TRAPPIST-1 planetary system, will it be the new home of mankind? Scientists gave six points.

In 217, NASA announced that seven planets about the size of the Earth were found orbiting a single star in the TRAPPIST-1 system. So what do we need to know about TRAPPIST-1 system?

in 217, NASA announced a historic discovery: for the first time, humans discovered seven planets about the size of the earth in a single-satellite system. Although astronomers have discovered planets similar in size to the earth before, they have never found so many that revolve around a star at the same time. This happens on a supercooled M-dwarf, whose name is TRAPPIST-1.

from the overwhelming multimedia reports, we summarized the following six important contents to help readers understand why TRAPPIST-1 and its seven planets are so important, and how this discovery leads to more questions about extraterrestrial life.

because the brightness and heat of each star in the universe are different, the range of suitable liquid water near different stars is also different. Because water is a key raw material for living things like us, this lukewarm distance range that just allows liquid water to exist is sometimes called the "golden zone" or the livable zone of stars.

of the seven earth-sized planets found around TRAPPIST-1, three are located in the livable zone. However, the distance from the parent star is not the only factor that determines the temperature of the planet: the atmosphere on the planet also plays a big role. For example, in our solar system, Venus, Earth and Mars are all located in the livable zone of our sun. Unfortunately, Venus is experiencing a runaway greenhouse effect. This greenhouse effect is creating a very thick atmosphere, which is as good at absorbing heat as a warm quilt. At the other extreme is Mars, where the atmosphere is very thin, resulting in a great temperature difference between day and night. Therefore, as long as there is an atmosphere, any one of the seven TRAPPIST-1 planets may have a temperature suitable for life, but the planets located in the livable zone are more likely.

Our sun is a common G-shaped star, that is to say, its luminous intensity is between white light and yellow light, and its surface temperature is 5-6 Kelvin, which is the middle part of the known star temperature range. TRAPPIST-1 is a supercooled M-dwarf, which means that it is 1 times smaller than our sun-in fact, it is only a little bigger than Jupiter-and its surface temperature is less than half that of the sun.

this lower temperature means that the habitable zone of TRAPPIST-1 is closer to the stars than that of our solar system. The period of revolution of the three planets found in the TRAPPIST-1 livable zone is between 6 and 12 days, which means that the "one year" span of any of these newly discovered planets is less than the two weeks mentioned on our planet. In fact, the entire TRAPPIST-1 system is only slightly larger than Mercury's orbit around the sun. It is even more impressive to find that three planets are still squeezed into a narrow livable zone at such a close distance.

the difference between another sun and TRAPPIST-1 is their activities. Dr Barbara Rojas Ayala, an M-dwarf expert and associate professor in Santiago, Chile, said that supercooled M-dwarfs may be very active. "Their flares may be very powerful, so their high-energy radiation in the form of X-rays and ultraviolet rays can affect the planet's atmosphere, thus affecting its livability.

the name TRAPPIST-1 comes from the TRAPPIST telescope in Chile. The telescope first identified TRAPPIST-1 system as a potential multi-planet system last year. Later, the European Southern Observatory's Super Telescope and Spitzer Space Telescope not only confirmed the discovery of the telescope, but also really discovered seven planets.

Dr. Rojas Ayala warned that our understanding of these planets is still lacking, and it is impossible to determine whether they are more like the Earth or Venus. "Only from the size characteristics of the earth and Venus, they are like twins, but obviously they have very different geological histories. These new planets will be exciting targets for the James Webb Space Telescope, which can tell us what their atmosphere is like. "

All seven planets are close to their stars, and the seven stars are also close to each other, which indicates that they may be tidal locking, that is, one side of the planet always faces TRAPPIST-1, while the other side always faces away from the star. Therefore, if you like the life of alternating day and night, then the journey to the planet in TRAPPIST-1 system may not be suitable for you. Those who have heard of the dark side of the moon may remember that the moon was also tidal locking by the gravity of the earth, although the so-called dark side of the moon is not really dark.

TRAPPIST-1 system is "only" 39 light years away from us, which is 1 times the distance from our nearest neighbor Alpha Centauri. Although 39 light years is close in astronomical sense, it is still 23 trillion miles away. Interstellar travel is still incredibly challenging-we haven't launched a probe outside the solar system, and humans themselves have never been farther than the moon.

TRAPPIST-1 is also younger than the earth's age of 4.5 billion years, only 5 million years. Although so young, it does not rule out the possibility that the planet orbiting it will be globalized, but it may not take long enough for the planet of TRAPPIST-1 system to evolve the creatures we know.

Therefore, at present, the most important thing is still to treat our own earth well, not to place hopes on the large-scale alien immigrants in the future.

The first exoplanet was discovered and confirmed in 1991. In less than 3 years, we have known that there are more than 3,4 planets orbiting other stars. Of course, apart from the dramatic event that Pluto was downgraded to a dwarf planet, our sun still has many planets. Now we know that there are seven planets, especially seven planets in or near the habitable zone of stars, which can exist around a single star, so our chances of finding planets suitable for life have actually increased seven times.

Perhaps more importantly, because the number of M-type dwarfs in the universe far exceeds that of stars like our sun, we are more likely to find new livable planets around M-type dwarfs, or even examples of potential livable planets, so there is a greater possibility of livable planets in galaxy regions that we have not yet explored.

1.WJ Encyclopedia

2. Astronomical terms

3. zhi is reproduced in the next engraving-Sabrina Stierwalt

. Please also obtain authorization, and pay attention to maintaining integrity and indicating the source.