The night sky is variable. Some nights are grey and overcast, some filled with stars, yet others are busy with the movement of clouds on weather fronts. Long shutter speeds are the key to capturing imaginative and beautiful images of the sky at night
If looking to shoot the Milky Way, shooting mid-summer (from May to July), when the galactic core is traveling through the dark sky above the horizon is optimal. For shooting general star trails, the optimal time is highly reliant on the time of year.
Moon phases have the power to disturb your image. Moonlight has the ability to wash out night sky images. If the moon is in any way brighter that the crescent, the colors of the Milky Way will be almost non-existent.