Orbiting Now · Earth observation

Imaging, radar and science satellites watching the planet below. Each line below is a real object in orbit, decoded from its Two-Line Element set — the standard shorthand that describes an orbit: inclination, period and altitude are derived here from the mean motion in the second line.

Space stationsBrightest payloadsNavigation (GPS)GeostationaryEarth observation

How orbits are measured

Inclination is the tilt of the orbit against the equator: the ISS’ 51.6° is a compromise between crew-launch capability from Baikonur and fuel cost, while sun-synchronous Earth-imaging orbits sit near 97° and pass over the same local time of day. Period follows altitude: low orbit circles Earth in 90–100 minutes; a geostationary orbit needs 35,786 km and exactly 24 hours, which is why it stays parked over one spot.

The congestion problem

Over 10,000 active satellites now orbit Earth, most in the Starlink-style shells of the 400–600 km band. Their combined brightness now affects ground-based astronomy, and every spent booster and collision fragment adds collision risk — the chain-reaction scenario called the Kessler syndrome. Deorbit rules (leave the orbit within five years, now tightening to 25→5) exist precisely for this.

See one yourself

On a clear night an hour after dusk, look for a steady bright light moving steadily across the sky — that is almost always a satellite, and the brightest are the station and the Iridium-style flares. Anything moving is in orbit; anything twinkling is a star.

Orbital elements: CelesTrak GP data (public TLE feed) · catalogue identifiers: USSPACECOM NORAD.