Angel Tarragon
Dawn Dragon
World Science: Habitable Planet Might Not Be So Far Off
An Earth-like, habitable planet may be in our stellar neighborhood, and could be found with a dedicated telescope, new computer simulations suggest.
Astronomers have long been looking for potentially habitable planets, and one team finally reported a candidate planetary system last year. But no place where researchers have pinned their hopes is nearly as close where the new study points.
The nearest stars to our Sun are in the three-star system called Alpha Centauri—a popular travel destination in science fiction, though it’s unlikely humans could get there anytime soon.
Using simulations based on current planet-formation theories, researchers concluded that Earth-like planets should have formed around one member of this system, the star Alpha Centauri B.
One of these worlds, they added, could well be orbiting in the star’s “habitable zone,” a region suitably warm for liquid water to exist on a planet surface.
“If they exist, we can observe them,” said Javiera Guedes, a graduate student at the University of California, Santa Cruz. Guedes is first author of a paper detailing the findings, accepted for publication by the research publication Astrophysical Journal.
“I think the planets are there, and it’s worth a try to have a look,” added astronomer Gregory Laughlin of the university, a coauthor. The investigators said they ran the reenactments repeatedly with different starting assumptions, and got at least one Earth sized planet each time, and in the habitable zone much of the time.
Most of the 228 planets discovered outside our solar system so far have been found through the Doppler method, which analyzes starlight to detect tiny wobbles in a star due to a planet’s gravitational pull. But it’s challenging to detect rocky, Earth sized planets because they cause only a tiny wobble.
But Laughlin said several factors make Alpha Centauri B an excellent candidate for finding terrestrial planets. These include the brightness of the star and its position in the sky, which gives it a long period of observability each year from the Southern Hemisphere. Laughlin said it would take five years of watching using a dedicated telescope to detect an Earth like planet around Alpha Centauri B.
Co author Debra Fischer of San Francisco State University is leading a program to intensively monitor Alpha Centauri B and neighboring Alpha Centauri A. Her team is using the 1.5 meter telescope at the Cerro Tololo InterAmerican Observatory in Chile.
Visiting any hypothetic aliens in Alpha Centauri would not be an easy project, despite the stars’ relative proximity of about 4.36 light-years. A light year is the distance light travels in a year, so it would take about four years for light to get there from here. Our fastest space crafts used to date would take about 60,000 years to go there, although some scientists predict new technology could reduce that time considerably.
The planet astronomers fingered last year as a potential site for life, called Gliese 581c, is about 20.5 light years away. Its habitability has since come under question, but some astronomers say another planet orbiting the same star might be liveable.
The Alpha Centauri triple stellar system is our closest neighbour in space. It lies 4.36 light years away in the direction of the southern constellation Centaurus. In the photo above, the two brighter stars of the system appear as merged together due to their luminosity and proximity. The small arrow at lower right indicates the location of the third, dim star, Proxima Centauri. (Credit: 1-Meter Schmidt Telescope, ESO)
An Earth-like, habitable planet may be in our stellar neighborhood, and could be found with a dedicated telescope, new computer simulations suggest.
Astronomers have long been looking for potentially habitable planets, and one team finally reported a candidate planetary system last year. But no place where researchers have pinned their hopes is nearly as close where the new study points.
The nearest stars to our Sun are in the three-star system called Alpha Centauri—a popular travel destination in science fiction, though it’s unlikely humans could get there anytime soon.
Using simulations based on current planet-formation theories, researchers concluded that Earth-like planets should have formed around one member of this system, the star Alpha Centauri B.
One of these worlds, they added, could well be orbiting in the star’s “habitable zone,” a region suitably warm for liquid water to exist on a planet surface.
“If they exist, we can observe them,” said Javiera Guedes, a graduate student at the University of California, Santa Cruz. Guedes is first author of a paper detailing the findings, accepted for publication by the research publication Astrophysical Journal.
“I think the planets are there, and it’s worth a try to have a look,” added astronomer Gregory Laughlin of the university, a coauthor. The investigators said they ran the reenactments repeatedly with different starting assumptions, and got at least one Earth sized planet each time, and in the habitable zone much of the time.
Most of the 228 planets discovered outside our solar system so far have been found through the Doppler method, which analyzes starlight to detect tiny wobbles in a star due to a planet’s gravitational pull. But it’s challenging to detect rocky, Earth sized planets because they cause only a tiny wobble.
But Laughlin said several factors make Alpha Centauri B an excellent candidate for finding terrestrial planets. These include the brightness of the star and its position in the sky, which gives it a long period of observability each year from the Southern Hemisphere. Laughlin said it would take five years of watching using a dedicated telescope to detect an Earth like planet around Alpha Centauri B.
Co author Debra Fischer of San Francisco State University is leading a program to intensively monitor Alpha Centauri B and neighboring Alpha Centauri A. Her team is using the 1.5 meter telescope at the Cerro Tololo InterAmerican Observatory in Chile.
Visiting any hypothetic aliens in Alpha Centauri would not be an easy project, despite the stars’ relative proximity of about 4.36 light-years. A light year is the distance light travels in a year, so it would take about four years for light to get there from here. Our fastest space crafts used to date would take about 60,000 years to go there, although some scientists predict new technology could reduce that time considerably.
The planet astronomers fingered last year as a potential site for life, called Gliese 581c, is about 20.5 light years away. Its habitability has since come under question, but some astronomers say another planet orbiting the same star might be liveable.
The Alpha Centauri triple stellar system is our closest neighbour in space. It lies 4.36 light years away in the direction of the southern constellation Centaurus. In the photo above, the two brighter stars of the system appear as merged together due to their luminosity and proximity. The small arrow at lower right indicates the location of the third, dim star, Proxima Centauri. (Credit: 1-Meter Schmidt Telescope, ESO)
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