Parker Solar Probe: Sun-skimming mission starts calling home
By Jonathan Amos
BBC Science Correspondent
12 December 2018
Just weeks after making the closest-ever flyby of the Sun, Nasa's Parker Solar Probe is sending back its data.
Included in the observations is this remarkable image of the energetic gas, or plasma, flowing out from the star.
The bright dot is actually far-distant Jupiter. The black dots are repeats that occur simply because of the way the picture is constructed.
Parker's WISPR instrument acquired the vista just 27.2 million km from the surface of the Sun on 8 November.
The imager was looking out sideways from behind the probe's thick heat shield.
The Nasa mission was launched back in August to study the mysteries of the Sun's outer atmosphere or corona.
This region is strangely hotter than the star's "surface", or photosphere. While this can be 6,000 degrees, the outer atmosphere may reach temperatures of a few million degrees.
The mechanisms that produce this super-heating are not fully understood.
Parker aims to solve the puzzle by passing through the outer atmosphere and directly sampling its particle, magnetic and electric fields.
"We need to go into this region to be able to sample the new plasma, the newly formed material, to be able to see what processes, what physics, is taking place in there," explained Nicola Fox, director of the Heliophysics Division at Nasa HQ in Washington DC.
"We want to understand why there is this temperature inversion, as in - you walk away from a hot star and the atmosphere gets hotter, not colder as you would expect."
Not only is Parker breaking records for proximity to the Sun, but it is also setting new speed records for a spacecraft. On the recent flyby, it achieved 375,000km/h. The fastest any previous probe managed was about 250,000km/h.
Parker will go quicker still on future close passes of the Sun.
The latest science from the mission is being featured here at the American Geophysical Union Fall Meeting - the largest annual gathering of Earth and space scientists.
https://www.bbc.co.uk/news/science-environment-46547588