The prospect of a visit to a “science museum” might elicit groans from some children. But the 55,000-square-foot addition opening this week at the New York Hall of Science is likely to have the most science-averse children riveted.

Ten years and $89 million in the making, the fiberglass-walled addition was designed by Polshek Partners Architects, best known for the Rose Center for Earth and Space at the American Museum of Natural History and the newly opened William J. Clinton Presidential Center in Arkansas. The addition doubles exhibit space and visitor capacity at the Hall of Science.

“This building is fun!” said Alan Friedman, the museum’s longtime director, as he toured the facility, which houses more than 250 exhibits and is located on the grounds of the 1964 Worlds Fair in Flushing Meadow. “The walls and ceilings are made of fiberglass, which is energy efficient, lightweight, cheap, and translucent. There are almost no shadows.”

New attractions allow children to operate a replica of the Mars Rover, climb a rock wall, and arm-wrestle over the Internet.

A week prior to opening, museum staff and construction personnel bustled about, putting finishing touches here and there in the White House-sized wing.

In late September, the museum’s redesigned outdoor rocket-park opened with its iconic, refurbished rockets and a climb-in capsule replica. Inside the museum’s central pavilion, Mr. Friedman, a physicist, gazed at the newly restored Mercury 1 space capsule now on display indoors. “That is not a replica,” he said. “It is literally the first space vehicle used to test the escape-mechanism on the first unmanned flight,” he said, pointing to a vessel the size of a playhouse suited for a couple of 3-year-olds. “They had to test it before they could put a man in it,” he said.

Mr. Friedman, like a proud parent, broke into a grin at each turn in the new wing. “In the last 10 years we have found forms of life we didn’t know existed,” he said of “The Search for Life Beyond Earth,” one of the new exhibits.

On the subject of life in outer space, Mr. Friedman said, “Extremophiles have encouraged us.” Visitors can view live and video examples of extremophiles – organisms that thrive in harsh conditions, like trout that prefer water just above freezing, shrimp that like theirs boiling, and lobsters that travel in herds along the sandy bottom of the ocean.

“We still think water is important,” he said regarding extraterrestrial life, and stepped onto a scale to demonstrate how much of his own body constituted liquids. “Fourteen point one gallons of water. It’s not sloshing around in me,” he explained. “It’s in the tissues.”

Tucked in an upstairs corner of the new North Wing, “Preschool Place,” a brightly painted area for children 6 and under, encourages youngsters to explore topics such as how bees make honey and communicate with each other. “Preschoolers can learn a whole lot more than we thought. It depends on how it’s presented,” said Mr. Friedman.

The rest of the second-floor open gallery is home to the “Connections: The Nature of Networks” and “The Sports Challenge” exhibits. “We couldn’t have built these exhibits 10 years ago, because the science behind them was not known,” said Mr. Friedman, showing “Connections: The Nature of Networks.”

“This exhibit is about networks,” he said. Telephones, computers, and railroads operate on networks, and the displays here demonstrate the differences between manmade and emergent ones seen in nature.

“There’s your original web builder,” Mr. Friedman said, pointing to a pair of large orb weaver spiders high on a platform in the middle of the exhibit space. “We hope they’ll make a pretty web for us,” he said.

In a glass tank filled with a substance resembling sawdust, a colony of leaf cutter ants tunneled and conducted business in their network.

“It’s a colony we are establishing,” Mr. Friedman said. He explained that the ant colony can last for a decade, although individual ants live less than two months. “They have farms – no master plan. It’s an example of an emerging network. The Internet grew as an emerging network like the ants,” he said.

Mr. Friedman then pointed to what he considers the most exciting part of the Connections display, Internet arm-wrestling. Here visitors explore “the science of touch” – its current use in microsurgery and future possibilities, such as a grandmother receiving a grandchild’s long-distance hug. Users sit down and wrestle with a mechanical arm operated over the Internet by a partner located elsewhere in the country or across the room.

“Kids almost always cheat,” Mr. Friedman said, explaining how they figure out the location of the camera and get a buddy to dodge it and give added arm strength to win the match. “It isn’t about winning,” he said. “It’s about ‘what else could we do with this technology?'”

The New York Hall of Science, 47-01 111th St., Queens, 718-699-0005, www.nyscience.org. General admission: adults, $9; children 5 to 17, $6; children 2 to 4, $2.50.