WASHINGTON – Lawmakers held a free-ranging and sometimes bewildering hearing Wednesday on the search for extraterrestrial life, gradually working around to the question of whether humans are alone in the universe. At the end of the 90-minute session, that issue remained unresolved.

Called “Astrobiology: The Search for Biosignatures in our Solar System and Beyond,” the House Science Committee’s hearing featured three witnesses with doctorates who are prominent in a scientific field that once was considered speculative.

Although the efforts of the world’s scientists have yet to yield even one confirmed example of extraterrestrial life, astronomers have discovered hundreds of planets outside the solar system, and many believe that the galaxy is swarming with potentially habitable worlds. Some of those would inevitably, in time, produce intelligent life.

The experts at the hearing — NASA astrobiologist Mary Voytek, Massachusetts Institute of Technology planetary scientist Sara Seager and science historian Steven Dick — advocated funding for the field, including investment in space telescopes that would be designed to detect chemical signatures of life in the atmospheres of distant, extrasolar planets.

Many of the questions from committee members were vague inquiries about whether astrobiology could be an inspiration for young people to get involved with science and engineering. The witnesses were asked how they got interested in astrobiology.

At one point, Florida Rep. Bill Posey asked the panelists what they considered to be the greatest danger to life on Earth. Dick said asteroids, Seager said overpopulation and Voytek mentioned the quest for energy resources.

Although the Democrats on the committee praised the witnesses and seemed to enjoy the discussion, the hearing — called by committee Chairman Lamar Smith, a Texas Republican — inspired partisan mockery outside the room. A news release from the Democratic Congressional Campaign Committee said the Republicans were holding a hearing on “space aliens” rather than on such issues as immigration reform or a minimum-wage increase.

“No wonder the American people think this Republican Congress is from another planet — they’re more interested in life in space than Americans’ lives,” said the DCCC’s Emily Bittner. “Saying this Republican Congress has misplaced priorities is an understatement of galactic proportions.”

The hearing Wednesday largely skirted the issue of extraterrestrial intelligence. Dick, author of “The Biological Universe,” suggested that NASA should resume funding of SETI, the search for extraterrestrial intelligence (typically with radio telescopes).

Not until the hearing was nearly over did a lawmaker address the issue head on. Rep. Ralph Hall, a Texas Republican who is the chairman emeritus of the committee, asked the panel: “Do you think there’s life out there, and are they studying us? And what do they think about New York City?”

Seager, whose work has earned her a MacArthur Foundation “Genius Grant,” would not speculate about intelligent life but said, “The chance that there’s a planet like Earth out there with life on it is very high.”

NASA’s Voytek was a bit more playful on the subject. “Whether they’re looking at New York or some small town in Indiana, the diversity of life here and the way that we live our lives is phenomenal, and I think it goes all the way down from humans to microbes,” she said.

Dick went with a Copernican principle of sorts: “I think the guiding principle holds that what’s happened here has happened elsewhere in our huge universe.”