Astronomers Just Uncovered Major Evidence for Planet 9

[00:00:00]Now, if Earth were the size of a nickel, Neptune would be about as big as a baseball. That's impressive, but it's nothing compared to the giant ninth planet [music] that might be hiding out there. Now, our planet nine's discovery saga might have finally come to an end.

[00:00:16]Turns out, the [music] problem wasn't where we were looking, but how. And researchers might have just made the biggest [music] solar system discovery in decades.

[00:00:25]You see, the idea of finding a planet beyond Neptune has been around for years now. I know, back in school, you probably learned that the ninth planet [music] was Pluto. But, forget about Pluto. It's been demoted to a less fancy category since 2006. What I'm talking about is the planet nine, a hypothetical giant [music] planet that could be our cosmic neighbor. We've never actually seen it, but scientists are pretty sure it's out there somewhere, hiding in the outer solar system.

[00:00:56]To explain why they think that, we need a sheet of paper. Hey, here's one. We place a coin on it, and suddenly, [music] it starts to move. Unless we're talking about some kind of superpower, there's no way this coin is moving on its own, right? So, you figure someone must be on the other side, holding a magnet and moving it around. You can't see the magnet, but it explains why the coin is moving. That's kind of what's happening with planet nine. We can't see [music] it, we can't prove it, yet, but its existence could explain the strange movements we see out there in space. For example, the planets in our solar system orbit on a flat plane that's [music] tilted about 6° relative to the sun.

[00:01:39]But, why 6°? Well, no one really knows for sure. Some scientists think those orbits might be slightly tilted because of the pull of a ninth planet. Its existence [music] could also explain the unusual paths of smaller objects in the distant [music] Kuiper Belt, a region full of icy debris that stretches far beyond Neptune's orbit. [music] Back in 2016, researchers from Caltech published a study [music] about Planet Nine. They suggested it could have a mass about 10 times that of Earth and follow a highly elongated path.

[00:02:12]>> [music] >> That's a scientific way of saying it takes forever to make one trip around the Sun.

[00:02:17]Because of that, it would be located in the outer solar system. I mean, far, far away. It would orbit the Sun about 20 to 30 times farther out than our most distant planet, Neptune.

[00:02:30]According to scientists, Planet Nine would take up to 20,000 Earth years to complete just one full orbit around the Sun.

[00:02:37]Since it's crazy far out there, it's almost impossible to see it. So, as cool as this hypothesis sounds, we've never found solid evidence that Planet Nine actually exists. But, we might be pretty close.

[00:02:51]In May 2025, a team at National Tsing Hua University might have made one of the most exciting solar system discoveries ever.

[00:03:00]All right, so there's a hypothesis that Planet Nine hasn't been discovered yet because we haven't been using the right method.

[00:03:07]>> [music] >> This new study raises an interesting question. What if Planet Nine actually looks brighter in infrared light than it does in visible light?

[00:03:16]Let me explain. Scientists have been trying to spot Planet Nine [music] by its reflected light. But, here's the problem. To spot it in visible wavelengths, sunlight would have to travel all the way out to Planet Nine, bounce off its surface, and then travel all the way back to Earth.

[00:03:33]If a Neptune-sized planet were about 10 times farther away than Neptune, it would look about 10,000 times fainter.

[00:03:40]But, a planet's [music] own thermal radiation, I mean, its heat, only has to make a one-way trip.

[00:03:45]>> [music] >> So, in infrared light, Planet Nine would only be about 100 times fainter. That's why it makes more sense to look for it using space-based infrared telescopes.

[00:03:56]And that's the idea behind this new study. The team started digging through archives searching for old infrared sky survey data, and they pulled it from two main sources. First, IRAS, a satellite launched in the '80s that scanned the sky for almost a year. Then, the Japanese satellite Akari, another infrared observatory that operated between 2006 and 2011.

[00:04:20]So, basically, they compared objects that showed up in IRAS database and noticed which ones had moved by the time Akari took its observations. And by doing that, the researchers found something incredible, an object that might just be our long, lost ninth planet. Because if something moves, it could be a planet orbiting the sun, right? And yeah, they did find some celestial objects showing tiny movements.

[00:04:46]But before jumping to conclusions, they had to rule out the parallax effect. And that's something really important when we're talking about solar system discoveries. [music] To explain it, I need you to do something. Hold one finger in front of your face. Close one eye, and now switch. Your finger seems to move a tiny bit, right? That's because you're looking at it from a slightly different angle from one eyeball to the other.

[00:05:11]>> [music] >> The same thing happens when we look out into space from Earth. Since our planet orbits the sun, our view of very distant objects shifts just a little.

[00:05:21]That effect is [music] called parallax.

[00:05:23]My point is, because of this effect, Planet Nine would appear to move across the sky as Earth goes around the sun.

[00:05:30]On any given day, it might seem to be in one spot, but 6 months later, when Earth is on the opposite side of the sun, it would look like it shifted. 6 months after that, it would seem to move back again.

[00:05:43]Scientists had to account for parallax.

[00:05:45]Actually, they had to remove its effects. So, the team looked at images of the sky taken on the same date every year. Because on that same date, Earth is always in the same spot [music] in its orbit. That means if Planet Nine is real, it would show up in the same place in those images every year. No fake wiggle from parallax, just its real position.

[00:06:08]This careful search led them to a single object, a tiny dot in the infrared data.

[00:06:13]The strange little spot have moved slightly along its orbit around the Sun over the 23 years between IRIS and a carry. Wait, could that be it? Did astronomers just confirm a hidden planet? Well, maybe, but don't get too excited. The data we have on its motion over that time is not enough to figure out its full orbit. So, for now, we still can't say for sure if this mysterious object is really Planet Nine.

[00:06:42]It's definitely a strong candidate, though. Based on how bright the object appears, the team estimates it could be pretty massive, and that came as a big surprise.

