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Stay informed and amazed by the latest findings from NASA's groundbreaking research.
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00:00They aren't supposed to exist. No one expected to find them.
00:05Scientists can't explain how they formed.
00:08And still, the James Webb Space Telescope has found them.
00:17These six galaxies, as massive as our home Milky Way, are full of mature red stars.
00:24They're so far away from us that they look like tiny reddish dots,
00:27even to this extremely powerful telescope.
00:31Astronomers have analyzed the light coming from these galaxies and estimated their age.
00:36They appeared 500 to 700 million years after the Big Bang.
00:43So far, nothing surprising.
00:45Galaxies that young aren't exactly rare.
00:48Scientists think that our first star clusters could have sprung up soon after the universe left the so-called Dark
00:55Ages.
00:58Those were the first 400 million years of its existence.
01:02At that time, only a thick fog of hydrogen atoms filled the cosmos.
01:08What is extremely bizarre about these galaxies is their tremendous size and the age of the stars inhabiting them.
01:16But this doesn't coincide with the existing ideas about what the universe looked like and how it evolved in its
01:22early years.
01:23Plus, it doesn't match with earlier observations made by the Hubble Space Telescope,
01:28wave's less powerful predecessor.
01:33So, according to scientists, what are early galaxies supposed to look like?
01:38The answer is simple, young and small.
01:41And indeed, previously, most early universe galaxies we found were just space babies, blue and small.
01:49They seem to have appeared out of the primordial cosmic soup just recently,
01:53and were still building their early stars and other structures.
01:59Most young stars are actually blue.
02:01As they age, they acquire a reddish glow after burning through their star fuel and cooling down.
02:07That's why astronomers were not ready to see old red stars in those ancient galaxies Webb Telescope was built to
02:14discover.
02:15Another thing they weren't ready to spot was galaxies more massive than a billion suns.
02:20And still, it happened.
02:24The most massive galaxies discovered recently seem to have masses just twice or four times lower than that of the
02:31Milky Way.
02:31And the most astounding thing here is that these galaxies were already that big when the universe was a mere
02:383% of its current age.
02:44But before astronomers start rewriting their theories, trying to explain how such huge galaxies formed so fast after the Big
02:52Bang,
02:53we need to make sure that what we're looking at isn't some other space phenomenon.
02:57Even so, most alternative theories need totally new concepts as well.
03:05One of them goes like this.
03:08Perhaps stars in the early universe emit light in some unusual, exotic way.
03:13And since astronomers didn't know about it, they didn't include this possibility in their models.
03:19Or our understanding of how stars form might be inapplicable to the early universe.
03:24If any of these theories turns out to be true, it'll overturn our understanding of star formation altogether.
03:34Now, how about we talk about the device that helped astronomers to discover those bizarre galaxies?
03:40The James Webb Space Telescope is an absolutely stunning piece of equipment,
03:46which is around 100 times more powerful than the Hubble Space Telescope.
03:50And the latter has observed places that are 13.4 billion light-years away.
03:56The James Webb Telescope is also on the pricey side, to put it mildly.
04:01Even though originally, the cost of the telescope was estimated to be just 1 to 3.5 billion,
04:08the whole development process cost around 10 billion dollars.
04:12For comparison, it cost NASA 4.7 billion dollars to build and launch the Hubble Telescope.
04:19It was another 1.1 billion to fix it in orbit.
04:26Even though the James Webb Space Telescope itself is three stories high and the size of a tennis court,
04:32its mirrors are the lightest large telescope mirrors of all time.
04:37During the manufacturing process, they underwent a 92% reduction in weight.
04:44When you look at them, the telescope's mirrors seem to be gold.
04:49But in reality, they're made of beryllium.
04:52This is a steel gray, lightweight, and brittle metal.
04:56A gold coating is applied to each mirror, that's true.
04:59But they can't be produced entirely out of gold,
05:02since this precious metal tends to expand and contract, even with small temperature changes.
05:10So, the total amount of gold in the James Webb Space Telescope is less than 2 ounces.
