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A Sun-Like Star Very Close to Us Might Have a Goldilocks Planet

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Artist’s impression of the Tau Ceti system. Created by J. Pinfield for the RoPACS network at the University of Hertfordshire, 2012.

A bunch of science-fiction stories just got a little bit more feasible: An international team of astronomers recently announced that Tau Ceti, one of the closest Sun-like stars, may have planets like our solar system. And one of them might be in the star’s habitable zone.

Tau Ceti is only 12 light years away from Earth, so close that at night, we can see it with the naked eye. Using 6000 observations from three different instruments, scientists have determined that its planets are between two and six times the mass of Earth, making it "the lowest-mass planetary system yet detected," according to a press release issued by the team.

The planet in Tau Ceti's habitable zone is about five times Earth's mass—the smallest planet found orbiting in the habitable zone of any Sun-like star—and could, theoretically, have conditions that are just right to support life (hence the term "Goldilocks planet").

Steve Vogt, a scientist from UC Santa Cruz who is on the team, said that this discovery is important because "it's in keeping with our emerging view that virtually every star has planets, and that the galaxy must have many potentially habitable Earth-sized planets. They are everywhere, even right next door!" Forget Mars—once NASA develops faster-than-light travel, these planets will take the search for life to a whole new level.

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Live Smarter
Researchers Say You’re Exercising More Than You Think
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They say a journey of a thousand miles starts with a single step. If the thought of a thousand-mile journey makes you tired, we've got some great news for you: You've probably already completed one.* A new study published in the journal Health Psychology [PDF] finds that people underestimate the amount of exercise they're getting—and that this underestimation could be harmful.

Psychologists at Stanford University pulled data on 61,141 American adults from two huge studies conducted in the 1990s and the early 2000s: the National Health Interview Survey and the National Health and Nutrition Examination Survey. Participants answered questionnaires about their lifestyles, health, and exercise habits, and some wore accelerometers to track their movement. Everybody was asked one key question: "Would you say that you are physically more active, less active, or about as active as other persons your age?"

The researchers then tapped into the National Death Index through 2011 to find out which of the participants were still alive 10 to 20 years later.

Combining these three studies yielded two interesting facts. First, that many participants believed themselves to be less active than they actually were. Second, and more surprisingly, they found that people who rated themselves as "less active" were more likely to die—even when their actual activity rates told a different story. The reverse was also true: People who overestimated their exercise had lower mortality rates.

There are many reasons this could be the case. Depression and other mental illnesses can certainly influence both our self-perception and our overall health. The researchers attempted to control for this variable by checking participants' stress levels and asking if they'd seen a mental health professional in the last year. But not everybody who needs help can get it, and many people could have slipped through the cracks.

Paper authors Octavia Zahrt and Alia Crum have a different hypothesis. They say our beliefs about exercise could actually affect our risk of death. "Placebo effects are very robust in medicine," Crum said in a statement. "It is only logical to expect that they would play a role in shaping the benefits of behavioral health as well."

The data suggest that our ideas about exercise and exercise itself are two very different things. If all your friends are marathoners and mountain climbers, you might feel like a sloth—even if you regularly spend your lunch hour in yoga class.

Crum and Zahrt say we could all benefit from relaxing our definition of "exercise."

"Many people think that the only healthy physical activity is vigorous exercise in a gym or on a track," Zahrt told Mental Floss in an email. "They underestimate the importance of just walking to the store, taking the stairs, cleaning the house, or carrying the kids."
 
*The average American takes about 5000 steps per day, or roughly 2.5 miles. At that pace, it would take just a little over a year to walk 1000 miles.

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Medicine
Scientists Are Working on a Way to Treat Eye Floaters With Lasers
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Even people with 20/20 eyesight should be familiar with this scenario: You're enjoying a clear view when a faint doodle shape drifts into your peripheral vision like an organism under a microscope. Floaters affect almost everyone, but there's currently no medically accepted, non-invasive way to treat them. Two doctors with Ophthalmic Consultants of Boston are working to change that. As IFLScience reports, the team believes that lasers may be the solution to bothersome eye squiggles.

As Chirag Shah and Jeffrey Heier write in their study in the journal JAMA Ophthalmology, lasers can be used to safely combat the underlying causes of floaters. Also known as muscae volitantes, Latin for “hovering flies,” the condition comes from physical debris leaking into your eyeball. The front of your eyes is filled with a liquid called vitreous humor, and when drops of that gelatinous substance break off from the whole, the bits cast shadows on your retinas that look like gray blobs. Because floaters literally float inside your eyes, trying to focus on one is almost impossible.

These spots aren't typically a problem for young people, but as you get older your vitreous humor becomes more watery, which increases the chance of it slipping out and clouding your vision. Retinal detachment and retinal tears are also rare but serious causes of symptomatic floaters.

Shah and Heier tested a new method of pinpointing and eliminating floaters with a YAG laser (a type of laser often used in cataract surgery) on 36 patients. An additional 16 test subjects were treated with a sham laser as a placebo. They found that 54 percent of the treated participants saw their floaters decrease over six months, compared to just 9 percent of the control group. So far, the procedure appears be safe and free of side effects, but researchers noted that more follow-up time is needed to determine if those results are long-term.

At the moment, people with symptomatic floaters can choose between surgery or living with the ailment for the rest of their lives. YAG laser treatment may one day offer a safe and easy alternative, but the researchers say they will need to expand the size of future studies before the treatment is ready to go public.

[h/t IFLScience]

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