The Changing of the Guard
As the Earth continues on its never ending journey, orbiting around the sun year after year, our evening view into the heavens is always changing. In April the nighttime side of the Earth is turning away from the bright winter constellations and toward the lesser awesome spring star patterns. The bright winter constellations are still hanging in there in the evening western sky but not for long. Next month most of them will already be below the western horizon as evening begins and we wonít see them in the evening again until late next fall. To be truly honest with you, many amateur astronomers, including myself, agree that until the summer constellations like Cygnus and Scorpio make their appearance we are officially in the spring doldrums of stargazing.
Despite that itís still worth your time to make the stars your old friends. For one thing, itís a heck of a lot more comfortable out there and the mosquitoes havenít even begun their summer campaign.
Without a doubt, the best thing to gaze at through your telescope this month is the planet Jupiter. It's by far the brightest star-like object in the post twilight evening sky. You can't miss it in the low eastern sky. This month the Earth and Jupiter are at their minimum distance from each other in 2017. Astronomers call this opposition. This month the largest planet in our solar system is less that 415 million miles away which, believe or not, is close for the Jovian planet. Even with a smaller telescope you can see up to four of Jupiterís brighter moons depending on where they are in their individual orbits around the big guy of the solar system. You might also see a few cloud bands on Jupiter.
In the early evening this month the Big Dipper is as high in the northern sky as it can be and itís upside down. Have you heard the old lore that claims we get more rain in spring because the Big Dipper is unloading on us? Itís easy to see how that rumor got started in the days of old because, at least in the upper Midwest, we get most of our rainfall in the late spring and early summer. The Big Dipper isnít considered an actual constellation though but rather the rear end and tail of Ursa Major, the Big Bear. Using the adjacent star map see if you spot the entire beast. Itís easier than you think!
Use the ďpointer starsĒ on the pot section of the Big Dipper opposite the handle to find Polaris, the North Star. Polaris is about three fist-widths at armís length down from the pointer stars. The North Star is the star at the end of the handle of the much dimmer Little Dipper. Polaris is also a very important star in our sky because it shines directly above the Earthís North Pole, making all of the stars in our sky appear to revolve around the stationary North Star once every 24 hours as the Earth rotates on its axis.
Over in the eastern sky thereís celestial kite is sideways kite on the rise. Itís the constellation Bootes, which according to the Greeks is supposed to be a farmer hunting down the neighboring constellation Ursa Major. Seeing Bootes as a farmer takes one heck of a sense of imagination. I prefer the sideways kite. Thereís a bright orange-tinged star at the tail of the sky. That Ďs Arcturus the brightest star in that part of the sky and the second brightest night time star. A fun little trick you can use to make sure youíre seeing Arcturus is to extend the arc made by the Big Dipperís handle beyond the end of the handle and youíll run right into Arcturus. Arc to Arcturus!
Mark your calendars and make your plans for the big solar eclipse this summer of August 21st. It'll be a deep partial eclipse around here with more than 80% of the sun's disk being covered by the moon in most of the upper midwest. You need to wear specialized eclipse glasses to watch any partial eclipse. It's not safe staring at the sun without them. You could do great harm to your eyes
It will be total eclipse through in a narrow strip that crosses the contiguous 48 state from Oregon to South Carolina. I've seen a total solar eclipse back in 1979 and believe me, if you have chance to travel and see it do so! I guarantee it will be worth it!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul, and is author of the book, ďStars, a Month by Month Tour of the ConstellationsĒ published by Adventure Publications. Available at bookstores and online at www.adventurepublications.net.
If you have any astronomical questions or want me to write about something youíre seeing in the night sky drop me a line at email@example.com