7 Things You Need to Know About Ashton Carter

— -- President Obama today officially nominated Ashton Carter to be his fourth secretary of defense in six years, calling him “one of our nation’s foremost national security leaders.”

“It’s fair to say on your one-year attempt at retirement from public service you failed miserably,” Obama joked to Carter, who has served nearly a decade in leadership at the Pentagon under the Clinton and Obama administrations.

Obama praised Carter, 60, as a trusted adviser who has counseled him in the situation room, adeptly helped pare down an unwieldy defense budget and oversaw U.S. combat operations in Iraq and Afghanistan. He has also won the respect and admiration of members of Congress on both sides of the aisle, and is expected to be easily confirmed.

But there’s more to the Pennsylvania native than meets the eye. Here are seven things you need to know about the defense secretary nominee:

1. He’s highly educated: Carter is a physicist and medieval historian by training, educated at Yale and Oxford and taught classes at Harvard, according to his official biography. In 1975, he published an article in Yale Scientific titled “Quarks, Charm and the Psi Particle.” His aides once referred to him as the “600-pound brain in the room.”

2. During nuclear threats to the United States from North Korea in 2006, he wanted to bomb Kim Jun Un’s country, or at least destroy a long-range ballistic missile that North Koreans were preparing. “The United States should emphasize that the strike, if mounted, would not be an attack on the entire country, or even its military, but only on the missile that North Korea pledged not to launch -- one designed to carry nuclear weapons,” he wrote in an op-ed for the Washington Post titled “If Necessary, Strike and Destory.”

3. He’s a “big Motown fan,” Obama said today. Obama quoted Carter’s favorite song, “Reach Out I’ll Be There” by the Four Tops, saying to his new would-be cabinet member, “Ash, I’m reaching out to you. You’ve been there.”

4. He once compared public service to being a Christian in the Roman Coliseum: “You never know when they are going to release the lions and have you torn apart for the amusement of onlookers. And then, of course, if your job is world affairs, reality intrudes even in Washington. Crises and emergencies and conflicts erupt around the world on their schedule, not yours,” according to his 2007 faculty autobiographical essay at Harvard.

5. He got fired from his first job for “wise-mouthing the owner.” He was 11 and working at a Philadelphia car wash.

6. Carter was passed up for the Pentagon’s top job two years ago when Leon Panetta stepped down.

7. Twitter users are mistaking him for either actor Ashton Kutcher or ‘90s pop star Aaron Carter, or joking about the similarities in their names.