`Earth-sized` habitable planets more common than thought
Washington: The number of potentially habitable planets is greater than previously thought and some of those planets are likely lurking around nearby stars, a new analysis by a Penn State researcher as concluded.
"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. There could be more," he added.
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," he added.
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," he added.
Kopparapu detailed his findings in a paper accepted for publication in Astrophysical Journal Letters.
More from India
More from World
More from Sports
More from Entertaiment
- Zee Media Exclusive: Kangana, Madhavan talk about their film 'Tanu Weds Manu Returns'
- DNA: Harmful chemicals found in Maggi, Nestle India still in denial mode
- CM Kejriwal shortlists 39 'unwanted' IAS officers in Delhi
- Rajasthan: Gujjars revive reservation agitation, block rail track
- Zee Media Exclusive interview with Congress leader Kamal Nath
- DNA: Modi-led NDA govt's hits and misses in one year
- J Jayalalithaa sworn-in as Chief Minister of Tamil Nadu
- Mumbai: One injured in shootout at Film City
- ISIS to buy first nuclear weapon from Pak?
- Mumbai: CCTV captures assailant with gun at Film City
- Dr Subhash Chandra Show: Aspiring for more than what you have!
- BJP now central pole of Indian politics: Arun Jaitley
- Zee Media Exclusive chat with 'Tanu Weds Manu Returns' cast Kangana, Madhavan
- Maharashtra FDA sends Maggi noodles for lab testing
- Mathura SSP receives death threat letter, message for PM Modi
- IPL 2015, Qualifier 2: CSK vs RCB - As it happened...
- India to soon have its own space shuttle!
- PM Narendra Modi graces Digvijay Singh's son wedding reception
- Rahul Gandhi to pressurise govt to act on one-rank-one-pension issue
- Goa Board SSC Exam Results 2015 announced
- ISIS close to buying nuclear weapon from Pakistan?
- CBSE 12th Results 2015: CBSE Board Cbse.nic.in & cbseresults.nic class 12th XII board exam Results 2015 date announced
- Manohar Parrikar visits forward areas along LoC, reviews security situation
- Businessman shot next to Amitabh Bachchan's shooting location in Mumbai Film City
- There will be no delay in appointing CIC, CVC: Jitendra Singh
- Credibility of Prime Minister's Office restored by BJP, says Arun Jaitley
- CBSE Board 10th Results 2015: Cbse.nic.in & Cbseresults.nic class 10th X board exam results 2015 date announced
- ISIS justifies raping slave girls, says Michelle Obama is 'worth $40'
- LIVE SCORE: 1st Test, Day 2 - England vs New Zealand
- Arvind Kejriwal to highlight AAP govt's 100 days work on Monday