☀️ Sun, Moon & Planets
The apparent rising and setting of the Sun is caused by this movement of Earth.
What is Earth's rotation?
Unlike sound, electromagnetic radiation can travel through this.
What is empty space (a vacuum)?
A telescope's ability to collect light is called this.
What is light-gathering power?
The force that keeps planets in orbit around the Sun.
What is gravity?
This instrument or recorded image displays light separated into its different wavelengths.
What is a spectrogram?
The changing appearance of the Moon throughout the month is called these.
What are phases of the Moon?
This electromagnetic wave has the longest wavelength.
What are radio waves?
A telescope with high resolution can better distinguish between these.
What are two objects that are close together?
This unit measures the distance light travels in one year.
What is a light-year?
This spectrum contains all colors or wavelengths without gaps.
What is a continuous spectrum?
This type of eclipse occurs when the Moon moves between Earth and the Sun.
What is a solar eclipse?
This color of visible light has the shortest wavelength.
What is violet?
Artificial lighting that makes the night sky brighter and faint objects harder to see is called this.
What is light pollution?
This unit is approximately equal to the average distance between Earth and the Sun.
What is an astronomical unit (AU)?
A hot, low-density gas produces this type of spectrum with bright lines.
What is an emission-line spectrum?
This type of eclipse occurs when Earth moves between the Sun and the Moon.
What is a lunar eclipse?
When light changes direction as it passes from one material into another, this occurs.
What is refraction?
This movement of Earth's atmosphere can make stars appear to twinkle and reduce a telescope's seeing.
What is atmospheric turbulence?
According to Newton's First Law, an object in motion will continue moving unless acted upon by this.
What is an external force?
When an object's light shifts toward red wavelengths, it is generally moving this direction relative to us.
What is away from us?
This is the apparent backward movement of a planet against the background stars.
What is retrograde motion?
When light bounces off an object, this process occurs.
What is reflection?
Telescopes placed in space have an advantage because they avoid this major problem affecting ground-based telescopes.
What is Earth's atmosphere?
Kepler's First Law states that planets orbit the Sun in this shape.
What are ellipses?
According to Wien's Law, hotter objects emit most strongly at these wavelengths.
What are shorter wavelengths?