Fun Space Facts
1) The solar system consists of the sun and everything that orbits (moves around) it.
The 8 planets orbit the sun and more than 160 smaller moons, orbit the planets. There are millions of other objects circling the sun, these include asteroids and comets. The pull of the sun’s gravity holds the solar system together.
2) The solar system began as a vast, swirling cloud of gas and dust called a Nebula
Most of it made of hydrogen, the least dense and most common element in the universe
3) Around 4.6 Billion years ago, the solar system began to form.
It may have been started by a huge explosion of a star like a supernova, and shockwaves from a the giant explosion would have compressed (squashed) the Nebula. Gravity the took over, pulling the Nebula inwards and causing it to collapse in on itself.
4) As the Nebula collapsed inward it started spinning.
Clumps of gas and dust formed in the collapsing cloud and grew bigger as gravity pulled more and more dust towards them. A dense mass formed at the centre of the nebula , which increased in temperature and size to become the sun. The remaining gas and dust flattened into spinning discs, later forming the planets.
5) There are still signs of the spinning motion of the shrinking nebula today.
The sun, the planets and moon all spin and the planets travel around the spinning sun.
6) The sun is the star at the centre of our solar system.
It looks so much bigger than the other stars in the sky because it is much closer to us. The sun is approx. 150 million kilometres from the earth.
7) The sun look smaller in the sky, but its a Giant compared to Earth.
It is so huge that 1300 Jupiter’s would fill the sun. A 1000 Earths to fill 1 Jupiter, if 110 Earths sat next to each other they would just fit across the centre.
8) The sun is made of super hot gases mostly hydrogen and helium.
Its core (centre) is the hottest part. The temperature here is at least 15million degree C, maybe even hotter.
9) Scientists worked out how the sun shines in 1920.
The extremely high pressure in the sun’s core causes particles of hydrogen to smash into each other and fuse (stick together) to form a new substance , helium. This is called nuclear fusion. Every time it happens energy is given out to the surface of the sun and into space.
10) About 4 million tonnes of the sun’s mass vanishes every second!
This happens because nuclear fusion changes some of the sun’s mass into energy. The sun has been losing this huge amount of every second for about 4.6 billion years.
11) Energy produced by nuclear fusion travels from the suns core to the surface.
This takes up to 200,00 years, then it leaves the sun and takes about 8 minutes to reach the Earth.
12) Mercury is the sun’s closest planet.
It is also the smallest planet in the solar system – a tiny planet less than half the size of Earth, it is made of rock with a big iron core and is very dense for its size.
13) Planets closer to the sun have to travel through space faster than those farther away, or they would pulled in to the sun.
Mercury’s orbit takes 88 earth days, however it’s spin is so slow that a day on Mercury lasts 176 Earth days.
14) Mercury has one of the biggest impact craters in to solar system.
It’s called the Caloris Basin and it measures 1550 kilometres across. It was caused when an object 100 kilometres across crashed in to Mercury.
15) The side of Mercury that faces the sun reaches 430 degree Celsius.
That’s hot enough to melt tin! The temperature on the side facing space (away from the sun) drops to -180 degrees Celsius , that’s the biggest difference in temperature between 2 sides on any planet in the solar system.
16) Only 2 space craft have visited Mercury so far.
Mariner 10 was the first in 1970 and Messenger arrived 2008. A 3rd spacecraft called Bepicolombo launched in 2018, and is due to arrive at Mercury in 2025.
17) The second planet from the sun is Venus. It is about the same size as Earth.
It is also the closest planet to Earth, although the two are very different. Venus has a rocky surface hidden by a very thick layer of carbon dioxide atmosphere that traps the sun’s heat , making Venus the hottest planet in the solar system.
18) Venus has the slowest spin in solar system.
It takes 243 Earth days to spin around once, compared to the 24 hours Earth takes.
Venus also spins in the opposite direction to Earth i.e. the sun on Earth rises in the east but on Venus it rises in the west.
19) One way to see Venus’ surface is to use radar.
Radar can send radio waves from spacecraft, through a planet’s atmosphere to bounce off the surface. Analysing these reflections revels the shape of the surface i.e. similar to how submarines learn the ocean floor.
20) Venus is a very volcanic planet, or at least it was in the past.
Its surface is dotted with over 1000 volcanoes – more than any other planet in our solar system. It is difficult to tell if they are still active today.
21) The famous explorer Captain James Cook sailed from England to Tahiti to see Venus crossing the sun in 1769.
