The wheel above shows the entire sky that is visible from Cambridge. Change the limiting magnitude to see more or fewer stars.

To change the displayed time, use the time and date controls at the top.

By clicking and dragging the wheel, you can turn it to place different green compass points at the bottom. If you stand outside and look in the direction you have chosen, the stars at the bottom of the wheel will match the ones you will see above the horizon in that direction.