After its launch a year ago, NASA’s Parker Solar Probe mission begins sending the first data after flying closer to the Sun than any other mission in history. The Parker probe is gradually helping us to unravel the mysteries that surround our star and we have the first discoveries.
The first data sent by Parker are related to the mysterious temperature of the Sun’s atmosphere, known as “crown”, which is hundreds of times hotter than its surface, as well as the precise origins of the solar wind, which is the stream of particles that are expelled throughout the Solar System and beyond.
Parker is on a mission of almost seven years that will repeatedly spend it near the Sun to gather information about the mysteries it hides and of which today we have no answers. Parker is currently in an elliptical orbit that brings it closer to the Sun approximately every five months.
With its last close encounter on September 1, the probe has completed three of those journeys. So far, Parker has flown less than 24 million kilometers from the Sun’s surface, almost twice as close as Mercury.
Previously, scientists had discovered that the solar wind appears to have two main components: a “fast” one that travels about 700 km per second, and comes from giant coronal holes in the polar region of the sun, and a “slow” wind, which travels below 500 km per second, whose origin is unknown.
The Parker solar probe observed disturbances in the movement of the solar wind that cause the magnetic field to bend on itself, a still unexplained phenomenon that could help scientists discover more information about how the solar wind moves from the Sun.
The Parker probe detected that this “slow” wind emanates from small coronal holes around the Sun’s equator, which are solar structures not previously observed. Early data show that these coronal holes are cooler, less dense regions through which magnetic fields flow into space, acting as channels for charged particles to move all the way through.
These strange changes, called “setbacks,” appear to be a very common phenomenon in the flow of the solar wind within Mercury’s orbit, and last from a few seconds to several minutes as they flow over the Parker probe. However, they do not appear to be present beyond the Sun, and so far we have had no way of seeing them without flying directly through that solar wind as Parker has done.
One of the problems of being so close to the Sun is that Parker will not be able to send direct photos, as if he turned towards the sun his camera would melt. For this reason, both the camera and the ship’s instruments point sideways, allowing the flow of particles that make up the solar wind to be measured.
Another discovery revealed that the particles in the solar wind seemed to be released in explosive flames, instead of being irradiated as if it were a constant current. This could explain why the atmosphere is extremely hot, with temperatures exceeding one million degrees, compared to the solar surface, where there are only about 5,000 degrees.
In yet another discovery, a strong presence of dust could be observed in the area near the Sun. During the closest approach to its orbit, Parker was struck with fine dust, scratching small regions of its thermal shield that appeared as white stripes in the images captured by the high-resolution camera. The researchers believe that they are the remains of asteroids and comets that approached the Sun, which ended up evaporating and leaving behind traces of dust.