This week we’re looking for an artificial star: the International Space Station. From London on July 15, the ISS will pass overhead and be brilliantly 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 risen to its zenith and passed through the constellation Draco, the Dragon.
At this point it will be 417 km (259 miles) above us and shining at magnitude -3.8, almost rivaling the brightness of Venus. Of the natural celestial bodies, only the moon and the sun are brighter than Venus.
The ISS will then fade as it begins to descend in altitude. It will pass from visibility sometime around 22.48 BST as it descends below 10° altitude.
For those who want to go for the double whammy, a decommissioned Atlas-Centaur rocket body will cross 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 halfway through the constellation of Boötes, the shepherd, between 22.09 and 22.10 BST.
To check timings at your specific location, visit heavens-above.com.
