About Us
For Teachers
Most Popular
Most Recent
Astronomy Links
Image Credits
Cornell Astronomy
Ask a Question
Home
Our Solar System
The Earth
The Moon
The Sun
Planets & Dwarf Planets
Comets, Meteors, & Asteroids
The Universe
Extrasolar Planets
Stars & Star Clusters
Supernovae
Black Holes & Quasars
The Milky Way
Galaxies
Cosmology & the Big Bang
Observational Astronomy
Stargazing
Telescopes
Lunar & Solar Eclipses
Timekeeping
SETI & Extraterrestrial Life
Physics
General Physics
The Theory of Relativity
People & Astronomy
Careers in Astronomy
Space Exploration & Astronauts
The History of Astronomy
Astronomy in the Arts
Blueshifts
Enter Part of Title
Display #
5
10
15
20
25
30
50
100
All
Is light blueshifted when it is gravitationally lensed?
(Intermediate)
What would the Big Crunch look like to an observer on Earth?
(Advanced)
Why are there blue shifted galaxies?
(Intermediate)
Random Question
What class of spiral galaxy is the Milky Way? (Intermediate)
Most Recent
What should I know about the upcoming Solar Eclipse (2017)? (Beginner)
Do galaxies that are receding from us faster than the speed of light disappear from our observations? (Intermediate)
Why are astronomers interested in gravitational waves? (Intermediate)
Can two galaxies move away from each other faster than the speed of light? (Intermediate)
What is a graviton? (Intermediate)
Why are there high tides during a Full Moon? (Intermediate)
Why is Neptune still considered a planet when Pluto crosses its orbit? (Intermediate)
Could there be objects orbiting interior to Mercury? (Intermediate)
Have the inner planets cleared their neighborhood? (Intermediate)
What caused the Big Bang and created the Universe? (Beginner)
Editor's Pick
What is the universe expanding into? (Intermediate)
What do I need to do to become an astronomer? (Beginner)
What's the difference between astronomy and astrology? (Beginner)
Why is looking out into space the same as looking back in time? (Beginner)
Can we find the place where the Big Bang happened? (Intermediate)
Most Popular
Today
This Week
This Month
All Time
What color is each planet? (Intermediate)
What is the difference between a "star" and a "sun"? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
Why do we not have eclipses every month? (Beginner)
How are light and heavy elements formed? (Advanced)
When was the last time all of the planets were aligned? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
What are constellations used for? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
How far is each planet from Earth? (Intermediate)
What color is each planet? (Intermediate)
What is that ring (or rainbow) around the moon? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
When was the last time all of the planets were aligned? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do we not have eclipses every month? (Beginner)
Why are the Moon and Sun sometimes orange or red? (Beginner)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
Why is the moon in a different place every night? (Beginner)
What color is each planet? (Intermediate)
What is that ring (or rainbow) around the moon? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
When was the last time all of the planets were aligned? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do we not have eclipses every month? (Beginner)
Why are the Moon and Sun sometimes orange or red? (Beginner)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
Why is the moon in a different place every night? (Beginner)
What's going to happen on December 21st 2012? (Intermediate)
What color is each planet? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
How far is each planet from Earth? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
How long does it take for the Sun's light to reach us? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
Our Reddit AMAs
AMA = Ask Me (Us) Anything
June 2014 AMA
July 2013 AMA
Q&A Categories
Home
Our Solar System
The Earth
The Moon
The Sun
Planets & Dwarf Planets
Comets, Meteors, & Asteroids
The Universe
Extrasolar Planets
Stars & Star Clusters
Supernovae
Black Holes & Quasars
The Milky Way
Galaxies
Cosmology & the Big Bang
Observational Astronomy
Stargazing
Telescopes
Lunar & Solar Eclipses
Timekeeping
SETI & Extraterrestrial Life
Physics
General Physics
The Theory of Relativity
People & Astronomy
Careers in Astronomy
Space Exploration & Astronauts
The History of Astronomy
Astronomy in the Arts