Meet the Planets
This closest planet to the Sun experiences extreme temperature variations due to its lack of an atmosphere.
Mercury
Our Sun is composed mainly of these two abundant gases.
Hydrogen and Helium
Comets are nicknamed "dirty snowballs" and develop this cloud of gas and dust as they heat up near the Sun.
A Coma
Formerly considered the ninth planet, it is now classified as a dwarf planet located in the Kuiper Belt.
Pluto
The Sun contains this percentge of the total mass of the entire solar system.
99.8%
Characterized by solid, rocky surfaces, this term describes the four innermost planets: Mercury, Venus, Earth, and Mars.
Terrestrial Planets
This ancient astronomical model proposed that Earth was the stationary center of the universe.
The Geocentric Model
Most asteroids in our solar system are found in a main belt located between these two planets.
Mars and Jupiter
This spherical shell of icy bodies surrounding the entire solar system is the ultimate source of long-period comets.
Oort Cloud
According to the reference chart, this planet takes 88 days to complete one revolution around the Sun.
Mercury
This hottest planet has a thick atmosphere primarily composed of carbon dioxide, resulting in a runaway greenhouse effect.
Venus
Proposed by Nicolaus Copernicus in the 16th century, this model placed the Sun at the center of the solar system.
The Heliocentric Model
Driven by intense tidal forces, this jovian satellite is famous for its active volcanoes.
Io
These two icy moons - one orbiting Jupiter and one orbiting Saturn - are prime targets in the search for extraterrestrial life due to their subsurface oceans.
Europa and Enceladus
Saturn
Known as gas giants or Jovian planets, Uranus and Neptune are specifically called this type of planet due to their blue coloration and unique magnetic fields.
Ice Giants
The Sun produces its immense energy through this nuclear process in its core, where hydrogen atoms combine to form helium.
Nuclear Fusion
When a space rock survives its trip through Earth's atmosphere and lands on the surface, it is called by this specific name.
Meteorite
This term refers to any planet that orbits a star outside our own solar system.
Spinning once every 9 h 50 min 30 s, this planet has the shortest period of rotation in the solar system.
Jupiter
Featuring polar ice caps and evidence of past water flow, this planet is currently being explored for signs of ancient microbial life.
Mars
This astronomer used telescopic observations - including Jupiter's four largest moons and the phases of Venus - to support the heliocentric model.
Galileo Galilei
Featuring a retrograde orbit, this largest moon of Neptune is believed to have been captured from the Kuiper Belt.
Triton
This spacecraft mission provided humanity's first unprecedented, close-up images of Pluto and its moons.
This planet has the most perfectly circular (least eccentric) orbit of all eight planets.
Venus