About twelve thousand years ago, a relatively normal star in the constellation Vela suddenly exploded, creating a strange point of light briefly visible to humans living near the beginning of recorded history. The outer layers of the star crashed into the interstellar medium, driving a shock wave that is still visible today.
Credit & Copyright: Jose Mtanous
A 0–9 score for how stirred up Earth’s magnetic field is, measured every 3 hours by magnetometers around the world. 0–2 is quiet, 3–4 is unsettled, and 5 or more is a geomagnetic storm. The higher it goes, the farther from the poles the northern lights reach. Around Kp 5, people in Washington State can sometimes see them low in the north.
A rough guide based only on the current Kp: Unlikely below 4, Possible at 4–5, Likely at 6–7, Strong at 8+. It isn’t for your exact location, so use “Your sky this week” for odds where you are. Clouds and city lights matter too.
Learn more at NOAA SWPCA stream of charged particles flowing from the Sun, measured by spacecraft about 1.5 million km (1 million miles) toward the Sun from Earth. It usually blows at 300–500 km/s. Faster than about 600 km/s often means stormier space weather, and whatever is measured now reaches Earth roughly 30–60 minutes later.
Learn more at NOAA SWPC