It is possible to work with 50mm but I recommend having a lens that has a focal length of 35mm or less. Next point to make is the tripod and tripod head. The tripod and it's head are usually purchased separately and there is a large variety to choose from. I recommend, while a bit pricey, it would be worth it to invest in a tripod and head made of Carbon Fiber or Basalt. Try to avoid aluminum as the metal vibrates a lot more than Carbon Fiber and Basalt tripods. They are also a lot lighter and it makes a world of difference to carry something that weighs 3 lbs over a distance of several kilometers and something that weighs 10lbs!
Once you have the right gear accumulated you will need some technical specifications to plug into the camera; however, It's not quite all as simple as plugging values into your camera to create dazzling pictures. These tips should help you learn the secrets; however, having a D/SLR camera will be very much worth your while as they come equipped with larger sensors (a square-like plane within the camera that accumulate light which are what translate into photographs on your memory card or film).
Seeing as you will be shooting at night you will need a relatively long exposure (10-30 seconds) to allow more light to come in through the lens and soak up on the sensor/film.
This isn't enough on it's own; however, you will also need to compensate by having a very large aperture (ironically this means your “f” number should be a small number; such as f/1.4-f/2.8 with the smaller number being the best).
Finally, your ISO/ASA setting should be high enough to compensate for the darkness in your scene. Depending on how well lit your surrounding area is will depend on what variation of values you need; so play around and see what you get ! A bright moon and starry night in your scene may have you using exposures as speedy as 8 seconds at an aperture of 2.8 like in this shot of the Aurora taken on September 13th, 2009:
You don't need a high end camera to take pictures of the Aurora. Having the ability to use high ISO effectively, however, will definitely help. Most cameras today can go up to ISO 3200. Myself using a 5D mark II I have taken it as high as 12800 ISO, but find my larger prints do best around ISO 4000 and under. Play around with it. Try different compositions. Include the human element, tell a story, record the event.