It's not uncommon to see distant planets in the night sky with the naked eye, but for one month this winter a rare alignment of five planets will greet early-morning stargazers.

As Mercury transitions into the morning sky, it will be visible in a line-up that includes (from the horizon up) Venus, Saturn, Mars and Jupiter - a five-planet parade that hasn't been visible since December 2004 into January 2005, according to astronomical website EarthSky.

To see all five planets, you'll need to get up before sunrise and look out to the eastern part of the sky. There, with a telescope or naked eye, you'll be able see all five planets, starting high up with Jupiter and ending with Mercury close to the horizon.

Five planets will appear in the early morning sky starting Jan. 20 in Oregon.

You'll have your biggest window on Wednesday, Jan. 20, from 6:40 a.m. to sunrise at 7:43. The five planets will be visible every morning (weather permitting) until about Feb. 20.

Jim Todd, director of space science education at the Oregon Museum of Science and Industry, said while it's not the rarest occurrence, it's certainly a good excuse to go out and explore the cosmos.

"For astronomy this is pretty exciting," Todd said. "It gets people talking about it, it gets people to go out and look."

--Jamie Hale | jhale@oregonian.com | @HaleJamesB