Melotte 15

Try saying that three times fast! Fortunately, the “Silver Sliver Galaxy” has a formal name that’s easier to pronounce: NGC 891. It’s about 30 million light-years away, and is thought to be very similar to what our own Milky Way galaxy would look like when viewed edge-on. Explore the wider-field image; click on it for…

AKA Abell 1656. There are tens of thousands of galaxies in this portion of the sky; almost everything in this image is an entire galaxy filled with hundreds of millions of stars. Whoah. And they’re hundreds of millions of light-years away. Click and zoom in to explore them all.

This is M17, the “Swan Nebula”. Everyone seems to see something different in it! To me the whole thing looks like a swan seen from the side, but my family sees different birds within it. It’s like seeing shapes in clouds, which makes sense, as this is just a really, really big cloud of gas…

Messier 88, within the constellation Coma Berenices, is part of the nearby Virgo cluster of galaxies. And by “nearby”, I mean 50-60 million light years away! The light we’re seeing from this galaxy originated from the time of the dinosaurs. Telescopes are really time machines. There are many other galaxies surrounding M88, both smaller and…

This is the Tulip Nebula in Cygnus, but see that shell-like structure just above it, to the right a little? That’s the bow shock wave of Cygnus X-1, a stellar-mass black hole! It’s one of the most powerful X-ray sources in the sky – but don’t worry, our atmosphere protects you from it. 20 hours…

Somehow I’ve neglected to go back to one of the showcase galaxies of the spring sky with newer equipment and software: M101, the “Pinwheel Galaxy.” Located about 21 million light-years away within Ursa Major, this relatively close galaxy shows lots of active star-forming regions revealed by red HII gas. Those red spots are nebulae in…