Observing opportunity for ERS-1
The wheel below shows the entire sky that is visible from Cambridge (change location), and shows the path of ERS-1 across the sky at 23:53 EDT on 23 August 2021. Change the limiting magnitude to see more or fewer stars.
By clicking and dragging the wheel below, you can turn it to place different green compass points at the bottom. The stars at the bottom of the wheel will then match the ones you will find above the horizon in that direction.