05:16That's a golf ball-sized piece of gold.
05:19And the gold plates covering the mirror are only 1,000 atoms thick.
05:25As for the telescope's abilities,
05:27it would be able to clearly see a U.S. penny from 24 miles away
05:31and a football from 340 miles away.
05:39James Webb's telescope side is cooling itself down,
05:42and its temperature doesn't rise higher than negative 370 degrees Fahrenheit.
05:48That's cool enough to make liquid nitrogen.
05:51A truly enormous five-layered sunshield surrounds the telescope
05:55and reflects away as much sunlight as possible,
05:58letting the telescope stay cool.
06:04JWST is believed to be able to detect water on distant exoplanets.
06:09For a long time, astronomers have been discovering planets orbiting stars outside of the solar system
06:14by monitoring slight dips in stars' light.
06:18Such dips happen when planets pass in front of them.
06:21Plus, it's possible to read unique signatures in the light.
06:24This can tell us about a planet's chemical composition.
06:28And the strongest and most readable signatures happen within the infrared spectrum.
06:33And guess what?
06:34James Webb has state-of-the-art infrared instruments.
06:37They can help scientists spot new planets
06:40and even identify the presence of water there.
06:45The telescope was launched near the equator
06:47because Earth spins a bit faster there.
06:50And this gave the rocket some extra push.
06:53When the James Webb Space Telescope runs out of fuel,
06:57it'll keep orbiting the sun indefinitely.
07:00On the other hand,
07:01even though the telescope wasn't actually designed to be serviced or upgraded,
07:05it might potentially be refueled with the help of robots.
07:09This would extend its lifespan.
07:13Interestingly, at first,
07:15astronomers were sure that finding something exciting with the help of James Webb would take time.
07:20They thought that the first discovered galaxies would be so small and dim
07:25that the telescope would only find some remote candidates at best.
07:30But it didn't go as planned.
07:32As soon as the first images were released,
07:34scientists started finding countless galaxies,
07:37bright, large, and impressively old.
07:40The competition is still long.
07:42One research group after another spots new record-breaking worlds.
07:47One astronomer even said that the scientific world was freaking out
07:51since no one had actually expected such impressive results.
07:55One of the main goals of the Webb Telescope
07:58is to observe the light from the very first stars and galaxies in the universe.
08:03Unfortunately, the farther away an object is,
08:06the faster it's moving away from us.
08:09And the longer the light has to travel,
08:11the more it stretches towards the infrared side of the spectrum.
08:14This is called redshifting in astronomy.
08:17But thanks to its infrared equipment,
08:19James Webb can reveal previously invisible worlds to us.
08:26So, thanks to this telescope,
08:28we've managed to see incredibly distant galaxies
08:30that were born around 3.8 billion years ago.
08:34It means that the light JWST detected
08:37took more than 13 billion years to reach Earth.
08:40Can you imagine that?
08:42But one of these galaxies stands out from the rest.
08:45It appears to be the oldest galaxy astronomers have discovered so far.
08:51It's called GLASS Z13,
08:53and it dates back to a mere 300 million years after the Big Bang.
08:59The previous oldest galaxy scientists identified
09:02was found by the Hubble Space Telescope,
09:05and it dates back to 400 million years after the Big Bang.
09:10During that scarcely probed era,
09:12the very first galaxies and stars started to appear.
09:16But how exactly did this process unfold?
09:19No one knows for sure, yet.
09:22It might have depended on the laws of some exotic physics,
09:25including the influence of dark matter and dark energy,
09:28or some poorly investigated communication
09:31between gas, dust, and starlight.
09:34With the help of the Webb Telescope,
09:36scientists can now test their theories
09:38about what was happening out there
09:40after the birth of the universe.
09:51Hundreds of millions of rocks orbit the Sun
09:53within the asteroid belt between Mars and Jupiter,
09:56but only some of them come relatively close to Earth.
10:00NASA classifies asteroids orbiting within 30 million miles of our planet
10:05as near-Earth objects.
10:07And inside this group,
10:08there are particularly worrisome objects.
