Hua Feng saw that scientists at the observatory observed that the planet orbited a red dwarf star Gliese 581. A red dwarf is a low-energy, smaller star. Red dwarfs emit faint red light that lasts longer than the Sun.

The newly discovered planet was named "581c". The discovery will certainly spark research into planets orbiting similar faint stars. About 80% of the stars in the vicinity of Earth are red dwarfs.

"581c" weighs about 5 times more than the Earth. The scientists who discovered "581c" are not sure whether it is a rocky planet like Earth or a "big ice ball" with liquid water on its surface. If it were made up of rocks like the Earth, it would be about 1.5 times larger in diameter than the Earth. If it's a "big puck", the diameter may be larger.

According to the theory, "581c" should have an atmosphere. But the components of the atmosphere remain a mystery. If the atmosphere is too thick, the planet's surface temperature will be too high.

However, scientists believe that the average temperature of "581C" is between 32 and 104 °C. The discovery sparked celebration among astronomers.

So far, all 220 exoplanets discovered by astronomers are either too hot, too cold, or too large to be inhabitable. And the newly discovered "581c" looks just right.

Chris McKay, an expert in cosmobiology at NASA, said: "This could be very important. This does not mean that there is life there, but it does mean that it is a planet similar to Earth, judging by its probable habitability. ”

Another astronomer hypothesized that, in addition to having the right temperature, the newly discovered planets could also be filled with liquid water. But that is not based on any evidence, but on the theory of planetary formation.

Other astronomers cautiously say it's too early to say whether there is water on 581c.

The galaxy in which the new planet is located is only 20.5 light-years away from Earth, and the star Gliese 581 in the galaxy is also one of the 100 closest stars to Earth.

Everyone who wants to go to planet "581c" must know that they will be heavier to sit on that planet, and that they will also get older faster, because it only takes 13 days for "581c" to orbit the star.

The acceleration of gravity on "581c" is 1.6 times that of Earth, so you will feel like you have gained 0.6 times your weight.

"581c" is 14 times closer to the star it orbits than the Earth is from the Sun. From "581c", the star in the sky is 20 times larger than the moon we see on Earth. And "581c" will most likely not rotate, so that half of it will always be day, and the other half will always be night.

The existence of terrestrial planets outside the solar system, and even the possibility that the plants on the terrestrial planets may be red The discussion about whether there is life on these planets continues. With the continuous advancement of cosmic exploration technology, astronomers have discovered more and more terrestrial planets, and the research on this aspect has been continuously valued by scientists.

A few days ago, astronomers from NASA found new evidence through spectral analysis through the analysis of the spectrum that confirmed the existence of terrestrial planets, and that life on these planets is very likely.

In the next decade, when astronomers can study terrestrial planets outside our solar system, they may find that the plants that grow on those planets are not green, but may be yellow, orange, or red. The color of the plant depends on the color of the stars in the galaxy in which the planet is located and the composition of the atmosphere that orbits the planet.

This conclusion was reached by scientists at the Virtual Planetary Laboratory of the California Academy of Sciences, sponsored by NASA. Scientists have used computer models to simulate a model map of the future search for and study of terrestrial planets.

The scientists published the latest findings in the journal Astrobiology, which also discusses how plants on terrestrial planets photosynthesize.

Nancy Creon, a biologist from NASA's Goddard Center for Space and Space Research, who led the study, said it was important to determine the range of colors that plants on extrasolar terrestrial planets might appear in, because scientists need to know what to look for when they have spectral information from these planets.

"Plants may have images of yellow, orange or red through photosynthesis," Creon said. I don't think it's possible to have blue, of course, green is the most likely, and that's the case with plants on Earth. ”

Victor Mydels, an astrobiologist from the California Institute of Technology and head of the Virtual Planetary Lab, said, "We have adopted interdisciplinary techniques in our research process, and the whole research activity includes many disciplines, including planetary science, biology and meteorology, and these interdisciplinary techniques make our research activities even more significant." At the same time, this research activity also provides many reliable references for us to detect the spectrum of terrestrial planets outside the solar system.

