Look up to catch stellar views of the International Space Station this week

Few people ever get to visit the International Space Station, but the next two weeks are a prime viewing window for folks in Washington and much of the Western United States who would like to watch the massive spacecraft as it whizzes overhead.

Through early June, the ISS will be transiting the night sky over Seattle and the Pacific Northwest multiple times — and thanks to a combination of decent weather and the seasonal track of the sun, even folks in Western Washington should have many chances to take in the show.

“We’re kind of lucky this year that it worked out right,” said John McLaren, president of the Seattle Astronomical Society. “In some years, this doesn’t happen.”

The ISS orbits the Earth every 90 minutes, and its path carries it over the Pacific Northwest — and most other spots on the globe — multiple times a day. But Earth-dwellers can only see the station when it’s dark on the ground where they are — and sunny 250 miles up, where the station is.

“Because we’re approaching the start of summer, that means the sun doesn’t get that far below the horizon,” McLaren explained.

So when the ISS passed over his home in Kent at 11:17 p.m. Tuesday, even though it was dark on the ground, the sun’s rays were angled just right to reflect off the spacecraft — which has only a few, small external lights— and make it visible.

This time of year, those conditions persist all night.

“Normally you might be able to see it for one pass a night or maybe two,” McLaren said. “What’s really unusual here is that we’re having nights when we can see four or five passes in one night.”

McLaren shot a one-minute exposure photo from his yard that shows the station as a bright streak, like a supersized meteor. Watching it with the naked eye, it looks like an extremely bright satellite, moving very fast.

“You look around and all of a sudden you see this thing just chugging across the sky,” said Seattle Astronomical Society member David Ingram, who tracked the station’s trajectory Tuesday night. “It’s pretty spectacular when it’s nearly 300 miles above our heads and it’s still in sunshine while we’re down here in darkness.”

The reflected light makes the space station one of the brightest things in the night sky, on a par with the planet Jupiter. And that means it’s visible from virtually anywhere.

“That’s the beauty of it,” Ingram said. “You could see it from downtown Seattle.”

With the space station passing over the area every 90 minutes, viewers can watch at their leisure. Each transit lasts between three and six minutes.

You can enter your location at several websites to find a list of transit start times and where in the sky to focus your attention. One of the easiest to use is NASA’s Spot the Station website (https://spotthestation.nasa.gov/home.cfm)

Another source is Heavens-Above.com.

For Seattle, promising time windows include: Wednesday, May 23 at 10:25 p.m.; Thursday, May 24, 9:33 p.m. and 11:10 p.m.; and Friday, May 25, 10:17 p.m. and 11:54 p.m.

The track shifts slightly each night. In general for the Puget Sound area, the station will appear somewhere in the west and move to the east. Sometimes, the bright dot vanishes as it moves into the Earth’s shadow.

With binoculars — and a steady hand — it’s possible to make out some features on the station, Ingram said. Even better is a telescope, which can provide much more detailed views.

One Seattle-area resident has actually spent time on the International Space Station — twice. Former Microsoft executive Charles Simonyi paid $25 million for a 14-day stay in 2007. He liked it so much he returned in 2009.

Six astronauts and cosmonauts are currently onboard for the station’s 55th expedition, which includes studies of thunder and lightning and of microgravity’s effects on bone marrow. On Thursday the crew is expected to rendezvous with the Orbital ATK Cygnus spacecraft, launched Monday.

The payload includes a self-contained experiment from researchers at Washington State University and Pacific Northwest National Laboratory to study plant growth and metabolism in zero gravity, with hopes of helping future astronauts grow plants for food and energy.

WSU scientists are also collaborating on a second experiment transported by the Cygnus spacecraft, designed to study clouds of atoms in temperatures colder than anything possible on Earth.