The Discovery History of Superterrestrial Planets

Scientists at the Geneva Observatory in Switzerland announced at the academic conference held in France on June 16, 2008 that they had discovered five new "super earths". Among the five "super-earths" discovered this time, three are located in the direction of easels and swordfish, 42 light years away from the earth, and their mass is 4.2 times, 6.7 times and 9.4 times that of the earth respectively. These three "super earths" revolve around a star slightly smaller than the sun. Period of revolution is 4 days, 10 and 20 days respectively. The fourth "super earth" revolves around the star HD 18 1433 with a period of 9.5 days. The star HD 18 1433 also attracts a planet similar to Jupiter, and the period of revolution lasts for three years. The fifth "super earth" has 22 times the mass of the earth and revolves once every four days.

Since 1995 discovered the first "super earth", astronomers have successively detected more than 270, most of which are as huge as Jupiter and Saturn, and few planets are similar in size to the earth. Because most "super-Earths" are too far away from us, astronomers can't directly observe them with the naked eye through ordinary astronomical telescopes, and can only "indirectly measure" the existence of "super-Earths" through detection means such as radio waves or spectral analysis. On June 5438+February 65438+June 2009, according to American media reports, an international research team composed of American and Australian scientists found that there are four terrestrial planets in two adjacent sun-like star systems, two of which are called "super-earths". Researchers believe that this discovery will provide important clues for human beings to find habitable planets, and the hope of finding habitable planets will greatly increase in the next few years.

Among these four terrestrial planets, two are called "super-earths", which are more massive than the earth, but less massive than Uranus and Neptune. The existence of these "super-earths" shows that it is only a matter of time before a livable planet similar to Earth is found.

Among the four newly discovered terrestrial planets, three are located around the star "6 1 virgo". The star "6 1 Virgo" is actually equivalent to the twin brother of the sun, 28 light years away from the earth and located in Virgo. At this time of year, people can observe Virgo for several hours in the night sky before the sun rises. The researchers estimated the possible minimum masses of the three planets. Chris Tinney, a member of the research team and an astronomer at the University of New South Wales in Australia, believes that the minimum mass of "6 1 Vir b" is about 5. 1 times that of the earth, and the mass of "6 1 Vir c" is about 18 times that of the earth. Tinny believes that "the mass of the smallest planet is just within the mass range of the super earth. This is the first time that a planet of this size has been found around a sun-like star. " Previously, scientists have found "super earth" around other stars, but those stars are much colder than the sun.

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Astronomers believe that this planet is closer to the earth than any exoplanet found outside our solar system.

Beijing, China, 12, 2009 17/ Sina Science and Technology reported that astronomers found an earth-like planet orbiting a dim star, only 40 light years away from the earth. It is a steaming "water world" with a volume six times that of the earth. It is believed that 75% of the earth's surface is covered with water, but because of its high temperature, it cannot support the existence of life on earth. There is evidence that this "water world" also has an atmosphere. Astronomers believe that this planet is closer to the earth than any exoplanet previously discovered outside the solar system.

By measuring the brightness reduction caused by the passing of the planet, scientists can calculate the density of the planet and make wise guesses about its composition. The newly discovered planet is named "GJ 12 14b". It is believed that three quarters of the surface is covered with water and ice, and only one quarter of the surface is rock.

Chakri Berta, a graduate student and astronomer at Harvard-Smithsonian Center, discovered this water planet. He said: "Despite the high temperature, this is still a world with water. Compared with any other known exoplanet, this planet is smaller, colder and closer to the Earth. "

Scientists believe that there must be something blocking the light from the parent star except the surface of GJ 12 14b, and there may be an atmosphere composed of hydrogen and helium around it. With the help of the Hubble Space Telescope, astronomers can determine the composition of the planet. David Charbonneau, director of the Mills project, said: "Since this planet is very close to the Earth, Hubble should be able to detect the atmosphere and determine its composition. With luck, it will be the first super earth with a proven atmosphere, although this atmosphere may not be as friendly to life as we know. "

This discovery was published in the journal Nature on June 6th, 65438. Professor Jeffrey Marcy, a famous planet hunter and a professor at the University of California, USA, speculated on the possible scenes of this water world in an article published in Nature magazine. He wrote: "It may have a very deep ocean and should be liquid. Due to the heat given by the parent star, its surface temperature reaches about 190 degrees Celsius. In addition, a steam atmosphere similar to a sauna may also exist. " Planets outside our solar system. Its working principle is "occultation observation"-when one or several planets pass in front of their parent star, the light of the star is partially blocked, and its brightness will decrease slightly accordingly. Through the unprecedented accurate photometry of Kepler telescope, we can detect this brightness change and infer the existence of occultation, that is, planets. After analyzing the data of Kepler telescope in the past seven months, the team of scientists at Harvard Smithsonian Center for Astrophysics discovered two planetary targets, which revolve around a star numbered Kepler -9. This star is about 2300 light years away from the earth.

