Ilan Kroo bought a four-bedroom, 2.5-bath home at 6 Sunhill St. in Portola Valley from Joseph Michael Whelan for $2.15 million on Dec. 2.

The 3,550-square-foot house was built in 1997.

Ilan Kroo works as a professor of aeronautics and astronautics at Stanford University. Previously, he worked in the advanced aerodynamic concepts branch at NASA's Ames Research Center.

He holds a B.S. in physics and a Ph.D. in aeronautics from Stanford University.

According to BlockShopper.com, there have been 57 home sales in Portola Valley during the past 12 months, with a median sales price of $2.14 million.

Address: 6 Sunhill Street
Buyer(s): Ilan Kroo
Seller(s): Joseph Michael Whelan (Trustee) and Trust Whelan
Sale date: Dec. 2, 2011