A project put together by NASA requires its one of its spacecraft to have an intently encounter with the Sun to resolve a laying enigma regarding the star. The NASA’s Parker Solar Probe is going to observe the Sun in its next mission, and researchers hope the probe will answer the longstanding solar enigma regarding the Sun’s outer atmosphere reaching millions of degrees hotness, but its surface is only approximately 6,000 degrees Fahrenheit (3,300 degrees Celsius).
A hypothesis states that this extreme heating comes from small magnetic waves flowing around between the Sun’s surface and the superior atmosphere. A new study based on a prior NASA expedition implies that the answer can be found in an area of the Sun known as ‘the zone of preferential heating.’
Justin Kasper is the lead author of the new study, a University of Michigan professor of climate and space sciences, and principal investigator for the Solar Wind Electrons Alphas and Protons (SWEAP) instrument on the spacecraft. He said that whatever the physics is the cause of this superheating, it’s an enigma that has been hunting the astronomy field for more than five centuries. Hopefully, the Parker Solar Probe will solve the mystery in two years.
Superheating is a peculiar process, scientists say. Some single chemical elements heat up to various temperatures, and some charged particles or heavy ions get hotter than the Sun’s innermost. This warm-up makes the solar atmosphere, also called ‘corona,’ to inflate above the star’s surface. That atmosphere can be seen during solar eclipses when the Moon goes by in front of the Sun, and as this happens, the corona shimmers brightly in the sky.
NASA’s Parker Solar Probe To Solve Another Puzzling Enigma Of The Sun
What scientists what to find out is how far above the Sun’s surface this heating expands. Even though Parker probe is not sufficiently close to the star to have hit that point yet, the scientists searched for it utilizing decades of solar wind studies from NASA’s Wind spacecraft, which was sent off in 1994 and is still functioning. More precisely, the researchers concentrated on observations of helium, a widely spread element in the Sun.
The researchers tracked the temperature of helium at various distances above the Sun, and the ratio of heat grow in that element decreases as ions in the solar wind crush with each other. Researchers discovered that the superheating area ends somewhere between 10 and 50 solar radii over the surface of the star.
More in-depth observations, however, implied that the outside edge might be linked with the Alfvén point, – small magnetic waves in an electrically conducting liquid, such as plasma, within a magnetic field – the distance above the surface at which fragments in the solar wind desert the Sun. Earlier research has depicted that the Alfvén point can fluctuate depending on the Sun’s active periods.
The team of researchers then analyzed Wind’s data of every year, and they discovered that the outer limit for the superheating area and the Alfvén point ‘moved in lockstep in a predictable fashion, despite being completely independent calculations,’ Kasper said.
Both these limits will keep moving as the Parker probe goes closer and closer to the star, so the scientists also estimated when the spacecraft would cross by those lines. The moment when the space probe can send data from these important areas should occur in 2021, and it will give researchers a totally new understanding at the Sun. The study has been published in the Astrophysical Journal Letters.