View the ISS as it passes over Ridgecrest

Find out when you can see the ISS pass overhead

Ralph Paonessa  –  December 4, 2020
Learn how and when to spot the ISS when it passes over our local skies. It appears several times each month.

Look up ISS passes for your location using these websites:

The International Space Station (ISS) orbits the Earth every 1.5 hours, with a constantly changing track over the ground. This constant movement allows it to fly over 85% of the globe every one to three days — and so it frequently passes overhead.

When these overhead passes occur near sunset or sunrise, the bright reflection of sunlight makes the station visible from the ground. Sometimes it will be the brightest object in the sky — a "star" that slowly travels across the night sky until it re-enters the Earth's shadow and gradually fades from view.

Because the ISS orbital parameters are known in great detail, we can predict exactly when and where in the sky the ISS will make a visible pass, and you can go outside on a clear night and spend a few minutes gazing as this enormous orbiting laboratory — as long as a football field including the end zones!  — slowly sails by, 250 miles overhead. Wave to the crew of three to six astronauts, because they just might be photographing you!

To see when the ISS will be visible from your location, there are a number of websites, smartphone apps, and computer programs you can use. You can even sign up for text message alerts from NASA! 

Here are some of my favorite sources. These links are centered on Ridgecrest, but you can specify any location.:

NASA: Spot the Station shows you the visible passes for your location for the next week. Look at the table and you'll see that passes vary in 

  • How long the station will be visible
  • The maximum altitude above the horizon
  • The area of the sky where it first appears, then disappears.

You can sign up for text message alerts from NASA. Just look for the link above the listings. As someone who is not a morning person, one feature I like is that you can specify whether you want alerts for morning or evening passes. Unfortunately, these are limited to passes that reach at least 40° above the horizon. But here in the desert, with our wide-open horizons, we can see it much lower.

The ISS passes vary quite a bit in brightness, depending on the angle of the reflective solar panels. Some passes will exceed the brightness of the brightest star or planet. The NASA site doesn't tell you this. So I always check my second source for this information:

Heavens Above Visible ISS Passes gives you similar information to the NASA website, but also includes the brightness (magnitude), as well as the actual start time of visibility. Note: You'll probably have to enter your location on your device, as this isn't passed in the above link. Look for the Location box at the upper right of the page. Remember that brightness increases with more negative magnitude values. 

As I write this, there are eleven visible passes in the next week, varying from a moderate Mag -0.3 (still brighter than almost all stars) to a spectacular Mag -3.7 — brighter than anything in the night sky other than the Moon! And that flyover will last 4 minutes and appear as high as 55° above the horizon. That's the kind of appearance that's worth putting on your calendar!

More tips

Click on a pass in Heavens Above to get a sky chart showing the predicted path.

The passes usually start very dim, then grow in brightness, and fade away at the end. Entice a few friends to join you. It helps to have several eyes scanning the sky to make the first sighting of what at first seems to be a star until you realize it's moving.

Take along the sky chart or jot down the direction where the ISS will first appear. Bring a compass (or use the one on your phone) if you're unsure of the directions.

Finally, you'll begin to notice that visible passes for your location come in "waves." And they will be all grouped into either the evening or morning. After a week of visible passes, the ISS will, sadly, disappear from our skies. That's just the nature of its changing ground track as the orbit gradually traces across the globe.

But soon it will be back for another wave. Just sign up for those NASA text alerts to know when!

File under: Local Observing