The story of ‘Oumuamua, the first visitor from another star system | Karen J. Meech

Translator: Anas Mohamed Auditor: Alaa Eladle NASA is always monitoring the potential dangers of asteroids colliding with Earth, So the Ban Stars telescope scans the sky every night Every morning, the telescope crew checks for potential objects Usually, they discover that they are simple things. But on October 19, 2017, The telescope detected a fast-moving object between the stars, This time the usual follow-up of location and velocity measurements It showed something completely different. On October 22nd, we have enough information Note that this object is not from our solar system. Whew! That's when I got a phone call, The call all solar system astronomers have been waiting for. Let me tell you just how exciting this is. (Laughter) NASA was expecting to see a stellar comet It has passed through the solar system since the 1970s, But until now, we haven't seen anything. Our solar system is huge, Even if we get a cluster from the nearest star system Which is 4.4 light-years (42 trillion kilometers) away.

It would take more than 50,000 years to arrive. So it's really a big deal. This astral visitor entered our solar system From above the surface plane of the planets, Coming from the constellation of fixed stars (Lyra), And he passed close to the sun on the 9th of September, Passing through the orbit of the planet Mercury. Now this is not a very close or unusual distance. It's easier to see things up close. On October 14th, Before we discovered it, it was at the closest point to Earth, Within about 15 million miles. This is really close based on astronomical criteria. Now instead of launching this impractical registry name, An abbreviation we called it "Rama," After the cylindrical spacecraft has passed through the solar system In the classic science fiction story by Arthur Clarke in 1973. But this was not entirely correct. So in honor of its discovery with a telescope in Hawaii, We consulted two experts on Hawaiian culture, One of them is an explorer and the other is a scholar of language.

To suggest a name. And they suggested the name Oumuamua, Which means the researcher or the messenger coming to us from the distant past. Now this finding is very important for a number of reasons. But what is important to me is what can tell us On the history of our solar system. The process of building a new solar system and the growth of planets It can be violent and chaotic. As the icy and rocky remnants are expelled from the new solar system, While the massive planets migrate through the debris disc From which those planets were formed. Have you ever felt an emotional shudder, Something so exciting happened that it shook you? Or something that affected you emotionally? Well it is for me. This was my wow moment. We already got a piece of material from another solar system Coming close enough to be spotted.

So what do you want to know about Oumuamua, The first visitor from another star system? Well, I can think of a lot of things But there is a difference between what you want and what you can take from it, 'Oumuamua was moving away and fading very quickly. In a period not exceeding a week, Its brightness decreased on a photometer. So this was all the time we had To study it easily. So we had to dispense with the processes of acquiring the time telescope, Which are usually competitive and subject to peer review for selection of proposals That takes months, It should be finished in less than a few days.

So the "polite" competition for resources began. Well, I won't cut it short, the rivalry was fierce. We have given up everything, And we worked around the clock, Trying to elaborate our proposals carefully To be sent to the directors of the Astronomical Observatory. Well, good news. We got enough time. Now, from a selfish point of view, The first thing we wanted to know was the size of Oumuamua.

Because in the end, he passed close to the earth, We did not know about it until recently. How bad would it be if it collided with the ground? Well, calculate the energy effect It depends on the square of the velocity multiplied by its mass And the mass depends on how large it is and what material it is made of. So how big is Oumuamua and what does it look like? Well, we can tell this from its brightness. Now, if you don't believe me, consider a brightness comparison Firefly in your backyard With navigational traffic lights from a distant aircraft. You know the plane's lights are brighter, It just appears dimmed because of its extreme distance. We also need knowledge The extent of reflection of Oumuamua's surface, And we don't have any evidence, But it is reasonable to assume that it is very similar to small asteroids Comets in our solar system, Or technically speaking, Something between the reflectivity of charcoal and wet sand.

These days, most large telescopes are used in so-called service mode. Meaning we must carefully develop all instructions And we send them to the telescope operator, And then we have to wait anxiously for the data to come back, We pray to our God that the weather is fair Now, I bet most of you are not holding jobs Accurately depends on how clear the weather was last night. Good, but we weren't going to have any second chances here. Because the weather was great, Oumuamua decided to disappear.

