When you take a picture, what you’re essentially doing is briefly exposing the camera’s sensor to light. The various settings on the camera control how much light hits the sensor. The three main settings are ISO, aperture, and shutter speed and determine the sensor’s sensitivity to light, the amount of light let into the sensor, and how long the sensor is exposed respectively.
Part of what makes Joshua Tree National Park such a great area to observe the night sky is the absence of light pollution. The more light pollution there is, the fewer things you can see in the night sky and the more washed out your picture will look. While just about anywhere in the park will offer a great view, there are a number of stargazing areas within the park as noted by the sign below. Keep in mind that much of the light pollution comes from the low desert and the west, so the farther east you go, the darker the skies will be.
You can also check out the Sky’s the Limit Observatory just outside the north entrance to the park. The campus is open to the public year-round and is where is park hosts various astronomical events. You can learn more about the observatory HERE.
