Planets

• Mercury:

Mercury, although being the closest to the sun (being 0.4 astronomical units away from the Sun), is not the hottest. With a radius of 1,516 miles (2,440 kilometers), Mercury is a little more than 1/3 the width of Earth. Mercury, being the fastest planet, has an orbit of around 29 million miles and speeds around the sun every 88 days. On its axis, it spins slowly and completes one rotation every 59 earth days. A Mercury solar day would be 176 Earth days.

Mercury doesn't have any moons or rings. Mercury’s structure has it being  the second densest planet, after Earth. Its outer shell is 400 kilometers (250 miles) thick and its inner core is 1,289 miles (2,074 kilometers). Its surface is similar to Earth’s moon, a grayish-brown with bright streaks called “crater rays.” The planet has craters from meteorites and comets along with large basins. Temperatures range from 800° and could drop to 290°on the surface.

• Venus:

The second planet from the sun, Venus, is about 108,000,000 km (67,000,000 miles) away from the sun. Venus is 7,521 miles (12,104 kilometers) across and is the brightest object in the night sky after Earth’s moon. For Venus days’ it would be 243 Earth days long. One trip around the sun is 225 Earth days. The planet's extremely slow rotation causes sunrise to sunset would take 117 Earth days. A complete cycle takes 584 days.

Venus has no moons or rings. Venus sits at a 23 degree tilt and doesn't have any seasonal temperatures. Temperatures are usually around 900° on the surface . Venus has an iron core and a thin rocky exterior. Most people seem to assume Venus is green, but it's actually brownish-yellow with high mountains (36,000 feet (11 kilometers)) and  thousands of volcanoes. Venus has clouds composed of sulfuric acid. At the surface its extremely hot with high pressure carbon dioxide that's corrosive.

• Earth:

Our home planet, fifth largest planet and only world with liquid water, Earth. Being 93 million miles (150 million kilometers) away from the sun and exactly one astronomical unit away. Earth is 3,959 miles (6,371 kilometers), biggest of the terrestrial planets. As Earth orbits the Sun, it completes one rotation every 23.9 hours. It takes 365.25 days to complete one trip around the Sun. 

Earth has one moon that helps stabilize Earth wobble and has a radius of 1,080 miles (1,738 kilometers). Which is the fifth largest in our solar system. Earth has no rings. Earth's axis of rotation is tilted 23.4 degrees with respect to the plane of Earth's orbit around the Sun. This tilt causes our yearly cycle of seasons. Earth has 4 main layers: inner core, outer, mantle, and crust. Earth 's surface has mountains, volcanoes, valleys, and has water that covers 70% of it. Earth's  78% nitrogen, 21% oxygen, and 1% other atmosphere and many climates makes it possible to easily live on it.

• Mars:

Most explored body in our solar system, Mars. Mars is 142 million miles (228 million kilometers) it is 1.5 astronomical units away from the sun. Mars has a radius of 2,106 miles (3,390 kilometers). Mars rotation is 24.6 hours, which is very similar to one day on Earth. A year on Mars lasts 669.6 sols, which is the same as 687 Earth days.

Mars has 2 small moons, Phobos and Deimos, that are  captured asteroids. Phobos is the innermost biggest moon that slowly moves towards Mars and is going to crash into the planet in 50 million  years. Mars has no rings, but when Phobos crashes there could be a dust ring around it. Mars has a dense core and between 930 and 1,300 miles (1,500 to 2,100 kilometers), a rocky mantle of 770 and 1,170 miles (1,240 to 1,880 kilometers), and a crust is between 6 and 30 miles (10 to 50 kilometers) deep. Mars has many interesting topographical features and has more colors than you may expect. It looks reddish, but that's not all, it also has browns, tans, and yellows. Mars is also home to the largest volcano in the solar system, Olympus Mons. There is water on Mars today, but the Martian atmosphere is too thin for liquid water to exist for long on the surface. Temperatures on Mars can be as high as 70° or as low as about -225°. 

