Solar system
The Romans called the sun Sol, which in English means sun. In ancient Greece, the sun was called Helios.
Light from the Sun can reach the Earth in only 8.3 minutes! This is called the speed of light. The Sun is nearly 93 million miles (approx 145 million km) from Earth
*Note that in the image above the sizes are to scale, but the relative distances are not.
· The solar system includes the Sun and all the objects that orbit around it due to its gravity. This includes things such as planets, comets, asteroids, meteoroids and moons.
· The Solar System formed around 4.6 billion years ago.
· There are eight planets in the Solar System. The four inner planets are Mercury, Venus, Earth and Mars while the four outer planets are Jupiter, Saturn, Uranus and Neptune.
· The inner planets (also known as terrestrial planets) are smaller and made mostly of rock and metal.
· The outer planets (also known as gas giants) are much larger and made mostly of hydrogen, helium and other gases.
· There is an asteroid belt which lies between the orbits or Mars and Jupiter, it features a large number of irregular shaped asteroids.
· For thousands of years humans were unaware of the Solar System and believed that Earth was at the center of the Universe.
· Astronomers such as Nicolaus Copernicus, Galileo Galilei, Johannes Kepler and Isaac Newton helped develop a new model that explained the movement of the planets with the Sun at the center of the Solar System.
· The Sun contains 99.86 percent of the Solar System's known mass, with Jupiter and Saturn making up making up most of the rest. The small inner planets which include Mercury, Venus, Earth and Mars make up a very small percentage of the Solar System’s mass.
Mercury Facts
Mercury is a small planet which orbits closer to the sun than any other planet in our solar system.
As well as being very hot, it features a barren, crater covered surface which looks similar to Earth's moon.
The surface of Mercury is very similar to our moon. It has a very barren, rocky surface covered with many craters.
Being so close to t he Sun, the daytime temperature on Mercury is scorching - reaching over 400 Degrees Celsius.
At night however, without an atmosphere to hold the heat in, the temperatures plummet, dropping to -180 Degrees Celsius.
Mercury has a very low surface gravity.
Mercury has no atmosphere which means there is no wind or weather to speak of.
There is also no water on the surface of Mercury, it is possible however that there could be water underneath the surface.
Likewise, there is no air on the surface but it could be trapped underneath
Venus Facts
Venus is a fascinating planet that is similar in size to Earth but very different in regards to atmosphere and surface conditions.
Its thick clouds lock in the heat while the surface rages with active volcanoes.
The atmosphere of Venus made up mainly of carbon dioxide.
Its size is slightly smaller than Earth.
It also features gravity similar to that of Earth.
Venus is surrounded by clouds consisting of mercury, ferric chloride hydrocarbons and sulphuric acid. These clouds create the most corrosive acid rain found anywhere in our solar system.
The clouds are so thick that little light even reaches the surface. The light that does reach the surface is converted to heat and can not escape the atmosphere making Venus the hottest planet at around 500 Degrees Celsius.
The surface of Venus is often described as a "stormy desert" full of many craters and very active volcanoes.
The surface is also likened to molten lead.
Venus features no liquid water.
Mars Facts
Mars, or the 'Red Planet' as it is sometimes known, has a dusty, rocky surface and a thin atmosphere. Its relatively calm conditions and close proximity to earth make it the most likely destination for future planet exploration by humans.
It has already been visited by a number of Mars Rovers in successful (and unsuccessful) robotic missions. These highly advanced robots gather samples and record important scientific data for scientists back on Earth to study.
Mars is nicknamed the red planet because it is covered with rust-like dust. Even the atmosphere is a pinkish red, colored by tiny particles of dust thrown up from the surface.
Mars experiences violent dust storms which continually change its surface.
Mars has many massive volcanoes and is home to Olympus Mons, the largest volcano in our solar system, it stands 21km high and is 600km across the base.
Mars has a very thin atmosphere made mostly of carbon dioxide. It is not thick enough to trap the sun's heat like Venus, so the planet is very cold. Temperatures range from -120 Degrees Celsius on winter nights to 25 Degrees Celsius in the summer.
Mars has many channels, plains and canyons on the surface which could have been caused by water erosion in the past.
Mars has very weak gravity which cannot hold onto the atmosphere well.
The polar ice caps consist of frozen Co2 (dry ice) which lies over a layer of ice.
Jupiter Facts for Kids
Jupiter is the largest planet in our solar system. Its famous 'Red Spot' and raging gas storms give it an impressive if not intimidating appearance.
As well as having many moons, Jupiter also has a number of rings similar to that of Saturn but much less noticeable.
Jupiter is the largest planet in our Solar system. It is so big that more than 1300 Earth's could fit inside it.
Thick, colorful clouds of deadly poisonous gases surround Jupiter. The quick spinning of the planet whips up the atmosphere, creating the bands around the planet.
