To top it all off, a dangerous NASA mission is about to send a spacecraft practically spitting distance from the Sun.
The Parker Solar Probe, launched in 2018, is designed to “touch the Sun,” as NASA puts it. Hearing on Dec. 24 Accelerated by gravity to more than 430,000 miles per hour, it will come within 3.8 million miles of the surface, making its closest approach.
No spacecraft has ever gone so fast or so close to the Sun.
NASA's top science administrator, Nicola “Nicky” Fox, said, “It's a journey into the unknown,” telling everyone, “It's the coolest, hottest mission under the sun.”
At a cost of $1.4 billion, the mission isn't cheap. That NASA would invest so much money and effort is a reminder that we do not fully understand the Sun, the basis for our survival.
“We live in the Sun's atmosphere. “Anything that happens on the Sun, we feel the effect on Earth,” Fox said. “When the sun sneezes, the earth catches a cold.”
The mission also has a more subtle agenda: advancing American space prowess. At a time when many countries are sending probes to the Moon, Mars and other places in the solar system, the technological innovations could be used for future space ventures.
“It's whether we're going to be on top of the world, or someone else is going to step in,” said Noor Rouwafi, an astrophysicist at the Johns Hopkins University Applied Physics Laboratory in Maryland and project scientist for the mission.
His eyes light up as he describes the spacecraft's amazing feat: “We almost landed on the star.”
How to see the sun
Fun fact: You can't land on the sun. There is not really a discrete surface. When scientists talk about the sun At the surface, they refer to the “photosphere,” the lowest visible layer of the atmosphere.
At its closest approach on Christmas Eve, the Parker probe will be seven times closer to the Sun than any other spacecraft. NASA engineers hope the public will understand that getting closer to the Sun is not a day at the beach.
“It is a high-risk mission. “When you get into the atmosphere of a star, it's very harsh,” Raoubi said.
The probe is equipped with instruments that take measurements of the solar wind, including temperature, density and speed. The solar wind reaches the outer edge of the solar system. Earth is completely submerged in it, but thanks to our planet's magnetic field, we are generally shielded from the most harmful solar radiation.
“We, we live in that environment. But we don't realize it because we have a geomagnetic field that protects us from these dangerous energetic particles and these blasts from the sun,” Rauvabi said. “That's why we have life on Earth.”
The solar wind is also safe because it limits the impact of cosmic rays—particles that move at tremendous speeds and come at us from all directions in our galaxy.
All these show that there is weather in space. A high-tech civilization should focus on space weather, because the solar material is an explosion A coronal mass ejection aimed directly at Earth can create a debilitating geomagnetic storm.
NASA and other government Agencies are particularly concerned about a repeat of the so-called Carrington phenomenon. In 1859, a coronal mass ejection hit Earth and caused telegraph lines to sing. A similar storm today could cause radio blackouts, knock out satellites or, in worst-case scenarios, shut down the power grid.
That's why engineers at Hopkins and NASA want to get comfortable looking at the Sun and understand its turbulent environment. But first, they had to figure out how to keep the Parker probe from being shot, fried, burned up, or destroyed in some other fashion by coronal mass ejections and the solar wind.
Two pieces of technology were critical to mission success. The most obvious is the heat shield. You can't fly near the sun without a good heat shield.
The shield is coated with an ultra-white plasma spray to reflect as much solar radiation as possible. The surface is perfectly smooth to prevent hot spots and cold spots. The shield has a carbon foam interior, sandwiched between layers of carbon composite similar to what you'd find in a golf club or tennis racket.
This 4.5 inch thick heat shield allows the side facing the sun According to NASA, the spacecraft's body is 89 degrees but will reach 2,500 degrees.
There's another reason why spaceships don't turn into molten goo: Although the temperature of the Sun's atmosphere can reach millions of degrees, the density is low, so an object flying through that region of space doesn't heat up easily.
This shield only works if it's always facing the sun directly, and the vulnerable hardware behind it is completely shaded. It requires precise navigation with multiple cameras using “fixed” stars as guides.
Solar panels are nifty. Flying closer to the sun and then farther away is a recipe for increased power. So can the panels Folded like bird wings and Push themselves away.
Mission scientists also had to overcome a major hurdle: unbending the laws of gravity.
“Believe it or not, it's very difficult to get anything close to the Sun,” Raoufy said.
This is because a spacecraft launched from Earth carries with it the angular momentum of our home planet as it orbits the Sun. Launching a spacecraft directly toward the Sun would require an incredible amount of fuel. One possible solution would be to send the spacecraft to Jupiter and then slingshot it back to the Sun. But it will take years.
NASA eventually chose a strategy that used multiple close passes Venus bleeds off some of the spacecraft's orbital momentum each time, allowing it to get closer to the Sun on each orbit.
A tense moment at work
The Parker spacecraft has made 18 trips around the Sun, and in late December it passed just 4.51 million miles from the surface, emerging from that scorching trip in tiptop shape.
The study has already collected a wealth of information about the Sun's corona, the outer layer of the Sun that is normally invisible to the human eye. A total eclipse on April 8 will give people on Earth a rare chance to see the corona when the Moon completely blocks the main disk of our burning star.
NASA can accurately map the path of the moon's shadow and the time of totality at each location on April 8. To a heliophysicist, a large star in the sky is not as predictable as it appears. One of the things scientists don't fully understand about the Sun is what they call the “coronal heating problem.”
Corona about 300 times Hotter than the surface of the Sun. It is contrary to common sense. On a cold night the air doesn't warm as you move away from the fire, but it does near the sun.
Scientists have been trying to solve the coronal heating problem for decades. Data from Parker's study, combined with observations during eclipses by solar physicists on Earth, may put to rest this one mystery of sunlight.
The tensest moments of the mission were when the spacecraft was swinging around the Sun and could not receive commands temporarily. That would happen the following December during a close encounter: for several days, the crew would not know if the spacecraft had survived.
“That spacecraft, it becomes part of your crew,” Fox said. She should know; He worked at the Applied Physics Laboratory before coming to NASA and served as the principal scientist on the Parker mission.
The study is named after pioneering astrophysicist Eugene Parker. As a young scientist at the University of Chicago, Parker proposed the existence of the solar wind in the 1950s. His idea was initially rejected and ridiculed by many scientists, but it was there Confirmed by subsequent space missions.
Parker himself participated in the 2018 publication of this study. According to NASA, he was the first to see the launch of a spacecraft bearing his name.
He died in 2022 at the age of 94.
Parker was amazed and thrilled when he first saw the spacecraft in the clean room at the Applied Physics Laboratory before launch, Fox said.
Later, as he watched the probe rocket into space to begin its historic journey, Parker became nostalgic, Fox recalled.
“It's very sad,” he told her. “It will never come back.”