[00:06:53]You see, previous NASA research ruled out any Jupiter-sized or Saturn-sized planets hiding out there, but a smaller world would have gone undetected. So, the scientists were looking for something just a bit bigger than Earth.

[00:07:06]But it turns out this mysterious planet might be more massive than Neptune.

[00:07:11]Now that they discovered Planet Nine, supposedly at least, the plan is to keep tracking it and collecting new data. But don't think the road ahead will be easy.

[00:07:21]Because since the a carry satellite spotted it for the first time, that object didn't just sit still. It's been moving slowly through space ever since.

[00:07:29]So, now scientists need to use regular telescopes on Earth to look for it again.

[00:07:34]And here's the tricky part. They're not exactly sure where it moved to. So, they have to to a pretty big patch of the sky. And so far, no matching object has been found.

[00:07:46]Whether this really turns out to be the Planet Nine discovery or not, only time will tell. For now, its existence is still up for debate. But with powerful new technology on the way, like NASA's Nancy Grace Roman Space Telescope, astronomers are more determined than ever to uncover the truth. And if Planet Nine really is out there, hiding in the cold, dark edges of our solar system, it's running out of places to hide.

[00:08:13]>> Look at this giant donut-shaped region far away from Earth, beyond the orbit of Neptune. We're talking about a distance of more than 2.5 billion miles. It's the Kuiper Belt, and something eerie and bizarre is happening there.

[00:08:29]Dwarf planets and other small objects dwelling there refuse to cluster together. Instead, they follow particular orbits, [music] which is weird. The reason might be a large, mysterious planet hiding beyond Pluto. Its gravity might be messing up the orbits of those Kuiper space bodies.

[00:08:51]Hear me out.

[00:08:53]Our solar system is made up of the sun and everything that goes around it because of the star's strong gravity.

[00:08:59]This includes the eight main planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

[00:09:07]There are also smaller things, like moons, asteroids, and Pluto.

[00:09:13]For a long time, people thought Pluto was the ninth planet. But when it was reclassified as a dwarf planet, scientists started looking for a new Planet X.

[00:09:22]Did they have a thing about odd numbers or what?

[00:09:26]And guess what?

[00:09:27]Some really think there might be a big, icy planet hiding far, far away beyond Neptune.

[00:09:34]This mystery planet is often called Planet [music] Nine.

[00:09:38]Now, Planet Nine hasn't been seen yet, but scientists think it might be out there because of some tiny faraway space rocks called ETNOs that move following bizarre, confusing paths.

[00:09:52]These paths seem to be grouped together and tilted in a way that doesn't happen by chance. This could mean there's a hidden planet pulling them into place with its gravity.

[00:10:01]If Planet Nine is real, it might be five to 10 times heavier than Earth. It would also be super far away, hundreds of times farther from the Sun than Earth is.

[00:10:13]Over the years, scientists have guessed different distances for its orbit. And the newest guess in 2025 says it could be about 290 times farther from the Sun than Earth.

[00:10:25]There are some cool ideas about where Planet Nine came from. It might have started as a big planet that Jupiter once kicked out of the inner solar system, or it might have come from another star, or even wandered around space on its own before getting caught by the Sun's gravity.

[00:10:42]Even though scientists have looked really hard using powerful telescopes, no one has actually seen Planet Nine [music] yet. And so far, its existence is still just a theory.

[00:10:54]But recently, a group of researchers tried something clever. They used data from two special space surveys called IRAS and Akari. [music] These two looked at the sky in invisible light, far infrared, about 23 years apart.

[00:11:11]Which is helpful because Planet Nine is supposed to move very slowly.

[00:11:16]The team focused on a special list from Akari, which is better at finding faint moving things in space.

[00:11:23]They guessed how bright Planet Nine might be and how fast it might move based on how big, faraway, and cold it could be.

[00:11:33]Then they looked for matching blips in the sky that were seen by both IRAS and Akari, but not in the exact same spot.

[00:11:41]That's because [music] a real planet would have moved a little over 23 years, and they indeed found 13 possible matches that could be Planet Nine.

[00:11:50]Their estimations were based on how far away the object seemed to be, 500 to 700 times farther from the Sun than Earth, and how heavy it might be, which is 7 to 17 times Earth's mass.

[00:12:05]After looking very carefully at all the images, they narrowed it down to one really good candidate. The two detections weren't in the same spot in both surveys, and the way they appeared in the Akari map matched what you'd expect from a slow-moving object. It showed up on one date and wasn't there 6 months earlier, but of course, there was a catch.

[00:12:27]Apparently, the old data isn't good enough to figure out the exact path of the potential planet.

[00:12:33]So, the team wants to do new follow-up observations using a special camera called DECam, which is really good at spotting faint, moving objects. That way, they can find out if this candidate is really Planet Nine.

[00:12:48]Additionally, it can help us learn more about how our solar system works and how it formed.

[00:12:55]If Planet Nine is ever discovered, it would totally change the way we understand our solar system. It could explain why some far-out space rocks in the Kuiper Belt tilt weirdly.

[00:13:06]The thing is, most planets go around the Sun in a flat-ish circle, but those far-away objects are tilted about 20°.

[00:13:15]Planet Nine might be the reason why.

[00:13:17]Next, we'd probably find out why those tilted objects seem to point the same way. Their orbits are grouped together in one direction. A big, hidden planet's gravity could be hurting them like sheep.

[00:13:31]There are also some strange tilted objects super far away. They don't make sense unless something big, like [music] Planet Nine, is tugging on them.

[00:13:40]A few space rocks orbit the sun backward between the big planets, [music] which is kind of the wrong way.

[00:13:47]That's super weird unless something big is messing with them.

[00:13:50]Some far-out Kuiper Belt objects keep crossing Neptune's path and haven't been flung away.

[00:13:57]That's because Planet Nine might be helping keep their orbits stable over a long time.

[00:14:04]Another cool thing is that if Planet Nine existed, it would be a super-Earth, a kind of planet we see a lot around other stars, but we don't have in our solar system yet.

