Past Forecasts
The Hydra Cluster of Galaxies
Within our own Milky Way galaxy, two bright, spiky stars stand like sentinels in the foreground of this cosmic snapshot. Far beyond them are the galaxies of the Hydra Cluster. In fact, while the spiky foreground stars are hundreds of light-years distant, the Hydra Cluster galaxies are well over 100 million light-years away. Three large galaxies near the cluster center, two yellow ellipticals (NGC 3311, NGC 3309) and one prominent blue spiral (NGC 3312), are the dominant galaxies, each about 150,000 light-years in diameter. An intriguing overlapping galaxy pair cataloged as NGC 3314 lies above and left of NGC 3312. Also known as Abell 1060, the Hydra galaxy cluster is one of three large galaxy clusters within 200 million light-years of the Milky Way. In the nearby universe, galaxies are gravitationally bound into clusters which themselves are loosely bound into superclusters. Superclusters in turn are seen to align over even larger scales.
Credit & Copyright: Rafael Sampaio
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.
- Kp 5 G1 minor
- Kp 6 G2 moderate
- Kp 7 G3 strong
- Kp 8 G4 severe
- Kp 9 G5 extreme
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