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00:00 If you look out into the horizon of an early morning sky, you may be able to spot the morning
00:04 star, Venus, shining prominently.
00:07 Venus is the second closest planet to the sun and one of Earth's nearest neighbours.
00:11 The latter half of the twentieth century brought about a whole host of missions to Venus, with
00:15 NASA and the Soviet Union both sending probes to investigate the planet.
00:19 Eventually, interest in reaching Venus lost its momentum and there have been few missions
00:24 in the previous two decades.
00:25 However, now NASA plans a new mission to Venus, which aims to learn more about the planet
00:31 than any carried out before.
00:33 This is Unveiled, and today we're answering the extraordinary question; why is NASA returning
00:38 to Venus, Earth's evil twin?
00:42 Do you need the big questions answered?
00:43 Are you constantly curious?
00:45 Then why not subscribe to Unveiled for more clips like this one?
00:48 And ring the bell for more thought-provoking content!
00:52 Throughout human history, Venus has been one of the most prominent objects in the sky.
00:56 It holds the award for being the brightest object in the sky after the sun and the moon.
01:01 It's long been known as both the "morning star" and "evening star", appearing low in the horizon
01:06 during dusk and dawn, leading the ancient Greeks to believe it was two separate objects.
01:11 Irrespective of its nickname, Venus is not a star, of course, but a rocky planet covered
01:15 in a thick, dense atmosphere.
01:18 Another title it's been given is "Earth's evil twin".
01:21 While Venus has a similar size and mass to our own planet, it has an extremely toxic
01:26 atmosphere primarily composed of carbon dioxide.
01:29 Dense clouds of sulfuric acid give the planet its yellow tint.
01:33 While human fascination with Venus harks back to ancient times, the first major discovery
01:38 about its nature came in 1761.
01:41 This was the discovery of Venus' atmosphere by Russian scientist Mikhail Lomonosov.
01:46 We didn't learn any major new information about the planet until the 20th century, when the
01:51 space race started to gain momentum.
01:53 It was the Soviet Union's Venera 1 that carried out the first flyby of Venus in 1961.
01:59 In fact, it was also the first spacecraft to ever perform an interplanetary flight.
02:04 However, contact with the probe was lost before the flyby.
02:08 The first truly successful interplanetary mission was completed by NASA a year later,
02:13 in 1962, with the probe Mariner 2.
02:16 Before this, people imagined that Venus' atmosphere might be obscuring a vibrant, tropical
02:22 world hidden deep below the clouds.
02:24 Science fiction writers from the time would depict the morning star as a vibrant and luscious
02:29 world, hosting jungles and dinosaurs, strikingly similar to an ancient Earth.
02:34 Unluckily for science fiction writers, Mariner 2 dispelled these far-reaching depictions,
02:39 discovering the planet's surface to be far hotter than imagined… and completely inhospitable.
02:45 The Soviet Union later launched many more Venera probes.
02:49 In 1965, Venera 3 became the first space probe to enter the atmosphere of another planet…
02:55 and to crash on the surface.
02:57 Unfortunately, communication was lost before it could transmit data back.
03:01 Venera 4, in 1967, was far more successful, entering the atmosphere and transmitting a
03:07 heap of exciting data back to Earth.
03:09 It found this atmosphere to be much denser and hotter than anticipated.
03:13 Both the Venera and Mariner missions continued throughout the following decades, with Venera
03:18 9 and 10 actually landing on the surface in 1975, and transmitting images of what they
03:24 saw back to Earth.
03:25 Both probes lasted roughly an hour before burning up, but still captured some of the
03:30 earliest images of a planet other than our own.
03:33 In 1982, Venera 13 and 14 managed to obtain the first images in colour of Venus' surface.
03:40 The Venera 15 and 16 orbiters brought the Venera program to a close, mapping out an
03:45 impressive 25% of the planet's surface.
03:48 The last probes to enter the atmosphere were Vega 1 and Vega 2 in 1985.
03:54 The Soviet probes brought with them landers and balloon explorers, which floated over
03:58 the surface, taking measurements from within the middle and most active layer of the Venusian
04:02 cloud system.
04:04 Since the 80s, numerous spacecraft have flown by the second planet, but visiting there was
04:08 not a primary goal for most of these missions.
04:11 There have only been two dedicated missions in the 21st century so far.
04:15 Entering orbit around Venus in 2005, the ESA's Venus Express carried out a lengthy analysis
04:21 of the Venusian atmosphere.
