Scientists at the European Southern Observatory (ESO) confirmed the discovery of an Earth-like exoplanet in the habitable zone of Proxima Centauri, as which is considered one of the greatest astronomical discoveries of the century. Details of this discovery were published in Nature .
Rumors about the existence of an Earth-like exoplanet began to appear from September 12 through the German weekly publication Der Spiegel . There quoting an anonymous source of the research team of the La Silla Observatory, and mentioned that “suspicion of the existence of a similar to Earth orbiting at a distance that could allow the presence of liquid water on its surface in Next planet Centauri, an important requirement for life “.
Now we know that these rumors are true. There is real evidence of the existence of a planet orbiting Proxima Centauri, a small star red dwarf type that is set just 4.25 light years away, a little closer to us than the famous binary pair Alpha Centauri A and B .
the planet has been we dubbed Next b , and the team of ESO estimates that its mass is about 1.3 times that of Earth.
“we live in a universe in which abound planets like ours. “
Its orbit is almost 7 million kilometers from Proxima Centauri, only 5% of the distance between Earth and our sun. But that star is much colder than the Sun, which means that Next b is still in what is known as “habitable zone” for an exoplanet with a temperature sufficient so that water is in liquid state on the surface.
Since it was discovered the first exoplanet in 1995, astronomers have been able to identify more than 3,000 of these planetary bodies in orbit around distant stars. “We live in a universe in which abound planets like ours,” he said at a press conference Pedro Amado, the Institute of Astrophysics of Andalusia. Overall it is estimated that the stars of red dwarf such as Proxima Centauri have small similar to our rocky planets.
According to lead author and coordinator of the project, Guillem Anglada-Escude Queen Mary University of London, the first indications of the existence of this planet appeared in 2013, but still did not have enough evidence to ensure the discovery. The latest observing campaign took the name “Red Dot Pale” (evidently because Proxima Centauri is a red dwarf), which was inspired by the famous phrase of Carl Sagan in which he described the Earth as a pale blue dot.
the team, consisting of 31 scientists from eight different countries were supported by the Doppler effect to detect a weak oscillation in the spectrum of light from Proxima Centauri, which is approaching and moving away from the Earth every 11.2 days. A variation of this type could be caused by the gravitational pull of a planet in its orbit. When comparing the program data Red Dot Pale with data that had been collected between 2000 and 2014, astronomers were able to confirm a peak in the Doppler shift indicating the presence (and therefore the discovery) of an exoplanet a close to Earth size
The technology to detect Next b has existed for at least ten years, then the question arises: why they have taken so long to make the discovery? This is because Proxima Centauri is a very active star, which means that its natural shine can be likened to signal a planet. The team relied on observations made with two other telescopes to compare how he had changed the brightness of the star over time, which allowed them to rule out the possibility of a false positive. The possibility that this signal is a false positive is just 1 in 10 million, according to Anglada-Escude
It is not yet clear whether this exoplanet has an atmosphere. Since Proxima Centauri is a very active star, Next b suffers from an X-ray flux approximately 400 times greater than we experience here on Earth, and this could avoid having its own atmosphere.
But Ansgar Reiners, of the University of Gottingen in Germany, said that this depends on how and when the exoplanet was formed. Whether it formed when I was at a greater distance from the star (and already had the presence of water), and eventually migrated to the star, or formed near Proxima Centauri. The first scenario would make it much more possible existence of a asmósfera.
“There are many models and simulations that produce different scenarios, including the existence of water and an atmosphere,” says Reiners. “We really have no idea today, but the existence [an atmosphere] is possible.” And that could be a great evidence for the possibility that the planet has life. In addition, the relative closeness of the exoplanet to our solar system makes robotic exploration is possible at any time.
“Proxima Centauri is a lot younger than our Sun, with a life expectancy of at 1,000 times less, “he said Abraham Loeb of Harvard University in the United States, who is also an adviser to the Star Initiative Yuri Milner. “A habitable planet around Proxima Centauri would be the most obvious location to which our civilization could migrate once the sun is dying, in about 5,000 million years.”
Announced last April, this initiative is a program of research and development of $ 100 million mark seeking the foundation for. the future of interstellar travel. The first step has to do with the development of “nanoships” that would be driven by light, which could travel at a speed of 20% of the speed of light. These ships could reach the star system Alpha Centauri in just 20 years. Currently, the project scientists are you trying to prove the feasibility of using powerful lasers to propel one of its solar sails.
According to Loeb, the discovery of a potentially habitable planet orbiting Proxima Centauri is a good candidate for a future mission of discovery. “A ship equipped with a camera and various filters could obtain color images of the planet and so let us know if green (which means it would host life as we know), blue (which would mean having oceans on its surface) or brown (or what is the same, it would be rocky). This sort of thing can not be known with telescopes that we have today on Earth. “
” We hope that within a generation we can launch the first ships, “said Peter Warden, the Foundation Award the Progress, during a press conference. “We now have at least a very interesting target in the crosshairs. We must obtain images to see if there is life on Next b, even considering the possibility of advanced life. Those are the biggest questions we have, and we believe we can answer this century “. [Nature]
Maddie Stone contributed to the development of this report.
Follow us on Twitter, Facebook and Flipboard.
No comments:
Post a Comment