Which is...
True or False: A light year is a measurement of distance.
True- even though it says "year" in the name, a light year measures how much light travels in a year
The distance from the Earth to the sun is called...
One astronomical unit, or 1 AU
Which is the only type of EM spectrum radiation that we can see with our eyes?
Visible Light
What do we call a group of stars, gas, and dust that are held together by gravity?
A galaxy
Put the following units in order of size from smallest to largest: AU, LY, kilometer, meter
(Smallest) Meter, Km, AU, LY (Largest)
True or False: Astronomers use AUs to measure the distance from the Earth to any space object, inside or outside the solar system.
False- Only Distances WITHIN the solar system are measured with AUs
Which type of EM radiation has more energy than X-Rays?
Gamma rays!
What are the 3 types of galaxy?
Spiral, Elliptical, and Irregular
Which is closest? An object that is 0.5 LY away, An object that is 1 LY away, or An object that is 100 AU away
The object that is 100 AU away is closest. There are over 63,000 AU in just 1 light year!!
The star Promixa Centauri is approximately 4.3 Light years from Earth. How long does it take light to travel from Proxima Centauri to the Earth?
4.3 years
Why wouldn't you use an AU to measure to the next closest star?
The distance is too great (the number would be huge).
Which type of EM radiation has the longest wavelengths and lowest frequency?
Radio waves
How many stars are found in the average galaxy?
A) thousands
B) millions
C) billions
C- There are billions of stars in each galaxy! The milky way galaxy is estimated to have between 100-400 million stars.
Which is larger? The moon, the sun, or the solar system?
The solar system- it contains the sun and everything else that orbits around it, including the planets and all of their moons!
A nebulae is 0.75 light years from the Earth. How long would it take the light from that nebulae to travel to the Earth?
0.75 years, or around 9 months.
True or False: It would be reasonable to assume that Planet Mercury is approximately 7 AUs from the Sun.
False- Mercury is between the Sun and the Earth, therefore it must be LESS than 1 AU from the Sun.
Which types of EM radiation are unsafe for living tissues to be exposed to due to their high energies?
Gamma Rays, X-rays, UV rays
All of the matter and energy that exists is called the:
Universe!
Which is larger- a galaxy or a nebulae?
A galaxy- many nebulas can fit into one galaxy.
9,500,000,000 km is equal to....
One light year! (You won't have to know that number for the test)
Why aren't light years used instead of AU when measuring the solar system?
Light years are much larger than the solar system, it is too big of a unit to use.
Why do scientists use radio and infrared telescopes to create images of planets in our solar system when we can see them perfectly well with visible light?
Other parts of the EM spectrum reveal other important information about the planets beyond what visible light shows. Radio waves can penetrate clouds and show us surface features, while Infrared telescopes can give us information about temperatures of planets.
Gravity!