The Indian Public School – Cambridge International
Physics - PP5
Name :
Grade 8
Date :
___________________________________________________________________________________
asteroid
meteor
meteorite
A
D
D
A
meteorites/the remains of asteroids found on Earth;
craters left after the collision;
fossils that indicate a mass extinction took place at a particular time.
(Melting rocks are thrown) large distances from the Point of
impact.
(There are intense blasts of) heat radiating/rushing
outwards from the impact.
(There are shock waves, in which) air is squeezed
to produce rings of very high pressure that expand
outwards from the impact.
shakes.
Clouds of dust and gas are thrown high into the Earth’s atmosphere which
can block the sunlight from reaching the surface and cause the climate to
change.
Smaller asteroids/rocks have collided with the surface causing
impact craters.
People and robotic probes have landed on the Moon’s surface and brought
samples of rock back to Earth.
That the Moon was probably formed when an object, roughly the same size
and mass as the planet Mars, collided with the Earth and pieces of
rock from both were pulled together by the effects of gravity.
Accept either ‘yes’ or ‘no’ for when accompanied by a suitable explanation.
Example for ‘yes’: asteroids have collided with the Earth in the past and have
caused mass extinctions. Example for ‘no’: large asteroids are thought to collide
with the Earth only once every 100 million years and we can track the
movements of the largest asteroids to predict if they will collide.
The Moon spins once on its axis in exactly the same amount of time as the
Moon takes to orbit the Earth once.
Hundreds of millions of years ago OR about 100 million years after the
Earth formed because it takes that amount of time to form and stay in
such a stable orbit.
Interstellar) gas and (interstellar) dust
Light produced by nearby stars is reflected off the
dust and gas.
The dust and gas form clumps as they are pulled towards each other
by the force due to gravity.
Eventually the atoms are squeezed so tightly together they overlap and
fuse together / join due to nuclear fusion, releasing large amounts of
energy.
Improvements in technology have resulted in larger, more sensitive
telescopes that can detect fainter stars.
The young stars were evidence that the nebula was forming stars and not
expanding outwards because of a supernova/exploding star.
Produced by an old star
Any two from: Circular cloud expanding from a central point;
central dim star that appears to have exploded to produce the nebula;
no evidence of new stars forming
It should expand outwards. Observing the nebula over longer periods of time
with sensitive telescopes should produce evidence of outwards movement.
655 light-years is the distance light travels in 655 years, so the light
we see today was produced 655 years ago.
We are too far away to be able to measure the distance precisely.
Inside the Milky Way. The galaxy is around 100 000 light-years across.
Any three from: surface water: none on the Moon, plenty on Earth;
atmosphere: none on the Moon, present on the Earth; asteroid impact
craters: many easily seen on the Moon, fewer on Earth that can be
easily seen; life: none on the Moon, many species on Earth; temperature:
very cold on the Moon, temperate/warm on Earth
The Moon was partly formed from rocks on the Earth and partly from other
rocks which could have been caused by an asteroid colliding with Earth.
Any two from: rocks collected from the Moon area mixture of rocks, some similar
to rocks found on Earth and others that are not; the Moon follows a stable orbit
around Earth that suggests it was formed many hundreds of millions of years ago
at a time asteroid collisions would have been more frequent; the Moon is very
nearly a smooth, rounded shape, suggesting it was not formed by
Earth capturing an asteroid, which are mostly not regular shapes.
Interstellar gas and dust slowly gathers into clumps due to the force of
gravity, the forces eventually squeeze the gas atoms so tightly together that
they fuse and release large amounts of energy.
Nuclear fusion
Hydrogen, helium
An asteroid collided with Earth causing the climate
to change quickly.
About 65 million years ago
Where all the individuals of many species of organisms die in a
relatively short space of time.
Clouds of dust and gas would have been thrown high in the atmosphere
blocking sunlight from reaching the Earth’s surface and causing the temperature
to drop.
Fossil records show that the plants in large areas
of the Earth’s surface were destroyed by wild fires.
Hydrogen and helium make up most of the gas found in nebulae.
These nebulae have often been formed when large stars explode at
the end of their lives. Eventually the nebulae starts to be drawn
together by gravity, forming clumps that squeeze hydrogen and helium
atoms together, causing nuclear fusion to start. The largest stars that
form in this way go on to explode and create new nebulae.