[00:14:15]>> [music] >> So, finding one here would make our solar system more like the others out there.

[00:14:22]Throughout history, people have been wondering if there could be hidden planets far beyond Neptune, >> [music] >> even before Pluto was found.

[00:14:32]Back in 1880, a guy named George Forbes guessed [music] there might be two unknown planets way out there. One about 100 times farther from the sun than Earth, and the other about 300 times farther.

[00:14:46]He thought these mystery planets might be pulling on some comets and changing their orbits, kind of like how Jupiter does with the comets near it.

[00:14:56]In 2004, scientists found a weird little world called Sedna. It had a strange path around the sun that didn't seem to be affected by [music] any of the known planets.

[00:15:07]It's closest point to the sun, called perihelion, is way too far for Neptune to be the reason.

[00:15:13]This made some scientists wonder if Sedna got pushed into its path by a hidden planet, maybe even something as big as Earth or bigger.

[00:15:23]Others thought maybe it was a star that flew by a long time ago or another star that formed near ours.

[00:15:31]Then, in 2014, another odd object was discovered. It had a very similar orbit to Sedna, which made people even more suspicious that there [music] could be something big out there messing with their paths.

[00:15:44]This kicked off a new round of the Planet X or Planet Nine hunt.

[00:15:50]At a meeting in 2012, a scientist named Rodney Gomes said that maybe there was a big hidden planet around 1,500 times farther from the Sun than Earth.

[00:16:01]He thought it could explain the orbits of other odd objects like some far out comets and centaurs, small bodies that wander among the giant planets.

[00:16:10]At that time, those who supported the Planet Nine theory believed that if it existed, it would move around the Sun in a huge stretched-out circle called [music] an elliptical orbit.

[00:16:21]It would be about 400 to 800 times farther from the Sun than Earth is, about 13 to 26 times farther than Neptune.

[00:16:30]If it really had that kind of orbit, it would take around 10,000 to 20,000 years to go around the Sun just once.

[00:16:38]>> [music] >> Plus, if it indeed orbited the Sun, it wouldn't follow the same flat path as the other planets.

[00:16:44]>> [music] >> Its path would be tilted by about 15° to 25°.

[00:16:49]The farthest point in its orbit, called aphelion, would be in the direction of the Taurus constellation.

[00:16:56]As for the closest point, it [music] would point towards Serpens, Ophiuchus, or Libra.

[00:17:02]As for the composition of Planet Nine, it would probably be a lot like Uranus or Neptune. It would have a thick atmosphere made of hydrogen and helium, and it would be super cold, -375° Fahrenheit.

[00:17:15]Its core would be made of iron, and its middle layer would be full of rock and water ice.

[00:17:21]At the same time, if the planet was smaller and denser, then it might be more like Earth with a rocky surface instead of a gassy one.

[00:17:30]According to a scientist named Mike Brown, if Planet Nine was real, a space probe would reach it in about 20 years if we used a powerful slingshot path around the Sun.

[00:17:44]>> Have you heard about Planet Nine?

[00:17:47]No, not Pluto. We're talking about something lurking on the outskirts of the solar system.

[00:17:54]A mysterious planet that exists in our solar system that we haven't yet discovered. [music] We've been looking for it for years, but finally, it seems like scientists found a key to solve this mystery.

[00:18:09]Planet Nine is a hypothetical planet.

[00:18:11]Astronomers have been on the hunt for it for quite some time now.

[00:18:15]But, it's so elusive that they've only been able to piece together a few details about its potential characteristics.

[00:18:24]One thing we do know is that Planet Nine has to be a massive world, possibly up to 10 times the mass of Earth.

[00:18:33]That's one big planet. It's also thought to be a distant wanderer, hanging out somewhere between Neptune and Pluto.

[00:18:42]Some scientists think [music] that Planet Nine might actually be a mini Neptune with a thick, gaseous atmosphere and a rocky core.

[00:18:51]Others speculate that it could be an icy world with a solid, frozen surface and a thick layer of hydrogen and helium gas.

[00:19:01]Of course, since we haven't actually found Planet Nine yet, we can't say for sure what it's like.

[00:19:08]We're not even sure that it even exists.

[00:19:11]Some say it's just a myth, like the tooth fairy or the Easter Bunny. But others are convinced that it's out there somewhere.

[00:19:19]And at the end of the day, we're not entirely sure if Planet Nine is even a planet. It might be a special kind of black hole or made entirely of dark matter.

[00:19:30]The search for Planet Nine began in the early 21st century when a group of astronomers realized [music] that something wasn't quite right with the outer reaches of our solar system.

[00:19:41]They noticed that [music] some distant objects, known as trans-Neptunian objects, were behaving in unexpected ways.

[00:19:49]Trans-Neptunian objects, or TNOs, [music] are like the cosmic version of those items in the back of your fridge that you forgot about for years.

[00:19:58]They're small, icy bodies that hang out in the Kuiper Belt, beyond Neptune.

[00:20:04]So, scientists noticed that these guys started behaving weirdly. At first, they thought it might be a fluke.

[00:20:12]But, as they dug deeper, they began to suspect that there was a ninth planet lurking out there.

[00:20:19]Why haven't we discovered it yet, you ask? Well, it may be because of Planet Nine's weird orbit.

[00:20:27]All the other eight planets orbit the Sun in roughly the same plane, which is like a flat disk. However, our hypothetical friend's orbit is different. [music] It might be tilted and move in a different direction compared to the other planets. Its orbit might also be [music] stretched out like an oval, rather than being nearly circular like usual.

[00:20:50]Because of this, Planet Nine might spend most of its time far from the Sun, like a true introvert. It only comes relatively close to the inner solar system every few thousand years.

[00:21:02]This would make it super faint and hard to spot. So, the only way we may discover it is by studying the gravitational effect it has on our solar system.

