This was a long day but a great one. The tour guides were awesome and so knowledgeable. Amazing views and so many stars. It does get cold - and they do provide you gear (which is great) but bring long pants, water, and layers - which, again, they recommend. You get picked up around 3-4 pm and then be brought back between 10:30-11:15 pm.
I'm not even an astronomy nut, but if I were, this would definitely be the place to go if you're here in Kona/Hilo.