Now that we're well into spring, you can easily see the Big Dipper at the start of the evening, suspended upside down, high above the northern horizon. It's nearly overhead.
If you're facing north it looks like the Big Dipper is dumping out on you. That and some tender loving care will keep lawns green, gardens growing, and farm fields productive, along with helping maintain weeds, dandelions, and mosquitoes. According to old-time lore, the overturned Dipper is one of the reasons we get so much rain this time of year.
The Big Dipper isn’t officially a constellation, but it makes up the rear end and the tail of the official constellation Ursa Major, otherwise known as the Big Bear. The four stars that outline the pot section of the Big Dipper also outline the bear's derriere. The three handle stars outline the bear’s stretched-out tail. How that tail got stretched out is a story for another day. The rest of the stars that make up the head and legs of the Big Bear aren't nearly as bright, but can be spotted relatively easily this time of year, even in areas of moderate light pollution.
Just as the official constellations have mythology and lore associated with them, so does the Big Dipper. In Britain, the Big Dipper is known as the Plough. In Germany, those stars were called “Charles’s Wagon”; in Ireland, “King David’s Chariot”; and in ancient Egypt, “The leg of the Bull.” Several Native American tribes pictured the bowl of the Big Dipper as a giant bear. They imagined the three handle stars as a family chasing the bear, with the father leading the charge, followed by Mom with a frying pan and one of the kids tagging along in the rear.
No one knows for sure how the Big Dipper got its name in America, but there’s reason to believe that it came from African American slaves prior to the end of the Civil War. Slaves would drink water out of large spoons made from hollowed gourds. They saw a similar shape in the bright northern stars and referred to it as “The Drinking Gourd.” It was associated with freedom because it's always in the northern sky. The slaves that managed to escape followed that drinking gourd north toward freedom. Eventually the gourd evolved to its present-day moniker, The Big Dipper.
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There’s a great natural eye test in the Big Dipper, in the form of double stars Mizar and Alcor in the middle of the handle. Mizar is a bright star, but Alcor is much dimmer. If you can see Alcor, your long-range vision is in great shape. If you can’t, maybe it’s time to visit the eye doctor and spruce up your vision.
Alcor and Mizar are sometimes called the horse and rider, with the brighter star Mizar playing the part of the horse and dimmer Alcor as the rider. Looks can be deceiving, though. These two stars are known astronomically as optical double stars; they have no physical relationship to each other. They just happen to be in the same line of sight. Mizar is 78 light-years away and Alcor is nearly 82 light-years distant.
Next week in Skywatch, I’ll have detail on the coming total lunar eclipse on Sunday night, May 15, 2022. It’s the first primetime lunar we’ve had since 2019.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul and is author of the book, “Stars, a Month by Month Tour of the Constellations” published by Adventure Publications. Send questions to mikewlynch@comcast.net .
The Rochester Astronomy Club welcomes new members and puts on public star parties. Their website is rochesterskies.org .
