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 68658
Do you believe in UFOs? (Beginner) Apr 99 52204
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 72933
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 56819
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 75166
How do you measure the mass of a star? (Beginner) Apr 99 124741
What direction do planets rotate? (Beginner) Apr 99 291910
Can you hear sounds in space? (Beginner) Apr 99 523259
How can we measure distances to more stars? (Intermediate) Apr 99 53152
Where did all the water in the universe come from? (Intermediate) Apr 99 97414
Why doesn't gravity change the speed of light? (Beginner) Apr 99 51948
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 36563
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 62966
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 52815
What are Altitude and Azimuth? (Intermediate) Apr 99 116786
Do dead stars still shine? (Beginner) Apr 99 80466
How does light pollution affect astronomers? (Intermediate) Apr 99 120222
Have gravitational waves been proven to exist? (Intermediate) Apr 99 50828
What is a Dyson Sphere? (Intermediate) Apr 99 45369
Why do we not have eclipses every month? (Beginner) Mar 99 243926
Do astronomers believe in astrology? (Beginner) Mar 99 63536
Which planets have rings? (Beginner) Mar 99 484310
What equipment do I need for astrophotography? (Advanced) Mar 99 54146
How are photons created and destroyed? (Advanced) Mar 99 105434
Why search for only Earth-like life on other planets? (Beginner) Mar 99 45672
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 143517
Why is twilight short near the equator? (Intermediate) Mar 99 139357
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 46865
Does the shuttle worry about space junk? (Beginner) Mar 99 41531
Why do stars change colour when they twinkle? (Beginner) Mar 99 148527
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 51037
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 60321
What do stellar classifications mean? (Beginner) Mar 99 45276
Could we be seeing dead stars? (Beginner) Mar 99 51067
Can one star orbit another? (Beginner) Mar 99 53061
Why can't you see stars during the day? (Beginner) Mar 99 163807
What would happen if you took off your helmet in space? (Beginner) Mar 99 177645
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 58370
Why is it important to study meteorites? (Beginner) Mar 99 70288
Why does the Moon look big on the horizon? (Intermediate) Mar 99 80650
When was the last time all of the planets were aligned? (Beginner) Mar 99 578551
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 106684
How do we measure distances to other stars? (Beginner) Mar 99 56433
What are the requirements for being a planet? (Beginner) Mar 99 216033
If comets are boiling away, why are there any left? (Intermediate) Mar 99 65946
What is sidereal time? (Beginner) Mar 99 56874
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 96679
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 305720
How are elements heavier than iron formed? (Intermediate) Feb 99 182132
Are time machines possible? (Intermediate) Jan 99 53160
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 55030
What is a nova? (Beginner) Jan 99 202732
Who first measured the speed of light? (Intermediate) Jan 99 149330
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 96256
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 284758
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 362327
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 55999
Where are stars born? (Beginner) Jan 99 87048
Can you see satellites? (Beginner) Jan 99 80740
What kinds of star clusters are there? (Intermediate) Jan 99 44819
What is the life cycle of a star? (Intermediate) Jan 99 303048
How do I tell which planet is which? (Beginner) Jan 99 73993
Why do stars twinkle? (Beginner) Jan 99 446809
Can HST see the Oort cloud? (Intermediate) Jan 99 41105
What is the shape of the universe? (Intermediate) Jan 99 95668
How can geometry be different in space? (Intermediate) Jan 99 50859
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 70406
Why are there blue shifted galaxies? (Intermediate) Jan 99 70936
What is a dimension? (Intermediate) Jan 99 67747
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 97195
Can you tell time by the Big Dipper? (Beginner) Jan 99 47329
How powerful are quasars? (Intermediate) Jan 99 45474
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 62372
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 49101
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 94233
Why do planets not twinkle? (Intermediate) Jan 99 127064
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 152965
What are the boundaries of the constellations? (Beginner) Jan 99 46546
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 71007
How do distant galaxies differ from those nearby? (Advanced) Jan 99 45877
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 620875
Do electrons age? (Beginner) Jan 99 43163
What causes seasons? (Beginner) Jan 99 99786
What is time dilation? (Intermediate) Dec 98 84346

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