The crossing was important to astronomers because they could use it to work out the size of the solar system. By observing the time Venus’ shadow took to cross the sun astronomers were able to calculate the distance between Earth and Venus.
22) The Earth is the third planet from the sun.
It is the only known planet in the universe to have liquid water and the ability to support life. It takes 24 hours to spin once and 365 days a year to orbit out sun
23) One of the rocky planets, Earth consists of serval layers.
The thin crust of rock that form its surface, sits on top of a deep layer of rock called the mantle. In the middle of the planet there is a solid iron core with liquid iron around it.
24) Earth’s atmosphere is a mixture of gases, main nitrogen and oxygen.
It also contains some water vapour, carbon dioxide and tiny traces of other gases. This mixture of gases is called air and without it life on earth would not be possible.
25) Earth tilts as it travels around the sun, like a spinning top leaning over.
This tilt produces the seasons; when the North pole tilts towards the sun the northern half of the earth is warm and southern half is colder. When the North pole tilts away from sun this is reversed.
26) The Earth behaves like a giant magnet with a north and south pole.
Liquid iron swirling around the Earth’s core creates electrical current which produces a magnetic field which surrounds the Earth to protect it.
27) Particles flying out of the Sun cause an eerie glow in the sky called Aurora.
Earth’s magnetic field steers the particles into the upper atmosphere near the North and South poles. Here they collide with particles of gas, making them glow.
28) Earth has one moon orbiting it.
The moon is made of rock and is about 384,000 kilometres from Earth. It is just over a quarter of the size of earth. The moon’s surface is as dry as dust, and covered with thousands of craters made by meteorites crashing into it.
29) Scientists think the Moon was part of the earth until about 4.4 billion years ago
Soon after the earth was formed, a Mars size object crashed into the Earth. The impact knocked chunks of rock out of the Earth , the debris collected together to form the moon. Life never began on the Moon as its gravity wasn’t strong enough to hold onto an atmosphere.
30) From Earth we always see the same side of the moon.
This happened because the moon spins at the same speed as it travels around the earth. The Moon’s far side was seen for the first time when the soviet LUNA 3 space probe photographed it in 1959. The first people to see the far side with their own eyes were the crew of the APOLLO 8 mission in December 1968.
31) The tides that rise and fall on Earth are caused by the Moon.
The Moon’s gravity pulls the Earth’s oceans towards it. The water piles up in a big swollen bulge on one side of earth with the bulge on the opposite side. As the Earth spins the piles of water sweep around the planet causing the high tides.
32) The moon is much smaller than the Earth, so its pull of gravity is weaker.
Gravity gives you your weight, so you would weigh less on the moon than on Earth. The Apollo astronauts who landed on the moon weighed just one sixth of their Earth weight while on the moon , so they could jump easily in their heavy space suits.
33) The Moon sometimes passes between the Sun and Earth, casting a a shadow on the Earth.
This is called a solar eclipse. If it looks like the Moon is taking a bite our of the sun it is called a partial eclipse. If the moon covers the whole of the sun its called a total eclipse.
34) During a total solar eclipse, the sun disappears behind the moon leaving just it bright corona (atmosphere ) visible.
This is a glowing ring of light around the moon . The sun’s atmosphere is incredible how it reaches more them 1 million degree Celsius.
35) During a total solar eclipse the Moon’s shadow races across the Earth at 1,700 kilometres an hour.
As darkness covers the land birds and animals fall silent – they think the night has come early.
36) How can the tint moon blot out the giant sun?
By a strange quirk of nature the moon is 400 time smaller than the Sun, but it is also 400 times closer to Earth than than the Sun, so from Earth the Sun and Moon look exactly the same size. This doesn’t happen anywhere else in to solar system.
We have not found another planet or solar system like that yet.
37) The Sun, Earth and the Moon can line up in a different way.
If the Earth comes between the Sun and Moon it casts a shadow on the moon. This is called a lunar eclipse. Lunar eclipses can be partial or total. There are at least 2 lunar eclipses every year.
38) If you see a streak of light in the sky, its probably a meteor or “shooting star” (although they are not stars).
Meteors are glowing streaks of light caused by pieces of space rock and dust as they enter our atmosphere and burn up.
39) Smaller space rocks burn up in the atmosphere, but the bigger pieces can reach the ground or splash into the sea. The cosmic arrivals are called meteorites, most are small and land unseen but sometimes a big one lands.
40) There are three main types of meteorites, these are stony (made of rock), iron (made of metal) and stony-iron (made of mixture of rock and iron). The plain stony meteorites are most common.
