As you can see from this photo you can create a lot of drama once the sun has gone down, and with the right equipment and a little bit of know-how its not as difficult as you may be imagining. What you are seeing is effectively a 3 hour exposure that has captured the movement of the stars as the Earth spins around it southern axis. However, for some reason or other, modern digital cameras just don't like very long exposures (hours not minutes) so we use another nifty menu option in the camera called the intervalometer timer. This basically allows us to tell the camera to take a picture every x number of minutes or hours for a certain period of time. This means that instead of doing a very long exposure we can lots of shorter ones and then stack them together in photoshop to create the same streaky or 'trail' effect.
In order for the stacking to be effective each picture needs to be exactly the same and as you are shooting a 30 second exposure it would make sense that a stable tripod is required for a successful star trail. As dramatic as the stars are on their own you will also need some form of foreground to tie the whole picture together and create a pleasing composition. The fantastic and prolific Albida trees on the Mana Pools floodplain provided the perfect foreground for this particular shot. So to the technicalities of shooting. Once you have found your foreground you need to point your camera just left of South, this will ensure you get the circle as appose to just streaks across the sky, and set your cameras ISO to 6400. Ideally you need to shoot with your widest lens as well as your fastest aperture (F2.8 is ideal) and set your focus on manual and then on infinity on the lens focus ring. Make sure you horizon is straight as you don't want to have to crop hundreds of pictures!
Once you are satisfied you have set up everything then find your cameras' intervalometer or interval timer shooting in the case of Nikon and see it to take 1 picture every 30 seconds for 2-3 hours. Be sure to shoot in RAW you you can tinker with the light balance afterwards and ensure that there is minimal ambient light (torches, camp lights etc) falling on your foreground. And also watch out, creating star trails can get addictive!