is a telescope positioned in space to avoid atmospheric interference and observe parts of the spectrum which cannot reach the Earth’s surface

is a collection of many millions or billions of stars held together by gravitational forces

is the increase in the wavelength of light (and decrease in its frequency) cause by the movement of a star or galaxy away from us

Observing the universe

Physics

The solar system

Orbital motion of artificial satellites: relationship between radius and speed

Birth of a star

Stellar evolution

The changing universe

In the Solar system and beyond unit, pupils learnt about the scale and content of the Solar system and the universe, and about gravitational force and the motions that cause days and seasons on the Earth.

This unit covers the solar system's features, including planets, moons, and satellites. It explains gravity's effect on orbits, the sun's formation from dust and gas, and fusion equilibrium. It also explores red-shift, evidence of an expanding universe, and the link to the Big Bang model.

Gravity in space

Which of the following optical instruments can improve what we can see in space?

What makes a star appear to twinkle in the night sky?

It is very expensive to construct and launch.

What are the advantages of using a space telescope compared to a telescope on Earth?

Their brightness varies in a regular pattern.

How do **Messier objects** that can be seen with a telescope differ in appearance from stars?

coloured lines that add together to make a visible spectrum

black lines on a visible spectrum caused by a telescope

black lines on a visible spectrum caused by gases around a star

black lines on a visible spectrum caused by air in Earth's atmosphere

What are absorption lines in a spectrum of light from a star?

there is less red light in the visible spectrum of the galaxy

there is more red light in the visible spectrum of the galaxy

absorption lines in its spectrum have lower than expected frequencies

absorption lines in its spectrum have higher than expected frequencies

What observation shows that **redshift** has occurred and that the wavelength of light from a distance galaxy has increased?

A {{}} star fuses hydrogen in its core. It is stable for long periods of time (often billions of years).

What type of star will the Sun change into next, after it stops fusing hydrogen in its core (in about 5 000 000 000 years)?

Sort the following stages of a star's life, for a star similar in size to the Sun, into the order in which they take place.

What is a neutron star that is formed from the core of a supernova? 

the core of a massive star compressed to a few thousand metres across

the core of a massive star compressed to a few hundred metres across

the core of a massive star compressed to a few metres across

the core of a massive star compressed to almost no size at all

What is a black hole that is formed from the core of a particularly large supernova? 

Observing the universe

Lesson outcome