Astronomy????? Flashcards
How long does it take the Earth to orbit the sun
About 365 days
At what angle is the earths axis of rotation tilted at
23°
What is the natural satellite of the earth
?the moon
How long does it take the moon to orbit the earth
28 days
What is a solar eclipse
When the moon blocks out the sun completely
When is a full moon
When the moon is on the opposite side of the earth to the sun
Name the order of the planets
Mercury Venus Earth Mars Astroid belt Jupiter Saturn Uranus Neptune Dwarf planet, Pluto
Describe mercury
Mercury is the closest planet to the sun. It has no atmosphere and so was heavily created as a result of meteor impacts. Most meteors (lumps of rock from the solar system) burn up in the arts atmosphere as shooting stars with only the heavier ones reaching the surface.
Describe Venus
Venus has a very thick atmosphere (mostly consisting of carbon dioxide).
Describe. Mars
Mars have a very thin atmosphere and some craters: but there also evidence (in the form of geological features) but there was once liquid water on the planet.
What are the four inner planets called
Rocky or terrestrial because they are in some way earth like and have roughly the same density
Describe the astroid belt
Asteroids are a regular lumps of metal and rock ranging from around 1000 km across down to the size of pebbles. The majority of them staying stable orbits around the sun, but occasionally one can have its motion disturbed by collision or gravitational interaction with Jupiter so that it tumbles towards the sun: i.e. towards the earth.
Describe Jupiter
Jupiter is the largest planet in the solar system, and like Saturn, your anus and that tune is described as a gas giant because it is made primarily of hydrogen. It has four large means that can easily be observed with an oculus from earth.
Describe Saturn
Saturn is the second largest planet and is famous for its ring system. The rings consist of a vast collection of bits of rock and ice ranging in size from find out to several metres in stable orbit around the planet.
Describe Pluto
Pluto is perhaps best described as a member of the Kuiper Belt a vast collection of rocky objects in the outer reaches of the solar system that is thought to be the origin of some comets.
What is the equation for the force of gravity, weight
Weight = mass x gravitational field strength
What is the difference between weight and mass
Weight changes depending on gravitational field strength and is measured in newtons
Mass stays the same where ever you go and is measured in kilograms
What is the weight of a man of mass 85 kg on the moon? Take the strength of the moons gravitational field to be 1.7 N/kilogram.
Weight = mass X gravitational field strength = 85 kg X1 .7 N per kilogram = 145 N
What is gravity
Gravity is a force that all masses exert on all other masses: it is the force that pulls you down towards the earth, and also the force that pulls the earth towards the sun. The strings of the gravitational force between two objects depends on (A) their masses and (B) the distance apart
What is the equation for orbital speed
Orbital speed = (2 X pi X orbital radius) ➗ time period
How can you calculate the speed of a planet in orbit
Average speed = distance moved ➗time taken
What does orbital speed mean
Time taken to orbit
What is a comet
Comments are icy mudballs or muddy snowballs that are highly elliptical (i.e. very oval shaped) orbit around the sun. That orbits take them from the synergy of the Sun (and thus the earth) to the outer reaches of the solar system, crossing the orbits of the planets as they do so.
Describe why we can see comments and about the speed as they travel
As they travel towards the sun, its gravity accelerates them so that when they reach the inner solar system they are travelling very fast – which is why comments do not stay visible in the night sky for very long. But they’ve are visible at all is due to the fact that the material on the surface of the comet nucleus sublimes as it is heated by radiation from the sun to form a tail that reflects sunlight
Describe the tail of a comet
The tail of a comet always point away from the sun as it is blown by the solar wind, a stream of radiation and charged particles emitted by our nearest star
Describe the movement of a comet
Comments are travelling fastest when they loop around the sun (at perihelion), and then as they flyaway the solar gravity decelerates them so that they are travelling at the slowest when they reach the most distant point (aphelion). The motion of comments can also be explained by thinking about energy
What is a galaxy
A large collection of billions of stars
What is the universe
A large collection of billions of galaxies
What is the sun apart of
It is a collection of about 200 billion stars that is called the Milky Way galaxy
What is the shape of the milky way
It is a disk shaped spiral
How often does the earth spin on its axis
Once every 24 hours
