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
Oxygen
Enter Part of Title
Display #
5
10
15
20
25
30
50
100
All
Can we harvest H & O from space to make water?
(Intermediate)
How can a star burn with no oxygen?
(Beginner)
Is the reddish dust of Mars biogenic?
(Intermediate)
Is there oxygen in the atmospheres of other planets?
(Intermediate)
What would happen if you took off your helmet in space?
(Beginner)
Where did all the water in the universe come from?
(Intermediate)
Why doesn't the hydrogen on Jupiter explode?
(Intermediate)
Random Question
Why is a day divided into 24 hours? (Intermediate)
Most Recent
What makes certain lunar eclipses so special? (Beginner)
Why is Earth's core molten? (Intermediate)
What will happen to Earth's tides as the moon moves away from us? (Intermediate)
How can spiral galaxies keep their shape? (Advanced)
Does a black hole have a "surface"? (Intermediate)
How can you link telescopes to make a bigger "effective telescope"? (Intermediate)
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)
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
How does the Moon stay "suspended" in the air? (Intermediate)
What color is each planet? (Intermediate)
How far is each planet from Earth? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
What are the names of the earth, moon, sun, and solar system? (Beginner)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Can artificial gravity be created in space? (Intermediate)
Is the distance from the Earth to the Sun changing? (Advanced)
Why do the planets orbit the sun? (Beginner)
What color is each planet? (Intermediate)
How far is each planet from Earth? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
Can artificial gravity be created in space? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Why are the Moon and Sun sometimes orange or red? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
What color is each planet? (Intermediate)
How far is each planet from Earth? (Intermediate)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
Can artificial gravity be created in space? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
Which planets have rings? (Beginner)
Why do airplanes take longer to fly West than East? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
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