How old is the moon?

The age of the moon is the subject of some debate within the scientific community. Some scientists think that the moon formed roughly 100 million years after our solar system formed, while others favor a date somewhere between 150 and 200 million years after the solar system’s birth. These dates would put the moon between 4.47 billion and 4.35 billion years old.

A new study published in Science Advances claims to put the controversy over the moon’s age to rest. A team of researchers think they have accurately dated the moon at 4.51 billion years old.

The researchers used moon rocks taken from the lunar surface during the Apollo 14 mission in 1971 for their study. Most moon rocks astronauts have brought back to Earth are composites of rocks fused together during meteor strikes, and that makes dating them tricky as the different pieces of the rocks will reflect different ages. To get around this, the researchers turned to zicorn, a very durable mineral found in both the Earth’s crust and in moon rocks.

“Zircons are nature’s best clocks,”said co-author Kevin McKeegan, a UCLA professor of geochemistry and cosmochemistry. “They are the best mineral in preserving geological history and revealing where they originated.”

McKeegan and lead author Mélanie Barboni focused on the tiny zicorn crystals that contained small amounts of radioactive elements, particularly uranium and lutetium. They isolated when these two elements has decayed to calculate how long the zicorn had formed and used that to provide what they contend is an accurate age for the moon.

This isn’t to say that the zicorn-dating approaching is without its own controversy. Speaking to The Verge about the findings, Richard Carlson, the director for the department of terrestrial magnetism at Carnegie Institution for Science, he praised the work but cited concerns about the zicorn approach. Namely, Carlson questions the assumption that the decayed ratios for the uranium and lutetium would be the same in the early days of the solar system as they would be today.

“It’s just a very complicated problem they are addressing here, which is why we still don’t have a clear answer to such an obvious question as the age of the Moon,” Carlson said.

Source:  mnn.com Continue reading “How old is the moon?”

6 ways a womans body will change when she turns 50

For many, 50 is the new 40. It’s a time of life when we mellow, become more content, have more of life under control. However, when it comes to your health, there are always things to rein in, especially if you’ve acquired some bad habits over time. Read on as our experts direct you to six things you should do during this decade to improve your health.

 

1. You’ll need a colonoscopy.

 

Provided you don’t have a family history or personal risk of colorectal cancer (in which case you’ve probably had a colonoscopy already), regular screening beginning at age 50 is recommended to prevent colorectal cancer. According to the American Cancer Society, preventing colorectal cancer (and not just finding polyps and cancer early) is a major reason for getting tested at this age. Talk with your physician about screening options.

 

2. You may need some vaccines.

 

While you may think things like the pneumonia vaccine are reserved for the elderly, think again, says Kathryn Boling, MD, a family medicine physician at Mercy Medical Center in Baltimore, who suggests you get this vaccine every five years starting at age 50 if you’re at high risk — meaning you have asthma or diabetes. At 50, be sure to get the Tdap (tetanus, diphtheria and pertussis) booster vaccine, which you need every 10 years. If you’ve never had the chickenpox or the chickenpox vaccine, the Centers for Disease Control and Prevention (CDC) says you can get the vaccine as an adult. And the CDC also recommends getting a flu shot.

3. Women will go through menopause.

 

During this decade you’ll experience lengths of time without your period or your period will end, Bitner says. Expect to experience symptoms such as vaginal dryness, low libido, consistent hot flashes, night sweats, belly fat weight gain and fatigue. “You may also start to deal with wrinkles, hair loss and pelvic prolapse,” she adds.

 

4. Your risk for heart disease may increase.

 

“In the first five years after menopause, the risk factors for cardiovascular disease escalate quickly if you aren’t living a healthy lifestyle and/or on menopause hormone therapy,” says Diana Bitner, MD, a physician at Spectrum Health Medical Group in Grand Rapids, Michigan. Even if you don’t have a family history of heart disease, at 50, ask your physician for a baseline electrocardiogram (EKG or ECG), which can help detect heart problems, Bitner says.

 

5. Expect aches and pains.

 

“At 50, all the folks who were lucky enough to get good genes from their folks begin to suffer from what others started noticing at 40,” says Barbara Bergin, MD, an orthopedic surgeon in Austin, Texas. “I never hear anyone say, ‘Everything went downhill at 60,’ because by then no one is surprised by the sudden onset of pain.” At 50, it’s likely you’ll notice that your knees and back feel tight if you’re been sitting for a while. “Your back and knees may feel painful when you stand up, too,” she says.

 

6. Your emotional health may suffer.

 

As your hormone levels fluctuate during menopause, your mood may be affected. It’s not uncommon for women going through menopause to feel depressed and have mood swings from happy highs to teary lows. Plus, getting a poor night’s sleep (or several of them) due to hot flashes would put anyone in a bad mood. Which is why it’s all the more important to find a way to cope. “Forming and/or using existing social networks and talking to friends will help you stay emotionally healthy,” Bitner says. Time to phone a friend.