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
Cosmology
Enter Part of Title
Display #
5
10
15
20
25
30
50
100
All
Can "tired light theory" explain the observed redshifts of galaxies?
(Intermediate)
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background?
(Advanced)
Can I calculate the size of the Universe by converting light years to kilometres?
(Intermediate)
Can the acceleration of the Universe be analogous to apparent acceleration in a airplane?
(Intermediate)
Can two galaxies move away from each other faster than the speed of light?
(Intermediate)
Can we find the place where the Big Bang happened?
(Intermediate)
Can we look back far enough in time to see the Big Bang?
(Beginner)
Can you use an infinite line of reflectors to send light to the edge of the Universe?
(Intermediate)
Cosmologists say the expansion of the universe is accelerating, what is driving this?
(Intermediate)
Could a different theory of gravity explain the dark matter mystery?
(Intermediate)
Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating?
(Advanced)
Could matter-anti-matter repulsion power the expansion of the universe?
(Intermediate)
Could neutrinos be dark matter?
(Intermediate)
Could our position in the universe affect our perceptions of the expansion?
(Intermediate)
Could the Universe have expanded faster than the speed of light at the Big Bang?
(Intermediate)
Could there have been multiple Big Bangs at different places in the universe?
(Intermediate)
Did the speed of light change over the history of the universe?
(Intermediate)
Did time go slower just after the Big Bang?
(Advanced)
Do galaxies that are receding from us faster than the speed of light disappear from our observations?
(Intermediate)
Does inflation allow for an infinite number of universes?
(Advanced)
Page 1 of 4
Start
Prev
1
2
3
4
Next
End
Random Question
What was the bright, smoothly moving star that I saw? (Beginner)
Most Recent
Is speed of light the same everywhere ? (Beginner)
How does Venus have sulphuric acid in it's clouds? (Beginner)
Earth's Bow Shock (Advanced)
How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
Why do rays from Sun appear to converge at a point? (Beginner)
But seriously: what was there before the Big Bang? (Beginner)
How far can photons move freely in the early universe (Advanced)
How likely is it that the Solar System has had or will have a close encounter with another star? (Intermediate)
How do we know what we observe is x light years away? (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 was the bright, smoothly moving star that I saw? (Beginner)
What would happen if the Moon fell out of its orbit around Earth? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Is it possible for amateurs to do optical interferometry? (Intermediate)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
Earth's Bow Shock (Advanced)
What kind of eyepieces do I need to look at planets? (Intermediate)
How can we see the Milky Way if we are inside it? (Intermediate)
What would happen if an asteroid 10 kilometers across hit the Earth? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
What was the bright, smoothly moving star that I saw? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How far is each planet from Earth? (Intermediate)
What would happen if the Moon fell out of its orbit around Earth? (Intermediate)
Earth's Bow Shock (Advanced)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
Which planet is most similar to Earth? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
How are light and heavy elements formed? (Advanced)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
What was the bright, smoothly moving star that I saw? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
How far is each planet from Earth? (Intermediate)
Why is the moon in a different place every night? (Beginner)
Earth's Bow Shock (Advanced)
How does the position of Moonrise and Moonset change? (Intermediate)
How are light and heavy elements formed? (Advanced)
Why do the planets orbit the sun? (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)
How do you measure the distance between Earth and the Sun? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (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)
When was the last time all of the planets were aligned? (Beginner)
How long does it take for the Sun's light to reach us? (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