In the latest issue of nature, published in the early morning of December 5, Beijing time, the hottest space probe in history, the Parker, is the absolute protagonist. A total of four academic papers come from its first batch of scientific data.
NASAs first solar probe was launched in August 2018, opening the first journey through the corona in the history of human space exploration. It was named after Eugene Parker, an American astronomer who proposed the solar wind theory.
From the inside to the outside, the solar atmosphere is composed of photosphere, chromosphere and corona. Counter intuitively, the temperature of the photosphere closest to the suns center is only a few thousand degrees Celsius, while the temperature of the corona in the outermost layer is as high as two million degrees Celsius. The primary purpose of Parkers mission is to understand the sources of energy in the corona. In addition, it also studies the solar wind, the flow of high-energy particles continuously emitted from the corona.
For this reason, it carries four sets of scientific instruments to collect data about particles, plasma, electromagnetic field, radio wave and corona structure.
Parker plans to fly past perihelion 24 times in its 6.4-year service life, and has completed three times, with an orbit height of about 24 million kilometers.
Before that, most scientists had studied the corona and solar wind on earth, separated by an entire astronomical unit, or about 150 million kilometers. The exploration data collected by Parker at close range helped to solve some mysteries.
For example, why does the solar wind accelerate away from the corona? What is the acceleration mechanism behind this? A paper published by the University of Michigan explains the magnetic field changes measured by the Parker. In addition, Parker measured the speed of the solar wind faster than any theoretical model.
A paper published by the University of California, Berkeley, focuses on slow winds with speeds below 500 kilometers per second, whose origins are just as puzzling as fast winds.. It is pointed out that the slow solar wind is emitted from some coronal holes near the solar equator. The so-called coronal hole is the irregular dark area of the corona in the X-ray or far ultraviolet photos.
Two other papers are from Princeton University and the U.S. Naval Research Laboratory. The former analyzes the high energy particle environment near the sun, while the latter observes the spectral lines of the corona, including the weakening of f-corona and the fine structure of k-corona.
Just this month, Parker plans to use the gravitational slingshot effect to throw itself further toward the sun. The orbit height of the fourth solar eclipse will be 4.5 million kilometers lower than the previous three. In the next five years, Parker will gradually adjust its orbit height and keep close to the sun.
If all goes well, the orbit height of Parkers last solar eclipse will be about 6 million kilometers.
During this period, the solar cycle of about 11 years is also in the rising period. Scientists may obtain more strong blast detection data, so as to understand the mechanism of the corona and the laws of solar activity, and improve the ability to predict space weather.
Source: Qiao JunJing, editor in charge of surging news