A small NASA probe is now exposed to harsh weather. On an unprecedented mission to get as close to the sun as possible, the Parker Solar Probe blasted off with scorching temperatures and intense sunlight as it gets closer and closer to the sun with each spin of its orbit. Parker has dressed appropriately for that trip, as it is covered with a thick shield specially made to protect scientific equipment and systems placed in it, with tubes containing flowing water to help him cool the atmosphere inside, as the temperature is only 26 degrees Celsius inside the probe, which launched its mission in the summer of 2019. The scientists have not been astonished by what he has revealed so far.

Our first scientific discoveries about the sun were the most important of all, which is that the earth is not the center of the universe as we thought in the past, but rather it revolves around the sun.

Over the centuries that have passed since Copernicus redrawn the map of the universe, scientists have slowly approached the heart of the solar system, through telescopes, then satellites and spacecraft, and they have learned a lot about nuclear fusion that feeds our star and other countless stars in various parts of the world. The universe, so that our understanding of the sun today and its precise mechanisms of action is more complex than ever before.

However, our understanding of it is still incomplete.

Parker reveals what we don't know

We humans, in our quest to find out what we don't know, seem like a curious child. Why is the corona of the Sun (its outer atmosphere) so hot? Where does the solar wind come from? Why is it thrown out of the wreath in this way? What causes solar flares, in which the sun throws more excited particles into space? These are some of the questions scientists hope Parker will answer before his mission ends in 2025.

The probe was named after "Eugene Parker", the American astrophysicist, who first described the dynamics of the solar wind in 1958. Few believed Parker's theory at the time, until NASA began sending robotic vehicles into the depths of the solar system a few years after the theory was developed, and its equipment began Feel the breeze of that wind. There is now no doubt about the theory, as for robotic vehicles, they follow the trails of the wind wherever they go, if the vehicles are able to reach it. In 2013, one of the famous “Voyager” probes, which traveled farther than any other probe did in the history of space, detected particles in the solar wind mixing with particles colder than them in interstellar space, where harsh atmospheres prevail in this cold The time is not at its hottest.

NASA revealed the first batch of Parker's discoveries in December 2019 and published them in four papers in the journal Nature. These discoveries came from measurements made on the corona, which is paradoxically hotter than the surface of the sun itself, as the corona extends for millions of kilometers from the surface towards space, and we cannot see it with our eyes from Earth except during a solar eclipse, when the moon casts its shadows on the earth, and blocks the sun’s disk from us , leaving a golden ring easily visible in the darkness of the sky at that time.

The corona releases a stream of high-energy particles known as the solar wind, which trails the length and breadth of the solar system, and even reaches beyond the asteroid "Pluto". The Parker probe has revealed that the solar wind is much more turbulent near the sun than when it reaches our neighborhood, traveling millions of kilometers. The wind drags the sun's magnetic field with it and spreads it through space, and even bends it enough so that the magnetic forces form complete rings that flip in place for a few minutes at a time, as if it were heading again towards the sun, after it first exited into space (and let's compare this complex field with the magnetic field The simple and stable Earth, and what the atmosphere near the sun might look like with those crazy reversals of gravity in its surroundings)*.Scientists did not expect the severity of such an effect, nor the frequency with which it recurs. They also found that the Sun's magnetic field accelerates particles streaming from the Sun more than any of their previous models tell us.

Looking for brakes: Venus makes the impossible possible

Astronomers have spent decades probing the depths of thousands of distant stars in the depths of the universe, some billions of light years away (a light year is the distance light travels in one year and is approximately 9.46 trillion km)*, but their closest star appears to be still locked away from them. his secrets.

Scientists have not succeeded in observing the sun closely with their equipment on Earth, not even through space missions that were previously focused on studying the sun and could not get close to it as Parker approached, and proximity is everything when it comes to studying the sun.

“Imagine that we live in the middle of a waterfall, and the water is constantly flowing alongside us as we seek to discover the source of the waterfall itself from above. Is there a snowy mountain that is melting at the top and pouring its water towards us? Is there a system that sprinkles water, for example? Or is the water coming from a lake, or Maybe it exploded from a hole in the ground? It's hard to guess by looking at where we are in the middle of the waterfall. So what Parker is doing is getting us closer to the sun than ever before to understand," describes Stuart Bell, a scientist at the University of California Berkeley, who is in charge of one of Parker's instruments dedicated to studying the solar wind by measuring magnetic fields, attempts to understand the nature of the solar wind.

