- The sun has a big year in 2024, starting with a total solar eclipse across the US.
- As the sun builds to maximum activity, watch out for the northern lights too.
The sun was showing off all last year, with dramatic eruptions, sunspots, giant "holes," and even a 14-earths-high tornado of plasma. But 2024 may be our star's biggest year yet.
That's what giddy NASA scientists told reporters at the fall meeting of the American Geophysical Union in San Francisco in December. In true NASA fashion, they're calling it the "heliophysics big year."
One of the main events this year will be a historically cool total solar eclipse crossing the US in April. It's estimated up to 7.4 million people will travel to the path of totality to witness the rare event.
Another exciting event involves NASA's prime solar probe, which is set to skim the sun's surface in December, flying closer than any previous spacecraft.
Meanwhile, the Northern and Southern Lights are sure to have an impressive year, as well.
Already, we've seen beautiful aurora reach as far south as Arizona within the last year. And as stormy activity on the sun, which helps spark aurora worldwide, is set to increase, we could continue to see the Northern Lights illuminate skies across the US at unusually low latitudes.
For viewers in Australia, New Zealand, and South America, the Southern Lights (aurora australis) will surely make spectacular displays too.
It will be about 11 years — a full solar cycle — before the aurora is so active again.
"The sun touches everything, and we are challenging you to experience the sun in as many ways as possible," Kelly Korreck, NASA's program manager for the upcoming eclipse, said during the AGU roundtable.
The sun's big year kicks off with a total eclipse
While the rest of us put on our eclipse glasses or look out for the pink and green ribbons of the aurora, astronomers will be busy at work. This year's solar events are a huge scientific opportunity.
For example, NASA is launching three rockets during the April total solar eclipse, loaded with instruments to study how the sudden darkness changes our upper atmosphere.
A total solar eclipse offers scientists a unique opportunity to observe the corona — the outer layer of the sun's atmosphere. The corona is over 100 times hotter than the sun's surface, but scientists can't explain why and it's one of the biggest mysteries in our solar system. Because the moon blocks the main disc of the sun during an eclipse, only the corona is visible.
NASA's Parker Solar Probe and the European Space Agency's Solar Orbiter will also be watching the eclipse from two different vantage points in space, as they orbit close to the sun. That extra data can help scientists get 3D observations of the corona, as well as validate measurements from Earth-based observatories.
That's just one fleeting moment of the sun's big year. Throughout 2024, as solar activity builds, countless observatories and physicists will be watching closely.
The sun will get more and more active
When the sun belches plasma and charged particles into space, they can speed toward Earth, travel down our planet's magnetic field lines toward the poles, and interact with molecules in our atmosphere to make the aurora. They can also bump satellites out of orbit and surge through technologies on the ground, triggering radio blackouts and meddling with GPS.
There's always a steady flow of this "solar wind," but eruptions on the sun can send a powerful flood of solar wind careening toward our planet. That's what scientists call space weather. These storms are happening more and more as the sun climbs toward peak activity.
People on Earth are safe from these blasts of solar activity, with the exception of rare cases where they might cause power or radio blackouts. But as NASA and other space agencies send humans back to the moon and on to Mars, space weather will become a safety issue for them.
Studying solar eruptions and flares can help scientists forecast space weather better in the future. That could be crucial for long-distance spaceflights.
"If we want to win the race to Mars then we have to have awareness of space weather all over the place," Nour Raouafi, a lead scientist for the Parker Solar Probe, said at the roundtable.
NASA to almost land on the sun at the end of the year
The "crown jewel" of the sun's big year comes on December 24, though, Raouafi said. That's when the Parker Solar Probe will fly closer to the sun than any spacecraft has ever gone, about 3.8 million miles from its surface.
For comparison, Earth is 93 million miles from the sun.
On this close flyby, the probe will face unfathomably extreme heat and radiation, with temperatures as high as 2,600 degrees Fahrenheit.
Collecting data so close to the source of the solar wind will help scientists understand how it forms. It will also fuel the study of the corona.
"This is a monumental achievement for all of humanity. This is equivalent to the moon landing of '69. Now we are basically almost landing on a star," Raouafi said.