HUNTSVILLE, Ala. (AP) — Huntsville native Dr. Mike Brown is arguably the world's best-known astronomer. His discoveries led to Pluto being stripped of its planethood. He's appeared on the cover of Time magazine and is the subject of an illustrated children's book.

But it wasn't until recently that Brown's seven-year-old daughter, Lilah, took note of his accomplishments.

"She's never been impressed by anything I've ever done until she learned that I'm getting a medal from the King of Norway," Brown said.

The Grissom High-educated planet hunter, who works for the California Institute of Technology, will share the 2012 Kavli Prize in Astrophysics for helping discover and characterize a distant region of the solar system known as the Kuiper Belt.

King Harald V of Norway will present the awards during a Sept. 4 ceremony in Oslo.

In addition to his wife and daughter, Brown's mother, Huntsville resident Barbara Staggs, and sister, Cammy Thornton, will be on hand for the festivities.

"I have to buy a ball gown," Staggs said Wednesday. "It's not one of those things you need a lot."

Although he's won oodles of scientific accolades, Brown, 47, said he is especially excited about being a Kavli Prize laureate. Billed as a more contemporary Nobel Prize, the Kavli recognizes scientists for their "seminal advances" in astrophysics, nanoscience and neuroscience.

He is sharing this year's prize in astrophysics with two fellow astronomers who first spotted the Kuiper Belt: David C. Jewett of the University of California, Berkeley and Jane X. Luu of the Massachusetts Institute of Technology.

Brown said he and Luu worked two doors down from each other at Cal-Berkeley when the Kuiper Belt research began in 1997.

Brown's January 2005 discovery of an object larger than Pluto inside the Kuiper Belt forced the International Astronomical Union to rethink whether Pluto was actually a planet. A year later, the group voted to reclassify Pluto and Brown's object, Eris, as dwarf planets.

Brown said Kavli officials called his home at 4:30 a.m. one morning in May to tell him he'd won this year's prize.

"When your phone rings at that hour, you automatically think something bad has happened," he said. "It took a while for my brain to switch from dread to, 'Wait a minute, this doesn't sound bad.'"

"There are a ton of astrophysicists who you could imagine could win one of these, so I didn't expect it."

In addition to his medal from King Harald, Brown and the other laureates will be feted for a week at state dinners, balls and lectures.

It gets better: Brown, Jewett and Luu will also share a $1 million cash prize courtesy of the Norwegian Academy of Science and Letters, the Kavli Foundation and Norwegian Ministry of Education and Research.

Brown said he and his wife, Diane, plan to spend the prize money making memories with Lilah, who is about to start second grade.

"We have huge lists of places we'd like to go -- maybe an African safari," said Brown.

While the Kavli honors his Kuiper Belt discoveries, Brown has moved on to bigger mysteries. He said he's currently focused on a region of deep space where he discovered a solitary object called Sedna in 2003.

"We still have not found another one, but they must be there," said Brown. "What I think is that these objects are going to be basically a fossil imprint of the very birth of the sun."