Planets, Moons, and Stars in Our Solar System

Our Solar System

The Sun is the center of the place we call the Solar System. The eight planets that orbit the Sun are:

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

There are also five additional celestial bodies classified as dwarf planets. The five recognized dwarf planets are Ceres, Pluto, Haumea, Makemake, and Eris.

The Sun

The Sun is a large ball of hydrogen, helium, and plasma. It is around four and a half billion years old and appears white in color from space. Its real name is Sol. From Earth, it appears to move along an imaginary line called the Ecliptic.

The Planets

Mercury

Mercury is the smallest planet and the closest to the Sun. You could fit 19 Mercurys inside Earth. It is gray in color and lacks an atmosphere, moons, and a ring system. It is classified as a terrestrial planet.

Venus

Venus is around the size of our planet, Earth. Its surface is orange, and its atmosphere is white. Like Mercury, Venus also has no moons or rings; however, it has an extremely thick atmosphere. Viewed from Earth, it also exhibits phases similar to the Moon. It is also a terrestrial planet. Its day is longer than its year, and it spins backwards (retrograde rotation).

Earth

Earth is a planet in our Solar System. A unique detail about Earth is that it is the only planet known to harbor life. It has one moon named Luna. Earth is home to over 8 billion people. Its land is green, and its oceans are blue. Its moon, Luna, is white in color. Like both Venus and Mercury, it is also a terrestrial planet.

Mars

Mars is reddish-orange in color. It has two moons that orbit it: Phobos and Deimos. It is home to the tallest volcano in the Solar System, Olympus Mons, and is the last of the terrestrial planets.

Jupiter

Jupiter is the largest planet. It is a Jovian planet and has around 90 currently recognized moons. It has four rings and four major moons. Its four major moons are Callisto, Europa, Ganymede, and Io. It is tan in color with stripes called zones (the lighter ones) and belts (the darker ones). It also has a massive storm called the Great Red Spot, which could fit three Earths.

Saturn

Saturn is another Jovian planet. It is also tan in color. It has a spot similar to Jupiter's, called the Great White Spot. It has a bluish, hexagon-shaped atmospheric current at its north pole. It has seven main brown rings and 146 currently recognized moons. Its major moons include Titan, Enceladus, Dione, Mimas, Rhea, Iapetus, and Tethys.

Uranus

Uranus is another Jovian planet. It has 13 rings and 27 currently recognized moons. It is light blue and rotates on its side (extreme axial tilt). Its major moons include Oberon, Miranda, Umbriel, Ariel, and Titania. It is the coldest planet in the Solar System.

Neptune

Neptune is also light blue and has a spot similar to Jupiter's Great Red Spot, called the Great Dark Spot. It has 16 currently recognized moons and five main rings. Its major moons include Triton, Proteus, Nereid, and Hippocamp. It is the farthest planet from the Sun and is the last of the Jovian planets.

Dwarf Planets

Pluto

Pluto used to be considered the ninth planet but was reclassified as a dwarf planet in 2006. It has five currently recognized moons and is brown in color. It has a prominent heart-shaped region on its surface called Tombaugh Regio.

Beyond Our Solar System

The Milky Way Galaxy

The Milky Way is a galaxy. Galaxies are vast collections of stars, gas, dust, and dark matter, often containing many solar systems. The Milky Way is our home galaxy.

Notable Stars

Here are a few notable stars:

• Proxima Centauri: The closest star to the Sun.
• Sirius: The brightest star in the night sky.
• Polaris: Also known as the North Star.