Astronomical Tools

Satellite Tracking Tool: Track the ISS, Hubble & More

The International Space Station passes over virtually all of Earth's populated areas, and you can spot it easily with your eyes alone — if you know where and when to look for it.

Celestial Objects to Observe

Satellite Transit Tool: Spot ISS Transits of the Sun and Moon

The International Space Station often passes close to the Moon, Sun, and naked-eye planets. Use this tool to plan viewing these close encounters.

Space Satellites

Space-Station Frenzy

For a few days each May, you might see the International Space whenever it passes overhead throughout the night.

sunlight twice reflected

Astronomy and Stargazing Projects

How to Catch an Iridium Flare

These communications satellites can briefly outshine Venus as they spray the ground with reflected sunlight.

International Space Station

Celestial Objects to Observe

Take a "Sat-seeing" Tour

It’s a bird! It’s a plane! It’s the International Space Station! Learn how to spot Earth's artificial satellites.

Celestial Objects to Observe

Have You Been Flashed By Iridium?

The Iridium satellites' antenna arrays are almost perfect mirrors. And when they catch the Sun just right — wow!