木星の周辺を回っているもっと小さな惑星を見てケプラーは、外出中の王の回りを取り囲む護衛を思いだしたので、それを衛星と名付けたのだ。の英語

The smaller planets hovering around the planet Jupiter reminded him of the guards surrounding a king when he walked outdoors, and Kepler called them satellites.

Danish astronomer whose observations of the planets provided the basis for Kepler's laws of planetary motion (1546-1601)

The planet orbits Proxima Centauri, a star only about four light years away from Earth.

In an article published online on Feb. 22 in the journal Nature, an international research team reported the discovery of seven Earth-size planets orbiting a star named TRAPPIST-1.

United States astronomer (born in the Netherlands) who studied the solar system and suggested in 1951 that there is a belt of comet-like debris at the edge of the solar system (1905-1973)

After further analysis, they concluded that the gravity of an unknown planet is affecting the orbits of those objects.

The European Southern Observatory recently announced that an international team of astronomers has found at least three earth-like planets orbiting a star only 22 light-years away from the earth in the direction of Scorpio.

With a special device called a "spectral composition mapper," it detected many small, exposed regions of water ice on Pluto.

As the capsule approached the ISS, astronauts aboard the ISS used a robotic arm to grab the Dragon and pull it in for docking.

According to Caltech's Assistant Professor Konstantin Batygin and Professor Mike Brown, the planet has a mass about 10 times that of Earth.

The capsule with the rock samples will then separate from the spacecraft, enter the Earth's atmosphere and land in the desert in Australia.

This nonprofit organization observes approaching asteroids and space debris such as detached rocket parts.

It was launched by the National Aeronautics and Space Administration (NASA) of the United States in 2006 to study Pluto and the Kuiper Belt objects.

any of numerous small celestial bodies composed of rock and metal that move around the sun (mainly between the orbits of Mars and Jupiter)

In an article published online on Aug. 24 in the journal Nature, an international team of scientists reported the discovery of an Earth-like planet orbiting the star nearest to the Sun.

According to the new definition, a planet is a celestial body that (1) is in orbit around the Sun, (2) is heavy enough to maintain a round shape by self-gravity, and (3) has cleared the neighborhood around its orbit.

He awarded medals to astronauts from several countries, including Noguchi Soichi of Japan, to honor their achievements in space exploration.

It opened its solar panels and started its 90-day exploration program to find signs of water on the planet.

Dr. Michael Brown, an astronomer at the California Institute of Technology in the United States, announced on July 29 that he and his team have discovered a new planet with a telescope at Palomar Observatory.

A team of astronomers from the University of California, Santa Cruz, and the Carnegie Institution for Science in the United States has recently discovered a planet with conditions similar to those on Earth.

The OPUSAT is scheduled to be launched with other satellites on the Japan Aerospace Exploration Agency's H-IIA rocket on Feb. 28.

On Aug. 24, the International Astronomical Union (IAU) adopted a new definition of a planet and decided not to call Pluto a planet any more.

German mathematician and astronomer who made accurate measurements of stellar distances and who predicted the existence on an 8th planet (1784-1846)

The research team used the European Southern Observatory's telescopes and other facilities to find a rocky planet similar to Earth.

Taking images of exoplanets is very difficult because they appear very faint next to the brightness of nearby stars.

Among over 400 planets that have been found outside the solar system, this one is considered to have a particularly strong chance of being habitable.

the earliest eon in the history of the Earth from the first accretion of planetary material (around 4,600 million years ago) until the date of the oldest known rocks (about 3,800 million years ago)

Toward the end of the 16th century a new star came into existence in the sky, which taught the people that even the stellar universe was mutable.

Italian astronomer who first noted lines (which he called canals) on the surface of Mars (1835-1910)

The birth of the solar system is estimated to have occurred about 4.6 billion years ago and included the formation of the sun, planets, moons and asteroids.