(Press-News.org) The number of potentially habitable planets is greater than previously thought, according to a new analysis by a Penn State researcher, and some of those planets are likely lurking around nearby stars.
"We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take," said Ravi Kopparapu, a post-doctoral researcher in geosciences. "That is a conservative estimate," he added. "There could be more."
Kopparapu detailed his findings in a paper accepted for publication in Astrophysical Journal Letters. In it, he recalculated the commonness of Earth-sized planets in the habitable zones of low-mass stars, also known as cool stars or M-dwarfs.
Scientists focus on M-dwarfs for several reasons, he explained. The orbit of planets around M-dwarfs is very short, which allows scientists to gather data on a greater number of orbits in a shorter period of time than can be gathered on Sun-like stars, which have larger habitable zones. M-dwarfs are also more common than stars like the Earth's Sun, which means more of them can be observed.
According to his findings, "The average distance to the nearest potentially habitable planet is about seven light years. That is about half the distance of previous estimates," Kopparapu said. "There are about eight cool stars within 10 light-years, so conservatively, we should expect to find about three Earth-size planets in the habitable zones."
The work follows up on a recent study by researchers at the Harvard-Smithsonian Center for Astrophysics which analyzed 3,987 M-dwarf stars to calculate the number of Earth-sized planet candidates in cool stars' habitable zones—a region around a star where rocky planets are capable of sustaining liquid water and therefore life. That study used habitable zone limits calculated in 1993 by Jim Kasting, now an Evan Pugh Professor in Penn State's Department of Geosciences. Kopparapu noticed that its findings, based on data from NASA's Kepler satellite, didn't reflect the most recent estimates for determining whether planets fall within a habitable zone.
These newer estimates are based on an updated model developed by Kopparapu and collaborators, using information on water and carbon dioxide absorption that was not available in 1993. Kopparapu applied those findings to the Harvard team's study, using the same calculation method, and found that there are additional planets in the newly determined habitable zones.
"I used our new habitable zone calculations and found that there are nearly three times as many Earth-sized planets in the habitable zones around these low mass stars as in previous estimates," Kopparapu said. "This means Earth-sized planets are more common than we thought, and that is a good sign for detecting extraterrestrial life."
INFORMATION:
Earth-sized planets in habitable zones are more common than previously thought
2013-03-12
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Stereotyping prime obstacle to women in commercial science
2013-03-12
COLLEGE PARK, Md. - Female professors are almost 50 percent less likely than their male counterparts to be invited to join corporate scientific advisory boards (SABs) and start new companies mainly because of gender stereotyping, says University of Maryland researcher Waverly Ding, an assistant professor of management at the Robert H. Smith School of Business.
Beliefs that women lack leadership and business savvy, and are not capable of helping new ventures attract investment, block their advancement in these areas, she says.
Ding, with co-authors Fiona Murray of MIT ...
Autistic children may be at greater risk of suicide ideation and attempts
2013-03-12
Children with an autism spectrum disorder may be at greater risk for contemplating suicide or attempting suicide than children without autism, according to Penn State College of Medicine researchers.
"We were looking at suicidal ideation and suicide attempts among children with autism versus those that didn't have autism," said Angela Gorman, assistant professor of child psychiatry, Penn State College of Medicine. "What we found is that there were some risk factors that were much more greatly associated with suicidal ideation and suicide attempts than others."
The ...
Digital records could expose intimate details and personality traits of millions
2013-03-12
New research, published today in the journal PNAS, shows that surprisingly accurate estimates of Facebook users' race, age, IQ, sexuality, personality, substance use and political views can be inferred from automated analysis of only their Facebook Likes - information currently publicly available by default.
In the study, researchers describe Facebook Likes as a "generic class" of digital record - similar to web search queries and browsing histories - and suggest that such techniques could be used to extract sensitive information for almost anyone regularly online.
Researchers ...
Less sleep leads to more eating and more weight gain, according to new CU-Boulder study
2013-03-12
Sleeping just five hours a night over a workweek and having unlimited access to food caused participants in a new study led by the University of Colorado Boulder to gain nearly two pounds of weight.
The study, performed in collaboration with the CU Anschutz Medical Campus, suggests that sufficient sleep could help battle the obesity epidemic.
"I don't think extra sleep by itself is going to lead to weight loss," said Kenneth Wright, director of CU-Boulder's Sleep and Chronobiology Laboratory, which led the study. "Problems with weight gain and obesity are much more ...
Study: 'Virtual' house calls comparable to in-person care for people with Parkinson's disease
2013-03-12
A small study of 20 people with Parkinson's disease suggests that "virtual house calls" using Web-based video conferencing provide clinical benefits comparable to in-person physician office visits, while saving patients and their caregivers time and travel.
"It appears we can use the same technology Grandma uses to chat with her grandson to provide her with valuable medical care in her home," says study leader Ray Dorsey, M.D., M.B.A., an associate professor of neurology at the Johns Hopkins University School of Medicine. "If this proof-of-concept study is affirmed, the ...
New add-on drug may improve memory in people with moderate Alzheimer's disease
2013-03-12
SAN DIEGO – A new drug may improve memory problems in people with moderate Alzheimer's disease, according to a phase IIa study released today that will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego, March 16 to 23, 2013. The drug is called ORM-12741.
The drug is the first to target a specific subtype of adrenergic receptors (alpha-2C) in the brain, which are believed to be involved in modulation of brain functions under stressful conditions, or the "fight or flight" response. For the clinical trial, 100 people with moderate Alzheimer's ...
Global consensus on concussion in sport
2013-03-12
An international panel of concussion experts has provided new guidelines on evaluating and treating concussions during sporting events and in clinical settings.
Dr. Willem Meeuwisse, a physician, researcher and leader of the University of Calgary Brain Injury Initiative with the Hotchkiss Brain Institute (HBI), Alberta Children's Hospital Research Institute (ACHRI) and the Faculties of Kinesiology and Medicine, co-chaired an expert panel and co-authored the document entitled "The Consensus Statement on Concussion in Sport; the 4th International Conference on Concussion ...
Men in same-sex marriages are living longer, according to new study
2013-03-12
The mortality rate for men in same-sex marriages has dropped markedly since the 1990s, according to a Danish study published online today (Tuesday) in the International Journal of Epidemiology. However, same-sex married women have emerged as the group of women with the highest, and in recent years, even further increasing mortality.
Denmark implemented the world's first national law on registered same-sex partnerships in 1989. Mortality was markedly elevated among people in same-sex marriages for the first several years after this, but since 1996, with the advent of effective ...
Sildenafil for heart failure does not result in significant improvement in exercise capacity
2013-03-12
Among patients with heart failure with preserved ejection fraction (a measure of heart function), administration of sildenafil for 24 weeks, compared with placebo, did not result in significant improvement in exercise capacity or clinical status, according to a study published online by JAMA. Some studies have suggested that phosphodiesterase-5 inhibitors (a class of drugs that includes sildenafil) may improve cardiovascular function. The study is being released early to coincide with its presentation at the American College of Cardiology's annual Scientific Sessions.
Heart ...
Combination therapy for heart failure does not reduce risk of CV death or rehospitalization
2013-03-12
Among patients hospitalized for heart failure (HF) with reduced left ventricular ejection fraction (LVEF; a measure of how well the left ventricle of the heart pumps with each contraction), initiation of the medication aliskiren in addition to standard therapy did not reduce cardiovascular death or HF rehospitalization at 6 or 12 months after discharge, according to a study published online by JAMA. The study is being released early to coincide with its presentation at the American College of Cardiology's annual Scientific Sessions.
"Inhibition of the renin-angiotensin-aldosterone ...