Space Physics

Question 1

Our solar system

Answer 1

One star - the Sun

Eight planets and dwarf planets that orbit the Sun

Natural satellites - moons that orbit planets

Part of the Milky Way Galaxy

Question 2

Formation of the Sun

Answer 2

The Sun was formed from a cloud of dust and gas (nebula) pulled together by gravitational attraction

Question 3

Fusion reactions in the Sun

Answer 3

When the Sun’s core became hot enough and dense enough, nuclear fusion reactions began

A star like the Sun is at equilibrium - gravity tends to pull it inwards, and radiation pressure from the nuclear reactions tends to expand it outwards

Question 4

Life cycle of a star

Answer 4

All stars begin life in the same way

A cloud of dust and gas, also known as a nebula, is mainly comprised of hydrogen

This then becomes a protostar, which goes on to become a main sequence star

Following this, stars develop in different ways depending on their size

Question 5

Sequence determining the life cycle of a star

Answer 5

Stars the same size as the Sun

Red giant star —- white dwarf —- black dwarf

Stars much bigger than the Sun

Red super giant star —- supernova —- neutron star, or a black hole (depending on size)

Question 6

Formation of new elements

Answer 6

Elements heavier than iron are formed in a supernova explosion of high mass stars