M51: Tidal Streams and H-alpha CliffsAn intriguing pair of interacting galaxies, M51 is the 51st entry in Charles Messier’s famous catalog. Perhaps the original spiral nebula, the large galaxy with whirlpool-like spiral structure seen nearly face-on is also cataloged as NGC 5194. Its spiral arms and dust lanes sweep in front of its smaller…Read More

Phaethon’s BroodBased on its well-measured orbit, 3200 Phaethon (sounds like FAY-eh-thon) is recognized as the source of the meteoroid stream responsible for the annual Geminid meteor shower. Even though most meteor shower parents are comets, 3200 Phaethon is a known and closely tracked near-Earth asteroid with a 1.4 year orbital period. Rocky and…Read More

The Shells and Jets of Galaxy Centaurus AWhat’s the closest active galaxy to planet Earth? That would be Centaurus A, cataloged as NGC 5128, which is only 12 million light-years distant. Forged in a collision of two otherwise normal galaxies, Centaurus A shows several distinctive features including a dark dust lane across its center, outer shells…Read More

The Great Meteor Storm of 1833It was a night of 100,000 meteors. The Great Meteor Storm of 1833 was perhaps the most impressive meteor event in recent history. Best visible over eastern North America during the pre-dawn hours of November 13, many people — including a young Abraham Lincoln — were woken up to see the sky erupt in streaks and…Read More

Pleiades: The Seven Sisters Star ClusterHave you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen with the unaided eye even from the depths of a light-polluted city. With a long exposure…Read More