This week we’re looking for an artificial star: the International Space Station. From London on 15 July, the ISS will pass overhead and will be dazzlingly bright.
The pass begins at 22.39 BST when the space station rises above the western horizon, but it is unlikely to be visible until it climbs higher than 10° in altitude at about 22.41 BST. Three minutes later it will have climbed to its very zenith, passing through the constellation Draco, the dragon.
At this point it will be 417km (259 miles) above us and dazzling at magnitude -3.8, which almost rivals the brightness of Venus. Of the natural celestial objects, only the moon and the sun are brighter than Venus.
The ISS will then fade as it starts to drop in altitude. It will pass from visibility sometime around 22.48 BST as it drops lower than 10° altitude.
For those who want to go for the double whammy, a defunct Atlas-Centaur rocket body will pass across the sky a little earlier that evening, between 22.03 and 22.13 BST. It will only reach the brightness of a modest star but will pass midway through the constellation of Boötes, the herdsman, between 22.09 and 22.10 BST.
To check timings at your specific location, visit heavens-above.com.