Downtown Austin may soon be the home of the largest planetarium in Texas.

The nonprofit Austin Planetarium and developer KUD International announced plans May 26 to build a 47-story tower near the Capitol building that would house a state-of-the-art science and technology museum.

The $240 million project would include a 157,000-square-foot facility located across the street from the Bob Bullock Texas State History Museum with a planetarium, an interactive science museum and a technology center showcasing Texas innovations.

"Austin is the largest city in the country without a planetarium," Austin Planetarium Marketing Coordinator Tyler Brown said.

He explained the project began with the idea for the planetarium only, but larger fundraisers pushed to expand the project as Central Texas also lacks a full-spectrum science museum.

According to Austin Planetarium, funding for one-third of the museum's cost has been identified so far.

The project is awaiting approval by the Texas Facilities Commission for a ground lease on the property located at North Congress Avenue and Martin Luther King Jr. Boulevard, which is currently a parking lot.

The development is expected to attract more than 600,000 annual visitors and will create more than 650 full- and part-time jobs in the area, more than $10 million in tax revenue over 10 years, ground rent revenue for the state and $60 million in annual economic impact.

If the proposal is accepted, Austin Planetarium expects the process will take approximately a year and that construction will begin shortly after an agreement is finalized.

Brown said the nonprofit is aiming for a groundbreaking in late 2013 or early 2014.