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 59867
Do you believe in UFOs? (Beginner) Apr 99 47101
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 59134
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 50617
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 68240
How do you measure the mass of a star? (Beginner) Apr 99 108116
What direction do planets rotate? (Beginner) Apr 99 249485
Can you hear sounds in space? (Beginner) Apr 99 477342
How can we measure distances to more stars? (Intermediate) Apr 99 47217
Where did all the water in the universe come from? (Intermediate) Apr 99 86924
Why doesn't gravity change the speed of light? (Beginner) Apr 99 47522
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 32019
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 58011
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 46302
What are Altitude and Azimuth? (Intermediate) Apr 99 101779
Do dead stars still shine? (Beginner) Apr 99 72457
How does light pollution affect astronomers? (Intermediate) Apr 99 108161
Have gravitational waves been proven to exist? (Intermediate) Apr 99 44822
What is a Dyson Sphere? (Intermediate) Apr 99 40868
Why do we not have eclipses every month? (Beginner) Mar 99 199907
Do astronomers believe in astrology? (Beginner) Mar 99 56296
Which planets have rings? (Beginner) Mar 99 428642
What equipment do I need for astrophotography? (Advanced) Mar 99 47646
How are photons created and destroyed? (Advanced) Mar 99 88073
Why search for only Earth-like life on other planets? (Beginner) Mar 99 40357
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 127267
Why is twilight short near the equator? (Intermediate) Mar 99 119588
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 41538
Does the shuttle worry about space junk? (Beginner) Mar 99 36679
Why do stars change colour when they twinkle? (Beginner) Mar 99 129653
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 44945
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 51956
What do stellar classifications mean? (Beginner) Mar 99 38836
Could we be seeing dead stars? (Beginner) Mar 99 44831
Can one star orbit another? (Beginner) Mar 99 46848
Why can't you see stars during the day? (Beginner) Mar 99 136584
What would happen if you took off your helmet in space? (Beginner) Mar 99 139586
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 50260
Why is it important to study meteorites? (Beginner) Mar 99 58093
Why does the Moon look big on the horizon? (Intermediate) Mar 99 74976
When was the last time all of the planets were aligned? (Beginner) Mar 99 490301
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 97755
How do we measure distances to other stars? (Beginner) Mar 99 50260
What are the requirements for being a planet? (Beginner) Mar 99 180900
If comets are boiling away, why are there any left? (Intermediate) Mar 99 60777
What is sidereal time? (Beginner) Mar 99 47956
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 87118
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 258187
How are elements heavier than iron formed? (Intermediate) Feb 99 146652
Are time machines possible? (Intermediate) Jan 99 48485
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 47470
What is a nova? (Beginner) Jan 99 187848
Who first measured the speed of light? (Intermediate) Jan 99 140354
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 85405
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 266879
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 332848
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 48970
Where are stars born? (Beginner) Jan 99 80325
Can you see satellites? (Beginner) Jan 99 74481
What kinds of star clusters are there? (Intermediate) Jan 99 39008
What is the life cycle of a star? (Intermediate) Jan 99 288388
How do I tell which planet is which? (Beginner) Jan 99 63742
Why do stars twinkle? (Beginner) Jan 99 401487
Can HST see the Oort cloud? (Intermediate) Jan 99 36029
What is the shape of the universe? (Intermediate) Jan 99 87404
How can geometry be different in space? (Intermediate) Jan 99 45414
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 64072
Why are there blue shifted galaxies? (Intermediate) Jan 99 63716
What is a dimension? (Intermediate) Jan 99 60582
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 84178
Can you tell time by the Big Dipper? (Beginner) Jan 99 42264
How powerful are quasars? (Intermediate) Jan 99 40784
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 54686
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 43264
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 76538
Why do planets not twinkle? (Intermediate) Jan 99 112590
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 136584
What are the boundaries of the constellations? (Beginner) Jan 99 40781
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 62752
How do distant galaxies differ from those nearby? (Advanced) Jan 99 39367
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 573493
Do electrons age? (Beginner) Jan 99 38007
What causes seasons? (Beginner) Jan 99 91550
What is time dilation? (Intermediate) Dec 98 74080

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