What's Directly Above And Below The Sun?

Kind: captions Language: en A planet-killing asteroid could already be hurtling toward the Earth, and we might not see it until it's too late. Despite the idea of 24/7 sky monitoring, there are still blind spots, and that's exactly where something catastrophic could come from. Objects can slip past our detection networks depending on their angle of approach, especially steep above the plane trajectories that no one is continuously watching. It's happened before, and it will happen again. We got lucky once. Next time, we might not. Humans have built systems designed to watch the sky for anything coming our way. Constant surveillance, precision tracking, the ability to map the paths of objects moving millions of miles through space. >> [music] >> And if something looks dangerous, in theory, we can respond. For decades, that idea has given billions of people a quiet sense of security. That idea is fundamentally flawed. On September 9th, 2017, an interstellar object slingshotted past the sun. [music] The cigar-shaped structure, estimated at around a quarter of a mile in length, traveled almost 196,000 miles per hour. Just over a month later, it made its closest approach to Earth, and nobody saw it. It wasn't until October 19th that the object was detected. [music] By then, it had already spent years in our vast solar system and was already on its way toward the exit. Weeks [music] had passed with this large anomalous object speeding through our solar system unseen. The object was later named Oumuamua. It passed through the solar system and left again without an impact. Now, imagine that same kind of arrival, but with something actually locked onto the Earth. A massive hunk of rock and metal moving straight through space toward us, and nothing in our satellite networks, telescopes, or monitoring systems picks it up in time. Not until it's already too late. If it happened once, it can happen again. How did we miss it? Simple. We weren't looking in the right places. Not because we didn't want to, but because we weren't able to. It turns out that even the most advanced observatories on the Earth, like Pan-STARRS and the Vera C. Rubin Observatory, have [music] blind spots. In other words, the planet defense systems that we count on aren't as reliable as they seem. They're designed to map objects moving across the full 3D dome of the night sky, but there are regions they struggle to watch clearly, especially the bright sun-facing areas where detection becomes far harder. It was from that same abyss that 'Oumuamua emerged, dropping into our system from above. By the time we understood what we had seen, it was already gone. It proved we were vulnerable. So, if we're blind to this part of the solar system, why haven't we simply sent some probes to take a look for us? To understand how humanity became so worryingly blind to this enormous existential vulnerability, we have to go back to the birth of our solar system. 4 and 1/2 billion years ago, it was a little more than a flattened disc of gas and dust spinning wildly in the deep darkness of space. It was collapsing, reshaping itself under gravity, and as it contracted, it didn't just fall inward, it spun faster. Collisions built structure. Small grains became larger bodies. At the center of it all was the future sun. The result was a single shared orbital plane, a cosmic [music] disc everything would eventually follow. Every planet and asteroid were in the same general lane of motion, and that structure shaped how we see everything around our solar system. For thousands of years, mankind watched the night sky and tracked the movements of stars, and because our planet moves along a flat ecliptic plane, all the other planets appear to move in narrow, predictable paths across the sky. In short, we grew up in a world where everything happened along the same horizontal axis, which embedded a kind of two-dimensional bias into our collective consciousness. And that bias has persisted right up to the time when we finally invented the type of technology we needed to build high-powered telescopes and send rockets into space. We still operated outside of the intense glare of the sun. We sent our our advanced probes outside of that glare, where they could function safely and consistently. [music] We built our detection and planetary defense systems with a heavy bias toward the ecliptic plane, because that's where most comets, asteroids, and debris were expected to emerge from. We built, in effect, a 2D surveillance system in a 3D universe. It all traces back to those ancient laws of physics that shaped the architecture of our solar system. It's [music] defined the orbits of the planets and the limits of where we looked. But, the void above and below was outside of that limit. This isn't a mere psychological bias that we can easily overcome. It is a physical barrier that demands an immense amount of energy for rockets to break through. [music] In the field of space exploration, distance and speed aren't necessarily the most important metrics. Instead, numerous theories and projections are built around a measurement known as delta V. It's arguably the only metric that matters. [music] It measures the total change in velocity a spacecraft is capable of producing. It's sometimes referred to as the fuel budget or the range of the rocket. Every maneuver in space, whether it be launching from the Earth, landing on the moon, or adjusting from one orbital trajectory to another, demands a certain amount of delta V. We've built rockets and probes with enough delta V to [music] explore the solar system and even leave it. So, why is it so difficult to send them