41) The biggest meteorite ever found in one piece weighs over 60 tonnes. It is a huge lump of metal known as the Hoba meteorite. It landed in Namibia, in Africa approx. 80,000 years ago.
42) Some meteorites come from the Moon or even Mars. They are blasted out of the surface by other rocks crashing into them. They then roam the solar system for millions of years before landing on earth.
43) Mars the fourth planet from the Sun, is known as “the red planet” due to its colour. It is the last of the terrestrial (Earth-like) planets, which are all made of rock and thought to have an iron core.
44) Mars has the biggest volcano in the solar system, called “Olympus Mons”. It is three times higher than mount Everest. Mars also has one of the biggest Canyons called “Valley Marineris” which is nine times longer, 20 times wider and 4 times deeper than the Grand Canyon in the USA.
45) The north and south poles of Mars are covered in ice. They stay frozen all year round. During the Martian winter the poles get so cold that carbon dioxide from the atmosphere freezes in to the poles.
46) More than 20 spacecraft have been sent to Mars since the 1960s, they have flown past Mars, orbited Mars, and landed on Mars. Four rovers have explored Mars’ surface. “Sojourner” was tiny, the size of a shoe box, “Spirit” and “Opportunity” were the size of golf buggys, whilst “Curiosity is the biggest yet (2020) – a nuclear powered rover the size of a small car.
47) There are plans to send astronauts to Mars later this Century. A spaceflight would take up to nine months. Astronauts would have to stay on Mars for 18 months before the Earth is close enough for a return trip.
48) Asteroids are huge chunks of rocks and metal cycling the Sun. Most orbit in a band between Mars and Jupiter in an Asteroid Belt. The biggest Asteroid is called “Ceres” which is 950 km across.
49) Asteroid means ‘Star-like’ because from the Earth, Asteroids look like tiny points of light. Astronomers can tell the difference because Asteroids cross the sky faster than stars and often in different directions. As an asteroid spins the amount of light it reflects varies. By measuring these changes in brightness astronomers can tell that most asteroids spin every 6-13 hours.
50) Some asteroids have their own moons. When the Galileo spacecraft was travelling through the Asteroid Belt on its way to Jupiter in 1993 it spotted an asteroid called ” Ida” with a tiny moon orbiting it. This was the first time we discovered Asteroids can have their own moons; more than 150 asteroids are now known to have Moons.
51) Asteroids sometimes wander into our part of the Solar System. Asteroids that come close to Earth are called Near Earth Asteroids (NEAs), and over 10,000 NEAs have been discovered though only a few hundred of them are big enough to be dangerous to Earth. Space is so vast that asteroids rarely hit Earth anyway A large one hits Earth every 500,00 years or so.
52) In 1996 a space Probe called NEAR Shoemaker was launched to study an asteroid call Eros. It orbited Eros for a year collecting information and then something it was not designed to do. It landed on Eros. Controllers on Earth slowly lowered its orbit until it touched down, and it is still their today.
53) Asteroids contain valuable minerals such as gold and platinum. One day these rare minerals will run out on Earth , so there are plans to send spacecraft to these asteroids and extract the minerals for us.
54) Jupiter is the Solar System’s biggest planet. It is 11 times the size of Earth. Jupiter along with Saturn, Uranus and Neptune are known as gas giants, because they are huge planets made of gas and liquid.
55) Jupiter is made mainly of hydrogen and helium. Below its atmosphere gas is compressed (squashed) so much that it changes into a liquid. Deeper still it is compressed even more causing the liquid to behave like liquid metal. As Jupiter spins this liquid metal creates a magnetic field which is the strongest in the Solar System. At the centre there is thought to be a small rock like core.
56) It takes less than hours for Jupiter to spin once. This is the faster than any other planet in the Solar System and even causes Jupiter to bulge in the middle.
57) The Great Red Spot is a permeant storm in Jupiter’s atmosphere. It is a vast hurricane, much larger than Earth. The storm has been raging for hundreds of years or longer, however we have discovered it is getting smaller.
58) Jupiter has the second most amount of moons. Due to its vast size, it has a very strong pull of gravity, and so far it has 79 confirmed Moons. The four biggest can be seen with binoculars, and they are known as the Galilean Moons, because they were seen for the first time by the Italian astronomer Galileo Galilei in 1610.
59) The Galilean moons were a surprise for astronomers. These icy worlds all have very different features and are not the dead dusty worlds that scientist expected them to be.