• Jupiter:

Our biggest planet, Jupiter. Jupiter is 484 million miles (778 million kilometers), Jupiter is 5.2 astronomical units away from the sun. Jupiter has a radius of 43,440.7 miles (69,911 kilometers). Jupiter has the shortest day, 10 hours. Jupiter makes a complete orbit around the Sun in 12 years. 

Jupiter has 80 moons, 4 big and several small. Only 57 of them have names. Jupiter’s biggest moons are Io, Europa, Ganymede, and Callisto. Jupiter does have moons and were a surprise to find in 1979. They were made from meteorites crashing into Jupiter's moons. Jupiter is gasses and dust being pulled together as has the same material of a star that didn't grow big enough to become an ignite. Jupiter doesn't have a true surface and has extreme pressures and temperatures. Jupiter is very colorful with its cloud bands and is likely made of ammonia crystals. Jupiter is well known for its belts and zones, white and red surrounding the planet moving it in different directions. Jupiter has many storms that extend over 60 miles and has prevailing winds, some reaching up to 335 miles per hour.

• Saturn:

The only planet with an average density less than water, Saturn. Saturn is 886 million miles (1.4 billion kilometers), Saturn is 9.5 astronomical units away from the sun. Saturn has a radius of 36,183.7 miles (58,232 kilometers).Saturn has the second-shortest day in the solar system. One day on Saturn takes only 10.7 hours. Saturn completes its orbit in about 29.4 Earth years. 

Saturn has 83 moons  with 63 being named and 20 awaiting for discovery. Saturn has rings and are the most visible too. They are made up of dust, comets, asteroids, shatter moons, ice, and clouds that all have their own speed orbiting around the planet. Saturn's ring system extends up to 175,000 miles (282,000 kilometers) each being apart by 2,920 miles (4,700 kilometers). Saturn sits at its axis tilted by 26.73 degrees. Like Jupiter, it is also a gas planet made of hydrogen and helium and has no true surface, but the core has irons and liquid metallic hydrogen. Saturn has winds in the upper atmosphere reach 1,600 feet per second (500 meters per second) and  pressure so powerful it squeezes gas into a liquid. Saturn has thick layers of clouds that appear as faint stripes, jet streams, and storms. Saturn has several shades of grays, yellows, and browns.

• Uranus:

The first planet found with a telescope, Uranus. Uranus is 1.8 billion miles (2.9 billion kilometers), Uranus is 19.8 astronomical units away from the sun.Uranus has a radius of 15,759.2 miles (25,362 kilometers). Uranus’s complete orbit is 84 years. One day for Uranus is 17 hours.

Uranus has 27 known moons. Uranus moons are interesting because of the names. While most of the planets moons are named off greek mythology, Uranus’s moon's name are characters by William Shakespeare and Alexander Pope. Uranus has 2 sets of rings. There are 9 dark gray rings and 2 blue outer rings. Uranus is the only planet whose equator is nearly at a right angle, 97.77 degrees. The tilt was likely due from a collision long ago. As an ice giant, Uranus doesn’t have a true surface. The planet is mostly swirling fluids. Uranus gets its blue-green color from methane gas in the atmosphere that absorbs red light resulting in a blue-green color of the planet.

• Neptune: 

The first planet located through mathematical calculations, Neptune. Neptune is  2.8 billion miles (4.5 billion kilometers), Neptune is 30 astronomical units away from the Sun. 

Neptune has 14 moons. One of the moons, Triton, is the only large moon to circle its planet in an opposite direction. Triton's thin atmosphere has been found to be heating up, but scientists do not yet know why. Neptune has at least 5 main rings and 4 prominent. Neptune is an two ice giants that 

Is made up of a hot dense fluid and a rocky core. Neptune does not have a solid surface. Like Uranus it also is made up mostly of hydrogen and helium with just a little bit of methane, but it is a more intense blue that researchers can't explain. Neptune's winds can be three times stronger than Jupiter's and nine times stronger than Earth's. These winds whip clouds of frozen methane across the planet at speeds of 1,200 miles per hour.