A new estimate released Monday suggests that the Milky Way galaxy is home to at least 17 billion planets similar in size to Earth.

It doesn't mean all are potentially habitable, but the sheer number is a welcome starting point in the search for worlds like our own.

Thousands of Spanish medical workers marched through downtown Madrid on Monday to protest against budget cuts and plans to partly privatize their cherished national health service.

The march is part of a series of such demonstrations, described as a "white tide" because of the color of the medical scrubs many protesters wear. Participants on Monday walked behind a large banner saying, "Health care is not to be sold, it's to be defended."

U.S. President Barack Obama on Monday announced his choice of Chuck Hagel as his next defense secretary and counter-terrorism adviser John Brennan to lead the Central Intelligence Agency, two potentially controversial picks for his second-term national security team.

Hagel has faced tough criticism from congressional Republicans who say the former Republican senator is anti-Israel and soft on Iran. Brennan, a 25-year CIA veteran, withdrew from consideration for the spy agency's top job in 2008 amid questions about his connection to criticized interrogation techniques during the George W. Bush administration.

Heart disease and diabetes get all the attention, but what about the many other ways obesity can damage your health?

Carrying too many pounds may lead to or worsen some types of cancer, arthritis, sleep apnea, even infertility. But a new poll suggests few Americans realize the links.

Roll up a sleeve for the blood pressure cuff. Stick out a wrist for the pulse-taking. Lift your tongue for the thermometer. Report how many minutes you are active or getting exercise.

Wait, what?

On his upcoming NBC comedy, Michael J. Fox will play a newscaster who had quit his job due to Parkinson's Disease but returns to work in the show's first episode because a new medical regimen has helped him control many of the disease's symptoms.

It mirrors the life of the former "Family Ties" and "Spin City" star, who said last year that drugs have helped minimize the physical tics of Parkinson's and have enabled him to take on more acting jobs.

Defending champions Novak Djokovic and Victoria Azarenka have been confirmed as the top seeds for the Australian Open starting next week.

Australian Open organizers stuck closely to the latest rankings to seed 32 players for each of the men's and women's draws.

Oklahoma City Thunder reclaimed the overall NBA lead with a 104-92 victory over the Toronto Raptors on Sunday, starting a challenging run of road games in winning style.

Elsewhere, high-flying Miami and Memphis posted wins while the Los Angeles Lakers' woes deepened with another home defeat.

Frank Lampard's departure from Chelsea at the end of the season now appears certain.

Lampard's agent Steve Kutner has told British media that Chelsea has no intention of offering the veteran midfielder a new contract when his current deal expires at the end of the season.

Barcelona coach Tito Vilanova returned to the touchline on Sunday for his first game since undergoing throat surgery to remove a second tumor from a saliva gland.

Vilanova was back on Barcelona's bench alongside assistant Jordi Roura for the Catalan capital derby against Espanyol, guiding his side to a 4-0 thrashing of its crosstown rivals to maintain its nearly perfect Spanish league campaign.