OUR SPACE: Parker touches the sun

Published 8:00 am Tuesday, December 31, 2024

With so many great accomplishments this year it seems we’ve seen everything in space exploration … and then the Parker Solar Probe manages to top it all — and on Christmas Eve, no less!

Loyal Our Space readers are familiar with the intrepid spacecraft who has been looping around the sun since 2018. Our local star is of course way too hot to land on, and its atmosphere equivalent, the corona, is many times hotter than its surface, so a quick flyby is the best anyone can hope for. Parker has been doing just that, and it’s been breaking record after record in the process.

Using Venus as a slingshot device, Parker has been getting closer and closer to the sun with each loop. The closer it gets, the faster it goes: orbital mechanics work very much in its favor there, as the incredible amount of heat would doom anyone who dares to linger.

No human-made object has ever been closer to the sun than the Parker Solar Probe was at 6:53am on Christmas Eve, a mere 3.8 million miles. That may seem like a lot, but we’re talking about a giant ball of glowing gas here, with a surface temperature of roughly 7,400F and a corona of around two million degrees! The temperature in the flyby zone was an estimated 1,800F, so you can imagine that going any closer is pretty much impossible.

During the actual flyby there was no contact with the spacecraft — all nonessential systems were in hunker-down mode while the science instruments gathered data, which were spooled back to Earth a few days later. And that’s when the scientists and engineers knew that the spacecraft survived its trip through hell.

Mind you, nobody was really worried about it. The entire point of Parker was to get this close to the sun, so it was built with those insane temperatures in mind. A hardcore heat shield was always pointed in the direction of the sun with the science cargo safely huddled behind it. Even its solar panels were folded back and tucked in for safety. Thankfully, due to its proximity to the sun, Parker has tiny solar panels. When you’re that close you get all the power you need with little effort!

The sun’s corona is still quite a mystery. Scientists are eager to find out why the corona is so much hotter than the surface of the sun itself, while the inner layers of the sun follow the logic of “the deeper you go the hotter it gets”. The sun’s enormously strong magnetic field and the solar wind are the prime suspects here but the mechanics of how this all happens are not known. Hopefully Parker will help us unpack this cosmic riddle.

During the point of its closest approach the spacecraft was going around 430,000 miles per hour. That’s a really tough number to imagine. How does “300 times faster than a fighter jet” sound? Yeah, still hard to grasp. Let’s just say that nothing that human beings have ever made has gone faster than that.

Parker has two more loops around the sun left before the end of its primary mission — one in March and one in June, and both times it will get close to this month’s record but not quite get there. After over 20 loops we’ll have to see what the future plans are for this daring explorer. Eventually it will run out of fuel and be unable to control its orientation, and if subsequent orbits bring it too close to the sun … well, that would be it.

The Parker Solar Probe was launched Aug. 12, 2018 from Cape Canaveral. It’s not easy to get a spacecraft to the sun, because you have to go fast enough to escape Earth’s gravity for a good bit, and then you have to hit the brakes somehow to fight the gravitational pull of the sun so you don’t simply plunge towards it and burn up. Looping around Venus was one of the ways Parker could productively alter its trajectory so it would only zip around the sun rather than going straight towards it. You can read a lot more about the spacecraft and its mission at https://parkersolarprobe.jhuapl.edu/ .

The mission is named for the late Dr. Eugene N. Parker, who pioneered our modern understanding of the sun. In the mid-1950s, Parker developed a mathematical theory that predicted the solar wind, the constant outflow of material from the sun. Dr. Parker passed away in 2022, but he was the first person to witness the launch of a spacecraft bearing their name.

And thus ends another spectacular year in space exploration, where it’s always “onwards and upwards.” Wishing you all a good start to 2025, and while so many things are uncertain, Our Space will continue to bring you the background stories of everything space-related in the new year!

—Beate Czogalla is the professor of Theater Design in the Department of Theatre and Dance at Georgia College & State University. She has had a lifelong interest in space exploration and has been a Solar System Ambassador for the Jet Propulsion Laboratory/ NASA for many years. She can be reached at our_space2@yahoo.com .