Topic 8 - Space Physics

• Objects orbit other objects due to gravity.
• Gravity acts towards the centre of the orbit.
• For circular orbits, the objects move at the same speed, but velocity is changing, so the object accelerates.
• If the orbital radius decreases, the gravitational attraction increases.
• For a stable orbit, orbital speed increases.
• Pluto is not one of the planets of the Solar System.
• The Asteroid Belt lies between Mars and Jupiter.
• Stars fuse elements up to iron.
• Elements heavier than iron are made in a supernova.
• Red-shift provides evidence for the expansion of the universe.
• A Black Hole is a region of space where gravity is so strong that nothing, not even light, can escape.
• A Nebula is a cloud of gas and dust.
• A Protostar is a star in the process of formation.
• A Main Sequence Star is a star on the main sequence.
• A Supernova is a star that has exploded.
• A Small, Sun-like Star is a star similar to the Sun.
• A Large Star is a star much larger than the Sun.
• A White Dwarf is a star with a very small mass.
• A Black Dwarf is a star with a very large mass.
• A Red Supergiant is a star larger than the Sun.
• A Red Giant is a star larger than the Sun.
• A Neutron Star is a star with a very large mass and a small radius.