All about Earth
A quick bio about the planet we call home.
Known as: Earth, world, home, our planet.
About: Earth is the third planet from the sun, the fifth largest, and the densest planet in our solar system. So far it's the only astronomically known planet to have life (However, NASA believes they have found a new life accommodating planet although not too much is known about it right now, so I'm leaving it as Earth is the only known one.) Radius: 6,371 Km Age: 4.54 billion years Distance from the Sun: 149,600,000 km Mass: 5,972,190,000,000,000 billion kg Population: 7.125 billion Its Moon: Earths moon is, well, the moon! Orbit Distance: 149,598,262 km Orbit Period: 365.26 Earth days Surface Temperature: -88 to 58°C (Space-facts.com, 2015) |
Day and night (AKA. Earth's rotation)
The reason we get day and night is because the Earth spins on it's axis. What exactly is the earth's axis, you may ask? It's an invisible line which the Earth rotates/spins around and it goes through the centre of the Earth. The moon also rotates but it also orbits the Earth at the same time. On Earth, when one half of the Earth is in day, the other is in night. The way it works is:
As the Earth spins, one side faces the sun, this side of the Earth is in day. The other side is in the dark, which is the side in night. The moon can be seen most times because of it's orbit around the Earth and also the way the sun is shining upon it. (For more information about the moon check out the Moon Page). One whole rotation of the Earth takes 24 hours, so that's why a whole day is 24 hours. As well as rotation on its axis, the earth also tilts, but more about that in the section for seasons on this page.
As the Earth spins, one side faces the sun, this side of the Earth is in day. The other side is in the dark, which is the side in night. The moon can be seen most times because of it's orbit around the Earth and also the way the sun is shining upon it. (For more information about the moon check out the Moon Page). One whole rotation of the Earth takes 24 hours, so that's why a whole day is 24 hours. As well as rotation on its axis, the earth also tilts, but more about that in the section for seasons on this page.
Why we have an extra day on a leap year (AKA. Earth's orbit around the sun)
The Earth, like every other planet in our solar system, orbits the sun. The Earth takes 365 and 1/4 days to go around the sun once, which is the same amount of days in a normal year. This is called a revolution. The reason we have an extra day every 4 years is because the earth takes 365 and 1/4 days to have a normal calendar year, the quarters add up and 4 quarters is a whole, so that's an extra day! [Coffey 2010].
Seasons (AKA. Earth's tilt)
The reason we have seasons is because the Earth isn't straight on it's axis, it's tilted. Unlike the incorrect statement that it's because the Earth is closer to the sun. Since the Earth is tilted, the sun's rays hit it different angles at different times as it goes around, causing seasons. The Earth's tilt is at an angle of 23.5 degrees. The tilt means that when it's summer in one hemisphere, that hemisphere will be tilted towards the sun, while the other hemisphere will be tilted away, and it will be winter there. It takes 6 months for summer to transition into winter, and in between the two, there are the seasons spring and winter.
Autumn occurs in the southern hemisphere when the north pole starts moving towards the sun, not completely there yet, but moving along. This puts the south pole tilted further away from the sun, which is why it's colder in autumn, but not as cold as winter. The same goes for spring in the southern hemisphere, just vice versa. [Barrow 2013].
Autumn occurs in the southern hemisphere when the north pole starts moving towards the sun, not completely there yet, but moving along. This puts the south pole tilted further away from the sun, which is why it's colder in autumn, but not as cold as winter. The same goes for spring in the southern hemisphere, just vice versa. [Barrow 2013].
Animation!
This animation is also on the Sun and Moon page, so it has information about the sun and moon as well! Enjoy!
References for this page
Barrow, M., 2013. Why do we have Seasons?. [Online]
Available at: http://resources.woodlands-junior.kent.sch.uk/time/seasons.htm
[Accessed 26 August 2015].
Coffey, J., 2010. Earth Revolution. [Online]
Available at: http://www.universetoday.com/60655/earth-revolution/
[Accessed 25 August 2015].
National Geographic, 2015. Axis. [Online]
Available at: http://education.nationalgeographic.com/encyclopedia/axis/
[Accessed 21 August 2015].
Spacefacts.com, 2015. EARTH FACTS. [Online]
Available at: http://space-facts.com/earth/
[Accessed 20 August 2015].
Available at: http://resources.woodlands-junior.kent.sch.uk/time/seasons.htm
[Accessed 26 August 2015].
Coffey, J., 2010. Earth Revolution. [Online]
Available at: http://www.universetoday.com/60655/earth-revolution/
[Accessed 25 August 2015].
National Geographic, 2015. Axis. [Online]
Available at: http://education.nationalgeographic.com/encyclopedia/axis/
[Accessed 21 August 2015].
Spacefacts.com, 2015. EARTH FACTS. [Online]
Available at: http://space-facts.com/earth/
[Accessed 20 August 2015].