Venus Mapper Project

...A group of celestial bodies that move in an elliptical motion around the sun due to the gravitational force of the sun. They are also called planets. From the inside, there are nine: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, and many of them have moons. There are also many asteroids between Mars and Jupiter, which are thought to be remnants of objects that could not be accumulated on the planets. The five planets Mercury, Venus, Mars, Jupiter, and Saturn are the constantly brightest celestial bodies in the sky, except for the sun and the moon, and so have been incorporated into human life since ancient times in the form of calendars and astrology.

*Some of the terms mentioned in the "Venus Mapper Project" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…太陽の万有引力に引かれてその周囲を楕円運動する天体群。遊星とも呼ばれる。内側から水星，金星，地球，火星，木星，土星，天王星，海王星，冥王星の9個があり，その多くは衛星をもつ。また火星と木星の間には数多くの小惑星があり，惑星に集積し切れなかったなごりの物体群と考えられている。水星，金星，火星，木星，土星の5惑星は太陽と月を除けば天空で恒常的にもっとも明るい天体であるから，太古より人類の生活に暦，占星術の形で取り込まれてきた。…

※「金星マッパー計画」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報