04:22 Originally, it was intended to operate for 500 days, but was extended multiple times
04:27 until it ran for an impressive nine years.
04:30 As of writing, there exists only one active mission to Venus; Japan's Akatsuki probe,
04:36 which has been orbiting the planet since 2015.
04:39 It's equipped with five cameras operating at different wavelengths, and is focused on
04:43 analysing the planet's atmospheric dynamics.
04:47 Fans of Venus should not be upset at its lack of recent attention, as there are plenty of
04:51 exciting plans to explore it further.
04:54 India is planning to put Shukrayan-1, an atmospheric balloon, into the planet's skies.
04:59 China, Russia, and the ESA all have their own orbiters in the works, all expected to
05:03 be launched in the next decade.
05:05 Arguably the most exciting ones coming up are NASA's Veritas and DaVinci missions,
05:09 planned to launch in 2029.
05:11 Veritas will be an orbiting spacecraft with the aim of mapping the planet out in the highest
05:16 resolution yet.
05:17 DaVinci is another orbiter, but will also deploy a probe into the atmosphere to better
05:22 understand its origins and evolution.
05:24 NASA also has a broader goal in mind for these probes; they want to understand the formation
05:30 of planets hospitable to life.
05:32 The morning star remains our most Earth-like neighbour, and like our own planet, resides
05:36 in the sun's Goldilocks zone; the sweet spot where liquid water can exist on a planet's
05:42 surface.
05:43 For all we know, Venus could have been habitable before life on Earth developed, and the two
05:47 may have closely resembled each other.
05:50 If this was the case, then what happened to change it into the toxic wasteland that it
05:54 is today?
05:55 Veritas intends to answer this question, determining in what way the planet diverged from its blue
06:00 twin.
06:01 The maps it will create are expected to be the most detailed imaging of the planet to
06:05 date, and will allow a comprehensive look at areas of high geological activity, including
06:10 volcanic eruptions.
06:11 DaVinci's atmospheric probe will get more up close and personal, taking photos of the
06:16 surface as it drifts down and lands in a region known as Alpha Regio.
06:21 Such ancient highland areas may be the key to learning more about Venus' past evolution.
06:25 Together, the two missions could paint a brand new picture of the planet's history.
06:30 Learning about this history has applications elsewhere, as it'll help us understand how
06:34 planets evolve in the universe as a whole.
06:37 We can use this information about the conditions needed for habitable planets to form in our
06:41 search for life outside the solar system.
06:44 Currently, we've discovered over five thousand exoplanets.
06:48 Having extensive knowledge about Venus will help us determine which of these exoplanets
06:52 are the best candidates for harbouring life.
06:55 This may be Earth's sister planet in terms of age, size and composition, but it diverged
07:01 long ago, down a very different path.
07:03 These upcoming missions give us hope that we could one day understand why Earth and
07:07 Venus became so different… which will help us decide what to look for in our search for
07:12 life outside the solar system.
07:14 What do you think the future holds for Venus?
07:17 Will we become more interested in this hellish world, or less?
07:20 Could humans ever hope to set foot there?
07:22 There have been some ambitious and bizarre outlines put forward for potential crewed
07:26 missions in the past… including a theorised bid to set up bases high in the Venusian atmosphere,
07:32 above its dense and poisonous clouds.
07:35 What will never change is the fact that Venus will never be naturally hospital to us.
07:39 For as long as humans are like we are and the planet is like it is, there is simply
07:44 no hope for survival.
07:45 But again, for NASA and the like, that's arguably more reason to investigate this world
07:50 further, as there are suggestions that Earth could end up suffering a similar fate to Venus
07:54 at some distant time in its future.
07:56 It's certainly worth getting to know this place, rather than ignoring it.
08:00 For now, it's highly unlikely that Venus will rival Mars for our affections any time
08:05 soon.
08:06 It's all eyes on the red planet, mostly because it seems to offer the most likely
08:10 route towards humans actually getting to another world.
08:13 And from there, who knows how far across the solar system and space we might be able to
08:17 reach.
08:18 If nothing else, Venus might yet cement its place as a cautionary tale for us to learn
08:23 about and learn from.
08:25 It's this planet's evil twin for a reason, and it won't be ignored.
08:30 And that's why NASA is returning to Venus.
08:32 What do you think?
08:33 Is there anything we missed?
08:35 Let us know in the comments, check out these other clips from Unveiled, and make sure you
08:39 subscribe and ring the bell for our latest content.

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