10:11Those are so large and orbit so closely to our home planet
10:14that they could turn into a real threat to the world
10:17should a direct collision occur.
10:19At the moment,
10:20NASA is keeping a close eye on an asteroid named Bennu.
10:24It's a fairly large space object
10:26that might smash into our planet in 159 years.
10:31According to the experts,
10:32the asteroid, which was first spotted in 1999,
10:35is quite likely to drift into the orbit of our planet.
10:39If it happens,
10:40it might collide with Earth by the 24th of September, 2182.
10:46Asteroid Bennu is thought to be taller than the Empire State Building.
10:50If that hits our planet,
10:51the collision will release 1,200 megatons of energy.
10:56That's an enormous amount of energy
10:58that nothing built on Earth could produce.
11:00Scientists from NASA believe that
11:02during the flyby in the 22nd century,
11:05there's a tiny chance that the asteroid
11:07will pass through a gravitational keyhole.
11:09That's a region of space
11:11that might set the space traveler on a certain path,
11:14which could result in the asteroid crashing into Earth.
11:17Bennu flies by our planet every six years.
11:20It has had three close encounters with Earth
11:23in 1999, 2005, and 2011.
11:27These days, scientists estimate the chance
11:29of the asteroid hitting our planet by 2182
11:32as 1 in 2,700.
11:36That's more than five times a person's chance
11:38of being struck by lightning.
11:40But even though Bennu's chance of colliding with Earth
11:43are quite low at the moment,
11:45the space rock has still been categorized
11:47as a, quote, potentially hazardous asteroid.
11:50All because it might come as close
11:53as 4.65 million miles from Earth.
11:56That's the reason why it's also classified
11:59as a near-Earth object.
12:01Bennu is a carbon-rich asteroid
12:03that was formed in the first 10 million years
12:05of the history of the solar system.
12:07That's around 4.5 billion years ago.
12:10No wonder this space body holds precious clues
12:13to the origin and development of the rocky planets
12:16of our solar system, which are, as you recall,
12:19Mercury, Venus, Earth, and Mars.
12:21Even better, it may contain organic molecules,
12:25similar to those that are crucial for life to evolve.
12:28In 2020, NASA's OSIRIS-REx
12:31managed to briefly touch the surface of the asteroid.
12:34It collected some samples
12:35and propelled off the space rock afterward.
12:38For NASA, it was the first mission of this kind.
12:42But it won't probably come as a surprise
12:44that Bennu isn't the only asteroid
12:47we should worry about.
12:48Asteroid 99942, Apophis,
12:52is another space body we'd better watch out for.
12:54It's a near-Earth object about 1,100 feet across.
12:59It was discovered in 2004,
13:00and at first, it was identified
13:03as one of the most dangerous asteroids ever detected.
13:06Ooh.
13:07Apophis gained notoriety very fast.
13:10It was believed to pose a serious threat to Earth.
13:13Experts predicted that it would come
13:15uncomfortably close to our planet in 2029.
13:19Luckily, after a more careful examination
13:21of Apophis and its orbit,
13:23astronomers concluded that there was no risk
13:26of the asteroid colliding with our planet
13:28for at least a century.
13:30The risk of an impact in 2029
13:32was rolled out completely,
13:33as well as the potential impact
13:35that could be caused
13:36by the asteroid's close approach in 2036.
13:41Interestingly, until March 2021,
13:44there was a small chance of a collision in 2068.
13:47But then, Apophis made a flyby of Earth,
13:50and astronomers took this chance
13:52to use powerful radars
13:54to estimate the asteroid's orbit
13:56around the Sun more precisely.
13:57This allowed them to rule out any impact risk
14:00for at least the next 100 years.
14:03Now, the reason why such discoveries make us so worried
14:07is that even a relatively small asteroid
14:10the size of a house
14:11can wreak havoc upon colliding with our planet.
14:14And if an asteroid is larger than 0.6 miles across,
14:18astronomers call it a planet destroyer.
