We know about deep time in the Driftless Region. Because the landscape was never smoothed by glaciers or filled with drift, the older rock layers are there for us to read and explore. Along with the ancient landscape, we enjoy the darkest skies in southern Wisconsin. It’s a perfect place for time travel.
Orion is a good guide. Look for him in the west in the evenings this month. The shiniest stars in and around Orion form an asterism called the Winter Hexagon. They will be the first stars to appear after sunset. These six stars are roughly 25 degrees apart. That’s the distance between your pinkie and thumb when your fingers are fully extended and your hand is held out before you.
You can use these six stars to travel back in time. The light from Sirius (the brightest) left in the fall of 2006. Above Sirius and going clockwise is Procyon whose light left in the fall of 2003. Photons from Pollux have been traveling since 1981. The light from Capella goes back to 1973, and the light from Aldebaran goes back to 1950. It’s fun to consider what we (or our ancestors) might have been doing in each of those years. The light from Rigel is far older and is from the vintage year of 1155.
Or you can imagine our music traveling out in an ever-widening sphere at the speed of light. We are broadcasting photons in the form of radio waves. Sirius is just now hearing Justin Timberlake’s “SexyBack”; Procyon is giving a listen to Beyonce’s “Baby Boy”; Kim Carnes’ “Betty Davis Eyes” has reached Pollux; Capella is enjoying Gladys Knight and the Pips’ “Midnight Train to Georgia”; Nat King Cole’s “Mona Lisa” has made it all the way to Aldebaran; and Rigel is missing out on some really great troubadour music.
While you are looking to the west and reminiscing about fine songs from the past, be sure to catch some other great sights. Venus will be just to the left of the Pleiades (“the seven sisters”) on April 10-12. The waxing crescent moon forms a nice cluster with the Hyades, the Pleiades and Venus on April 20. The moon is alongside Venus on April 21 and passes through the Winter Hexagon on April 22 and 23. If you are an early riser, watch for a total lunar eclipse in the west on Saturday, April 4. The moon starts entering Earth’s shadow at 5:15 and will continue to darken until it sets at 6:45 just as our sun is rising in the east.
Enjoy the old light from the old rocks of our Driftless Region.
John Heasley is an astronomy educator and stargazer who enjoys connecting people with the cosmos. He volunteers with NASA/JPL as a Solar System Ambassador. For more information about stargazing in southwest WI, see Driftless Stargazing LLC , Kickapoo Valley Reserve, Iowa County Astronomers, and Starsplitters of Wyalusing.
“Driftless Dark Skies” appears monthly in the Voice of the River Valley