If you head outside when the dawn light just begins to swell and look low in the eastern sky you’ll immediately notice a pair of bright objects. The “big” one is Venus, and sitting on top of it is the star Spica, Virgo’s brightest. They’ve been closing in on one another for days. Normally, the a planet and star approach one another, pass and separate, but not this time. Instead, we’ll see Venus and Spica stick together at least through Nov. 18.
So what’s going on? You’ll recall that Venus is fresh to the morning sky after passing between the Earth and sun on October 26. Venus is the faster planet because it orbits closer to the sun. Since it’s this side of the sun when it laps the Earth, it’s traveling fast from our perspective. We watch it speed from the evening to the morning sky and climb the eastern sky at dawn in a hurry.
Spica’s moving, too. It slowly moves up in the morning sky, gaining a little bit of altitude each morning. Its day-to-day slog to the west is caused by Earth’s motion around the sun. Earth’s speed varies little, so Spica climbs out the east at a constant rate of about 1° per day. Venus on the other hand is rapidly moving up and away from the sun (again because it’s close to the Earth right now) fast enough to keep up with Spica. As a result, they stay close together in the sky for more than a week instead of just sliding past each other.
This affords skywatchers lots of chances to see the two shiny objects close together day after day after day. The best viewing time is between an hour and a half to an hour before sunrise when they’re both visible in a semi-darkened sky. For me that’s around 5:30-6 a.m. local time. If you have 10x binoculars or a small telescope, they’ll reveal that Venus is a skinny crescent. Look low in the east and start your day with beauty.