President Obama and his family will spend this evening gazing at the stars with a group of professional and amateur astronomers, who have been invited to the White House for a star party. The president’s kickoff address will be broadcast live on NASA TV at 8 p.m. EDT. 

The party marks the International Year of Astronomy (IYA2009), celebrating the 400th anniversary of Galileo Galilee’s first use of a telescope to observe the sky. It also coincides with Space Week, which began Sunday and ends on Oct. 10.

More than 20 telescopes will be set up on the White House lawn as the astronomers, the first family and a group of middle school students study the mountains of Earth’s moon, Jupiter and its moons, and other stars.

The party, which is organized by the White House, Office of Science, Technology and Policy, and NASA comes after a six-month campaign by the IYA2009 team and Chicago-based amateur astronomer Audrey Fischer.

"We're delighted that President Obama will take a break from his pressing terrestrial concerns to personally witness some of the same celestial spectacles that Galileo first studied 400 years ago and that revolutionized our understanding of the universe and our home planet," said Stephen Pompea, the U.S. program director for IYA2009 and an astronomer with the National Optical Astronomy Observatory.