UNITED STATES (VOP TODAY NEWS) — On April 28, 2021 at 9:33 UTC, NASA’s Parker solar probe reached the vast envelope of the solar atmosphere known as the corona and spent five hours within it. The spacecraft for the first time entered the boundaries of the outer layer of the atmosphere of our star.
“This marked the achievement of the main goal of the Parker mission, as well as the beginning of a new era in understanding the physics of the solar corona,” said Justin C. Kasper, lead author of the study and professor at the University of Michigan, USA.
The outer boundary of the Sun begins at the Alfven critical surface – the point below which the Sun and its gravitational and magnetic forces directly control the solar wind. Many scientists believe that unexpected reversals of magnetic field lines, called switchbacks, are born in this region of our star’s atmosphere.
Then, in April, the probe spent five hours below the Alfven critical surface in direct contact with the solar plasma. Below this surface, the pressure and energy of the magnetic field of our star exceeded the pressure and energy of the particles.
To their surprise, the researchers found that there were folds on the Alfven critical surface. The data shows that the largest and most distant fold on this surface was formed by a “pseudo-streamer” – a large magnetic structure over 40 degrees in size that was found deepest on the visible surface of the Sun. At present, it is not exactly clear why the pseudo streamer led to the “squeezing out” of the Alfven critical surface and its distance from the Sun.
The researchers noticed much fewer magnetic field “reversals” below the Alfven critical surface than above it. This could mean that reversals are not forming in the crown. An alternative version is that low rates of magnetic reconnection on the solar surface could cause less intense mass transfer into the observed solar wind flux, which caused a decrease in the number of “turns”.
The probe also recorded signs indicating a possible increase in the power of the radiation flux directly inside the corona, which may indicate previously unknown physical processes that affect the heating and dissipation of energy.
The work was published in the journal Physical Review Letters.
This article is written and prepared by our foreign editors writing for VOP from different countries around the world – edited and published by VOP staff in our newsroom.
Contact us: [email protected]
VOP Today News — Breaking news source, real-time coverage of the world’s events, science, technologies, life, politics, business, finance, economy, markets, war and conflict zones.
We are the Voice of People — the only funding and support we get from people – we are categorically not funded by any political party, any government somewhere or from any grouping that supports certain interests – the only support that makes VOP possible came from you.