RMNP Astronomy Fest Friday-Saturday. Lots of people will be seeing stars — weather permitting — when Rocky Mountain National Park hosts a free, nighttime astronomy festival on Friday, Aug. 2, and Saturday, Aug. 3, on both sides of the park. On the east side, there will be interactive daytime activities and solar viewing opportunities at the Fall River Visitor Center, which is located just outside the park entrance, so park entry reservations are not required.