60) Jupiter’s largest moon Ganymede is also the biggest in the solar system. It is 1.5 time the size or our moon. Ganymede is covered with a deep layer of ice. The second largest Moon around Jupiter is Callisto and it is the most heavily cratered object in the Solar System.
61) Io is the Solar System’s most volcanically active moon. More than 150 volcanoes spew yellow, red, and black sulphur onto the surface. One of its volcanoes Loki gives out more heat than all of Earth’s active volcanoes combined.
62) Europa is covered with unusually smooth ice; scientist think the ice may be floating on an ocean of water that keeps freezing. By the heat of Europa, this ocean could be around 100 kilometre deep and could contain life if condition are right. In the future probes may explore Europa’s ocean for signs of life.
63) Four of Jupiter’s smaller moons circle the gas giant within Io’s orbit, they are called Metis, Adrastea, Amalthea and Thebe. All are odd shapes as they don’t have the mass needed to form a round spherical shape.
64) Saturn is the Solar System’s second biggest planet, and it is surrounded by a huge shinning rings. Like Jupiter, Saturn is made almost completely of hydrogen and helium below its thin atmosphere, and are compressed so much that they become a liquid .
65) Millions of ice particles make up Saturn’s rings, this is what makes them so bright. They orbit the planet like tint moons reflecting sunlight. The rings are thought to be the remains of a destroyed moons, comets, or asteroids.
66) Like the other gas giants Saturn’s upper atmosphere blows around the planet in bands. This means that the gas is moved around at high speed, forming huge storms. Saturn is home to many storms include vast hurricanes at both it poles.
67) If you could find a big enough bath of water Saturn would float in it. This is because despites its huge size it has the lowest density of all the planets.
68) Saturn has more moons than Jupiter; so far it has 82, the largest number of all the planets. Saturn and its moons were explored by the Cassini spacecraft, which arrived at Saturn in 2004. It discovered moons that are to small to be seen from Earth.
69) Some of Saturn’s moons orbit inside its rings. These are called shepherd moons because they herd the ring particles together. Shepherd moons give Saturn’s rings sharper edges.
70) Titan, Saturn’s largest moon is bigger than Mercury. It is the only moon in the solar System with a thick atmosphere. Since its arrival Cassini’s observations have allowed scientist to discover much more about the solid surface hidden below Titan’s atmosphere.
71) The European Space Agency landed a mini-probe called Huygens on Titan in 2005. It was carried to Saturn by the Cassini spacecraft. Huygens found lakes on Titan but instead of water they are filled with chemicals, including ethane, and methane. Huygens also carried a microphone that picked up the sound of wind blowing on the moon, this was the first sound ever recorded on another planetary body.
72) Saturn’s moons are amazingly varied. They differ in shape and size and have different types of surfaces. Cassini has explored these moons in great detail allowing scientist to study them more closely.
73) Uranus, the seventh planet from the Sun, is about four times bigger than Earth. It has an atmosphere of hydrogen and helium, and below it is an ocean of liquid water, ammonia and methane surrounding a rocky core.
74) Unlike the other planets Uranus spins on its side. This means that one pole faces the sun for 42 years and then the other pole faces the sun for 42 year. Scientist think that Uranus may have been knocked onto its side when an earth size object crashed onto it while it was forming.
75) Uranus has 27 moons; its biggest moon Titania is less than half the size of our moon. Even though it is so small, it was spotted as long ago as 1787 by the astronomer William Herschel, who also discovered Uranus.
76) Only one spacecraft has visited Uranus – Voyager 2. It left Earth in 1977 and arrived at Uranus 11 years later, in 1986. It is still the only spacecraft to have visited all four gas giants.
77) The last gas giant of the Solar System is Neptune. It is the smallest gas giant, but still nearly four times bigger than Earth. Like Uranus, it is an icy world made of hydrogen and helium, as well as water, ammonia and methane.
78) Neptune was the first planet found by mathematics. Astronomers noticed that Uranus was being tugged by the gravity of another large body, which affected its orbit. Calculations showed astronomers where to look and in 1864 Neptune was found.
79) Neptune’s winds are the fastest in the Solar System, they race Neptune at almost 2400 kilometres per hour. It is thought that heat bubbling up from Neptune’s core creates these winds. Neptune’s surface is also streaked with clouds high in the atmosphere.
80) When Voyager 2 photographed Neptune in 1989 it captured a large dark storm as big as Earth. The storm was called the great dark spot, but when the Hubble Space telescope turned towards Neptune in 1994 the great dark spot had disappeared.