[00:21:14]And this isn't the first time astronomers have gone looking for a new planet. Back in the 19th century, there was a similar hunt for a hypothetical Planet X.

[00:21:24]But this time, they were armed with much better technology and a much better sense of humor.

[00:21:31]They began calling their elusive quarry Planet Nine, which was much catchier than Planet X.

[00:21:37]They even came up with a hashtag for the search, Pluto Lives.

[00:21:42]It was a reference to the fact that Pluto had been kicked from the planet gang, and some astronomers were eager to find a new planet to [music] take its place.

[00:21:51]But the search for Planet Nine has been no easy task. It's like trying to find a lost sock in the laundry basket the size of a football stadium.

[00:22:01]It's so far away and so faint that even the most powerful telescopes can't see it. Instead, astronomers have had to rely on indirect evidence, like the strange orbits of TNOs, [music] to try to figure out where it might be.

[00:22:17]Some scientists have even supposed that it might be a wandering rogue planet, which would explain why it's so hard to find.

[00:22:25]But they haven't [music] given up hope.

[00:22:28]Till this day, they're scouring the skies using all sorts of high-tech telescopes [music] and fancy algorithms to try and spot this elusive planet.

[00:22:38]And fear not, dear curious human, because it looks like after so many years of research, we may have finally found the key to solve this mystery.

[00:22:49]Astronomer Man Ho Chan from Hong Kong has a theory.

[00:22:53]He believes that Planet Nine could have a bevy of moons.

[00:22:57]That's right. Not only is it a giant planet hiding out in the depths of [music] space, but it's also a bit of a hoarder.

[00:23:06]Moons are all the rage in the outer solar system.

[00:23:09]>> [music] >> In fact, almost every planet here has at least one moon, except for Mercury and Venus.

[00:23:15]Earth has just one, >> [music] >> which is kind of sad if you think about it.

[00:23:19]Even non-planetary bodies like Pluto have at least a couple of moons. A bit unfair, isn't it?

[00:23:25]Anyway, taking this into account, let's go moon picking with Planet Nine.

[00:23:30]The region between the rock-filled Kuiper Belt and the rock-filled Oort Cloud, where this planet is predicted to be, should be ripe for the picking.

[00:23:39]Chan made some calculations and determined that it would be stranger if the elusive planet didn't have any satellites.

[00:23:47]According to his calculations, an object [music] the mass of Planet Nine should capture at least 20 TNOs as large as almost 90 miles across.

[00:23:57]It's like our mysterious planet is playing [music] cosmic Pokémon with these guys. So, what if Planet Nine has moons?

[00:24:05]Would that make any difference? Kind of yes. They could give us some indirect clues to finally locate this mysterious planet.

[00:24:14]Now, you might be thinking, how in the cosmos can we possibly spot these teeny tiny moons?

[00:24:20]It's not like they're going to wave a giant flag or blast some Beyoncé tunes to get our attention. Well, apparently the key lies in something called tidal heating.

[00:24:31]Tidal heating might sound like a new workout trend, but it's a real scientific phenomenon.

[00:24:37]It happens when two celestial bodies are close together. You see, tides aren't just about the rise and fall of the ocean. They're also the result of gravity pulling unevenly on a planet or moon.

[00:24:50]When a planet and a moon are close enough to each other, their gravity pulls on each other, creating a bit of a football shape.

[00:24:57]And as these celestial bodies move around each other, they shift shape and generate friction inside, which produces heat.

[00:25:07]Wow, who knew that Planet Nine could have a workout routine? Perhaps we should start calling it gym planet instead.

[00:25:16]Anyway, >> [music] >> if Planet Nine has any moons, the gravitational pull from these moons would cause it to change [music] shape constantly, generating heat in the process.

[00:25:26]And we might be able to detect this mysterious [music] planet through the heat produced by those moons, even though it gives off no other signals.

[00:25:35]Now, before [music] you get too excited, finding them won't be a walk in the park. They're incredibly small and would be very [music] far away from us. But hey, nothing worth discovering ever came easy, right?

[00:25:47]Scientists [music] are optimistic that with the right technology, they can spot this telltale sign.

[00:25:53]It will be easier for us to spot them with fancy instruments like modern telescopes. Talk about cool [music] friends to have, right?

[00:26:02]Sure, the process of finding it may be difficult and time-consuming, but the potential payoff is huge. Finding this [music] planet could explain a lot of the strange behavior observed in TNOs, the Kuiper Belt, [music] and beyond.

[00:26:16]As we've already mentioned, they've been acting super weird lately, tilting and aligning in suspicious ways.

[00:26:24]If this planet doesn't actually exist, we have yet to explain what is the reason for this strange behavior.

[00:26:31]In any case, the search for Planet [music] Nine is one of the most exciting and intriguing quests in modern astronomy. It's like a cosmic scavenger hunt, and everyone's invited to join in on the fun. So, grab your [music] telescopes and let's go planet hunting.

[00:26:47]Who knows? Maybe we'll find it sooner than we think.

[00:26:52]Well, apparently Earth may not be the only place where you can have a glass of water. Scientists found one more world that looks very promising because it might have liquid water on its surface.

[00:27:05]Even Mars can't compete with that.

[00:27:08]This planet is not too far from Earth and orbits a star called GJ 887.

[00:27:15]Look, this is Earth and this is the Sun.

[00:27:18]Zooming out, see this speck of light?

[00:27:20]It's the star we're talking about. This star is 10.7 light-years away from ours.

[00:27:26]For comparison, Earth is way, way less than one light-year away from the Sun.

[00:27:31]And a spacecraft could get us to the Sun in a few years. But with our modern technologies, we would need over 270,000 years to get to that star system.

[00:27:42]And still, that's close by space standards, of course.

[00:27:47]Scientists call the planet a super-Earth because it's bigger [music] than our planet, more than six times the mass of Earth.

[00:27:55]That's heavy enough to have strong gravity and a thick atmosphere.

