When NASA announced its probe to contemplate the Sun from criminal record close distances one of its stated destination was tosample the solar corona , evocatively referred to as “ equal the Sun ” . There would , however , be a break between achieving this goal and knowing that it befall . Now the distance way has confirmed the Parker Solar Probe figure the Saint Elmo’s light in April , collecting datum that will be study for many class , eventually perhaps settling the longstanding question of why the corona ishotter than the Sun ’s surface .
declare inPhysical Review Letters , the passage through the St. Elmo’s fire is a first for a human - made musical instrument , adding to Parker Solar Probe ’s alreadyrecord - give mission .
Not being solid , the Sun lacks an univocal edge as to where it stop and space begin . The Saint Elmo’s fire is advert to as the Sun ’s atmosphere and represents the neighborhood in which solar material is constrained by gravity and magnetic fields . Beyond it , thesolar windtakes over , sending textile for good outwards from the Sun , rather than cycling towards and off as hap within the corona .
While uranologist were positive a dividing production line exists between the corona and the solar wind , known as the Alfvén critical surface , they were unsure of its location , with estimates drift from 6.9 - 13.8 million kilometers ( 4.3 to 8.6 million miles ) from the surface of the Sun . Moreover , they do recognize the correct figure would only be an average , with the corona expanding and contracting like an unpredictably played concertina . Whether a peculiar orbit pass through it could depend on the timing of its escape .
On April 28 , Parker was 13 million kilometers ( 8.1 million miles ) , or 18.8 solar radii , from the Sun ’s surface and encountered speck and magnetised conditions expect to be find within the corona . The case was not denote immediately because it took a while to work the data , and NASA scientists then need to exhaustively check their findings rather than make a premature announcement .
" Parker Solar Probe “ refer the Sun ” is a monumental moment for solar science and a truly remarkable feat , " said NASA ’s Dr Thomas Zurbuchen in astatement . " Not only does this milestone provide us with deeper insight into our Sun ’s organic evolution and its impacts on our solar organization , but everything we learn about our own lead also learn us more about asterisk in the sleep of the cosmos . ”
Parker ’s exploration of the corona start well before it reached it . Magnetic structures , do it as switchbacks , zig zag through the solar lead . In 2019 Parker reveal these are much more common than previously recognise . Since then Parker has got near enough to reveal at least some switchbacks protrude at the solar control surface and are unco productive in helium .
The probe even legislate through a “ pseudostreamer ” an immense structure radiate from the Sun ’s Earth’s surface see during total eclipses . Inside the pseudostreamer Parker find the tumultuous conditions of the corona quietened down , with slower move particles and few switchbacks . The Parker team impute this to magnetised fields strong enough to dominate atom movement .
Even on the original strait , Parker went in and out of the corona several time , reflecting the crinkly nature of the Alfvén decisive Earth’s surface , and the shallowness of the pas .
However , last month Parker passedconsiderably closerto the surface of the Sun . It ’s probable that this pass involved a much long passage through the corona , with accompanying more elaborate data . put up it can resist the searing heat , future passes will take Parker nearer still , reaching almost half the April passing ’s distance . Combined with an overall trend for the corona to expand as activeness movement towards thenext solar maximum , we can expect much more in - astuteness explorations .
Icarus , your dream is fulfilled .