Its brightness was not constant. Now, from here we can see Oumuamua racing between the stars. It is pivoted in the center. The stars fade away as the telescope is tracking its movement. It began to fade after that shine and fade and shine and fade again. Sunlight is also reflected from four sides of a rectangular object. The maximum brightness changes Which brings us to an unbelievable end to what he looks like. As shown in this artist's impression, Oumuamua as it seems so long and narrow, With an axis ratio ranging from 10 to 1. Assuming it's dark, that means it's half a mile long. There is nothing else in our solar system that looks like this. We only have a handful of things that even have an axis ratio Greater than 5 to 1. So we don't know how this was formed. But that may be part of its formation process in its original solar system. Oumuamua's brightness was changing every 7.34 hours, Or so we thought. As more data emerged from other teams, Various numbers announced. Why, the more we know about something, It became difficult to explain? Well, it turns out that 'Oumuamua doesn't spin in a simple way.

It wobbles like the top. So when it rotates on its short axis, It also rotates around its long axis It swayes up and down. This movement is full of energy and activity Almost be the cause of his slander so violently Outside his original solar system. Now how can we explain what it looks like by how bright it is Much dependent on how it rotates, Now we must rethink what it might look like, And as shown in this beautiful painting by space artist (Bill Hartman), We think Oumuamua might be more than a flat oval.

So let's get back to energy science. what's it made of? Well, ideally we'd love to have a piece of Oumuamua. In the lab, so we can study it in detail. But even private industry cannot launch Spacecraft within a week To something like this, Astronomers must rely on remote observation. So astronomers will look at how light interacts with the surface. It might absorb some of the colors, giving it a chemical imprint, Whereas maybe the other colors won't.

On the other hand, some materials may reflect blue more Or red light efficiently. In the case of 'Oumuamua it reflects red light more. This makes it look a lot like the surface of a comet rich in organic matter Recently visited by the spacecraft (Rosetta). But not every substance that appears red has the same composition. In fact, minerals that have small bits of iron in the surface It can also appear red. As does the black side of Saturn's moon (Iapetus), Shown in these images is from the Cassini spacecraft. Meteorites consisting of nickel iron, i.e. metal, She can look red. So while we can't figure out what's on the surface, We know very little about what is in it. However, we know it has to at least be strong enough Lest it fly away with its rotation, So it is likely that its density is similar to that of rocky asteroids; Like minerals, it also has the greatest density.

Good, at the very least, I want to show you One of the beautiful color images We got it from one of the ground-based telescopes. Well I admit it's not all that amazing. (Laughter) We just don't have the degree of purity. Even the Hubble Space Telescope. It doesn't show a much better look. But the importance of Hubble data is not because of the pictures. But because it expands our observation to the outside About two and a half months after the discovery, Which means we get more locations along the orbit, That will let us discover the origin of Oumuamua.

So what is "Oumuamua" exactly? We definitely think it's likely a residual archaeological relic From configurations of another planetary system, Some Driftwoods. Some scientists think that Oumuamua may have formed Near a star denser than ours, The tidal forces of the star ripped apart planetary materials Early in the history of the solar system. Still others believed that something formed During the last stages of a star's life, Perhaps during a supernova explosion of this star, Planetary materials have also been torn apart. Whatever that is, we think it's normal, But in fact we cannot prove that it is not something artificial. Color, odd shape, and fluctuating motion There may be other explanations.

Now while we can't believe it's alien technology, Why not do the obvious experiment and look for a wireless signal? This is exactly what the Breakthrough Lesson Project did. But until now, Oumuamua has remained completely calm. Now can we send a spacecraft to Oumuamua? And finding a final answer to this question? Yes, we already have the technology, But it will be a long and expensive journey, And we will have to get away from the sun a lot So the final approach path will be very difficult. So I think maybe Oumuamua has a lot to teach us, Indeed, he may have more surprises in store While scientists like me continue to work with the data. Most importantly, I think this is a visitor from afar It really came to us with an indication that our solar system is not isolated. We are part of a much larger environment, In fact, we may be surrounded by stellar visitors We don't even know that. This is an unexpected gift It may raise more questions than provide answers. But we were the first to welcome a visitor from another solar system.

thank you. (clap) Jadida Eisler: Karen, thank you. I definitely enjoyed this conversation, thank you. As far as I can remember, we found that he was too late in his journey towards us. Can future technology like the Large Global Observing Telescope help us? To discover these things sooner? Karen Mitch: Yeah, hopefully we'll start seeing a lot of these things. Ideally, we would like to find one as it approaches the sun. Because we want to save time to do all the science. Or even more perfect, We'll have a spacecraft ready to go, Stable somewhere on points (Lagrange) 4 and 5 Somewhere near the ground, So that when something happens, we can chase after it. Karen: Great, thank you very much. Let's thank Karen again. (clap).

You May Also Like