We took a bus up to Glacier Point at night (or you can drive up early and watch the sunset) for an astrology presentation. Was a lot of fun - especially for kids. But bring a blanket as it gets really cool at night up there. We actually saw the space station travel across the sky while we were there, and the guide was very knowledgeable. There's a small amphitheatre where you sit during the stargazing, and the presenter uses a laser pointer to point out the different constellations. You can also see across the valley to where campfires are burning at the base of Half Dome and on Sentinel Dome. You can get tickets for the tour at the Yosemite Lodge. If you drive up to Glacier Point, leave early as it takes 40-45 minutes from the valley. The road is long and winding.
The Yosemite Lodge also sells a variety of bus tours, including a one-way bus ride up to Glacier Point during the day so you can hike back down to the valley via either the Four Mile Trail, or the Panarama Trail. The tickets are $25.00 for adults. Leave a couple of hours to traverse down the Four Mile trail as you will stop to watch deer cross your path, and twice as long (at least) for the Panarama Trail. It gets crowded before sunset at Glacier Point as everyone tries to photograph Half Dome at sunset. It really is spectacular and you'll not get tired of the views.
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