A NASA spacecraft is about to give astronomers an epic early Christmas present with the closest ever flyby of the sun on Dec. 24, but if you're wondering exactly when the ambitious solar encounter will occur, don't worry. We've got you covered.
The NASA spacecraft, called the Parker Solar Probe, is on course for what will be a record-setting close flyby of the sun on Christmas Eve, when it will fly through the star's outer atmosphere at 6:53 a.m. EST (1153 GMT) and pass within 3.8 million miles (6.1 million kilometers) of the star's surface The flyby is the final trial for the Parker Solar Probe, which has made a series of ever-closer swings by the star (and seven flybys of Venus) on its mission to understand the sun like never before.
"No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory," said Nick Pinkine, Parker Solar Probe mission operations manager at the Johns Hopkins Applied Physics Laboratory (JHUAPL) in Maryland, in a statement. "We're excited to hear back from the spacecraft when it swings back around the sun."
What time will NASA's Parker Solar Probe fly through the sun?
As mentioned above, the Parker Solar Probe's closest sun flyby will occur on Tuesday, Dec. 24, at 6:53 a.m. EST (1153 GMT). At that exact time, the spacecraft will be at its closest point it will ever be to the sun: 3.8 million miles.
The Christmas Eve flyby will mark Parker's 22nd close encounter with the sun since its launch in 2018 (the first time it "touched the sun" was in 2021). The spacecraft will be flying at about 430,000 mph (692,000 kph), a mind-blowing speed which it reached by accelerating up via gravity assists from its seven Venus flybys, most recently in November.
During the Dec. 24 sun flyby, the Parker Solar Probe will fly through the sun's corona, its super-hot outer atmosphere, to study exactly why the region is so hot and other solar phenomena. The spacecraft has already set a new record as the closest human-built object to fly so close to the sun, and is flying seven times closer to the star than any other spacecraft.
Can I watch the Parker Solar Probe sun flyby online?
No, you will not be able to watch the Parker Solar Probe's sun flyby live online.
Unlike NASA rocket launches and Mars landings, the sun flyby will not be webcast or livestreamed in real time. Instead, NASA and the Parker Solar Probe mission team are providing updates on the spacecraft's status online in several places.
You can follow NASA's Parker Solar Probe mission blog (the agency's mission website is also a good place for details) or find updates at the JHUAPL Parker Solar Probe site. You can also find updates on NASA's @NASASun X page.
While you can't watch the Parker Solar Probe's flyby live, you can track the spacecraft's progress online. NASA's Eyes On The Solar System Parker Solar Probe page allows users to follow the spacecraft and see where it is any any given time.
JHUAPL also has a great walkthrough of the Parker Solar Probe sun flyby called "A Star Explored," that serves as a great guide to the flyby and mission.
How hot will Parker Solar Probe get during its sun flyby?
Christmas Eve may be a good time to roast chestnuts on the fire (or maybe toast marshmallows), but Parker Solar Probe scientists have built their spacecraft to avoid getting burned by the sun.
During its Dec. 24 flyby, the Parker Solar Probe is expected to experience temperatures of up to 1,800 degrees Fahrenheit (980 degrees Celsius) as it swings by the sun. But the spacecraft can take the heat.
The Parker Solar Probe's spacecraft components and science instruments are protected by heat shield that is 8 feet wide (2.4 meters) and 4.5 inches (11 centimeters) thick. The shield, made of a type of carbon foam, is positioned on the sun-facing side of the spacecraft and is designed to withstand temperatures of up to 2,500 F (1,377 C).
"One yard behind that, where the body of the spacecraft resides, it is almost room temperature," JHUAPL mission officials wrote in an overview. "And all its systems will need to work perfectly for Parker to gather data from this dynamic environment near a star where no spacecraft has dared travel."
And in case you're wondering about the max temperature fo the sun, our guide on how hot is the sun is can answer those questions.
How long is Parker Solar Probe's sun flyby?
This Christmas Eve sun flyby is pretty fast. (What else would you expect from a spacecraft traveling at 430,000 mph?) But for the Parker Solar Probe mission team, the actual encounter will last over a week.
"This is one example of NASA's bold missions, doing something that no one else has ever done before to answer longstanding questions about our universe," said Arik Posner, Parker Solar Probe program scientist at NASA Headquarters in Washington, in the Dec. 20 statement. "We can't wait to receive that first status update from the spacecraft and start receiving the science data in the coming weeks."
Here's a rundown of when to expect updates from the Parker Solar Probe.
Friday, Dec. 20
For Parker's mission controllers, the encounter began in earnest on Friday, Dec. 20. That's when the Parker Solar Probe sent its final signal to Earth indicating it was beginning the flyby.
"Mission operators at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, received a beacon transmission from Parker, through NASA’s Deep Space Network complex in Canberra, Australia, at 7:20 p.m. EST today indicating all spacecraft systems were operating normally," NASA wrote in a update on Dec. 20.
That's the last NASA and JHUAPL scientists will hear from the Parker Solar Probe until after the flyby, Space.com has learned.
Tuesday, Dec. 24
This is Parker Solar Flyby day. The mission team will be out of contact with the spacecraft, but it should be executing its programmed actions to perform the flyby.
At the time of the flyby, be on the lookout for a potential video or statement release from NASA and JHUAPL mission team members to mark the event.
Friday, Dec. 27
Only on Friday, Dec. 27, do NASA and JHUAPL mission controllers expect to hear their first signal from the Parker Solar Probe after its flyby.
Don't expect much, like new photos or sun videos. This check in from the Parker Solar Probe is expected at midnight and will be a beacon only to indicate the spacecraft made it through the flyby and include some status on its "general health."
Thursday, Jan. 1, 2025
Happy New Year! To ring in 2025, the Parker Solar Probe is expected to send its first telemetry and "housekeeping" data back to its mission operations center at JHUAPL.
The timing of this tag up from Parker is fluid as it will depend on where the probe is in its path around the sun, JHUAPL officials told Space.com. However, the contact here will again be a health checkup for Parker, allowing its mission team to check the spacecraft's systems and instrument health, as well as if its data recorders are full from the flyby.
The first science data downloads from Parker (like images or other observations) are not expected until late January, according to JHUAPL.
What happens after the Parker Solar Probe's sun flyby?
The Christmas Eve solar flyby of the Parker Solar Probe may be its closest sun flyby of its mission, but it won't be the last.
In all, the $1.5 billion Parker Solar Probe mission is designed to make at least 24 close flybys of the sun. This Dec. 24 flyby is No. 22. After this encounter, the spacecraft is expected top make at least two more sun flybys before its seven-year primary mission ends in 2025.
The next sun flyby by Parker will be on March 22, 2025. The final scheduled flyby, called "Perihelion 24," will be on June 19, 2025. Both of those future flybys are expected to approach the sun from a similar distance as the Dec. 24 event.
"The spacecraft will remain in this orbit for the remainder of its primary mission, completing two more perihelia at about the same distance and speed — a record 430,000 miles (692,018 kilometers) per hour — in March and June 2025," JUAPL officials wrote in November after the final Venus flyby. "After that, the team will decide whether to keep the spacecraft in that orbit or reposition it."
Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.
