According tomedia reports, NASA has a large number of robots patrolling the solar system, perhaps the most powerful of which is the Parker Solar Probe (PSP). The ship, about the size of a small car that orbits the sun, is equipped with revolutionary technology that allows it to “touch” the sun. On Wednesday, NASA researchers released the first set of scientific data from the mission, the first from one of the solar system’s most extreme environments.
“We’ve learned a lot about our planet over the last few decades, but we really need a mission like the Parker Solar Probe mission to get into the sun’s atmosphere,” said Nour E. Raouafi, a project scientist at the Johns Hopkins Applied Physics Laboratory. What we know in these three solar orbits alone has changed many of our understandings of the sun. “
NASA is believed to have launched PSP on August 12, 2018 and successfully put the heat-resistant spacecraft into an elliptical orbit around the sun. Because of its speed in orbit, it has earned itself the title of “the fastest man-made object in history” and has used Venus as a gravitational aid, and will continue to shorten its distance from the solar system’s large heater.
The study, published Wednesday in the journal Nature, details the data obtained by the PSP on the measurement of the inner plasma halo of the sun, the corona, and the analysis of PSP’s “contact” with the sun in November 2018 and April 2019, respectively. The corona is between 2 million and 5 million degrees Fahrenheit, and astronomers are puzzled by the way it heats and the subatomic particles move.
In addition, the corona produces solar wind, a stream of energy particles that radiates into the solar system. In the past, astronomers have been able to measure these streams of particles closer to Earth, but thanks to advanced tools installed on the PSP — a wide-field imager and three separate devices that measure solar wind particles — more secrets of the sun have begun to be revealed.
The solar probe’s wide-area imager (WISPR) acts as the probe’s “eye”, allowing researchers to perform imaging of the solar wind formation structure in the corona. WISPR sent back a stunning first beam of light images in September 2018, followed by an equally stunning image from the sun’s interior in December of the same year.
Russ Howard, wISPR’s lead researcher, examined the images taken by the instrument to identify the structure in the solar wind. These images reveal new dynamics of the corona’s “flowing light”, the magnetic ring formed by bright solar radiation, and provide an opportunity to observe faint coronal rays. The team was able to observe the intensity of dust scattering light in the region around the sun, confirming observations from Earth. However, they were surprised to find an unusual distribution of intensity closer to the sun.
This change in intensity may mean a “dust-free zone” closer to the sun’s surface. But Howard and his colleagues caution that WISPR does not directly observe the hypothetical dust-free zone, and that this unusual intensity distribution may be explained. This assumption will be confirmed as PSPs continue to distance their distance from the sun over the next few years.
The solar wind is not as predicted.
Another surprise finding was made by a team led by Justin Kasper. Kasper and his colleagues used solar wind electron alpha particles and proton instruments on the PSP to gather information about the movement of electrons, hydrogen and helium ions in the solar wind. When the sun spews these particles, they eventually collide with SWEAps that record their properties — typically more than four times per second.
As large amounts of particles hit the SWEAP instrument and were supported by FIELDS instrument data on psP, Kasper and his team found that the solar wind near the sun behaved strangely because of the reversal of the magnetic field. The speed of the solar wind appears to have peaked during a reversal, and the team believes that when these flowing particles move away from the sun, they may move along the S-shaped curve.
Previously, scientists had measured that solar wind particles would pass through the Earth like bullets in a straight path from the sun. But Kasper’s team found an amazing increase in the “rotational flow” of the solar wind, which is not in line with any previous model of how the solar wind rotates. The wind is still spinning closer to the sun, and the reason behind it remains unclear.
“The huge solar wind rotation that I saw at the first encounter was a real surprise,” Kasper said at a news conference. While we hope to eventually see the rotation closer to the sun, the high-speed motion we saw for the first time was nearly 10 times larger than the standard model predicted. “
As PSPs continue to orbit the sun, researchers will be better able to observe the solar currents near the sun. The authors note that this is crucial to understanding how the sun loses angular momentum and spin as it ages.
What will be found next?
By December 26, the probe will fly venus for the second time, when it uses Venus’ gravity to further narrow its orbit to bring it closer to the sun. The flyby will also see the PSP accelerate — orbiting the sun at 109 kilometers per second — until its third Venus Day in July 2020.
The PSP’s activities will last five years, and by 2025 it will be the closest to the Sun, with a distance of less than 7 million kilometers. Over the next five years, the constant distance will be important in understanding the complexity of the corona, the surface of the corona, how the solar wind is blown into the universe, and how it affects the rest of the solar system.