Because during certain special periods in the growth of the planet, it will reveal a lot of information through the light emitted to the outside world, such as whether there is water or life on the planet, and this information is necessary for us to explore terrestrial planets. ”

Myers, who was the first scientist to combine biology and planetology, said that such a model could not be constructed through planetology, biology or meteorology alone, and that interdisciplinary collaboration was needed to make a breakthrough in this area.

In this project, the scientists focused their research on the principle that plants use the energy of light to produce sugar, which is commonly referred to as photosynthesis by plants on Earth, because the pigments formed by photosynthesis must coincide with the spectrum of these rays.

The light rays that hit a planet are not only related to the source of the light, but also to the atmosphere around the planet. For example, the ozone layer above the Earth can attract ultraviolet rays from the sun's rays.

"This confirms that the number of photons in the spectrum is very important for us to find terrestrial planets." Most of the particles in the sun's rays hitting the Earth are red, which is why all plants on Earth are green. On Earth, plants attract blue and red light, and the energy contained in these two types of light can meet the needs of the plant, so there is no need to attract other light. As a result, the color of the plant reacts to green. ”

It is also possible that a terrestrial planet outside the solar system revolves around a planet similar to the Sun and may have an atmosphere similar to that of the Earth, so it is possible that plants may appear on the planet that can also absorb the energy of red, blue, and green rays, but the color of these plants will not necessarily reflect green. Because red light is not necessarily the most of the light it absorbs, if other light accounts for the majority, then the plant will show other colors, such as yellow or red.

There may be other factors that affect the color of plants, such as the ozone layer, carbon dioxide and water vapor in the air, and the chemical reaction of stellar rays with the planet's atmosphere. "We have taken these factors into account when building this terrestrial planet model, and we have also found that there is also an ozone-like layer of material over the terrestrial planet that is effective against intense ultraviolet rays and protects life on the planet."

Earth-like planets should have water a few feet to tens of feet underground, and the stars in their planetary systems should be cooler than the Sun, but still meet the needs of photosynthesis. All in all, the model we have built is a powerful weapon in the search for terrestrial planets and even life on them. ”

Astronomers used to think that there were few terrestrial planets outside our solar system, but with the development of cosmic exploration technology and the development of new space telescopes, they have discovered more and more planets of the same size as Jupiter. Therefore, there is reason to believe that there are many terrestrial planets in the universe.

"We may not be able to find a planet like Earth, but there may be widespread bacterial life on these terrestrial planets," Myeders said. If we can find an environment suitable for life on a terrestrial planet, then we should assume that there may be life on that planet. ”

The Virtual Planetary Laboratory is a branch of NASA's Space Biology Research Facility, established in 1997 to promote, manage, and lead interdisciplinary astrobiology research and to train a new generation of astrobiology researchers [6]

This is a hypothetical map of the star system of the planet, codenamed Kepler-22b, released by NASA on December 5, compared to the solar system.

NASA announced on December 5 that scientists have used the Kepler space telescope to discover a new habitable planet in a star system about 600 light-years from Earth, which is also the smallest and most suitable planet ever discovered for the presence of liquid water on the surface. The planet, codenamed "Kepler-22b", has a radius of about 2.4 times the radius of the Earth, is located in the middle of the "habitable zone" of the star system, the main composition is not yet known, and the period of orbiting the star is about 290 Earth days.

According to a comprehensive foreign report, the International Astronomical Organization said on the 18th that a newly discovered planet seems to be suitable for the conditions for life as we know it. Not too big and not too small, not too cold and not too hot.

The planet, Kepler-186f, orbits a star 500 light-years from Earth, about the size of Earth. As astronomers explained, it orbits its star at a distance just enough to have liquid water on the planet's surface. We know that this is the basic condition for the existence of life.

But Quintana, a planetary scientist at NASA, said via VoIP that it wasn't exactly the same as Earth. NASA planetary scientist Quintana said, "It's more like a cousin on Earth than a twin sibling." It shares characteristics with Earth, but their parent star is very different. ”

Kepler-186f orbits stars smaller than the Sun and cooler than the Sun. However, astronomers write in scientific journals that the planet is more similar to Earth than most of the hundreds of planets discovered previously.