Space Station Eases Back into the Evening Sky

A firefly makes a statement during a 30-second time exposure of the International Space Station made on July 15, 2020 near Duluth, Minn. Bob King

It's a pleasure to have the International Space Station (ISS) back in the evening sky. Since it always appears in twilight, and the sun sets early in November, you never have to stay up late to catch a look. Passes start as early as 5:15 p.m. and finish up around 7 p.m. 

With the successful SpaceX launch of the Crew-1 mission on Nov. 15, the orbiting laboratory is now full up with seven souls aboard. They're all speeding across the sky at around 17,100 miles per hour (27,600 kph) at an average altitude of 250 miles (400 km).

How the heck can you eat Thanksgiving dinner under those conditions? Same as eating a meal on an airplane. Since everything around you is traveling at the same speed, each item is at rest relative to the other as long as you maintain a constant speed.

Standard space station menu. NASA

Last year's Thanksgiving meal included prepackaged turkey, green beans, mashed potatoes and gravy, cornbread and cranberry-apple dessert. Although I haven't been able to find this year's menu I suspect similar choices will be available. Either way, food must be carefully packed to avoid crumbs which could float around the space station and damage equipment. On Earth, gravity and the dog take care of that.

Seeing the ISS is easy. It first appears low in the western sky, anywhere from southwest to northwest, and travels east, the same direction as the Earth rotates. When low in the sky it looks like a bright star. But as the station climbs in altitude it can wax in brilliance and sometimes rival Venus. A full pass from west to east takes about 5-6 minutes. 

The ISS remains visible during twilight because it's really, really high up — more than 45 times the altitude of Mt. Everest — and still catches sunlight long after the sun has set for the earthbound. By nightfall however it succumbs to Earth's shadow. If you watch regularly, sooner or later you'll see it fade and disappear long before it reaches the other side of the sky. That's because it's moving into Earth's shadow. The planet's shadow eclipses the station just like the moon in a lunar eclipse.

This Heavens Above map shows the path the ISS will take across the sky tonight (Nov. 21) over the Duluth, Minn. region from 6:04 - 6:09 p.m. It first appears just below Jupiter and Saturn and disappears in Earth's shadow close to Mars. Chris Peat with additions by the author

The ISS will be making evening passes over many northern hemisphere locations now through mid-December. Go to Heavens Above and select your city by clicking on the blue Change your observing location and other settings link. Then return to the home page and click on the blue ISS link to see a 10-day table of passes that includes time, direction, brightness and altitude. The higher the negative number in the brightness column, the brighter the pass. Click on any pass time and a map appears showing the station's path across the sky. 

You can also get a list of customized passes by downloading the free ISS Spotter app for iPhone and ISS Detector for Android devices. From some locations for the next couple days (including the Duluth, Minn. region) the station will pass near the planetary duo of Jupiter and Saturn as it rises in the southwestern sky. Get your camera ready!

Clear skies and happy nights.