Kartchner Caverns State Park and Patagonia Lake State Park are each hosting star parties Saturday. “They’re getting more popular all the time,” said Ellen Bilbrey, an Arizona State Parks spokeswoman. More than 10 of the state’s 27 parks offer star parties. “There’s more and more interest in this kind of science programming.”

In addition, the views are stunning, she said, advising that people who want to spend the night under the stars need to reserve a camping spot ahead of time.

Kartchner Caverns State Park

The lineup

2 to 5 p.m.: Safely view the sun through a special telescope.

5:30 p.m.: David O’Brien, a research scientist at the Planetary Science Institute in Tucson, will present “The Giant Asteroid Vesta: Highlights from NASA’s Dawn Mission.” NASA’s Dawn mission completed its yearlong orbital exploration of the asteroid Vesta at the end of 2012, and is on its way to its second target, the asteroid Ceres, where it will arrive in 2015. O’Brien will talk about historical studies of Vesta, its relation to meteorites found on Earth, and the latest results from the Dawn mission’s exploration.

6:30 p.m.: Look at planets, stars, comets, galaxies, and more through astronomers’ telescopes. Participants should bring a folding chair, red light and sweater or jacket.

Where: Kartchner Caverns State Park is located on Highway 90, nine miles south of Interstate 10 near Benson.

Cost: Park entrance fee is $6 per vehicle is waived with a reservation for a guided tour — which are offered during the day. The Rotunda/Throne Room Tour and the Big Room Tour are each $23 for ages 14 and older; $13 for ages 7 to 13. Ages 6 and younger are free for the Rotunda/Throne Room but are not allowed in the Big Room. Full hookup camping sites are $25.

Patagonia Lake State Park star party

Astronomers from the Sonora Astrological Society provide telescopes, and will talk about the elements of the ni ght sky as darkness descends. Visitors should bring water, snacks, a red light (to protect everyone’s night vision), and a sweater or jacket.

When: 7 p.m.

Where: Visitors center. The park is seven miles past the town of Patagonia. Take Interstate 10 east to Arizona 83 south to Arizona 82.

Cost: The entrance fee is $10 to 15 per vehicle (up to four adults). Primitive to full hookup camping sites cost $17 to $28.