Earth
This unit is defined using the distance between the Sun in the Earth.
What is an Astronomical Unit (AU)?
The Moon's gravitational pull on Earth is strongest at what point in its elliptical orbit?
What is the closest point in the orbit?
What is Voyager 1?
Light can be described as having this shape as it travels through space.
What is a wave?
At a star's death, it may briefly release more light than its entire galaxy combined in this rare phenomenon.
What is a supernova?
What is the tilt of the Earth's axis?
During this type of eclipse, the Moon and the Sun are on opposite sides of the Earth.
What is a lunar eclipse?
The Sun makes up approximately 99.9% of what property of the solar system?
What is mass?
Using a spectroscope to split light into its constituent wavelengths can reveal this property of a light source.
What is elemental makeup?
The James Webb Space Telescope is optimized for seeing this type of light, emitted in greater proportions by cooler stars.
What is infrared light?
Though approximately circular, the Earth's orbit (like most orbits) is best described as this shape.
What is an Ellipse?
The amount of time between two full moons.
What is 29.5 days?
During this type of eclipse, only the corona of the Sun is visible; the rest is blocked by the Moon.
What is a total solar eclipse?
When a celestial body is moving towards us at a high speed, this phenomenon can be seen in its light.
What is blueshift?
By taking measurements 6 months apart, while the Earth is on opposite ends of its orbit, this calculation method allows us to calculate the distance to nearby stars.
What is parallax?
This feature of the Earth refracts light, causing the Moon to glow red during a lunar eclipse.
What is the atmosphere?
What is a waning crescent moon?
This causes the sun to appear yellow on Earth, but white in space.
What is the Earth's atmosphere?
At a subatomic level, this is the most common way that a photon is created.
What is electron movement between energy levels? (falling from a higher level to a lower level)
To determine the luminosity of a star, one must know these two other properties of the star.
What are distance and brightness?
This term is used to describe the weakened tides on Earth when the Sun and Moon are not in alignment with one another.
What is the neap tide?
This term describes the property of the Moon that causes us to see the same face of the Moon at any point in its orbit.
What is tidally locked?
Since the Sun is burning primarily hydrogen, it is in this phase of a star's lifecycle.
What is the main sequence?
This phenomenon can be seen in light from ultra-distant galaxies that has been stretched by the expansion of the universe.
What is redshift?
This star, part of a binary system located only 8.6 light years away from the Sun, is the brightest star in the night sky.
What is Sirius A?