[00:27:59]Another interesting thing is that, unlike many stars [music] of its type, GJ 887 doesn't flare up much.

[00:28:07]Big stellar flares can blast away a planet's atmosphere. The fewer flares there are, the better chance a planet has of holding onto air, water, and maybe even life.

[00:28:19]When astronomers talk about the habitable zone around a star, they mean a spot that is not too hot and not too cold where water could exist on the surface.

[00:28:30]But water isn't just about temperature.

[00:28:32]You also need air. Without an atmosphere, any water would evaporate or boil away instantly.

[00:28:39]According to researchers, the star's planet, GJ 887d, might actually have an atmosphere, which makes it a true habitable zone planet.

[00:28:49]Now, scientists already found two other planets around the same star back in 2020.

[00:28:55]But, both were too close to the star, way too hot for liquid water to survive on their surfaces.

[00:29:01]The research also hinted at a third planet around this star. But, at first, scientists weren't completely sure it was real. They thought the data could have been a fluke or weird blips in the measurements.

[00:29:14]But, after 5 more years of watching the star, the planet was confirmed.

[00:29:19]It orbits its star every 51 days or so.

[00:29:23]So, you'd celebrate your birthday once every 51 days there.

[00:29:27]That's even shorter than a year on Mercury, which [music] means the planet is very close to its star.

[00:29:33]Then, why doesn't it burn up and could even host life?

[00:29:37]The thing is, the star, GJ 887, is smaller and dimmer than our sun. That's why it doesn't blast this third planet with heat.

[00:29:46]>> [music] >> So, even with a shorter orbit, the planet's temperatures should be only a little warmer than those on Earth.

[00:29:53]Now, the good news is that the conditions on this new super-Earth might actually allow water to pool somewhere instead of evaporating immediately. No wonder this discovery is a big deal. For one thing, we might finally find life beyond Earth.

[00:30:09]Because where there's liquid water, there's a good chance of life. Plus, if we ever had to leave Earth, GJ 887d could be a strong contender for our new planet.

[00:30:22]Now, one big problem for planets around small stars is flares. Many red dwarfs blast their planets with intense bursts of radiation, stripping away any atmosphere.

[00:30:33]Without air, water can't stick around, and life doesn't have any chance to survive.

[00:30:39]It's probably why Proxima b, the nearest planet outside our solar system, likely has no atmosphere at all.

[00:30:47]But, GJ 887 is unusually calm. It doesn't flare like other small stars. Of course, this might just be temporary, or it could last for billions of years.

[00:30:58]Either way, it makes GJ 887 d more promising for holding on to air.

[00:31:04]The planet is also heavy, which means a lot of gravity. It would make launching rockets tricky, and it wouldn't be an easy feat to go for a walk there.

[00:31:14]But, heavier gravity is also good for keeping a thick atmosphere.

[00:31:19]If it developed on the planet, it could protect the surface and trap just enough heat.

[00:31:25]Unlike some planets, our guy doesn't pass in front of its star from our point of view. That means we can't easily measure its atmosphere by seeing how the starlight filters through it.

[00:31:37]Instead, astronomers need to use the radial velocity method, which detects tiny wobbles in the star caused by the planet's gravity.

[00:31:45]We still have a lot to learn about this world that might turn into a top travel destination one day.

[00:31:53]Every year, astronomers discover new planets outside our solar system. So far, we've found over 6,000 exoplanets, planets orbiting stars other than the sun.

[00:32:04]What interests us the most are planets that could host life, or at least have the right conditions for it.

[00:32:11]The big goal is finding stable liquid water on the surface, not frozen solid or boiling away into space.

[00:32:19]For water to stay liquid, a planet can't be too far from its star. Too far, and all the water will freeze into ice. Too close, and it will boil off like water on a stove.

[00:32:30]And since every star is different, each one has its own habitable zone, depending on its size, temperature, [music] and brightness.

[00:32:38]So far, telescopes around the world have found about 70 planets in a habitable zone, but only 30 of them are rocky like Earth, where oceans might actually exist.

[00:32:50]The thing is, only rocky planets can have oceans because they have a solid surface where water can collect. Plus, such planets also have gravity, which helps keep water in liquid form. Without it, water would [music] quickly evaporate into space or freeze solid.

[00:33:07]Now, having these condition doesn't mean life is guaranteed.

[00:33:12]Venus and Mars are technically in [music] the Sun's habitable zone, but Venus is a roasting oven, and Mars is a frozen desert. Life there seems unlikely.

[00:33:23]Or, take this planet for example.

[00:33:26]This super-Earth is 20 light-years away.

[00:33:29]Astronomers spotted it in January 2025 using telescopes at ESO in Chile. At first, it sounded very promising, but the planet's orbit is very stretched out like a long oval. That means it swings in and out of the habitable zone during its year.

[00:33:46]When it's far from its star, freezing winter lasts forever, not exactly life-friendly.

[00:33:53]But, even a perfect orbit isn't always enough.

[00:33:56]In the Gliese 667 C system, 22 light-years away, astronomers found three planets in the habitable zone.

[00:34:05]But one, it's planet F, is tidally locked. One side always faces the star and is scorching hot. The other side is in permanent shadow, freezing cold. Life could only survive in a thin strip between the two regions, or if strong winds spread heat across the planet.

[00:34:24]A true habitable planet also needs protection from cosmic rays, like a magnetic field and a thick atmosphere.

[00:34:31]Otherwise, radiation from the star will fry any chance of life.

[00:34:37]Take the TRAPPIST-1 system, discovered in 2016.

[00:34:41]Three planets orbit in the habitable zone, but TRAPPIST-1 b is tidally locked, gets blasted by stellar radiation, and has no atmosphere at all.

[00:34:52]The other two planets might have atmospheres, but we don't know yet if they can block out harmful radiation.

[00:35:00]Red dwarf stars, small, cool, dim, and also the most common in our galaxy, make things trickier. Their habitable zones are close to the star, so any planets there get hit by strong solar flares.

