Update at 3:05 p.m. ET:
NOAA's Space Weather Prediction Center now reports:
"The coronal mass ejection (CME), originally expected to arrive around 0800 UTC (3:00 a.m. EST) today, January 9, was observed at the ACE spacecraft just upstream of Earth at 1932 UTC (2:32 p.m. EST)."
The SWPC goes on to say that "the original forecast continues to be for G3 (Strong) Geomagnetic Storm activity on January 9 and 10."
"Aurora watchers may be in luck for tonight."
Also, The Associated Press reports that Orbital Sciences Corp.'s resupply mission to the International Space Station - delayed on Wednesday over concern that the CME might cause problems for the Antares rocket has successfully launched from Wallops Flight Facility in eastern Virginia.
Here's our original post:
If you're bracing for the impact of the sun's superhot plasma, you'll have to hold on a bit longer: The arrival of a coronal mass ejection from the X1.2-class solar flare that erupted earlier this week is a little behind schedule, according to NOAA's Space Weather Prediction Center.
The coronal mass ejection, or CME, has been Earth-bound since the solar flare was spotted at 1:32 p.m. ET Tuesday. It was preceded by a small M-class flare (see below).
As The Two-Way's Bill Chappell has reported, these events can kick it into high gear, reaching speeds well over 1,000 miles per second.
Even so, the Space Weather Prediction Center issued this report around 7:30 a.m. ET:
"The CME, originally expected to arrive around 0800 UTC (3:00 a.m. EST) today, January 9, is now slightly overdue."
Overdue? How long? We're not quite sure, but NOAA's forecast of the CME arriving Thursday still stands.
It's important to note, as NASA does, that "these particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground." The X-class flares are, however, nothing to be trifled with, according to SpaceWeather.com:
"Scientists classify solar flares according to their X-ray brightness in the wavelength range 1 to 8 Angstroms. There are 3 categories: X-class flares are big; they are major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. M-class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Minor radiation storms sometimes follow an M-class flare. Compared to X- and M-class events, C-class flares are small with few noticeable consequences here on Earth."
Space.com says NOAA is expecting the flare to spark geomagnetic storms in Earth's magnetic field when a wave of superhot solar plasma associated with the flare the CME reaches Earth in the next few days. It could trigger spectacular auroras as far south as Illinois and Colorado and possibly disrupt power lines and radio transmissions.
AuroraWatch UK has "urged people not to be overly confident of viewings," according to The Telegraph.
"This is the first significant flare of 2014, and follows on the heels of a midlevel flare earlier in the day," NASA spokeswoman Karen Fox of the agency's Goddard Space Flight Center in Greenbelt, Md., wrote in a statement earlier this week. "Each flare was centered over a different area of a large sunspot group currently situated at the center of the sun, about halfway through its 14-day journey across the front of the disk along with the rotation of the sun."
Despite its tardiness, the CME has already complicated things here on Earth. On Wednesday, it forced the delay of a resupply mission to the International Space Station. The launch of Orbital Sciences' unmanned Antares from Wallops Island, Va., was pushed to Thursday afternoon.