Space Flashcards
What is Gravity?
Gravity is an attractive force between two objects.
Is Gravity a strong or weak force?
Gravity is a weak force
What is the formula for the Attractive force?
G(m1 m2/r^2)
Does the attractive force get larger or smaller if the distance is increased?
The attractive force gets smaller with distance increasing.
What is the inverse square law?
If you double the distance, the force is reduced to a quarter of its original value.
Two objects have a Gravitational force of 800 million newtons. If the distance between these objects is doubled, what is the force now?
200 million newtons. 800/4=200
What force causes the Earth to orbit the sun?
Gravity
Why does the Earth orbit the sun?
Earth is moving at a very fast velocity, and the sun’s gravitational field strength is pulling the Earth in. These forces cancel out hence why Earth is orbiting the sun.
At the right speed, gravity can go objects to go into orbit.
What is the shape of orbit of planets
It is elliptical
What is the moon orbiting?
The Earth
How long does it take the moon to orbit the Earth?
Roughly 28 days.
What is the sun?
A star
What differs stars from planets?
Stars emit their own light, while planets do not. Also, planets orbit a star but a star does not orbit a planet.
How are stars held together?
By their own gravity
How can we see planets and moon in the night sky?
The light from stars is reflected.
The moon is a ________ of the Earth. What fills the blank space?
satellite
Is the moon a natural or artificial satellite of the Earth?
Natural satellite
How many phases does the moon have?
8
True of false. The same side of the moon is always facing us.
True
Why do eclipses occur?
Eclipses occur because the Earth, Sun and Moon line up and they are on the same plane.
What is a lunar eclipse?
A lunar eclipses when the Earth blocks the moon from the sun
What is a solar eclipse?
When the moon casts a shadow on Earth.
Why don’t we have eclipses every month?
The moon’s orbit is on a different plane from the Sun-Earth orbit, so often the moon and the Earth and the sun will not line up.
What is a satellite?
A satellite is something that orbits planets or stars. For example, the moon is a satellite of the Earth and the Earth is a satellite of the Sun.
What are the 2 types of satellites?
Natural satellites and Artificial satellites
What are artificial satellites?
Satellites that are man made
What are natural satellites?
Satellites that are naturally occurring
What are the three types of artificial satellites?
LEO, MEO, GSO
What does LEO stand for?
Low earth orbit
What does MEO stand for?
Medium earth orbit
What does GSO stand for?
Geo-stationary orbit
What is the maximum height of LEO satellites?
600km
What is the maximum height of MEO satellites?
20,400km
What is the maximum height of GSO satellites?
36,000km
What are satellites used for?
Communication, navigation, studying stars, military uses, observing weather and space telescopes.
What are some features of LEO satellites?
Used for communication
Has the cheapest orbit
Produces great images
What are some features of MEO satellites?
Used for navigation, communication and geodynamical phenomena
What are some features of GSO satellites?
Always orbit above one point on the Earth
Orbits above the equator
Orbits Earth with same speed that Earth is rotating
Why are satellites used to study stars and not telescopes?
The Earth’s atmosphere and pollution on Earth obscure the stars.
What are some issues with sending manned space missions?
The person will have health problems, mental health issues, they will be needed to be supplied food. It costs more.