in a different direction and map the space above and below us? It all comes down to one thing, gravity prison. When a rocket takes off from the Earth's surface, it inherits the Earth's orbital velocity, traveling around the sun at a rate approaching 19 miles per second. That powerful forward momentum is helpful when you want to travel to another location along that same plane, somewhere like Mars, for example. If we want to send a rocket to the outer edges of the solar system past Pluto, it would only need an additional delta V of around 10 miles per second. It's because the rocket or probe is benefiting from Earth's orbit. It's already moving the right way. It just needs a relatively small push to move further across the plane. If we want to turn a corner, however, and move out of that elliptic plane, that means a much greater amount of energy. To pull off a maneuver like that, you can't rely on Earth's orbit. You have to fight against it, canceling out that horizontal momentum while accelerating the spacecraft in a completely different direction. Because of this, the estimated amount of delta V required to achieve a 90° solar polar orbit is approximately 20 mi per second. Double the amount of energy needed to get past Pluto and exit the solar system. It's like launching a rocket from the Earth, pushing it to maximum speed, and then trying to stop it instantly by slamming it into a wall at 67,000 mi per hour. That kind of maneuver is beyond what our current propulsion systems are built to handle. This is the gravity prison. The laws of orbital mechanics and the pull of our planet effectively lock us into a flat horizontal corridor that's almost impossible to escape. Almost. Because despite this massive barrier, NASA actually managed to send one probe out of the plane in 1990. What it found broke our understanding of the Sun. NASA called its 1990 probe Ulysses, and it represented something unprecedented. A blind [music] and daring leap into the unknown. Because engineers couldn't rely on conventional chemical propulsion alone to conquer the delta V barrier, they had to get creative. Ulysses was launched towards Jupiter. The gas giant's huge gravitational field slingshot at the probe out of the ecliptic plane and into a high inclination polar orbit around the Sun. Somehow it worked. The data started pouring in, and it defied every expectation. Before the Ulysses mission, the scientific community operated according to a rigid belief in something called the Parker spiral model. It dictates that the Sun's magnetic field twists into a neat spiral-like structure as it extends across the solar system. According to this model, the solar poles were relatively quiet and orderly regions where magnetic lines returned to the star, Ulysses revealed that our polar magnetic fields are unwound and chaotic. Far from following a precise predictable [music] pattern, the lines are wildly disorganized and entirely unpredictable. This suggests that all of our established mathematical models of solar physics weren't [music] just a little off, they were missing 50% of the picture. In an instant, entire theories and formulas fell apart. Everything we thought we knew about the most important star of all had been rewritten. The drama didn't end there. The environment that Ulysses encountered above the Sun was almost unimaginably violent. Solar winds reach speeds of around 466 to 497 miles per second. That's almost double the winds found at the solar equator. It was the equivalent of passing from a breezy day at the beach into a category 5 hurricane simply by changing latitude. The space above us was not some peaceful, empty, uninteresting void. It was a torrent of energetic chaos, a world wind of magnetic violence far beyond our wildest expectations. The swift solar winds of the poles were only the beginning. >> [music] >> As scientists scrambled to analyze the new data, they realized that this was just one part of a much larger systemic crisis. The space above us isn't just unstable, it is crushing our entire solar system. For generations, space agencies presented a clear visual model of our solar system and its position in the wider galaxy. We were told that our world and the planets that share the surrounding space travel through the universe inside a stable, symmetrical, bubble-shaped shield, the heliosphere. It was a reassuring concept. We didn't have to worry about world-ending catastrophes and interstellar radiation because there was always this vast, invisible force field to keep us safe. That model isn't exactly wrong, but it misses something vital. Our so-called shield is under immense pressure, and the cracks are already starting to show. In recent years, data gathered by deep space probes and interstellar satellites has revealed that the cosmic architecture we depend on is being forcefully altered. Professor Merav Opher, one of the world's leading astrophysicists, famously concluded that while sphere may be a part of the name, the heliosphere is anything but spherical. It's more like a flat croissant. A flat croissant that is constantly being crushed and warped by intense magnetic pressure, leaving dangerously thin spots at the poles. In other words, Earth's protective magnetic field bends, stretches, and shifts over time. It's not a secure bunker or an impenetrable barrier. It's more like a plastic tent with a sagging roof struggling to withstand the weight raining down from above. The fragility of our situation was highlighted in 2009. NASA's Interstellar Boundary Explorer satellite, or IBEX, turned toward the edges of our solar system and saw something humanity had never seen before. The so-called IBEX ribbon, a massive, mysterious