Parker Solar Probe is 1st spacecraft that touches the sun
The announcement was made by scientists at the American Geophysical Union meeting, New Orleans, on December 14, 2021. The Parker Solar Probe, a probe that flies through the sun’s upper atmosphere (its wispy corona), on April 28, 2021, they said. Parker Solar Probe has been collecting magnetic fields and particles from the corona. It has made discoveries that far-flung spacecraft cannot make. The solar wind, which is a stream of charged particles that are released from the corona of the sun, is an example. Parker Solar Probe discovered zigzag structures within the solar wind, which scientists call switchbacks. Cool!
The results of Parker Solar Probe’s first expedition into the upper atmosphere of the sun were published by the peer-reviewed Physical Review Letters on the same day. The results were also published by the Astrophysical Journal.
The Alfven critical surface must be reached
NASA launched Parker towards the sun 2018, 2018. The Alfven crucial surface marks the beginning and end of the solar wind. Although the sun does not have a solid surface it does have an edge. The boundary is where solar material is no longer bound to the sun through gravity and magnetic forces.
The solar wind is made of solar material that is sufficiently energetic to cross the Alfven critical face. It carries magnetic field lines along with it. The wind stops moving fast enough to travel back to the sun once it crosses the boundary.
Scientists have estimated that the Alfven critical area was between 10 and 20 solar radiations from the sun’s surface. This would be equivalent to between 4.3 and 8.6 million miles (7 or 13.8 million km), from the sun. Parker was 18.8 solar radiations (about 8 million miles, or 13 million kilometers) above the solar surface when it finally came close enough to the sun. Parker entered the solar atmosphere for the first time on April 28, 2021.
The unique features of the sun’s borders
Parker Solar Probe found that the boundary, also known as the Alfven critical area, isn’t flat and round. The edge is wrinkled. As it dived in and out of this boundary, the spacecraft went through valleys and spikes. Parker was just 15 solar radii away from the sun’s surface, which is approximately 7 million miles (11 million km). It passed through a pseudostreamer in this area, which is a feature of the corona. The pseudostreamers are tall structures that rise high above the sun’s surface and can be seen during solar eclipses.
It was like being in the eye of a hurricane while you were inside the pseudostreamer. The spacecraft was less bombarded by particles because the conditions were more calm and slow. The magnetic field was the dominant force in this area, proving that Parker was within the Alfven critical surface.
Solar maximum and switchbacks
During periods of high solar activity, the sun’s corona grows in size. The sun is currently in solar cycles 25 and should peak at its maximum activity (solar maximum), around 2025. Parker will be able to spend more time in the corona as a result of this expansion.
Parker is currently investigating a strange behavior in the sun’s magnetic fields. These switchbacks were first noticed by scientists in the mid-1990s. They were thought to be limited to the sun’s polar regions. Parker discovered that the zigzags of the solar wind are not uncommon and common in 2019. Parker now has twice the distance to the sun than it did in 2019. This means that it can see the source of these strange structures: the solar surface. The photosphere or visible surface of the sun is where the switchbacks are located.
Parker found that switchbacks are distributed in patches and contain a greater percentage of helium than other elements. This is a sign that they originated from the photosphere. Parker found that patches of switchbacks were aligned with magnetic funnels, which emerge from the photosphere within convection cell structures called supragranular.
Parker Solar Probe: More mysteries
Astronomers hope to uncover a long-standing mystery: Why is the corona hotter than the surface?
Scientists are eager to find out more about the superheated corona, and what drives the solar wind at supersonic speeds. They will be able to forecast and predict space weather events that can impact Earth’s environment, and sometimes even human technology.
Bottom line: Parker Solar Probe was the first spacecraft ever to touch the sun. It reached the sun’s corona in April 2021 and sampled its atmosphere.