One of the planets numbered Kepler -9b has an orbital period of only 19 days around its parent star. The other one, Kepler -9C, takes 39 days to make a revolution.

The researchers found that the orbits of the two planets changed periodically. This means that there is "gravitational vibration" between the two planets-their gravitational interaction affects their respective orbital characteristics. Using these data, researchers can calculate the mass of two planets. The calculation results show that these two planets are gas giant planets slightly heavier than Saturn.

But when the researchers tried to explain the brightness loss of the central parent star by the size of these two planets, they were surprised to find another faint occultation star. The weak signal detected indicates that there is a smaller planet in this galaxy with an orbit closer to the parent star. Its orbit period of revolution is 1.6 days. The mass of this planet is about 1.5 earths, and it is a terrestrial planet made of rocks.

But researchers can't celebrate yet, because such a weak signal has many interference factors. The background star or companion star in binary system will also produce similar signal effect. "So far, we can only say that we have found a very interesting signal, and we hope we can get more information soon," Matt holman said. He is the chief scientist of this research. But even if this signal turns out to be an Earth-like planet, it is unlikely that humans will want to emigrate there: according to its orbital position, the surface temperature of this planet is about 1900 degrees Celsius. On September 29th, 20 10, astronomers from the National Science Foundation of the United States announced the discovery of a planet which is the most similar to the Earth so far, and its environment and temperature in some areas are suitable for human habitation.

This planet named Gliese 58 1g is located in Libra and orbits the red star Gliese 58 1, which is much smaller than the sun. The star is 20 light-years away from the Earth, and astronomers found that there are six planets orbiting Gliese 58 1. The other five (Gliese 58 1b to Gliese 58 1f) are not located in the "habitable zone" (habitable zone), but this one is located in the habitable zone, and its temperature is neither too hot nor too cold, so liquid water can form oceans, lakes and rivers.

Gliese 58 1g is probably a rocky planet with water and atmosphere on its surface. Its diameter is about 1.2 to 1.4 times that of the earth, and its mass is about 3. 1 to 4.3 times that of the earth. Its gravity is close to the earth, and the average surface temperature is between -3 1 and-10. The temperature of the red dwarf star it surrounds is only 1/50 of that of the sun, and its volume is 1/3 of that of the sun. Gliese 58 1g orbits its "sun" for only 37 days. One side of Gliese 581g is always facing the "sunshine" and the other side is always in darkness. Therefore, its sunny side may be very hot, the temperature can reach more than 100 degrees, and the temperature of the backlight side can be tens of degrees below zero.

For living or future human immigrants, the most suitable place is the "gray" zone-the transition zone between darkness and light in Gliese 581g. According to their different longitudes, many life can find a stable climate suitable for their emergence and evolution.

Astronomers have discovered nearly 500 planets outside our solar system. However, they are almost too big, made of gas instead of rock, and the temperature is either too hot or too cold for our life. Justin, an astronomer at Pennsylvania State University, said, "This is the first planet that really excites me." He thinks this planet is very suitable for breeding life.

Finding life on other planets does not mean finding aliens, but even finding a single-celled bacterium on another planet will shake the view that life on earth is unique. However, we still have many unsolved mysteries about this planet. Scientists can't confirm whether there is water on it and what is its atmospheric composition, but because its environment is very suitable for the existence of liquid water, and there seems to be life where there is water on the earth, Justin thinks that "the possibility of life on this planet is 100%".

Relatively speaking, the time to find this planet is not long and the difficulty is not great. Astronomers believe that there are millions of such terrestrial planets waiting for us to explore. The discovery of gliese 58 1g is based on the observation results of Hawaiian W.M. Keck Observatory 1 1 year. The combination of modern advanced science and technology and traditional ground telescopes continues to play an important role in exploring exoplanets. 2011In early May, an international team of astronomers composed of MIT, Columbia University, Harvard University and Santa Cruz, California officially announced this discovery: Pandora.

The planet number is: 55 Cancri e, which surrounds the star number 55 Cancri A, and it only takes 18 hours to make a revolution. In other words, you don't need a calendar to live on this planet, just remember to bring a watch. And the sun you see is 60 times bigger and 3600 times brighter than what you see on the earth. The surface temperature of this planet is 2700 degrees Celsius. Astronomers at MIT believe that there can be no atmospheric structure at such a high temperature, but some scientists believe that gravity is strong enough to retain part of the atmosphere. Because of the high brightness of the main star, many sensitive measurements can be made. For scientists, the planet is a perfect laboratory, which can comprehensively study the formation, evolution and whole life cycle of the planet.

However, this planet cannot be directly observed, even with a powerful telescope. The star in this planetary system, 55 Cancri A, can be observed with the naked eye in the next two months if it is on a clear night.

A planetary system consisting of 55 Cancer stars. The first planet was discovered by a research team in California in 1997, and it was named 55can CRI B. In the following five years, the team discovered two other planets, namely 55 Cancri c and 55can CRI D. In 2004, the research team in Texas discovered 55can CRI E. In 2008, it was the fifth planet in the planetary system.

