Ask an Astronomer Team

Dave Kornreich

Dave was the founder of Ask an Astronomer. He got his PhD from Cornell in 2001 and is now an assistant professor in the Department of Physics and Physical Science at Humboldt State University in California. There he runs his own version of Ask the Astronomer. He also helps us out with the odd cosmology question.

Display # 
Title Created Date Hits
Why do most moons orbit their planets at the equator? (Intermediate) Apr 99 84411
Do you believe in UFOs? (Beginner) Apr 99 61609
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 101635
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 67295
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 87602
How do you measure the mass of a star? (Beginner) Apr 99 152503
What direction do planets rotate? (Beginner) Apr 99 380072
Can you hear sounds in space? (Beginner) Apr 99 587813
How can we measure distances to more stars? (Intermediate) Apr 99 64021
Where did all the water in the universe come from? (Intermediate) Apr 99 118717
Why doesn't gravity change the speed of light? (Beginner) Apr 99 59750
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 44933
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 72060
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 66940
What are Altitude and Azimuth? (Intermediate) Apr 99 143661
Do dead stars still shine? (Beginner) Apr 99 94963
How does light pollution affect astronomers? (Intermediate) Apr 99 143136
Have gravitational waves been proven to exist? (Intermediate) Apr 99 62748
What is a Dyson Sphere? (Intermediate) Apr 99 53486
Why do we not have eclipses every month? (Beginner) Mar 99 318798
Do astronomers believe in astrology? (Beginner) Mar 99 78187
Which planets have rings? (Beginner) Mar 99 566488
What equipment do I need for astrophotography? (Advanced) Mar 99 64983
How are photons created and destroyed? (Advanced) Mar 99 141960
Why search for only Earth-like life on other planets? (Beginner) Mar 99 55299
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 172344
Why is twilight short near the equator? (Intermediate) Mar 99 182264
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 56076
Does the shuttle worry about space junk? (Beginner) Mar 99 50480
Why do stars change colour when they twinkle? (Beginner) Mar 99 185230
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 62339
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 75902
What do stellar classifications mean? (Beginner) Mar 99 56404
Could we be seeing dead stars? (Beginner) Mar 99 62934
Can one star orbit another? (Beginner) Mar 99 61797
Why can't you see stars during the day? (Beginner) Mar 99 210540
What would happen if you took off your helmet in space? (Beginner) Mar 99 244756
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 76920
Why is it important to study meteorites? (Beginner) Mar 99 91334
Why does the Moon look big on the horizon? (Intermediate) Mar 99 90606
When was the last time all of the planets were aligned? (Beginner) Mar 99 720775
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 123191
How do we measure distances to other stars? (Beginner) Mar 99 66685
What are the requirements for being a planet? (Beginner) Mar 99 305509
If comets are boiling away, why are there any left? (Intermediate) Mar 99 76055
What is sidereal time? (Beginner) Mar 99 76278
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 113673
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 382298
How are elements heavier than iron formed? (Intermediate) Feb 99 225867
Are time machines possible? (Intermediate) Jan 99 61015
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 68166
What is a nova? (Beginner) Jan 99 229636
Who first measured the speed of light? (Intermediate) Jan 99 168002
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 118880
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 314945
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 406155
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 69555
Where are stars born? (Beginner) Jan 99 99211
Can you see satellites? (Beginner) Jan 99 93853
What kinds of star clusters are there? (Intermediate) Jan 99 54837
What is the life cycle of a star? (Intermediate) Jan 99 326638
How do I tell which planet is which? (Beginner) Jan 99 98458
Why do stars twinkle? (Beginner) Jan 99 557639
Can HST see the Oort cloud? (Intermediate) Jan 99 50059
What is the shape of the universe? (Intermediate) Jan 99 110236
How can geometry be different in space? (Intermediate) Jan 99 59402
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 82803
Why are there blue shifted galaxies? (Intermediate) Jan 99 83915
What is a dimension? (Intermediate) Jan 99 80880
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 118269
Can you tell time by the Big Dipper? (Beginner) Jan 99 56835
How powerful are quasars? (Intermediate) Jan 99 53523
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 75200
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 59958
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 118804
Why do planets not twinkle? (Intermediate) Jan 99 154235
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 217894
What are the boundaries of the constellations? (Beginner) Jan 99 57511
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 86205
How do distant galaxies differ from those nearby? (Advanced) Jan 99 57205
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 700833
Do electrons age? (Beginner) Jan 99 51552
What causes seasons? (Beginner) Jan 99 118839
What is time dilation? (Intermediate) Dec 98 102599

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