[00:35:13]Our closest potential second home, Proxima Centauri b, faces this problem.

[00:35:20]Unfortunately, it doesn't transit or cross its star from Earth's point of view, so we really can't study its atmosphere or see if it can protect life.

[00:35:30]And [music] even planets that tick all the boxes, the perfect orbit, habitable zone, atmosphere, can still be nightmarish like Venus.

[00:35:40]A circular orbit, habitable zone, thick atmosphere, and yet it's basically an oven with crushing pressure inside.

[00:35:48]Even Earth itself isn't perfect for life everywhere. The North and South Poles are freezing.

[00:35:54]The Atacama Desert is almost completely dry, so life struggles there, too.

[00:35:59]That's why astronomers aren't stopping at planets in the habitable zone.

[00:36:03]They're now hunting for signs of life in the air. Certain gases can hint at life.

[00:36:08]CO2 [music] and methane might come from biology, or they might not. Some gases, like dimethyl sulfide, are thought to come only from living things, but scientists aren't 100% sure.

[00:36:21]So, the tricky part is, how can we tell if a gas is made by life or by rocks and chemistry alone. Well, we've got new telescopes like ESO's extremely large telescope [music] that can give us much more detail.

[00:36:36]They could help us find more planets in the temperate zone and even reveal [music] certain traits that would tell us if a planet is truly habitable.

[00:36:46]For what seems like ages, scientists have been hunting for another Earth, perhaps to find cosmic neighbors >> [music] >> or maybe just to have a backup planet for potential relocation in case we can't turn this one around. Now, thanks to the James Webb Space Telescope, they might finally have a strong candidate.

[00:37:05]It's called Trappist-1e and is located 40 light-years away.

[00:37:10]1e orbits a small star called Trappist-1.

[00:37:14]It's an intriguing system that has seven Earth-size planets, all of which are nicknamed with letters from B to H.

[00:37:22]Well, 40 light-years won't be reachable anytime soon, but still close, well, in space terms at least. Our galaxy, the Milky Way, is about 100,000 [music] light-years across. So, compared to that, 40 is like a walk down the driveway, or [music] at least will be if our spaceships achieve a speed close to the speed of light, just like in the movies. Remember, a light-year isn't a measure for time. It's how far light can travel in 1 year, which is close to 6 trillion miles, [music] which is a lot of zeros. So, multiply that by 40 and you get the location of Trappist-1. So, bring a big lunch.

[00:38:02]T1 is a red dwarf, a type of star that's basically like a dimmer and smaller version of our sun. It's only a bit bigger than Jupiter.

[00:38:11]Among this family, 1e sits in the star's sweet spot, the so-called Goldilocks [music] zone. Not too hot, not too cold, and a distance where liquid water could exist on a planet surface if it has the right atmosphere. Perfectly habitable, at least for creatures resembling Earth's [music] residents. However, it's not just located at just the right distance, which is a huge plus. 1e also happens to be a rocky planet. Its size and mass are close to Earth's, which suggests it has a similar density and structure, as well as [music] similar gravity, meaning no cool jumps like on the moon.

[00:38:50]Now, Webb has [music] picked up hints that there could be an atmosphere. The planet might be wrapped in gases like nitrogen, [music] carbon dioxide, and methane. We have such a mix over here, too. Earth's air is built from the same elements.

[00:39:03]Atmosphere matters. Mars lost most of it. Venus has too much, and Earth got it just right. That's why we have cozy weather and oceans. If 1e really does have something similar, it could mean clouds, rain, and maybe even seas. The stuff that would make Earthlings feel at home.

[00:39:23]However, here is where it gets interesting.

[00:39:26]>> [music] >> We mentioned that 1e is a red dwarf star, and that makes it dim, hundreds of times dimmer than the sun. If you were standing on 1e, the star would look way bigger in the sky than our sun does here. But, it would glow red and dull.

[00:39:41]It would be like living under a never-ending sunset. You might think, [music] "Sweet, it would be romantic."

[00:39:47]Until it gets old. I mean, cold. It has to be freezing, right?

[00:39:52]After all, how can such a faint star provide enough heat for life the way our sun [music] does? Well, funny enough, you won't need super winter resistant jackets. The trick is distance.

[00:40:04]Trappist-1e orbits extremely close to its star, just about 3% of Earth's distance [music] from the sun. If the planet were sitting where Earth is, it would be a ball of ice. But, being so close also means that its year is only around 146 hours.

[00:40:20]>> [music] >> That means it takes six Earth days for one e to resolve around T1. Celebrating birthdays [music] every 6 days sounds like a great deal, huh? That's a lot of cake.

[00:40:32]But wait, does that mean that each season would last about 36 hours? No, because the planet is almost certainly tidally locked. That means one side bakes in endless daylight and the other side is stuck in eternal night. Not exactly Earth 2.0. Without an atmosphere, you'd get a scorched wasteland on one side and an ice cube on the other. But with an atmosphere, the air can spread [music] the heat around, smoothing things out. In theory, the comfiest spot [music] might actually be the twilight strip between day and night, the so-called terminator line.

[00:41:08]Again, a permanent sunrise or sunset.

[00:41:11]>> [music] >> Instagrammers would love it.

[00:41:13]Red dwarfs are actually the most common stars in our galaxy, [music] making up about 70% of all the stars we know about. And they live practically forever. Our sun is projected to last 10 billion years. Red dwarfs [music] could go on for trillions. That's more than enough time for life to develop.

[00:41:32]However, the short straw is that red dwarfs are kind of feisty. They erupt with powerful flares that blast out intense radiation. So, for planets orbiting so close, those flares can strip away atmospheres and sterilize the surface.

[00:41:48]>> [music] >> It's like having a dream house with a beautiful view near a dynamite factory.

[00:41:52]Oops.