The discovery process of these five planets is based on Doppler technology. Stars will swing due to the gravity of nearby planets, and then the parameters of the planets can be determined by measuring the change of starlight wavelength. Rebekah, a doctoral student in astronomy at Harvard University, and Daniel, an alien expert in Santa Cruz, California, reanalyzed these data in 2004 and thought that the orbital period of 55 Cancri e was smaller than originally thought. Later, Winn of the Massachusetts Institute of Technology and Matt Holman of the Smithsonian Center for Astrophysics applied to use the MOST space telescope for observation. It is found that the transit period is only 17 hours 4 1 minute, which is consistent with the previous analysis, while the light of the star is only dimmed by 1/5000 in each transit. These data also conclude that the diameter of this planet is about 2 1000 km, which is about 60% larger than the earth.

This discovery excited Professor Matthews, an astronomer at Columbia University: Just like Captain Kirk did in Star Trek, we (science) will eventually catch up with science fiction. Kepler -22b is the first exoplanet located in the livable zone confirmed by NASA in February, 201/. It revolves around a star very similar to the sun. NASA confirmed that Kepler -22b planet is suitable for human habitation. 20 12 On February 2nd, an international research team announced the discovery of a "super earth" outside the solar system, which may be suitable for life.

Astronomers discovered this "super earth" while studying a dwarf star numbered GJ667C 22 light years away. Its mass is at least 4.5 times that of the earth, and its cycle around dwarfs is 28. 15 days. Dwarf GJ667C itself is a member of the Trinary star system with three planets. Except for this "super earth" numbered GJ667Cc, the other two planets are not suitable for known life.

In a paper to be published in the new issue of Astrophysics Journal Newsletter, the researchers said that from the distance between this "super earth" and dwarfs, the surface temperature of this "super earth" should be similar to that of the earth, and there may be liquid water. However, this judgment needs more observation to confirm. "This planet is the' best new candidate' to support liquid water and possible life," said Guilleme Anglada-Escude of Carnegie Institute for Science, who is in charge of the research. 20 12 on February 20th, astronomers confirmed the existence of a new planet GJ 12 14b in the universe. This exoplanet is also called "super earth", and its atmosphere may be rich in water vapor or covered with dense fog. So astronomers think there may be different substances there.

American astronomers observed this earth-like planet with Hubble telescope, which is only 40 light years away from the earth and orbits a dim red dwarf star. The diameter of GJ 12 14b is about 2.7 times that of the Earth, and its mass is 7 times that of the Earth. The temperature of the planet is very high, which may reach 230 degrees Celsius, so there may be different substances there.

This is the first "super-Earth" exoplanet with an atmosphere discovered by human beings, and the others are gas giant planets. It is also estimated that 75% of the surface area of this planet is covered by water vapor, so staying on it is likely to feel like a "sauna". But this is the planet with the lowest temperature found by humans after such observations.

"GJ 12 14b is different from all the planets we know," said Berta, the principal researcher of the Smithsonian Center for Astrophysics at Harvard University.

20 12, 1 1 year1October, astronomers searching around for planets that may be suitable for life have a new candidate: a world with the size of seven earths in neighboring galaxies.

This planet is located in an easel, about 42 light years away from the earth. Previously, it was thought that there were only three planets around the easel star named "HD40307", but there were three other planets in the star system through highly sensitive data filtering methods. The farthest planet is in the "best position"-the distance from the star is just enough for liquid water to exist, so there may be life. According to the British "Mirror" reported on March 27th, Scott Sheppard, an astronomer at Carnegie Institution of Science in the United States, discovered a pink planet on the edge of the solar system and named it after the vice president of the United States. This is a dwarf star named 20 12 VP 1 13. It is 450 kilometers in diameter and is located at the edge of the solar system outside Pluto. Scientists once thought there were no planets there. This planet made of pink ice and rocks is orbiting the sun.

This planet is the second celestial body found in the mysterious area between the solar system and outer space, and it is called the "Naio Nebula". Astronomers believe that there may be thousands of previously unknown objects orbiting the sun in areas far away from the sun. Scientists believe that the way this new planet orbits the sun indicates the possibility of the existence of a "super earth", which may orbit the sun for a long time.

Follow-up reports will be continuously updated. On March 7, 20 15, British scholars confirmed the existence of "super earth", which is the first livable planet outside the solar system.

A group of scientists reported in the journal Astronomy and Astrophysics that this planetary system consisting of four planets has been hidden in the M-shaped Cassiopeia in the northern hemisphere, which is "only" 2 1 light-year away from the Earth.

2065438+On July 23rd, 2005, the newly discovered alien planet Kepler 452b was located in Cygnus, with a diameter of 1.6 times that of the Earth and an Earth Similarity Index (ESI) of 0.83.

This is the first "livable" planet discovered for 20 15. It revolves around the same type of star as the sun and is similar in size to the Earth. It may have an atmosphere and flowing water, and it is called Earth 2.0, that is, "the cousin of the Earth".