Visible Passes of the International Space Station and Other Satellites

The International Space Station (ISS) regularly passes through our skies. It appears like a very bright star moving from west to east, at an angular velocity similar to a plane, and taking a few minutes to cross the sky. During morning passes, especially the very early morning ones, the satellite may be in the Earth’s shadow, and therefore invisible, for the first part of a pass. Similarly, the satellite may enter the Earth’s shadow during the late evening passes, and disappear from view. Note that many other, fainter, satellites are also visible. The ISS is by far the brightest, being as large as a football pitch.

There is an excellent website called Heavens Above which provides up-to-date predictions of the ISS and many other satellites for your exact location. For most visual purposes you can use Guernsey on Heavens Above as an accurate enough location. Then click on “ISS” for Space Station predictions. The table then shows:

• The local time, altitude (in degrees above the horizon) and compass direction to look when it first becomes visible.
• The time, altitude and direction when it reaches maximum altitude.
• And the time, altitude and direction when it disappears.

In the evening the “end” time may be when it disappears into the Earth’s shadow; and in the morning the “start” time may be when it emerges from the Earth’s shadow.

Transits

If you're interested in attempting to capture a transit of the ISS across the Sun* or the Moon, your exact and accurate coordinates are more important. A transit will show the silhouette of the space station as it passes across the bright object behind. These transits are very quick, about 1 - 1.5 seconds if you're in the correct location, so preparation and planning is important. For this purpose, you may find this Transit Finder website of interest.

Gallery

Atlantis Launch

Launch of the last Space Shuttle Atlantis on 8th July 2011, STS-135, marking the historic final flight of NASA’s 30-year Space Shuttle Program. The four-member crew delivered essential supplies to the International Space Station using the Raffaello multipurpose logistics module.

Atlantis Launch

The Space Shuttle rapidly disappeared into cloud, leaving just a smoke trail.

Endeavour & ISS

The International Space Station preceded the Space Shuttle Endeavour, flight STS-118 (next photo) by 3 minutes in this sequence taken on 09 August 2007.

Endeavour & ISS

The International Space Station (previous photo) preceded the Space Shuttle Endeavour, flight STS-118 by 3 minutes in this sequence taken on 09 August 2007.

ISS & Jules Verne ATV

The International Space Station (left) preceded (by about 20 seconds and 150 km) by the fainter Jules Verne Automated Transfer Vehicle (ATV) on 31 March 2008. They were passing above Polaris, and through Ursa Major.

ISS & Ursa Major

The International Space Station moving from Gemini to Ursa Major on 23 November 2011 (Guernsey 60-second all-sky camera image).

ISS Moon Transit

Occasionally the Space Station passes in front of the Moon as in these two images taken on 16 February 2016 and 22 May 2016.

ISS Moon Transit

Occasionally the Space Station passes in front of the Moon as in these two images taken on 16 February 2016 and 22 May 2016.

ISS Sun Transit

The International Space Station crossing the face of the Sun on 10 June 2017.