structure made up of enhanced energetic atom emissions spanning across the sky, containing particle densities that are two to three times higher than the surrounding space. The IBEX ribbon acts as a kind of magnetic mirror, which reflects escaped solar wind particles right back into the core of the solar system. It's like a glowing neon fence surrounding our entire solar system. We had no idea it was even there until 2009. But that same energetic ribbon extends right through the high latitude polar regions of our dynamic shield. That same barrier meant to protect us from lethal radiation in our space is not fixed. It shifts and flexes at its edges over time. Because we've been so busy looking out across our own flat 2D plane, we had no way of knowing about it and no way of tracking its changes over time. In fact, the only way to monitor the highly active poles required an extreme gravitational maneuver. All of the problems outlined so far boil down to one underlying cause, the conservation of angular momentum. It's that very same physical law that formed our solar system and gave our planet life that blinds us today. >> [music] >> It's a true case of cosmic irony. Billions of years ago, it was the conservation of angular momentum that helped the early condensing chaos of the solar system to flatten and extend outward into a life-sustaining disk. A miracle of physics that paved the way for life as we know it. Without flattening, the Earth wouldn't have formed. It wouldn't have begun to follow the perfectly precise stable circular orbit it has to follow to sustain life. >> [music] >> That flat ecliptic plane, the end result of angular momentum, the only reason we exist at all. Yet, that same law of physics now traps us in a gravity wall prison. If humanity truly wants to set up an early warning or defense system above the solar system to scan for signs of the next Oumuamua, it can't fight the rules of physics. It has to use them to its advantage. In real terms, that means the only option is to slingshot us where we want to go. If we can survive it, that is. One of the ways we're ever getting out into the abyss relies on a high-stakes orbital strategy called the Oberth maneuver, otherwise known as a powered flyby. It's an extremely risky orbital technique in which a spacecraft allows itself to fall inside of a gravity well. It waits until the very last moment, the lowest point of that well, to fire its engines. This in turn takes advantage of the so-called Oberth effect, which states firing a rocket's engines at a high velocity produces far more kinetic energy than doing so at lower speeds. If we can't achieve enough delta V through conventional propulsion, this becomes our only remaining option. We have to literally make a spacecraft fall into the sun. As it falls deeper and deeper, it'll accelerate to an extreme speed, activating [music] its onboard propulsion systems at the very nadir of its orbit. This would give it a boost that might just be big enough to send it slingshotting out of the ecliptic plane. It's an extreme maneuver. At that distance from the sun, no conventional spacecraft would survive. Even our strongest current heat shields would melt in an instant. The spacecraft would be subjected to a thermal bombardment it would have no hope of withstanding. And with no shields to guard them, all of the sensors, cameras, and communication systems, and other components required to collect and send data back to the earth would be vaporized. In short, [music] this desperate jailbreak gamble requires technology we don't have yet. Until then, we're sitting ducks. A potentially world-ending threat could be somewhere in space right now speeding toward us. The world's leading space agency spend vast amounts of time and resources on planetary defense initiatives. They scan the stars for signs of potentially hazardous asteroids PHAs with an estimated diameter larger than 460 ft and an orbit that brings them within 4.64 million miles of the earth's path. There are thousands of known PHAs in existence today. There could be countless others we don't yet know about. Less than 1% of known PHAs have an inclination greater than 45°. The interstellar void, the vast regions above and below our solar system, doesn't follow the same flat plane we live in. Oumuamua wasn't a one-off, it was a warning shot. It was the wider universe sending us a message that we aren't safe as we have been led to believe. The space that surrounds us is much greater and more dangerous than we ever could have imagined. Since Oumuamua's arrival, much has changed in the way we observe the universe. We retuned software algorithms for the upcoming Vera Rubin Observatory, approving an ESA Comet Interceptor mission, and scanning the skies to specifically chase the next object. A potential [music] planet killer might already be on the way, set to descend through the thin flaking layers of our crushed croissant shield. It might pass the blind spots of the Pan-STARRS and other observatories ready to catch us all entirely off guard. It won't announce itself, and it won't follow the rules we want it to. [music] Our survival depends on mapping the full 3D sphere of our origin, breaking past the Delta V barrier, using gravity assists, and looking above and below, not just across the plane. Until then, we're relying on telescopes, surveys, and deflection physics to keep us safe from the one impact we never see coming. And that only works until it doesn't. There is little we can do if a planet killer is already on its way. Watch the last 60 minutes before asteroid impacts with Earth to see what those final moments would actually look like. Or click on this video.