On a clear, cool night in the early 1960s, a father drove his young, pajama-clad daughter to one of the T-head piers on Corpus Christi Bay to marvel at an object in the sky.

The girl who peered up at the sky was Sandy Wood, and this year marked her twentieth anniversary as the voice of the nationally syndicated radio program StarDate. Speaking in her distinctive warm and soothing tone over synthesized tinkling chimes, Wood provides a daily two-minute peek into the world of astronomy, expounding on topics as varied as newly discovered quasars and the best place to watch a meteor shower.

The show, which is heard every day by some 2.2 million listeners on more than 300 radio stations, has inspired an untold number to go out to their backyards to gaze at the stars.

Some of that owes to Wood’s almost otherworldly voice. Over the years she has received many letters, a number from men who try to envision what she looks like. “Invariably they imagine me as some voluptuous brunette, very, very tall with long hair and long fingernails,” said Wood, 63. In reality, she is just shy of five feet tall. “I’m not a babe; I’m a grandma,” she added.

People also often assume from Wood’s authoritative delivery that she is an astronomer, she said. But she is not—although she describes herself as “a science addict”—and the bulk of the scripts are written by Damond Benningfield, a science journalist who has been the show’s producer since 1991. To gather material, Benningfield reads research journals, goes to conferences and interviews prominent astronomers. He tries to cover all aspects of astronomy, from the Big Bang to magnetars to how various cultures have viewed the stars through the ages.

“One of the things I love about astronomy is that there’s always something new,” Benningfield said. “With the improvements in technology in just the time I’ve been doing StarDate, there are more big telescopes, there are more space telescopes and what people are discovering just seems to increase exponentially.”

In 1976, Deborah Byrd, a science journalist, founded the astronomy hot line that would become StarDate. The hot line attracted the notice of a producer at KLBJ-FM in Austin, who turned it into a radio show that was broadcast for a year under the name “Have You Seen the Stars Tonight?”—a reference to the song co-written by Paul Kantner of Jefferson Starship.

StarDate made its nationwide debut in 1978, after Byrd secured a grant from the National Science Foundation. (Byrd left StarDate in 1991 and founded EarthSky, another successful science radio program.) Today, the show is produced by the McDonald Observatory at the University of Texas at Austin.

StarDate is “a charming little program that people appreciate,” said Sandra Preston, the assistant director for education and outreach at the observatory, who has been with the show since its beginning. Joel Block narrated the program for its first thirteen years, and Preston and Benningfield selected Wood as his successor. “Her voice was very friendly and very clear,” Preston said.

Wood made her debut on September 16, 1991, with a show about the moon’s apparent proximity to Uranus and Neptune. “Tomorrow, you’ll also need a telescope to see Uranus. It will appear so close to the moon that it will become lost in the moon’s glare,” she said.

More than 7,300 shows later, Wood has no plans to stop. “I hope to do it until my voice completely fades out or I get too senile to read,” she said.

Wood, who was born in San Antonio and grew up in Corpus Christi, has no professional voice training. She started in radio in 1968 while studying drama at Texas A&I University in Kingsville, where her future husband had a summer job at a local AM station. The station manager, looking for a female voice, asked her to record a spot for a local department store. Impressed, he invited Wood to become a D.J.

“It was something very novel, because women were not on the air at that point pretty much at all,” Wood said. “I was one of the first female disc jockeys in the Southwest.”

She spent the 1970s moving around South Texas with her husband, setting up FM radio stations in towns from Alice to Brownsville to Del Rio. He handled the business side of things while she wrote copy and recorded announcements.

Wood now lives in San Antonio and commutes to Austin twice a month to record StarDate. She is also the announcer for the local public television station and does one or two commercials a month.

While she is not a scientist, Ms. Wood said she has a natural awe for astronomy. “I think that sometimes comes through in my delivery,” she said.

Being the voice of StarDate is “a great way to be anonymously, partially famous,” Wood said. Several times a year, after hearing her name, people will recognize her as the program’s narrator, but only once has a person picked her out by her voice alone.

“Of all places, I was in Las Vegas,” she said. “I was in a dress shop buying something and someone said, ‘Gosh, your voice is familiar.’ We talked a lot, and as the conversation went on, she said, ‘Are you the woman on the radio who talks about the stars?’”