[00:41:54]That's what makes TRAPPIST-1e [music] so exciting. If it does have an atmosphere, it would mean it's somehow resisted billions of years of flare activity. And it might not be the only one. There could be plenty [music] of exoplanets like this out there.

[00:42:10]Now, you may be wondering how scientists could possibly know what's going on with a small planet that's so far away.

[00:42:17]Well, they study light using [music] a technique called transit spectroscopy.

[00:42:22]When TRAPPIST-1e passes in front of its star, the light filters through its edges, revealing clues about its air.

[00:42:29]Repeat enough [music] times, and we start to see what it's really like. As one of the most important features of the James Webb telescope, it doesn't just snap pretty pictures. It dissects that light into thousands of slices, each revealing a different clue.

[00:42:44]It's also great when you remember that E1 is just one of seven planets that orbit so close. So, scientists [music] have a lot to study in that part of the universe.

[00:42:54]Each transit gives them a little more data, and after enough passes, they can start to rule things out. No thick hydrogen blanket? Check. No Venus-style [music] carbon dioxide swamp? Looking that way. What's left is a planet that might just might have something closer [music] to Earth's atmosphere.

[00:43:14]In other words, nobody's sending probes to TRAPPIST-1e anytime soon. But, with telescopes like Webb, [music] we can already peek at its air from across the galaxy.

[00:43:25]If you follow space-related news, you are already aware that [music] 1e isn't the first so-called Earth-like planet that reached headlines. Astronomers have been teasing us with candidates for years, and each one comes with a but. As in, however, not your butt.

[00:43:43]For example, Kepler-186f. [music] Back in 2014, it was the first Earth-size planet spotted in the habitable zone of a star. People were really excited. NASA even made a sci-fi-style travel poster. The catch?

[00:43:59]Oh, well, just one minor thing, the fact that it's about 500 light-years away.

[00:44:04]Even And we build a spaceship that could cruise at a tenth of light speed, which we can't, it would still be a 5,000-year-long trip. Then there's Proxima Centauri b.

[00:44:15]This one is close, just 4.2 [music] light-years away, orbiting the nearest star to our sun.

[00:44:21]On paper, it's a dream. However, its [music] star is even moodier than t1.

[00:44:26]Proxima exhales massive radiation flares regularly, which makes everything unpredictable [music] and unstable.

[00:44:34]And then we have K2-18b.

[00:44:37]The James Webb telescope [music] actually spotted methane and carbon dioxide in its atmosphere. Gases, which might hint at biological activity.

[00:44:46]Sounds great, except the planet is more like a mini-Neptune, probably wrapped in thick gas layers, and unlikely to have a solid surface to stand on.

[00:44:56]The bottom line? When compared to all of these, Trappist-1e looks like the most [music] promising one. Close enough to study, rocky enough to stand on, and sitting in a sweet spot where liquid water could exist if conditions line up.

[00:45:12]Of course, we still need more data. 1e could turn out to be a barren rock. But the bigger story is that we're [music] getting better at this. A few decades ago, we didn't know if other solar systems even existed. Now, we've found over [music] 6,000 exoplanets, with more getting added almost every week. Odds are, plenty of them will be rocky, Earth-sized, and orbiting in the Goldilocks zone. Maybe we can't go there, but they could mean the discovery [music] of extraterrestrial life. That's the exciting part. Every time Webb or the next generation of telescopes take a look, we inch closer [music] to answering the big question. Are we alone, or is the universe full of neighbors? Hey, get your dog off my lawn.

[00:46:00]>> Look at this fascinating planet. It looks as if it's burning. It must be hotter on its surface than in the middle of Death Valley.

[00:46:08]The ground is parched, cut by giant cracks.

[00:46:12]There's not a drop of water in this boiling world.

[00:46:15]Now, it's the [music] same planet, but it looks like a totally different place.

[00:46:20]Everything is frozen. The temperatures are so low, there isn't even a tiniest chance that life could survive on this planet.

[00:46:28]This bizarre world is called HD20794d, >> [music] >> and it's located 19.7 light years away from Earth in the constellation Eridanus.

[00:46:40]This planet is a super-Earth. This term means that it is larger than Earth, but smaller than such ice giants as Neptune.

[00:46:48]What makes this planet especially interesting [music] is its unusual orbit, which moves it in and out of its star's habitable zone, the region where temperatures might allow liquid water to exist.

[00:47:01]Now, we haven't seen this unusual planet directly.

[00:47:04]Astronomers detected it [music] by measuring tiny wobbles in its star using two powerful instruments, ESPRESSO [music] and HARPS, located at telescopes in Chile.

[00:47:15]These instruments measure radial velocity, which is the small movement a star [music] makes as a planet's gravity tugs on it. The larger the wobble, the more massive the planet.

[00:47:27]Later, astronomers analyzed the data [music] and figured out that the planet in question has a mass around six times greater than Earth.

[00:47:35]It orbits a star, which is [music] slightly smaller and dimmer than our sun.

[00:47:40]What makes this star unique is that it is bright enough to be seen with the unaided eye, unlike many other stars that host exoplanets.

[00:47:49]You won't be able to see them without a telescope.

[00:47:52]The star system has been observed for over 20 years. Astronomers have long suspected it had multiple planets.

[00:48:00]In 2011, scientists [music] discovered two other super-Earths orbiting the star every 18.3 and 89.6 days, respectively.

[00:48:10]For some time, researchers thought they had found a third planet with an orbital period of 40 days. Later, they realized they had made a mistake.

[00:48:21]But recently, after [music] reanalyzing years of data, astronomers have confirmed that the third planet does exist, and it's our extreme HD 20794d.

[00:48:33]A researcher from the University of Oxford [music] played a key role in identifying the planet.

[00:48:39]He used a special computer algorithm called YARARA to separate the planet's weak [music] signal from the background noise.

[00:48:47]It helped him confirm that the planet truly existed and was pretty unique.

