Gravity is force that attracts objects
toward the centre of the Earth.
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Earth’s Gravity
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- holds everything on Earth on the ground and stops it flying off into space.
o - holds our Earth together keeps the Moon orbiting our Earth.
BSL Version
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Our Earth, Saturn, Jupiter, comets,
etc all orbiting our Sun.
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Gravity Acts
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- gravity acts on all matters in the Universe.
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o - stars burn by squeezing their matter together – this is caused by gravity.
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o - the force of gravity depends on mass (the amount of matter in an object) and distance.
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o - the more mass an object has and the closer it is to another object – the more strongly its gravity pulls (like Earth pulling Moon).
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o - the Black Hole has the strongest gravitational pull in the Universe.
BSL Version
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Law of Gravity
- the basic laws of gravity can be used for anything, including detecting an unseen planet by studying the flickers in another star’s light.
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- Einstein’s theory of general relativity shows that gravity not only pulls on matter, but also bends space and even time itself.
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Orbits
Orbits are the result of a perfect balance between the force of
gravity on an object and its forward momentum – keeps it flying straight onwards.
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Earth Satellite Orbits
International Space Station (ISS)
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- Pulls the ISS toward Earth’s surface, because the International Space Station (ISS) must maintain a specific speed to stay in orbit around Earth.
o - 17,500mph – the ISS orbits Earth at a speed of about 17,500 miles per hour, which matches the rate at which Earth’s surface curves.
o - this allows the ISS to maintain a fixed distance
from Earth while traveling around the world.
o - Gravity – the basic laws of gravity can be used for anything, including detecting an unseen planet by studying the flickers in another star’s light.
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BSL Version
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Satellites Watch – ISS visible passes (Heavens Above)
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Back to The Universe / next to Dark Matter page.