Hubble Space Telescope

Check pass times for your place in SkyMate. Passes are visible around dusk and dawn. Hubble always appears relatively low unless you live within about 30° of the equator.

The Hubble Space Telescope has been in orbit since April 1990. It is about the size of a school bus, and its images and measurements have changed our understanding of the universe, from the age of the cosmos to the atmospheres of exoplanets.

Astronauts visited Hubble five times between 1993 and 2009 to repair and upgrade it, including fixing a flaw in its main mirror. Since 2024 it has operated using a single gyroscope to extend its life.

Hubble orbits at a little over 500 km altitude, circling Earth about every 95 minutes. You can see it from the ground as a moving point of light, roughly as bright as a moderately bright star, though much fainter than the ISS.

Its orbit is tilted only 28.5° to the equator, so it is best seen from places closer to the equator. From mid-northern or mid-southern latitudes it passes low in the southern (or northern) sky, and from farther away it never rises.

Hubble moves across the sky at a similar speed to the ISS, but it is smaller and higher up, so it looks fainter. Like other satellites, it is only visible when you are in darkness and it is still lit by the Sun, which mostly means in the hours after sunset or before sunrise.