NASA's Parker Solar Probe Reports Successful Closest Approach To Sun

Following its record-breaking closest approach to the Sun, NASA's Parker Solar Probe has transmitted a beacon tone back to Earth indicating it's in good health and operating normally. NASA: The mission operations team at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland received the signal just before midnight EST, on the night of Dec. 26. The team was out of contact with the spacecraft during closest approach, which occurred on Dec. 24, with Parker Solar Probe zipping just 3.8 million miles from the solar surface while moving about 430,000 miles per hour.

The spacecraft is expected to send back detailed telemetry data on its status on Jan. 1. This close-up study of the Sun allows Parker Solar Probe to take measurements that help scientists better understand how material in this region gets heated to millions of degrees, trace the origin of the solar wind (a continuous flow of material escaping the Sun), and discover how energetic particles are accelerated to near light speed. Previous close passes have helped scientists pinpoint the origins of structures in the solar wind and map the outer boundary of the Sun's atmosphere.

Question

[smooth wombat]

How do they determine the surface of the Sun? I realize it's a giant ball of gas, but every picture we see of solar prominences and so forth shows a roiling surface.

Re:

[nospam007]

"How do they determine the surface of the Sun? "

They'll land during the night to take photos. :-)

Re:

[smooth wombat]

Cool. Wasn't aware this was part of the mission.

Learn something new every day. :)

Re:

[marcle]

You're right, there is no "surface." There are only layers of hot gases, plasma, etc. The Parker Probe descended further than any previous man-made objects (the ones that returned, that is), but
it was still an orbital fly-by.

Re:Question

[necro81]

As others have noted, there isn't a surface to speak of. However, the luminous disc of the sun - the photosphere, where emitted light originates - is at a radius of ~432,000 mi [690e3 km] from the center of the sun [ref [nasa.gov]]. This is the "surface" you'd see when viewing the sun through a solar filter, the portion that gets covered during a solar eclipse. For casual discussion, this is as good a reference to use as any.

This is the feelgood Christmas drama I needed.

[joeblog]

I've been bing watching Netflix Christams romcoms with my recently widowed mom, and this is way better than any of them.