Astronomy
Science whose aim is the observation and knowledge of celestial bodies: position, movement, structure, evolution and so forth.
CELESTIAL BODIES
Masses of natural matter (as a planet or nebula) located in space.
solar system
Region of our galaxy under the influence of the Sun; includes eight planets and their natural satellites as well as dwarf planets, asteroids and comets.
planets and satellites
Planets and dwarf planets orbit the Sun, satellites orbit the planets. They are represented from left to right from the Sun, based on their relative sizes.
Sun
Star composed of 92.1% hydrogen atoms and 7.8% helium atoms, around which the planets gravitate; represents more than 99.8% of the solar system’s total mass.![structure of the Sun [1]](/images/astronomy/celestial-bodies/sun/structure-sun_1.png "structure of the Sun [1]")
![structure of the Sun [2]](/images/astronomy/celestial-bodies/sun/structure-sun_2.png "structure of the Sun [2]")
Moon
Earth’s only natural satellite; devoid of water and atmosphere, it displays a highly uneven surface.
meteorite
Fragment of rock, iron or another mineral that crashes into Earth instead of completely burning up as it crosses the atmosphere.
comet
Small icy body that partially evaporates as it approaches the Sun; made up of a head with a solid core and tails composed of gas and dust.
star
A sphere of gas massive enough to generate light and heat through nuclear reactions that transform hydrogen into helium in its core.
galaxy
Grouping of stars and interstellar matter linked together by gravitation; each galaxy comprises an average of 100 billion stars.
