gcse science P1

The solar system

·         Sun-> mercury->Venus-> earth>mars->Jupiter->Saturn->Uranus->Neptune->Pluto

·         Comets/asteroids/dust/dwarf planets also orbit the sunthese are much smaller than the planets.

·         The solar system is about 5000,0000,000 years old

·         The Earth is one of the eight planets orbiting the Sun

·         The Universe is considered to be everything there is, though most of it is thought to be empty.

·         the diameter of the Earth is 12,800km (7,953 miles)

·         the diameter of the Sun is 109 times that of the Earth’s

·         the Earth is 150 million km (93 million miles) from the Sun

·         the distance to the nearest star is four light years.

·         The solar system was formed by clouds of dust and gas.

·         A cloud started to get squeezed slightly. Once the particles got closer to get other, gravity took over, this pulled things closer together until the whole thing collapsed on itself. At the centre of this a protostar was formed. When the temperature got high enough, a process called fusion started-hydrogen nuclei joined together to make helium. Fusion gives out massive amounts of heat and light ,so our star was formed. All of the chemical elements in the clouds with heavier atoms than helium and hydrogen were also formed in the stars by the fusion of different nuclei. Around the sun, material from the cloud containing hydrogen, helium and heavier elements started to clump together these became the planets.

Beyond the solar system

·         We’re in the milky way galaxy

·         Our sun is one of thousands of millions of stars which form the milky way galaxy – about 1 in 100,000,000,000

·         The sun is about halfway along one of the spiral arms of the Milky Way.

·         The distance between neighbouring stars in a galaxy is usually millions of times greater than the distance between planets in the solar system.

·         The whole universe has more than a thousand million galaxies.

(smallest)

Distance of the earth

Diameter of the sun

Diameter of the earth’s orbit

Diameter of the solar system

Distance from the sun to the nearest star

Diameter of the Milky Way

Distance from the Milky Way to the nearest galaxy

(largest)

Different stuff in space

Age

Earth

5000 million

Sun

5000 million

universe

14,000 million

Looking at the sky

·         Everything we know about stars and galaxies has come from the light, and other radiations, that they give out this gives us information about the distances to stars, and about how they are changing..

·         Looking at the sky with the naked eye shows the Sun, Moon, stars, planets and a few cloudy patches called nebulae, telescopes were invented and developed, astronomers could see that some of the nebulae were in fact groups of millions of stars. These are galaxies.

·         Telescopes allowed astronomers to answer a question that had baffled scientists since the astronomer…