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 57308
Do you believe in UFOs? (Beginner) Apr 99 45733
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 56211
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 48907
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 66299
How do you measure the mass of a star? (Beginner) Apr 99 104272
What direction do planets rotate? (Beginner) Apr 99 239544
Can you hear sounds in space? (Beginner) Apr 99 466179
How can we measure distances to more stars? (Intermediate) Apr 99 45622
Where did all the water in the universe come from? (Intermediate) Apr 99 84329
Why doesn't gravity change the speed of light? (Beginner) Apr 99 46272
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 30822
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 56688
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 44748
What are Altitude and Azimuth? (Intermediate) Apr 99 96999
Do dead stars still shine? (Beginner) Apr 99 70429
How does light pollution affect astronomers? (Intermediate) Apr 99 104925
Have gravitational waves been proven to exist? (Intermediate) Apr 99 43115
What is a Dyson Sphere? (Intermediate) Apr 99 39646
Why do we not have eclipses every month? (Beginner) Mar 99 172850
Do astronomers believe in astrology? (Beginner) Mar 99 54048
Which planets have rings? (Beginner) Mar 99 413834
What equipment do I need for astrophotography? (Advanced) Mar 99 45938
How are photons created and destroyed? (Advanced) Mar 99 82954
Why search for only Earth-like life on other planets? (Beginner) Mar 99 38998
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 121188
Why is twilight short near the equator? (Intermediate) Mar 99 114193
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 40174
Does the shuttle worry about space junk? (Beginner) Mar 99 35431
Why do stars change colour when they twinkle? (Beginner) Mar 99 124960
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 43372
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 49023
What do stellar classifications mean? (Beginner) Mar 99 37286
Could we be seeing dead stars? (Beginner) Mar 99 42994
Can one star orbit another? (Beginner) Mar 99 45316
Why can't you see stars during the day? (Beginner) Mar 99 131197
What would happen if you took off your helmet in space? (Beginner) Mar 99 132814
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 48078
Why is it important to study meteorites? (Beginner) Mar 99 54850
Why does the Moon look big on the horizon? (Intermediate) Mar 99 73337
When was the last time all of the planets were aligned? (Beginner) Mar 99 442172
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 95143
How do we measure distances to other stars? (Beginner) Mar 99 48678
What are the requirements for being a planet? (Beginner) Mar 99 172102
If comets are boiling away, why are there any left? (Intermediate) Mar 99 59481
What is sidereal time? (Beginner) Mar 99 45797
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 84278
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 245679
How are elements heavier than iron formed? (Intermediate) Feb 99 139406
Are time machines possible? (Intermediate) Jan 99 47218
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 45488
What is a nova? (Beginner) Jan 99 184558
Who first measured the speed of light? (Intermediate) Jan 99 137736
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 82363
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 261411
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 327281
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 47215
Where are stars born? (Beginner) Jan 99 78653
Can you see satellites? (Beginner) Jan 99 73078
What kinds of star clusters are there? (Intermediate) Jan 99 37541
What is the life cycle of a star? (Intermediate) Jan 99 284485
How do I tell which planet is which? (Beginner) Jan 99 61486
Why do stars twinkle? (Beginner) Jan 99 391267
Can HST see the Oort cloud? (Intermediate) Jan 99 34778
What is the shape of the universe? (Intermediate) Jan 99 84976
How can geometry be different in space? (Intermediate) Jan 99 44000
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 62496
Why are there blue shifted galaxies? (Intermediate) Jan 99 61773
What is a dimension? (Intermediate) Jan 99 58796
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 80926
Can you tell time by the Big Dipper? (Beginner) Jan 99 40846
How powerful are quasars? (Intermediate) Jan 99 39557
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 52929
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 41822
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 73054
Why do planets not twinkle? (Intermediate) Jan 99 108802
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 130812
What are the boundaries of the constellations? (Beginner) Jan 99 39355
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 60581
How do distant galaxies differ from those nearby? (Advanced) Jan 99 37748
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 556354
Do electrons age? (Beginner) Jan 99 36632
What causes seasons? (Beginner) Jan 99 89110
What is time dilation? (Intermediate) Dec 98 71055

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