With every step the Parker probe approaches the sun, it is reaping the rewards of one of the most difficult feats of robotic space exploration we've seen. This seems a paradox, but reaching the sun is much more difficult than leaving the solar system entirely, as the solar gravity pulls everything that surrounds it, from huge planets to small moons, but these bodies also revolve around the sun at tremendous speeds, which is exactly what prevents Falling towards the sun itself. “To get to Mars, all you have to do is increase your orbital velocity slightly, but to get to the sun, you have to completely slow down your momentum (which I acquired it from the earth from the beginning so that it would not hit the sun itself and melt into it)*.

No existing rocket technology has enough power to cancel the effect of Earth's motion in this way, so Parker gets the backing of the other planets. Engineers must turn Parker's rudder along with Venus seven times over the mission years so that Parker can use the gravity of Venus to restrain his speed.

And so, as Parker keeps flying toward Venus and spinning around it, each time reducing the diameter of his orbit, getting rid of the momentum the Earth gave him, and then getting closer to the center of the solar system.

Parker caressing the sun

Kelly Cork still contemplates her spacecraft's sun-drenched moments, how the probe sped through a roaring stream of ultrafast particles, only to plunge moments later into a quieter location where plasma flows like sea waves. No instrument has ever crossed this mysterious barrier, but Parker did for the first time in history and entered the sun's atmosphere. "It's a very interesting site, or let me say very scorching.. We touched the plasma and gases that are actually part of the Sun," Cork, a scientist at the Harvard-Smithsonian Center for Astrophysics, told me.

NASA's probe made a historic leap in April of last year towards the sun, but scientists waited until the end of the year to announce the news to the world after they analyzed the data and confirmed that the spacecraft had indeed crossed the first layer of the sun's corona. And soon, NASA unleashed a metaphorical statement when it said that Parker "touched" the sun, since the probe, in fact, cannot reach the photosphere, which emits sunlight, and is its actual surface. However, the photosphere itself is not a solid surface like the Earth's, so we should use a term that is not necessarily purely scientific, and say that Parker teased the sun.

When Parker blasted toward the corona last year, he discovered a region where solar material volatilizes before escaping the sun's grip and becoming solar winds that the sun blows away from it. And when that wind reaches the ground, we feel it as a steady breeze. But within the corona, Parker spotted individual currents of those winds, which are like water blasting from a balloon with holes as described to me by Stuart Bell, adding: “We are so close now that we are beginning to see distinct sources of those winds, and how they merge together as they exit from the sun".

There is no way to study the properties of the Sun, to which Parker was subjected while in its atmosphere, from our remote location. The only way was to get in and out of that world. Parker repeated his trip into the corona last November as it orbited the sun, so scientists are looking to turn to a new batch of data. As for the probe, it is on its way to caress the sun again at the end of February, and prepares its unique protective shield to protect its contents from those inflamed atmospheres, as small grains of cosmic dust have already caused wounds in some parts of the probe, and cosmic dust is debris from space between Stars drawn by the Sun or the remnants of comets evaporating after they got too close to the Sun.

"We've had two collisions of this kind that killed non-vital parts of the probe's sensors," Justin Kasper, a solar astrophysicist and a member of Parker's team told me, a worrying situation, he says, but Parker will eventually survive (calculated). minute) even as it gets closer to the sun. Parker should pass by Venus two more times in the next few years to get closer to the sun and give us a closer look at the corona, before its mission ends at the end of 2025.

NASA can decide to extend the probe's operations, but if it just shuts down Parker, the probe will not be able to keep its heat shield directed at the sun, Cork explained to me, and then the probe will melt into a piece of charred iron that will continue to orbit around the sun for millions of years without ever being They fall into the sun (or melt into it)*, as do hundreds of bodies that tirelessly orbit our star. And if a collision of cosmic debris here or there does not destroy Parker, the Sun will eventually do so after billions of years when its nuclear fuel runs out and expands and swallows the entire interior of the solar system (extending to Mars and the asteroid belt between it and Jupiter)*.

For now, Parker looks fine. He took a black-and-white recording while immersed in the corona last year that shows the dancing lines of the solar wind shimmering white in the sunlight, the distinctive shape of the Milky Way and a stream of other stars in the background.

It seems fanciful for Korek for something she touched to enter the atmosphere of the sun. She looks at the sun differently from most of us as a solar astrophysicist, and has ideas about space probes and hot plasma during sunny days on Earth, and she concluded: "I remember being on the beach looking up and thinking that Parker was there, very close to the sun, at the same moment...and here I am sitting and enjoying the sun at 147 million kilometers away."

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This article was translated from The Atlantic and does not necessarily represent the Meydan website.

Translation: Nour Khairy.