How to Spot

The ISS is roughly football-field-sized, sits about 250 miles above Earth, travels at about 17,500 mph, and completes an orbit every ~92 minutes, circling Earth about 16 times per day. Its orbit is inclined about 51.6° to the equator, so its ground track passes over more than 90% of Earth’s population and it never goes farther north than 51.6° N or south than 51.6° S. It shines by reflected sunlight, is often the third-brightest object after the Sun and Moon, appears as a steady white dot with no blinking, and can flare slightly when sunlight glints off its solar panels.