé. Une autre découverte passionnante est que
07:33toutes les roches étudiées jusqu'à présent par Perseverance contiennent des matériaux
07:38à base de carbone, les mêmes que ceux qui composent la vie sur Terre. Le rover Perseverance
07:43de la NASA est également équipé d'un instrument appelé MOXIE, qui a réussi pour la première
07:48fois à produire de l'oxygène à partir du dioxyde de carbone présent dans l'atmosphère
07:52martienne. Au cours de ses essais, MOXIE a produit environ 113 grammes d'oxygène, soit suffisamment
07:59pour permettre à un astronaute de respirer pendant environ 4 heures. Il a même dépassé
08:03les attentes, produisant jusqu'à 12 grammes d'oxygène par heure. Après deux ans de bon
08:08fonctionnement, MOXIE a terminé son dernier test en septembre 2023. Nous faisons ainsi un
08:13pas de plus vers la colonisation de Mars. Mais revenons à la découverte de ces anciens
08:17rivages martiens. Elles pourraient nous permettre de voir la planète rouge sous un nouveau jour.
08:21De l'eau aurait coulé à sa surface pendant des dizaines de millions d'années, creusant
08:25des lacs, des rivières, et même un vaste océan. Quelles autres erreurs avons-nous commises ?
08:30Des dinosaures martiens se promenaient-ils dans les vastes vallées verdoyantes de la planète
08:35rouge ? Ou s'agissaient-ils de créatures marines étranges et impossibles à imaginer ? Nous ne le
08:40savons pas encore. Mais une chose est très probable. Mars a connu une période de chaleur,
08:44avec de l'eau, et peut-être même de la vie.
Comments