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BASIC FACTS ABOUT OUR SOLAR SYSTEM
Mercury is the planet closest to the Sun in our Solar System. This small, rocky planet has almost no atmosphere. During the long daytime (which lasts 58.65 Earth days), the temperature is hotter than an oven; during the long night (the same length), the temperature is colder than a freezer. Mercury is so close to the Sun that you can only see it near sunrise or sunset. Mercury is a heavily cratered planet; its surface is similar to the surface of our Moon.
It is the smallest planet in our solar system. Mercury is only slightly larger than the Earth's moon.
Mercury has a huge range in temperatures. Its surface ranges in temperature from -270°F to 800°F
LENGTH OF A DAY AND YEAR ON MERCURY
Mercury rotates VERY slowly. Each day on Mercury takes 117 Earth days.
It takes 88 Earth days for Mercury to orbit the sun once.
Venus is the second planet from the sun in our solar system. It is the hottest planet in our Solar System. This planet is covered with fast-moving acid clouds which trap heat from the Sun. Its thick atmosphere is mostly carbon dioxide. Venus has an iron core but only a very weak magnetic field. This is a planet on which a person would die in the poisonous atmosphere, be cooked in the extreme high heat, and be crushed by the very high atmospheric pressure.
Venus is also known as the "morning star" or the "evening star" since it is visible and quite bright at either dawn or dusk.
Venus is the hottest planet in our Solar System. Its cloud cover traps the heat of the sun (the greenhouse effect), giving Venus temperatures up to 870°F.
LENGTH OF A DAY AND YEAR ON VENUS
Venus rotates VERY slowly. Each day on Venus takes 243 Earth days.
It takes 224.7 Earth days for Venus to orbit the sun once.
The Earth is the third planet from the Sun in our Solar System. It is the planet we evolved on and the only planet in our Solar System that is known to support life. The Earth is the fifth-largest planet in our Solar System. The Earth has one moon. The diameter of the moon is about one quarter of the diameter of the Earth.
The temperature on Earth ranges from between -127°F to 136°F. The coldest recorded temperature was on the continent of Antarctica. The hottest recorded temperature was on the continent of Africa.
The Earth's atmosphere is a thin layer of gases that surrounds the Earth. It is composed of 78% nitrogen, 21% oxygen.
Oceans cover about 70% of the Earth's surface. The oceans contain roughly 97% of the Earth's water supply.
LENGTH OF A DAY AND YEAR ON EARTH
Each day on Earth takes 23.93 hours.
Each year on Earth takes 365.26 Earth days.
The Earth's rotation is slowing down very slightly over time, about one second every 10 years.
Mars, the red planet, is the fourth planet from the sun and the most Earth-like planet in our solar system. It is about half the size of Earth and has a dry, rocky surface and a very thin atmosphere. The surface of Mars is dry, rocky, and mostly covered with iron-rich dust. There are low-lying plains in the northern hemisphere, but the southern hemisphere is dotted with impact craters. The ground is frozen; this permafrost extends for several kilometers. The north and south poles of Mars are covered by ice caps composed of frozen carbon dioxide and water.
Olympus Mons, the largest volcano on Mars; it is perhaps the largest volcano in the Solar System. It is 17 miles (27 km) tall and over 320 miles (520 km) across.
Mars' surface temperature averages -81 °F. The temperature ranges from a high of 68° F to a low of -220° F. Mars is much colder than the Earth.
LENGTH OF A DAY AND YEAR ON MARS
Each day on Mars takes 1.03 Earth days (24.6 hours).
A year on Mars takes 687 Earth days. That is almost 2 earth years.
Jupiter is the fifth and largest planet in our solar system. This gas giant has a thick atmosphere, 39 known moons, and a dark, barely-visible ring. Its most prominent features are bands across its latitudes and a great red spot (which is a storm).
Jupiter is composed mostly of gas. It also has an extremely strong magnetic field. It is slightly flattened at its poles and it bulges out a bit at the equator.
Jupiter is a little more than 11 times the diameter of the Earth. Jupiter is so big that all the other planets in our Solar System could fit inside Jupiter if it were hollow.
Jupiter is made up of gases and liquid.
The temperature of Jupiter is about -244 F.
LENGTH OF A DAY AND YEAR ON JUPITER
It takes Jupiter 9.8 Earth hours to rotate once.
It takes 11.86 Earth years for Jupiter to orbit the sun once.
Saturn is the sixth planet from the sun in our solar system. It is the second-largest planet in our solar system (Jupiter is the largest). It has beautiful rings that are made mostly of ice chunks (and some rock) that range in size from the size of a fingernail to the size of a car.
Saturn is made mostly of hydrogen and helium gas.
Saturn is visible without using a telescope, but a low-power telescope is needed to see its rings.
Saturn is about 9.4 times the diameter of the Earth. 764 Earths could fit inside a hollowed-out Saturn.
The temperature on Saturn -290° F
LENGTH OF A DAY AND YEAR ON SATURN
Each day on Saturn takes 10.2 Earth hours.
It takes 29.46 Earth years for Saturn to orbit the sun once.
Uranus is the seventh planet from the sun in our solar system. This huge, icy planet is covered with clouds and is encircled by a belt of 11 rings and 22 known moons. Uranus' blue color is caused by the methane gas.
Uranus is a frozen, gaseous planet with a molten rock core.
Uranus is about 4 times the diameter of the Earth. It is the third-largest planet in our Solar System (after Jupiter and Saturn).
The temperature on the surface of Uranus' cloud layer is -350°F
LENGTH OF A DAY AND YEAR ON URANUS
Each day on Uranus takes 17.9 Earth hours.
It takes 84.07 Earth years for Uranus to orbit the sun once.
Neptune is the eighth planet from the sun in our solar system. This giant, frigid planet has a hazy atmosphere and strong winds. This gas giant is orbited by eight moons and narrow, faint rings arranged in clumps. Neptune's blue color is caused by the methane gas.
Neptune is the fourth largest planet in our Solar System (after Jupiter, Saturn, and Uranus).
Neptune is 3.88 times the diameter of the Earth. If Neptune were hollow, it could hold almost 60 Earths.
The temperature is -373 F.
LENGTH OF A DAY AND YEAR ON NEPTUNE
Each day on Neptune takes 19.1 Earth hours.
It takes almost 165 Earth years for Neptune to orbit the sun once. Since Neptune was discovered it has not yet completed a single revolution around the sun.
Pluto was classified as a dwarf planet in 2006; before that it was considered to be a planet, the smallest planet in our solar system. Pluto is smaller than a lot of the other planets' moons, including our moon.
Pluto is 5 times SMALLER than Earth.
Pluto is VERY, VERY cold. Its temperature is -393°F
LENGTH OF A DAY AND YEAR ON PLUTO
Each day on Pluto takes 6.39 Earth days.
It takes 247.7 Earth years for Pluto to orbit the Sun once.
Check your weight on different planets