It's not just astronomers who like big numbers.

Each year, about 19 billion Lego bricks are produced. With more than 400 billion pieces worldwide, if stacked on top of each other, that's enough to connect the Earth and the moon 10 times over.

If that fact gets your brain buzzing, head to the University of Hawai'i's Institute

for Astronomy in Manoa tomorrow. You won't find a ladder to the moon, but you will find a giant Lego moon base built by astronomer Roy Gal and fellow members of the Lego Enthusiasts Association of Hawaii. The exhibit — possibly the largest Lego moon base on O'ahu — will be set up in the Moon Room as part of the annual IFA Open House.

"(Open House) is another opportunity to share our excitement and enthusiasm about the new discoveries of astronomy and the beauty of the universe," said IFA director Rolf Kudritzki. "We promise a most interesting day with a lot of science and a lot of fun."

For stargazers, 2009 is a special year, designated by the United Nations as the International Year of Astronomy.

A full roster of Open House short lectures will discuss new discoveries and the 2008 solar eclipse. They'll also pass on information about astronomers at Mauna Kea Observatory, who discover farflung stars and look back to the origins of the universe.

In the IFA courtyard, kids can challenge parents at Astro-Jeopardy, watch planetarium shows, try rocket launching, search for sunspots and make sundials.

At the Mars Rescue Mission, kids can assemble rescue pods out of Lego bricks and race them across simulated Mars terrain.

And, in the library, dozens of UH astronomers, including those working on the killer-asteroid hunting Pan-STARRS project, will be on hand to answer questions.

Members of the Hawaiian Astronomical Society, the Bishop Museum Science Center, Ironwood Observatory and the Windward Community College Center for Aerospace Education will lend a hand.