At Tessmann Planetarium, It’s a Starry, Starry Day

When it’s smoggy or overcast in Orange County, there is still a place you can see the night sky. In fact, you can see these “stars” during the daytime.

The place is the Tessmann Planetarium and Museum on the Santa Ana campus of Rancho Santiago College. The planetarium is so realistic that the stars appear to twinkle over silhouettes of the San Bernardino and Santa Ana mountains.

2 to 3: The planetarium schedules tours by appointment on three weekday mornings. On Sunday afternoons, the public is invited to just drop in.

The parking lot in front of the planetarium says “30-minute parking,” but you can ignore this sign on Sundays. One warning: Be prompt. You can’t enter once the lights are dimmed and the show has begun.

Visitors pay an entry fee ($2 for adults, $1 for students and seniors) and are invited to sit along the cushioned benches that ring the room. The benches are designed with high backs so that an adult can rest his or her head and gaze heavenward comfortably during the hourlong show.

In the center of the planetarium is a large sphere. As the lights dim and the show begins, this sphere rises silently toward the ceiling. The sphere is pinpricked and lit from within so that the light creates a map of stars against the blackened dome.

The planetarium’s creators have somehow managed to simulate the white intensity of the North Star and the orange shading of Jupiter.

Sunday shows are scripted and narrated by the Orange County Astronomers, a group of avid stargazers. The shows change regularly. In February, the group began an exploration of “Contact: The Search for Extraterrestrials.” March’s program is “Clusters of Stars.”

By projecting slides against the dome’s still-darkened inside, the astronomy club members tell their particular story of the month.

Later, they offer some general stargazing tips and lore about how the stars got their names.

3 to 3:15: After the show, stroll out behind the planetarium and take a look at the rocky water fountain. Though not large, it is pleasant.

It is dedicated to a geology instructor, Thomas M. Hartnett, who “inspired students to learn about and care for the Earth.”

Rancho Santiago, like most colleges, has kiosks where students and others post bulletins. If you are interested in a cheap room, salsa dance lessons or a benefit to raise money for Vietnamese refugees in Southeast Asia, check out the kiosks for details.

3:15 to 5: Less than three-quarters of a mile from campus is a pretty little park and access to the Santa Ana River bicycle path.

Alona Park runs along the river. If you enter at 21st Street, you will find the best spots for picnicking, complete with tables and outdoor grills. There is a basketball court, baseball diamond and swings and slides.

If you are more interested in the bicycle path, enter Alona Park at 19th Street. Follow the path that runs between the condominium building and the baseball diamond. Turn left, and you’re there.

As concrete riverbeds go, this is one of the more scenic. The muddy water flows at some depth at this time of year. Wooden bridges, no longer in use, cross overhead.

As you travel beneath busy surface streets and a Kool cigarette billboard, the riverbed seems like a quiet hideaway.

1. Tessman Planetarium and Museum Building M100 Rancho Santiago College 1530 W. 17th St., Santa Ana

Tours by appointment at 9:30 a.m. Monday, Wednesday and Friday. Drop-in tours at 2 p.m. on Sundays. (714) 564-6600.

2. Alona Park and Santa Ana River trail English and 19th streets, Santa Ana.

PARKING: Free parking in front of planetarium on Sundays.

BUSES: The 60 OCTA bus stops at the campus and at English and 17th streets.