If you were to descend into Jupiter, the thin, cold atmosphere becomes thicker and hotter, gradually turning into a thick, dark fog. In the blackness about 1000km down the pressure squeezes the atmosphere so hard that it becomes like liquid.
At the centre of Jupiter is a rocky core, slightly bigger than Earth but weighing about 20 times more.
Surrounding the core is an ocean of liquid hydrogen, about 1,000 kilometres deep.
Jupiter has many storms raging on the surface, most notably the big red spot which is the largest hurricane in our Solar System. It's been raging for over three hundred years.
Jupiter has a very strong magnetic field, you would weigh two and a half times as much as you would on earth.
Jupiter has many moons circling around it. Four of these moons are bigger than Pluto
Saturn Facts for Kids
Perhaps the most beautiful planet in our solar system (other than earth of course) due to its spectacular ring system, Saturn is a gas giant that features many extreme physical features and atmospheric conditions.
Saturn is the second largest planet in our solar system and is another gas giant.
Saturn has a small rocky core covered with liquid gas.
It is surrounded by a system of rings that stretch out into space for thousands of kilometres.
The rings are made up of millions of ice crystals, some as big as houses and others as small as specks of dust.
Saturn is very light as it is made up of more hydrogen than helium so it is less dense. If we could fit Saturn into a bathtub it would float (but that would have to be one big bathtub!)
Like Jupiter, Saturn has many moons which surround it.
Saturn is not a peaceful planet. Storm winds race around the atmosphere at 800kmp/h.
Saturn has a very strong magnetic field which traps energy particles resulting in high levels of radiation.
Uranus Facts for Kids
Uranus likes to be a bit different.
It shows off a majestic blue/green haze due to its high levels of methane gas and rolls like a barrel rather than spinning like Earth and the other planets in our Solar System.
ranus spins lying on its side (like a barrel), this is perhaps due to a large collision early in its formation.
Uranus was the first planet discovered by telescope.
Since Uranus takes 84 Earth years to go around the sun, this means that each of its poles is in daylight for 42 years and in darkness for the next 42.
Uranus’s atmosphere is mostly hydrogen but it also contains large amounts of a gas called methane. Methane absorbs red light and scatters blue light so a blue-green methane haze hides the interior of the planet from view.
Uranus hides its interior but scientists guess that under the hydrogen-methane atmosphere is a hot, slushy ocean of water, ammonia and methane thousands of miles deep wrapped around a rocky core.
Neptune Facts for Kids
Neptune is a large planet that experiences extreme atmospheric weather conditions.
After the demotion of Pluto, it now holds the distinction of being further away from the sun than any other planet in our solar system.
Neptune is a large planet, nearly four times the size of Earth.
Neptune suffers the most violent weather in our Solar System.
Storms have been spotted swirling around its surface and freezing winds that blow about ten times faster than hurricanes on Earth make it the windiest planet.
Neptune is a large, water planet with a blue hydrogen-methane atmosphere and faint rings.
Neptune is covered in thin wispy white clouds which stretch out around the planet.
Pluto Facts for Kids
Don't forget Pluto! Sure it may not be officially recognized as a planet anymore but it's still there and offers a lot of interesting facts and cool information.
Check out these fun Pluto facts for kids
Pluto was the smallest and furtherest planet from the Sun in our solar system, now it is not even officially recognized as a planet!
In 2006 Pluto was demoted to the status of dwarf planet.
Because it is so far away from the sun it is very cold with temperatures ranging form -235 Degrees Celsius to -210 Degrees Celsius.
Pluto consists of rock with a very thick coating of ice.
The atmosphere of Pluto consists of nitrogen with some carbon monoxide and methane.
1. What is the closest planet to the Sun?
2. What is the name of the 2nd biggest planet in our solar system?
3. What is the hottest planet in our solar system?
4. What planet is famous for its big red spot on it?
5. What planet is famous for the beautiful rings that surround it?
6. Can humans breathe normally in space as they can on Earth?
7. Is the sun a star or a planet?
8. Who was the first person to walk on the moon?
9. What planet is known as the red planet?
10. What is the name of the force holding us to the Earth?
11. Have human beings ever set foot on Mars?
12. What is the name of a place that uses telescopes and other scientific equipment to research space and astronomy?
13. What is the name of NASA’s most famous space telescope?
14. Earth is located in which galaxy?
15. What is the name of the first satellite sent into space?
16. Ganymede is a moon of which planet?
17. What is the name of Saturn’s largest moon?
18. Olympus Mons is a large volcanic mountain on which planet?
19. Does the sun orbit the Earth?
20. Is the planet Neptune bigger than Earth?
Space Quiz Answers
1. Mercury
2. Saturn
3. Venus
4. Jupiter
5. Saturn
6. No
7. A star
8. Neil Armstrong
9. Mars
10. Gravity
11. No
12. An observatory
13. Hubble Space Telescope
14. The Milky Way Galaxy
15. Sputnik
16. Jupiter
17. Titan
18. Mars
19. No
20. Yes