31772a6dd13fa30012a6de614c7ac0fc9734955e5797a33812 Money And Knowledge: Milky Way may hold 4.5 billion Earth-like planets, one of which sits nearby

Milky Way may hold 4.5 billion Earth-like planets, one of which sits nearby



It seems the Milky Way may have more than one Earth.
According to a team of astronomers, a planet similar to Earth may lie much closer to us than previously thought. The potential Earth-like planet is estimated to be just 13 light years away, or 77 trillion miles.
While astronomers have yet to discover the planet, recent research on red dwarf stars suggests that upwards of nearly 5 billion Earth-like planets may exist in the Milky Way alone.
When considering the sheer size of the universe, the potential Earth-like planet is much closer than scientists ever imagined. While the proposed distance may seem like quite a lot, relative to the vast expanse of the cosmos, it’s fairly short. According to the study’s lead author, Harvard University graduate student Courtney Dressing, if the Milky Way was the size of the United States, the distance between Earth and an Earth-like planet is the equivalent of a stroll across Central Park in New York City.
“The nearest Earth-like planet is simply a stroll across the park away,” Dressing said at a press conference in Cambridge, Massachusetts.
The Harvard-Smithsonian Center for Astrophysics research team was able to reach its conclusion regarding the existence of an Earth-like planet based on their research of red dwarfs stars. There is an estimated 75 billion red dwarfs in the Milky Way galaxy, making it the most abundant type of star. According to astronomers, six percent of red dwarf stars contain a planet similar to Earth, leading them to calculate the figure. In order to be considered “Earth-like,” the planet must match in size to Earth and receive as much light from its star as Earth receives  from the sun. The ultimate goal of finding Earth-like planets is to narrow down the search for extraterrestrial life forms on alien planets.
Despite fitting the criteria of being “Earth-like,” co-author David Charbonneau pointed out that these planets are quite a bit different from our native planet. Most of these differences are attributed to differing distances between the planets and their red dwarf stars.
Red dwarf stars are usually much smaller than the sun in our solar system so the Earth-like candidates must orbit much closer to the red dwarf than Earth does the sun. While the planets may be rocky like Earth, the astronomers pointed out that they may have drastically different atmospheres and thus very different life forms.
Some red dwarf stars are also much older than the sun in our solar system This has led scientists to wonder if life on Earth-like planets could be more highly evolved than life on Earth.
It should be noted that this is not the first study to attempt to estimate the number of Earth-like planets in our own galaxy. A number of studies released over the past several months have put forth estimates ranging from billions to trillions of Earth-like planets. Among the most interesting analysis comes from a study based on initial data from from NASA’s Kepler space telescope, which  says the Milky Way galaxy may be home to at least two billion Earth-like planet. The figure, at the time, was far higher than astronomers predicted.
That said, the new finding is “extraordinarily exciting” for astronomer John Johnson of the California Institute of Technology, who said discovering a true Earth-like planet will likely occur during our lifetime.
“It’s right within reach,” he said. Scientists are “hot on the trail of finding life elsewhere in the galaxy.”
While estimates for the number of Earth-like planets continue to grab headlines, NASA astronomers say they expect the figures to be refined over time as its planet-hunt telescope, Kepler, continues to collect data on exoplanets.
These latest findings are based on data from NASA’s Kepler space telescope and they are set to be published in The Astrophysical Journal.