AUSTIN, Texas, Nov. 20 (UPI) -- U.S. scientists said Thursday they discovered vast water glaciers under blankets of rocky debris on Mars, suggesting possible life beyond Earth.

"These results are the smoking gun," said Ali Safaeinili, a shallow-radar instrument team member with NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The glaciers are the largest reservoir of water ice found on Mars that isn't at the polar caps, John Holt of the University of Texas at Austin's Jackson School of Geosciences wrote the journal Science.

"Just one of the (glacial) features we examined is three times larger than the city of Los Angeles, and up to one-half-mile thick, and there are many more," he said.

"In addition to their scientific value, they could be a source of water to support future exploration of Mars," Holt said.

The buried glaciers lie in the 1,400-mile-wide, 6-mile-deep Hellas Basin region of Mars' southern hemisphere, thought to have been formed some 4 billion years ago, when a large asteroid hit the surface.

Radar has also detected similar-appearing aprons extending from cliffs in the northern hemisphere, Holt and 11 co-authors said.

"The fact that these features are in the same latitude bands -- about 35 to 60 degrees -- in both hemispheres points to a climate-driven mechanism for explaining how they got there," Jet Propulsion Laboratory Mars Odyssey Project Scientist Jeffrey Plaut said.

Abuse of politicians' DNA feared

BOSTON, Nov. 20 (UPI) -- Two scientists called for ground rules to prevent an abuse of genetic information about U.S. presidential candidates, which will likely available in four years.

"By then, advances in genomics will make it more likely that DNA will be collected and analyzed to assess genetic risk information that could be used for or, more likely, against presidential candidates," bioethicist George Annas and neurologist Robert Green of Boston University write Thursday in the New England Journal of Medicine.

They argue presidents deserve some privacy when it comes to their health, even if the public has legitimate interest in a leader's health.

"If for no other reason, I want my president to get all the medical help he or she needs without going through, 'What would the public think if I go to a doctor, especially if I seek mental health care?'" Annas told The Boston Globe.

In addition, no one can really predict what someone's genes mean for a four-year presidential term, the professors write.

While genome information can be helpful, a lot of it produces "false positive" findings and much data, even if accurate, will be overinterpreted, the professors write.

"We're going to need some scientists who are non-partisan to authoritatively tell the public this is meaningless," Annas told the Globe.

Johns Hopkins University's Genetics and Public Policy Center Director Kathy Hudson tells USA Today she's concerned "genetic paparazzi" will surreptitiously obtain someone else's DNA and have it sequenced.

233,000 Americans don't know they have HIV

WASHINGTON, Nov. 20 (UPI) -- Some 1.1 million people in the United States are infected with HIV and nearly 233,000 are unaware of their infection, a forum on HIV research said Thursday..

Major barriers still stand in the way of making testing for the human immunodeficiency virus the norm, despite the U.S. Centers for Disease Control and Prevention's recommendation of routine HIV testing of people age 13 to 64.

The Forum for Collaborative HIV Research is holding a two-day National Summit on HIV Diagnosis, Prevention and Access to Care in Washington.

HIV is a virus that can lead to AIDS, which causes the human immune system to fail, leading to life-threatening opportunistic infections.

More than one in five people with HIV remain unaware of their status and fail to get life-extending medical help, and many infected people unknowingly spread the virus, contributing more than a third of new infections, experts at the forum said.

The summit brings together some 300 leading HIV researchers, healthcare providers and policymakers to examine the state of the "neglected" U.S. HIV epidemic and the critical role of routine HIV testing.

Testing barriers will be identified and a national plan of action will be presented, organizers said.

Study: Females bond through language

LONDON, Nov. 20 (UPI) -- The cliche of females being the chattier sex proves true, at least in female-centric monkey groups such as macaques, a British study found.

Female macaques made 13 times as many friendly noises as males, two researchers from London's Roehampton University found in a study.

Nathalie Greeno and Stuart Semple listened to a group of 16 female and eight male macaques living on Cayo Santiago, also known as Monkey Island, off Puerto Rico for three months.

They counted the grunts, coos and girneys -- friendly chit-chat between two individuals -- while ignoring calls related to food or a predator, New Scientist magazine reported.

"The results suggest that females rely on vocal communication more than males, due to their need to maintain the larger social networks," Greeno said.

Females were also more likely to chat with other females than with males, the researchers found.

Greeno said this was likely because female macaques formed solid, long-lasting bonds as they stayed in the same group for life and relied on their female friends to help them look after their offspring.

By contrast, males roved between groups and chatted with both sexes equally.