New Feature: Weekly Starmaps!

We’re pleased to announce this new feature: weekly star maps showing the positions of the constellations and what planets are “up”.

Each map is also tailored to a time after twilight for the evening sky: so it will be a little earlier in the winter months, and later in the summer months.

If you want to get a map for the future, we’ll have them available several months out.

There’s also a PDF version that you can print out.

The Changing of the Seasons

The night sky shifts with the seasons because Earth is continuously orbiting the Sun. As we move through our orbit, the Sun appears to drift slowly eastward against the background stars — about one degree per day — and this nudges the whole celestial sphere a little earlier each night. The effect adds up to roughly four minutes per day, or about 30 minutes per week.

In practical terms, the sky you see at 10:00 PM on August 10th looks essentially identical to the sky at 9:30 PM on August 17th, and 9:00 PM on August 24th — the same stars in the same positions, the same constellations overhead. Only the planets move noticeably against this backdrop, drifting slowly from week to week on their own schedules. That’s why the time shown on each StarMap steps back by about half an hour every week: we’re always targeting the same quality of darkness, just at the moment in the evening when the sky actually looks that way.