If you’re out enjoying the predawn darkness Saturday, you’ll likely see a number of bright streaks peppering the sky. These are Orionid meteors, which belong to an annual shower that peaks before dawn. Observers under a dark sky could see up to 20 meteors per hour shortly before twilight begins, when the constellation Orion the Hunter climbs highest in the south. (The meteors appear to radiate from a point in northern Orion.) With the Moon absent from the morning sky, viewing conditions could hardly be better this year. The Orionids will remain visible until Oct. 26. And keep this in mind when you spot a meteor: There's a 75 percent chance it's a remnant of Halley's comet.
The Great Square of Pegasus is a large constellation that's easy to find this time of year. (Credit: © T. Credner & S. Kohle, AlltheSky.com) For the rest of the week, look high in the sky and you should see autumn’s most conspicuous star group. The Great Square of Pegasus stands out in the evening sky at this time of year, though it appears balanced on one corner and looks more diamond-shaped. These four almost equally bright stars form the body of Pegasus the Winged Horse. The fainter stars that form the rest of this constellation’s shape trail off to the square’s west. Venus appears 1.3° southwest of the 3rd-magnitude star Gamma (γ) Virginis this morning.
Read the rest of this week's observing guide from Michael Bakich on Astronomy.com.