Tonight take a minute to check out the sky. You'll see a Blue Moon.

By now, we all know that when a calendar month contains two full moons, the second one is the Blue Moon. But Sky & Telescope magazine says that's not necessarily correct.

According to an article about the astronomical phenomenon, investigation of farmers' almanac items from 1819 to 1962 that refer to more than a dozen Blue Moons shows that not a single one was the second full moon in a month. Rather, there's a seasonal pattern. Full details can be found in What's a Blue Moon?

The recent research notwithstanding, the chart below that accompanies the S&T story shows the North American Blue Moon monthly patterns from 1998 projected through 2020.

And whatever the scientific explanation, it's still a cool event. So go out tonight and enjoy it!

Chasing the moon: If you're reading this in Europe, your Blue Moon will be at the end of June. This Web page explains all the time zone variables, as well as links to a Blue Moon Calculator to help you keep track of the Man in the Moon regardless of where in the world you live.

Here's your financial hook: Moonlighting is, of course, making extra money at another job, often at night, to supplement your full-time employment.

But just like at your main job, taxes are due on any secondary income.

If you have a moonlighting job that's paid on a contract basis, then you, the overworked individual, have to make sure you send in your income tax payments, usually via quarterly estimated tax vouchers. The next one of those is due June 15.