The journey to the Sun’s corona begins. It will not arrive until 2025 , but this journey towards our star aims to answer a question that has been puzzling physicists for decades: why is the sun’s atmosphere so much hotter than its surface? ? The solar atmosphere, called the corona, is a violent and chaotic region of the sun that can emit large explosions of particles and plasma, generating a “space weather” that can disrupt our communications here on Earth.
According to the American Geophysical Union , during Hurricane Irma in 2017, a solar flare made radio transmissions in the worst affected areas more difficult; that is, the solar storm made the earth storm more dangerous. And scientists fear that a large enough solar storm could destroy power grids.
The source of the mystery is the solar corona
The spacecraft that will travel much closer than any spacecraft , as it will gradually approach until it plunges into the Sun’s corona, owes its name to the scientist Eugene Parker , who theorized about the existence of the solar wind: pieces of matter so energized by the Sun that escape its gravity and spread out in all directions.
The space probe will have to complete 26 orbits around the sun over the next seven years . And, as it gets closer to the star, the probe will have to deal with thousands of degrees of heat without melting.
“The sun is a star, and it is alive every second,” says Nour Raouafi, a solar physicist at the Johns Hopkins University Applied Physics Laboratory. “And we are sending a spacecraft that will fly in this very atmosphere. It is a historic moment .”
How to get to the sun
After launching from Cape Canaveral, Florida, the probe will make its first pass in the sun in about three months. But it will actually take 7 years to reach the solar corona. During those seven years, the Parker probe will use Venus’s gravity to alter its orbit, gradually getting closer and closer to the sun.
When the spacecraft reaches its closest approach in 2025, it will travel at a maximum speed of 700,000 kilometers per hour , making it the fastest spacecraft in the history of space exploration. When it is very close to the sun, we will not be able to communicate with it. The sun itself is a great radio transmitter; any signal from the Parker probe will be lost in the noise.
Won’t the ship melt?
The probe is equipped with a telescope to take photos of the corona and with instruments to record magnetic activity and charged particles. All these instruments need to operate at around 29.5ºC, which is a challenge considering the environment in which they will be operating. The temperature of the solar corona is millions of degrees, but the Parker probe will not get that hot. For one thing, while the particles emitted by the sun are very hot, they are not tightly bound.
That said, the Parker probe will still have to deal with a heat of 1,370 ° C at its closest approach to the sun, which is almost the temperature of magma.
Surprisingly enough, Parker will be able to handle this heat. A carbon heat shield combined with a water-powered radiation system will be able to prevent the ship’s electronic components from burning out. For this to work, there is a catch: the heat shield must always point in the direction of the sun (does anyone remember the movie ‘ Sunshine ‘?). The heat shield cannot be tilted more than one degree in any direction without risking damaging the rest of the ship.
” The Parker probe will revolutionize the understanding of our closest star ,” NASA states in a mission presentation paper.
We are eager to discover how solar winds originate and what happens at such a close distance from our star.
Reference: NASA
Image credit: NASA / Johns Hopkins APL / Steve Gribben