81) Neptune has 14 moons, four of which are shepherd moons. The biggest is Triton which was discovered just 17 days after Neptune it self. Triton is so cold that it has ice volcanoes shooting out a mixture of liquid nitrogen, methane and dust.
82) A comet is a mountain of rock and ice orbiting the Sun. Most comets are too far away for us to see them but occasionally they come closer to the Sun. The Sun’s heat changes some of the ice into gas, the gas and dust flying off the comet form long bright tails.
83) A comet’s tails always points away from the Sun, sunlight and particles streaming away from the Sun called the Solar Wind sweep the tails back away from the Sun.
84) in 1994 a comet slammed into the giant planet Jupiter. The comet was called Shoemaker-levy 9. As it headed for Jupiter pieces of the comet hurtled into Jupiter’s atmosphere more then 200 times the speed of a jet airliner creating fireballs and huge dust clouds.
85) The whole Solar System maybe surrounded by millions of comets. Scientists think that some of the comets may come from vast clouds of icy rocks that surround the entire Solar System. This is called the Oort Cloud. Others come from a closer region outside Neptune called the Kuiper Belt.
86) The comets we see from time to time spend only a tiny part of their orbit near the Sun, the rest of time their long thin orbit takes them far away to the outer reaches of the Solar System. These can take thousands of years to orbit the Sun, whilst some comets get caught up in much smaller orbits and appear every few years.
87) Dwarf planets are smaller worlds orbiting the Sun that are not big enough to be classed as planets. There are 5 official dwarf planets but dozens more have been found and may soon join the dwarf planet club.
88) Pluto was a considered planet for 76 years. When Pluto was discovered in 1930 it became the Solar System’s ninth planet, but when astronomers started finding more smaller worlds like Pluto they decided to call them Dwarf planets , so in 20006 Pluto become a Dwarf planet. Pluto’s orbit is oval-shaped, sometimes crossing inside Neptune’s orbit.
89) Only one dwarf planet has been found in the asteroid belt between Mars and Jupiter. it is called Ceres and it is also classed as a large asteroid. Other dwarf planets orbit the sun in the Kuiper belt beyond the furthest planets.
90) Eris’ discovery made astronomers rethink Pluto’s status as a planet. Eris has more mass than Pluto so both were classed as dwarf planets, Eris is the most distance dwarf planet made of rock and ice.
91) Dwarf planet Haumea is a very strange shape. It spins so fast that it stretches out into a the shape of an rugby ball (American football). Further out from Haumea, Makemake’s surface has a large amount of solid frozen methane found as a gas on Earth.
92) Before the space age people thought intelligent creatures lived on Mars. So far life has not been found on Mars, or anywhere else in the solar System, but scientist are still searching.
93) Two Viking spacecraft landed on Mars in 1976 to look for signs of life. When they tested the Martian soil the results seemed to show signs of microscopic living organisms, however scientists decided that the chemical activity found wat not evidence of Martian life. In 2013 the Curiosity rover found evidence in Gale crator of an environment that could have supported microscopic life billions of years ago.
94) In 1996 scientists thought they may have finally found signs of Martian life. They discovered worm-like features in a meteorite from Mars that looked like microscopic fossils of bacteria, but other scientists disagree. It will take more exploration to know for definite if life ever existed on Mars.
95) Life in the Solar System was previously thought to only be possible in a narrow band called the ‘Goldilocks Zone’, but now scientists think life could exist elsewhere. One of the most promising possibilities is Jupiter’s moon Europa where there is thought to be an ocean of water underneath its icy Surface.
96) In the distance future the Moon will look much smaller to our descendants. This is because its orbit is slowly moving away from Earth. Every year the Moon moves 3.8 centimetres away from the Earth.
97) The sun is gradually growing bigger and brighter. This is because the amount of hydrogen gas in the Sun is decreasing over time. In about a billion years it will begin to evaporate the Earth’s Oceans.
98) In about 4 billion years a galactic collision will take place. The Milky-Way Galaxy that includes our solar system will collide with our Neighbour Galaxy Andromeda, although we think the Earth and Solar System will survive.
99) About five billion years from now the Sun will run out of hydrogen and other fuels it needs. Nuclear fusion will stop and the Sun will swell up into a massive red giant star and cool down.
100 ) The red giant star will eventually blow away its outer layers of gas. This will leave a glowing halo of gas around the star, the remaining star will then shrink to become a tiny white dwarf star. The white dwarf will cool and fade away over billions of years.