[00:48:52]Unlike the planets [music] in our solar system, which have mostly circular orbits, the newly discovered one follows a highly elliptical, >> [music] >> stretched-out orbit.

[00:49:02]It takes 647 days to complete one trip around its star. That's just 40 days shorter than Mars's orbit around the Sun.

[00:49:11]At its furthest point, the planet is twice the Earth-Sun distance, which makes it an icy world far outside the habitable zone.

[00:49:20]At its closest [music] point, it moves inward to 0.75 AU, where it enters the habitable zone, where liquid water might exist. [music] This extreme movement creates truly bizarre seasons.

[00:49:33]For some part [music] of its orbit, HD 20794d is frozen, like an icy [music] wasteland. As it approaches its star, temperatures rise, and ice likely melts, forming temporary oceans.

[00:49:47]The planet then experiences [music] a short, scorching summer.

[00:49:52]It is so hot that the water on its surface might evaporate into the atmosphere.

[00:49:57]Shortly after, the planet [music] moves away again.

[00:50:01]It triggers a gloomy fall with rains followed by a deep freeze in winter.

[00:50:07]In other words, >> [music] >> the planet switches between extreme cold and intense heat, which makes [music] it a very unpredictable place for life.

[00:50:16]If any life forms exist there, they certainly need to adapt to dramatic changes in temperature and environment.

[00:50:24]Why does the planet follow such a mind-boggling orbit?

[00:50:27]It might be a leftover effect from events billions of years ago when the planetary system was still forming.

[00:50:35]At some point, another large planet may have disturbed the orbit of our extraordinary friend.

[00:50:41]Another possible explanation is that a giant planet once existed in the system and its gravity [music] pushed HD 20794d into an elongated path. Later, this [music] giant planet may have been ejected from the system, leaving the smaller planet in its current [music] orbit.

[00:51:00]This theory makes sense because the two other planets in the system, B and C, have more normal circular orbits.

[00:51:08]The discovery of this planet is so exciting because it [music] challenges what we know about habitable planets.

[00:51:15]Most planets in the habitable zone stay there permanently, but HD 20794d [music] only passes through it.

[00:51:23]Scientists want to know if such a planet could [music] still support life, even briefly.

[00:51:28]So, future telescopes will study the atmosphere [music] of this planet looking for signs of water, gases, or even life.

[00:51:37]Another super-Earth that might have [music] the right conditions for life orbits a star 137 light-years away.

[00:51:44]In space terms, >> [music] >> this is considered relatively close.

[00:51:48]A light-year is around 6 trillion miles.

[00:51:52]The planet is called [music] TOI-715b, and it's about 1.5 times the size of Earth.

[00:52:00]Unlike HD20794d, it's permanently located in the habitable zone.

[00:52:06]Look, that's what astronomers [music] think the planet might look like.

[00:52:11]TOI-715b orbits its star very quickly, completing a full orbit in just [music] 19 days.

[00:52:19]But even though it's close to its star, it may not be extremely hot, all because its star [music] is a red dwarf.

[00:52:27]That's a type of star that is smaller and cooler than our sun.

[00:52:32]This means TOI-715b could have a milder temperature compared to other exoplanets that orbit closer to hotter stars.

[00:52:42]NASA discovered the planet using the Transiting Exoplanet Survey Satellite.

[00:52:48]This space telescope finds planets by watching for small dips in a star's brightness, which happen when a planet passes in front of it.

[00:52:56]Since red dwarfs are smaller and dimmer than the sun, planets passing in front of them are easier to detect.

[00:53:04]Astronomers are planning to study the planet further using the James Webb Space Telescope.

[00:53:11]>> [music] >> This powerful telescope, located 1 million miles away from Earth, can analyze the atmospheres of distant [music] planets.

[00:53:19]If TOI-715b has an atmosphere, JWST could help scientists determine [music] what gases are present in it, and whether such conditions could support liquid water >> [music] >> or even life.

[00:53:34]One more promising world for our search for extraterrestrial life is [music] an extremely dense super-Earth in the K2-360 system.

[00:53:44]An international team of researchers from Japan and Europe [music] has discovered this remarkable multi-planet system orbiting a sun-like star located 750 light-years away.

[00:53:57]This system has two planets [music] including one of the densest rocky planets ever found.

[00:54:03]The K2-360b [music] is a rocky super Earth about 1.6 times the size of Earth but with a mass 7.7 times greater. This makes it as [music] dense as lead.

[00:54:17]The planet orbits its star incredibly fast completing one full orbit in just 21 hours. It's the densest [music] known ultra-short period planet with well-measured properties.

[00:54:29]As for its sibling, this is a much larger outer planet with at least 15 Earth [music] masses.

[00:54:35]It takes 9.8 days to orbit its star.

[00:54:39]Sadly, since it does not pass in front of its star from our viewpoint, scientists cannot determine [music] its exact size.

[00:54:48]The unusually dense planet might be the core of a much larger planet.

[00:54:53]Over time, intense radiation from its parent star may have blown away its outer layers >> [music] >> leaving behind only its dense rocky core.

[00:55:02]So, in fact, this planet [music] could show us what might happen to some planets that are too close to their stars.

[00:55:10]Astronomers think that the planet [music] may have moved inward over time due to interactions with its larger companion planet.

[00:55:17]One possibility is high eccentricity [music] migration where a planet's orbit becomes highly stretched out due to gravitational interactions [music] before gradually becoming more circular near the star.

[00:55:30]Another theory is that the [music] planet's spin and axial tilt can cause its orbit to become more circular.

[00:55:37]Such planets are rare, [music] and finding one with a massive outer companion can help scientists refine their theories [music] about how planets form and evolve in extreme environments.

[00:55:49]With its help, [music] we might also understand how rocky planets evolve and what happens to planets that [music] get too close to their stars.

[00:55:59]>> That's it for today. So, hey, if you pacified your curiosity, then give the video a like and share it with your friends. Or, if you want more, just click on these videos and stay on the bright side.