The nearest galaxy to the sun, Centauri, has an exoplanet in its system called Proxima Centauri B, which is a very peculiar kind of planet, according to astronomers, because it's the closest planet to Earth found so far. And its star, Centaur, is smaller than the Sun. Recently, though, scientists seem to have found something amiss!
Proxima B is a planet slightly larger than Earth that rotates and orbits in its habitable zone. Scientists suspect there could be water on it, and perhaps even life. Although Proxima B is similar to Earth, it is a strange planet. Proxima A's parent star, Centauri, is a strange three-star, and astronomers still don't understand how this system works. The other two are tentatively binary, meaning they both orbit the same center of gravity, and are collectively known as Alpha Centaur!
According to astronomers, the main star of Centauri can pass through two other stars or have a gravitational center of mass in orbit with it. If so, it would take half a million years to orbit Alpha Centaur. It would take millions of years to stay in the region. Red dwarfs like "Near neighbors" were thought to be too close to each other to support habitable planets, but because of their orbital distances, they are now the best places to look for habitable extrasolar planets, according to astronomers. The Guardian published a curious message from the constellation Centaurus B.
The signal appears to be coming from our nearest star, which is 4.2 light years away. Some think it's a high-tech signal of alien intelligence, but in fact it's the opposite, but we won't know what it means until we get to Proxima Centauri to observe it. But it's impossible to reach Proxima B, so astronomers have to look at it from Earth 39bet-kết quả bóng đá-kết quả xổ số miền bắc-kèo bóng đá -soi cầu bóng đá-đặt cược.
In the meantime, they published it in a report by Harvard astronomer Arxiv Loeb. Loeb, who has expertise with Kriedberg in the field of planetary atmospheres, speculated that a civilization operating near its small red dwarf star would most likely be trapped by constant tides, similar to the Earth-moon system. Loeb says it is very difficult to find stars near Centaurus without dedicated instruments. To find the extrasolar planet's main star, astronomers had to use tricks that make the planets wobble slightly as they orbit the star.
Using the European Southern Observatory's telescope, astronomers in Chile performed a Doppler oscillation of Proxima Centauri by looking for the Doppler effect, or changes in apparent wavelength, and found that the object is surrounded by a planet slightly larger than Earth in diameter, about 4.3 million kilometers from its parent star. But the galaxies are very different from one another. The red dwarf Centaur is a much cooler star than its neighbor, with only 15 percent of the Sun's radius. So Proxima B is actually closer to Proxima Centauri than Earth. Because it sits in the habitable zone, a small star should look more coordinated, but the good news is that flares occur more often on red dwarfs than on the Sun. As a result, its planets experience more extreme space weather than Earth does in neighboring galaxies.
As humanity struggles with major issues such as climate change and its worsening effects, people sometimes consider whether it is possible for humanity to survive on another planet, given the increasing difficulties faced by life on Earth. Proxima B isn't necessarily habitable, even though it's in the habitable zone. For example, even though it's in the habitable zone, the distance from its host star, water can pool on the planet's surface. But we have to consider whether the planet actually has water, or whether the atmosphere can last in that orbit. At this point, all theories agree that Proxima B has the right atmosphere, but it's so close to its parent star that the average amount of radiation produced by proxima Centauri is high.
At high levels of ultraviolet light, atmospheric molecules are ionized, breaking up electrons and forming a beam of charged particles. The attraction between the two different charges pulls more negatively charged electrons out of the atmosphere, creating a strong charge separation that pushes positively charged ions out into space and causes Proxima B to experience radiation hundreds of times more intense than Earth. These radioactive materials can release enough energy to slowly separate heavy elements like oxygen and nitrogen from the lightest hydrogen molecules. The researchers looked at two factors that increase losses in the atmosphere to see how this process changes, starting with the temperature of the thermosphere, or hollow space. They found that as more solar radiation warms the thermosphere, so does atmospheric escape, an anomaly recently discovered on Proxima Centauri.
The researchers also took into account the size of Proxima B's polar cap, the region where atmospheric escape occurs. At their magnetic poles, planets are the largest polar caps susceptible to magnetic effects, and when the magnetic field lines at the poles close, the caps become constrained, trapping charged particles in the vicinity of Earth. On the other hand, when magnetic field lines are open, more escapes occur, providing a one-way path into space. The researchers demonstrated that if it had the highest thermosphere temperature and a fully open magnetic field, under scientists' minimum temperature and closed magnetic field assumptions, most of the mass would escape within 2 billion years. In other words, the planet would eventually lose the conditions for life to exist, too.
Because red dwarfs are the coldest, smallest and most ubiquitous stars in the galaxy, they are often the target of exoplanet searches. Planets need to stay in tight orbits, however, and scientists have found that such close distances are not promising for atmospheric survival or sustainability unless atmospheric losses are offset by some other process, such as massive volcanic activity or comet bombardment. We think that if there is life on Proxima B, it could be quite different from life on our own planet, because this species would need to emerge and grow in a completely different environment. So our best hope is to drill down and look for life below the surface. So do you think there's any hope for life on Proxima B? Feel free to leave your comments!