For years, Maricopa County, Ariz., has been ground zero in the debate over immigration.

On one hand, the massive county, which includes the state capital of Phoenix, has a growing Latino population. On the other, it's home to publicity savvy Sheriff Joe Arpaio, who has made his name by strictly enforcing, some say overstepping, immigration laws.

Peter O'Toole announced his retirement from show business on Tuesday. The actor is best known for the title role in Lawrence of Arabia 50 years ago. Melissa Block spoke to O'Toole in 2007 and offers this look back.

Supermarkets have spent decades catering to the needs and wants of baby boomers, and now the millennial generation is disappointed with what they're finding at traditional grocery stores, and are shopping elsewhere in greater numbers.

In fact, a new market research report called Trouble in Aisle 5 reports that millennials buy only 41 percent of their food at traditional grocery stores, compared to the boomers' 50 percent.

We now know that Pluto, the dwarf planet formerly known as a planet, has one more moon orbiting it. Using the Hubble Space telescope, astronomers have discovered Pluto's fifth moon.

NPR's Joe Palca filed this report for our Newscast unit:

"The new moon is tiny, something between six and 15 miles across. It showed up in nine separate images the space telescope made in the last month. The latest image came earlier this week.

The Wall Street Journal is calling it without any couching. The headline:

'The U.S. Housing Bust Is Over'

The lede:

"The housing market has turned—at last.

"The U.S. finally has moved beyond attention-grabbing predictions from housing 'experts' that housing is bottoming. The numbers are now convincing.

Finally, there's some good news about Alzheimer's disease.

It turns out that a few lucky people carry a genetic mutation that greatly reduces their risk of getting the disease, an Icelandic team reports in the journal Nature.

The mutation also seems to protect people who don't have Alzheimer's disease from the cognitive decline that typically occurs with age.

Eleven-year-old Woosuk Kim sees his mother only three or four times a year. That's because he's part of what Koreans call a "goose family": a family that migrates in search of English-language schooling.

A goose family, Woosuk explains, means "parents — mom and dad — have to be separate for the kids' education."

Woosuk's father brought him and his little brother to America two years ago to attend Hancock Park Elementary, a public school in Los Angeles. The boys' mother stayed in South Korea to keep working.