14:21The impact energy released by such an asteroid
14:24after striking Earth could be devastating.
14:26That's why knowing where such asteroids are
14:29and in what direction they're moving is crucial.
14:33The problem is that our capability
14:34to protect the planet from asteroid impacts
14:37is not top-notch yet.
14:39If such a catastrophe was about to occur,
14:42we would need some time to prepare,
14:44because an asteroid collision is no joke.
14:47Probably the most well-known asteroid impact site
14:50is the Chicxulub Crater.
14:52It's the evidence of the terrifying collision
14:54that led to the extinction of dinosaurs.
14:57Strangely, this crater isn't very visible.
14:59But some others are.
15:01For example, Behringer Crater in Arizona,
15:04which is also called Meteor Crater.
15:06It looks rather blood-chilling
15:07when you think about the collision
15:09that led to its appearance.
15:12In any case, we now know that space rocks
15:15hit not only the Earth,
15:16but also the Moon, Mercury, and Mars.
15:19No rocky planet in the solar system
15:21is safe from asteroid impacts.
15:24That's why we have an entire scientific enterprise
15:27whose goal is to find and catalog
15:29the asteroid population of the solar system.
15:32Now, it might sound a bit scary,
15:34but there are around 25,000 asteroids
15:37larger than 460 feet in diameter
15:40near the orbit of our planet.
15:42Such a space rock is large enough
15:44to wipe an entire city off the face of the Earth.
15:47So far, less than 50% of such asteroids
15:50have been detected and tracked.
15:52There are also an estimated 230,000 objects
15:56equal to or larger than 160 feet in size.
16:00Those are capable of destroying
16:02a concentrated urban area.
16:04And still, fewer than 8% of those
16:07have been detected.
16:07There are also tens of millions
16:10of smaller near-Earth objects.
16:12They are larger than 33 feet across
16:14and might cause some surface damage.
16:16Less than 1% of such small space bodies
16:19have been discovered so far.
16:23Now, the thing is,
16:24the inner solar system is extremely challenging
16:27for asteroid search.
16:28Each night, there are only two 10-minute windows
16:31when astronomers can observe the region.
16:33All because the sun's glare creates
16:36a very bright background glow.
16:38Plus, the atmosphere of our planet
16:40also distorts and blurs observations.
16:43Spotting asteroids in such conditions
16:45is beyond the capabilities of most telescopes.
16:48A unique instrument is needed
16:50to fulfill this task.
16:51And the tool of choice
16:53is the Dark Energy Camera
16:54at Cerro Tololo Inter-American Observatory
16:58in Chile.
16:58This device wasn't designed
17:00to hunt asteroids.
17:01Researchers built it
17:02to search for another elusive target,
17:05Dark Energy,
17:06the mysterious force
17:07driving the expansion of the universe.
17:09The DEC is supposed to observe
17:11hundreds of millions of galaxies.
17:13That's why it's both wide and deep.
17:16This way,
17:17it can both peer deep into the universe
17:19and capture a wide field of view,
17:22which helps it record
17:23the motions of galaxies
17:24and the conditions
17:25in the early age of the universe.
17:28But it also means
17:30that the DEC
17:30is perfectly suited
17:32to spotting asteroids
17:33near the sun.
17:35Inner asteroids are rare,
17:36and deep images are necessary
17:38because such asteroids are faint.
17:40Scientists need to be able
17:42to fight
17:42both the bright twilight sky
17:44near our star
17:45and the distorting effect
17:46of Earth's atmosphere.
17:48And the DEC
17:49can help them achieve their goal.
17:51The Dark Energy Camera
17:52was built to carry out
17:54the Dark Energy Survey,
17:55which finished in 2019.
17:57Now astronomers can direct
17:59the power of the camera
18:00towards other tasks.
18:01They claim that the DEC's survey
18:04is one of the most sensitive searches
18:06ever performed
18:07for objects near Venus's orbit
18:09and within the orbit of our planet.
18:11It provides us a great chance
18:13to find out
18:14what kinds of objects
18:15are lurking
18:16in the inner solar system.