Is That The Space Station Overhead? Heck Yeah!

The ISS is the biggest and consistently brightest satellite in the night sky. It's visible this month moving from west to east during evening twilight. A typical pass lasts about 5 minutes. Credit: NASA
The ISS is the biggest and consistently brightest satellite in the night sky. It’s visible this month moving from west to east during evening twilight. A typical pass lasts about 5 minutes. Credit: NASA

December brings an entire month of evening space station passes for many locations in the northern hemisphere.  And because night comes quickly in this solstice month, lots of us will have the opportunity to spot it. You can always tell the International Space Station (ISS) apart from every other satellite by its sheer brilliance. When orbiting silently overhead at an altitude of some 250 miles (400 km), it can shine brighter than Jupiter and nearly as bright as Venus. Closer to the horizon, the station is still dazzles but not as much as during an overhead pass because it’s not only 250 miles up but also hundreds of miles off in the distance. Being farther away, it appears fainter.

Look closely at the color of the station during a pass and you’ll notice it’s not pure white like some satellites. Its many solar arrays are insulated with a gold-colored foil called kapton which give the ISS a warm, yellowish hue. The arrays contain a total of 262,400 solar cells and cover an area of about 27,000 square feet (2,500 square meters). This acre-sized plot of silicon sun-sucking silicon supplies the 75 to 90 kilowatts of power needed by the station and astronauts.

French astronaut Thomas Pesquet tweeted this photo looking down over France from aboard the ISS on Nov. 30, 2016. He writes: "A strange feeling. Looking at Earth and thinking what friends and family are doing."
French astronaut Thomas Pesquet tweeted this photo looking down over France from aboard the ISS on Nov. 30, 2016. He writes: “A strange feeling. Looking at Earth and thinking what friends and family are doing.”

There are currently six astronauts aboard the ISS. They were expecting the Russian cargo ship, Progress 65, to arrive with supplies, but unfortunately, six and a half minutes into its flight a problem developed that caused the ship to come crashing back to Earth. Cargo packed inside the Progress 65 included more than two and a half tons of food, fuel, and supplies for the space station crew, including approximately 1,400 pounds of propellant, 112 pounds of oxygen, 925 pounds of water, and 2,750 pounds of spare parts, supplies and scientific experiment hardware.

All the astronauts living at the station are safe and doing well; a Japanese cargo ship is scheduled to bring needed supplies on Friday, Dec. 9.

You have many options for finding out when the space station will pass over your domicile. You can sign up for free e-mail alerts from NASA at Spot the Station, type in your zip code at Spaceweather’s Satellite Flybys site, log on to Heavens Above and select your town then click the ISS link for a table of passes or download and install the ISS Spotter (iPhone) or  ISS Detector (Android). How easy!

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Using Minneapolis as an example, there will be a brilliant pass of the ISS Sat. Dec. 3 starting about 6:18 p.m. local time. Just before 6:22 p.m., the station will fade out nearly overhead in the W of Cassiopeia when it enters Earth’s shadow. Credit: Heavens Above/Chris Peat with additions by the author

The space station always begins its arc in the western sky and travels eastward. Occasionally, you’ll notice that it fades from view long before it gets to the eastern horizon. This is especially surprising when it happens right over your head. All satellites shine by reflected sunlight. Because they’re very high up, they catch the sun’s rays long after it gets dark here on the ground. But eventually the Earth’s shadow catches up with the space station. When it does, the light fades, and the ISS dims and disappears from sight. It’s exciting to watch from the ground, and for the astronauts on board, too. From their perspective, it’s another of the 17 sunsets they get to see every single day!

To keep abreast of all the cool goings-on with the astronauts, check out the ISS Twitter feed.