What’s Up in the Sky – October, 2019
There Is More In the Sky Than You Think
Last month I wrote about several late summer/early autumn constellations, including Scorpius and Sagittarius in the south and Cygnus, Lyra, and Aquila overhead, whose member stars form the Summer Triangle. Although the former are no longer visible, the latter are still high overhead, so perhaps you may begin your observing by revisiting the Swan, the Lyre, and the Eagle.
The coming week is probably better for lunar observing since the Moon will be full next Sunday. The Moon is great for binoculars or a small telescope. Look along the terminator (boundary between light and dark) for craters whose basins are in the dark but central peak is still in the sunlight. Without much effort, lunar maps can be found online or in bookstores. These can be used to identify craters, mare, rilles and other features.
After the 15th, moonlight will not interfere with your attempts to observe small, faint constellations such as the three I am about to describe. Direct your attention again to the Summer Triangle by facing south and locating the bottom star, Altair, just below Deneb, overhead, and Vega, the brightest of the three, to Deneb’s right. Unless you are in a very good dark location, use binoculars to scan the area of the sky just above Altair. You should find a small grouping of four stars resembling a small arrow pointing left with two feathers at the right. This is little Sagitta, Latin for “arrow” and not to be confused with Sagittarius, the Archer. Sagitta is the third smallest constellation, but one that is easy to recognize. Now see if you can spot it with your naked eye.
Next scan left about the same distance as before and you will come to another constellation that looks like its name, Delphinus, the dolphin. Look for a diamond of four stars with two more to its right. You should see the dolphin jumping out of the waves of the Milky Way, with his tail arched behind him.
Stars and constellations are not the only items of interest up there. A number of satellites, including the International Space Station, make visible passes that can be fun to watch. Check out heavens-above.com for more information. Or, visit NASA’s web site to sign up for email alerts for visible passes of the ISS,
Finally, a spacecraft that flew under the radar, so to speak, was recently launched by the Planetary Society. It is called LightSail 2 and it is able to control its orbit solely on the power of sunlight. LightSail 2 was first proposed by Planetary Society founders, Carl Sagan, Bruce Murray, and Louis Friedman in the 1970s. Carl even appeared on the Tonight Show where he shared the concept with Johnny Carson. It never got off the drawing board.
But the Society persevered, and the concept was resurrected in 1999. A couple of failures later, the latest version is now safely in Earth orbit, controlled solely by the pressure of the sunlight.
LightSail 2 is just the latest of our many instruments that improve our understanding of what’s up in the sky.
This month in history:
Oct. 1: Yerkes Observatory dedicates 40 inch refractor – 1897
Oct. 4: Space Age begins when Sputnik 1, first artificial satellite, is launched – 1957
Oct. 9: Johannes Kepler observes supernova – 1604
Oct. 14: Chuck Yeager breaks sound barrier – 1947
Oct. 22: First record of solar eclipse – 2136 BCE
Oct. 26: First flyby of Saturn’s moon Titan by Cassini spacecraft – 2004
Oct. 30: STS-61A Challenger Space Shuttle launched – 1985
