EM Spectrum
Which type of electromagnetic radiation has the longest wavelength?
Radio waves
What is the main source of light for Earth?
The Sun
What does a telescope collect from objects in space?
Light or other electromagnetic radiation
What is the distance light travels in one year called?
A light-year
What force keeps planets in orbit?
Gravity
Which type of electromagnetic radiation has the highest frequency and energy?
Gamma rays
What type of electromagnetic radiation is often connected to heat?
Infrared
Why does a larger telescope usually produce a brighter image?
It collects more light.
What is a light-year used to measure?
Distance
A planet passes between Earth and its star and blocks some of the star’s light. What might scientists detect?
A temporary decrease in brightness
As wavelength decreases, what happens to frequency?
Frequency increases.
Why do different stars appear to have different colors?
Their surface temperatures are different.
Why are some telescopes placed above Earth’s atmosphere?
The atmosphere can blur or block some types of radiation.
If a star is 500 light-years away, how long does its light take to reach Earth?
500 years
Why do stars appear to twinkle when viewed from Earth?
Earth’s atmosphere bends and distorts the starlight.
Which has more energy: red light or blue light?
Blue light
Why can’t humans see infrared or ultraviolet radiation?
Their wavelengths are outside the range of visible light.
A telescope detects radio waves instead of visible light. What type of telescope is it?
A radio telescope
Why do we see distant stars as they were in the past?
Their light takes time to reach Earth.
A galaxy’s light shifts toward the red end of the spectrum. What does this suggest?
The galaxy may be moving away from us.
Why can radio waves travel through Earth’s atmosphere more easily than some other types of electromagnetic radiation?
Earth’s atmosphere is more transparent to radio waves, allowing them to pass through more easily.
An object gives off mostly ultraviolet radiation. What can scientists infer about its energy compared with an object giving off mostly infrared radiation?
The ultraviolet-emitting object is producing higher-energy radiation.
DAILY DOUBLE: Why do astronomers use different types of telescopes to study the same object?
Different wavelengths reveal different details about the object.
Why can studying distant galaxies help scientists understand the history of the universe?
The farther away a galaxy is, the farther back in time we are observing it.
A scientist wants to study a very cold cloud of gas and dust in space. Which type of radiation would be especially useful?
Infrared radiation