Starry starry night

Here in Tucson, the night sky is an awesome sight. Thanks to the presence of the Kitt Peak Observatory just outside town, many suburban streets do not have street lighting - which means we see a lot of stars. When I moved here a few years ago from the other side of the globe, the first thing I noticed (after the absence of the Southern Cross) was that you can always see the entire moon here, even when it's a crescent. Its full shape is always visible as a circular shadow.

I'm terrible with constellations, but Orion is hard to miss - and it's visible in both hemispheres. I've learned to pick out a few more constellations now, as well as super-bright Venus and red Mars.

Living near both an airport and an Airforce base, we do of course see a lot of UFOs at night. It's fascinating how viewing an aircraft from different angles and altitudes, under different conditions such as cloud cover and other obstacles, can have such a major impact on your perception.

Tonight while walking the dog, we saw the most amazing shooting star. A green fireball exploded across the sky, trailing flames, then turned white and continued on like a flare. It covered a much larger arc than a typical shooting star and lasted about four seconds. It lit up the neighborhood. Incredible!

Bring on the scientists: The American Meteor Society website says that a green fireball means the meteor contained nickel.