NASA JPL pinpoints the moment the interstellar visitor passes closest to our planet.
The livestream will now begin Friday at 11 p.m. EST, Dec. 19 (0400 GMT on Dec. 20), weather permitting, after rain prevented a broadcast on Thursday night.
The interstellar comet will pass safely by Earth, giving astronomers their best chance to study it up close.
The Geminid meteor shower peaks overnight tonight. Here's when to look for the most shooting stars — and where to aim your gaze.
Auroras may be visible from Alaska to Illinois as an incoming coronal mass ejection is expected to slam into Earth.
The powerful X1.1 solar flare from sunspot region 4298 sparked strong radio blackouts on the sunlit portion of Earth at the time of eruption.
Auroras may be visible from Alaska to New York as a speedy solar wind and incoming coronal mass ejection are expected to buffet Earth's magnetic field.
A powerful X1.9 solar flare from new sunspot AR4299 triggered strong radio blackouts, as giant sunspot AR4294 rotates into view with more activity likely.
High above a storm, a mysterious red ring appeared for a split second. Here's how one photographer captured the elusive "elve."
Auroras may be visible from Alaska to New York as a speedy solar wind is set to spark geomagnetic storm conditions overnight.