Santa's sleigh or the International Space Station? How to spot a bright Christmas flyby Dec. 24 and 25

Early risers across North America and Europe may notice something unusual in the skies this Christmas, a bright, silent light, gliding smoothly overhead in the hours before sunrise on Dec. 24 and Dec. 25.

It won't blink like an airplane and it won't leave a trail behind. Instead, it will appear suddenly, move steadily across the sky and fade away just minutes later. To young, eager eyes already awake and brimming with excitement, it might look like something (or someone) making a quiet journey through the dawn sky.

The timing matches a well-known object passing overhead.

This Christmas, the International Space Station is also perfectly placed to reflect sunlight down to Earth during early-morning passes, making it one of the brightest objects in the sky.

Whether you choose to see it as a seasonal mystery or a space-age marvel, the sight may be brief, but it is beautiful and easy to spot with the naked eye  — so long as you are in the right place at the right time.

In the table below, we have listed some of the best times to look up over major cities, weather permitting — information gathered from AstroViewer.net.

To see the flyby, head outside with a clear view of the sky. You don't need binoculars or a telescope to spot it, just your eyes and a little patience.

The bright light comes from the International Space Station. It shines when sunlight reflects off the large structure while it orbits Earth every 90 minutes.

For those who want to check future sightings, or quietly confirm what they've seen, NASA's Spot the Station service shows when the space station will pass overhead from any location.