What NASA’s historic solar mission has to do with the 2024 northern lights and eclipse today

Today, humanity reached a historic milestone as NASA’s Parker Solar Probe came closer to the sun than any spacecraft in history. At just 3.86 million miles (6.1 million kilometers) from the sun’s surface, the probe broke records for speed as well as proximity, traveling at a staggering 430,000 mph.

Parker reached its landmark at 11:53 UTC (6:53 a.m. EST) on December 24, bringing it within 4% of the Earth-Sun distance, well within Mercury’s orbit.

It was humanity’s closest encounter with a star, a feat inextricably linked to two spectacular things happening in 2024 – the North American total solar eclipse on April 8 and the global aurora displays on May 10 and October 10.

Here’s everything you need to know about the science behind NASA’s Parker Solar Probe and its remarkable achievement.

Parker Solar Probe: Mission Explained

The imminent Dec. 24 flyby was the ultimate goal of the historic mission conceived more than 65 years ago. Its mission is to help solar scientists better understand the sun, whose magnetized material creates the solar wind in the solar system.

This so-called space weather eventually interacts with Earth’s atmosphere to cause the Northern Lights, but stronger geomagnetic storms can also threaten GPS satellites, wreaking havoc on Earth, as well as posing a risk to power grids.

Parker Solar Probe: Space Weather

The key to understanding the origins of space weather lies in understanding the sun itself, which is why NASA and the Johns Hopkins Applied Physics Laboratory have asked Parker to make direct measurements of the sun’s corona. This outer, hotter atmosphere of the sun — visible from Earth only during a few minutes of totality during a total solar eclipse, as occurred on April 8, 2024 across North America — can reach several million degrees Fahrenheit, where the the solar wind originates. Parker became the first spacecraft to fly through the corona in 2021.

“We are learning new science about the corona and the solar wind,” said Dr. Nour Raouafi, project scientist at the Johns Hopkins Applied Physics Laboratory, during a media roundtable at the American Geophysical Union’s annual meeting on Dec. 10, 2024.

Parker Solar Probe: Solar Corona

Solar scientists are especially trying to understand where the solar wind accelerates to supersonic speeds. They think the secret may be understanding why the corona is an order of magnitude hotter than the sun’s surface.

Parker’s data are also helping solar scientists understand how coronal mass ejections – clouds of charged particles ejected from the sun – are born and structured. “CMEs wipe out everything in front of them, leaving a near-perfect vacuum behind them,” Rawafi said. “It’s no wonder that when one of them hits our magnetosphere, it wreaks havoc, like the superstorms in May and October.”

It refers to two powerful geomagnetic storms that resulted in intense global displays of the aurora borealis, which, in the US, were seen as far south as Arizona and Florida.

Parker Solar Probe: The Journey and What’s Next

Parker has been preparing for its closest flyby of the sun since it launched on August 12, 2018. On June 30, Parker completed its 20th close approach to the sun, achieving its distance record of approximately 4.51 million miles (7.26 million kilometers). ) from the solar surface. It then made its 21st close approach to the sun on September 30, reaching an identical distance from the sun.

In recent months, it has been in position for today’s record-breaking approach, completing its last Venus gravity assist maneuver on Nov. 6, when it passed within 233 miles (376 kilometers) of the planet’s surface. The flyby adjusted Parker’s trajectory to its highly elliptical final path around the sun, where it will stay for the rest of its mission.

After its close flyby today, Parker will complete two more hyper-close passes at the same distance on March 22 and June 19, 2025.

I wish you clear skies and open eyes.