Astronomers have long studied the universe for signs of life elsewhere.
They even say that many distant worlds have conditions that could be suitable for life.
But two new studies claim that we may have missed a key issue: wind.
Scroll down to watch the video
The approximately exoplanet of Proximate Earth is thought to be in orbit within the habitable zone of our closest stellar neighbor, only 4.2 light years away. The impression of an artist is represented, but researchers now believe that a stellar wind may have stripped it of the ingredients for life
THE STELLAR BELLY
The stellar wind is the powerful and incessant flow of particles that flow outward from a star.
The Earth is protected from the weight of the Sun's wind by a magnetic field that surrounds the planet.
The field, called the magnetosphere, diverts most of the stellar wind that could break in Earth's atmosphere, but exoplanets orbiting near red dwarf stars may not be so lucky.
The two research papers published in Astrophysical Journal Letters reveal that the stellar wind may have stripped many candidates of their chance to live.
& # 39; The traditional definition and climate models of the habitable zone consider only the surface temperature, & # 39; Chuanfei Dong of Princeton, who led the first study, said.
"But the stellar wind can contribute significantly to the long-term erosion and atmospheric loss of many exoplanets, so climate models only tell part of the story."
The first document badyzes the time scale of atmospheric retention in Proxima Centauri b (PCb), which orbits the star closest to our solar system, about four light-years away.
The second document questions how long the oceans could survive in the "water worlds": planets that could be hundreds of miles deep.
Studies show that stellar wind, a steady stream of charged particles moving into space, could severely reduce the atmosphere of these planets for hundreds of millions of years, rendering them incapable of housing life as we know it.
In Proxima Centauri b, the model indicates that the high pressure of the stellar wind would cause the atmosphere to escape and prevent the atmosphere from lasting long enough to give rise to a life based on the surface. ow it. "
The evolution of life takes billions of years," Dong said.
Our results indicate that similar PCBs and exoplanets are generally not able to withstand an atmosphere at sufficiently long timescales when the stellar wind pressure is high. & # 39;
& # 39; It's only if the pressure is sufficiently low & # 39; he said. , And if the exoplanet has a reasonably strong magnetic shield like that of the Earth's magnetosphere, the exoplanet can retain an atmosphere and has the potential for habitability. & # 39;
WHAT IT DOES NEXT B UNIQUE
Distance : This is the closest terrestrial planet we could find.
In orbit around our nearest star, the planet is only four light-years away.
Missions to send spacecraft to the planet for signs of life are already in planning, and could happen within decades.
Composition : The planet is rocky and similar in size to Earth.
Temperature: It is located in the "habitable zone" of its star, which means it could be liquid water on its surface – a key ingredient for extraterrestrial life.
The temperature on the planet's surface could be between -90 ° and 30 ° Celsius (-130 and 86 Fahrenheit).
Atmosphere : If Proxima b has an atmosphere, the simple ingredients-water, carbon dioxide, and rock-that are necessary for the formation of biochemical cycles we call life, could all be present and interacting on the surface of the planet.
Researchers simulated the photochemical impact of light from stars and the electromagnetic erosion of the stellar wind in the atmosphere of exoplanets.
They also found that the habitable zone surrounding the red stars could evolve over time, which means that the atmosphere could have eroded too soon, even if the exoplanet was protected by a strong magnetic field such as the magnetosphere that surrounds the Earth .
such nearby planets could also be blocked by tides like our moon, with one side always exposed to the star.
The resultant weak global magnetic field and the constant bombardment of the stellar wind would serve to intensify the losses of atmosphere on the side of the star.
The results indicate the high probability of dry surfaces on planets orbiting red stars that may have once housed oceans that could give life, the researchers concluded.