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 51865
Do you believe in UFOs? (Beginner) Apr 99 42482
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 50395
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 44602
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 62372
How do you measure the mass of a star? (Beginner) Apr 99 95177
What direction do planets rotate? (Beginner) Apr 99 217368
Can you hear sounds in space? (Beginner) Apr 99 440572
How can we measure distances to more stars? (Intermediate) Apr 99 41665
Where did all the water in the universe come from? (Intermediate) Apr 99 78452
Why doesn't gravity change the speed of light? (Beginner) Apr 99 43131
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 27888
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 53426
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 40952
What are Altitude and Azimuth? (Intermediate) Apr 99 89754
Do dead stars still shine? (Beginner) Apr 99 65948
How does light pollution affect astronomers? (Intermediate) Apr 99 97882
Have gravitational waves been proven to exist? (Intermediate) Apr 99 39088
What is a Dyson Sphere? (Intermediate) Apr 99 36538
Why do we not have eclipses every month? (Beginner) Mar 99 130426
Do astronomers believe in astrology? (Beginner) Mar 99 49428
Which planets have rings? (Beginner) Mar 99 382967
What equipment do I need for astrophotography? (Advanced) Mar 99 41768
How are photons created and destroyed? (Advanced) Mar 99 73255
Why search for only Earth-like life on other planets? (Beginner) Mar 99 35397
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 110508
Why is twilight short near the equator? (Intermediate) Mar 99 101589
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 36798
Does the shuttle worry about space junk? (Beginner) Mar 99 32312
Why do stars change colour when they twinkle? (Beginner) Mar 99 114793
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 39739
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 40823
What do stellar classifications mean? (Beginner) Mar 99 33668
Could we be seeing dead stars? (Beginner) Mar 99 38702
Can one star orbit another? (Beginner) Mar 99 41785
Why can't you see stars during the day? (Beginner) Mar 99 118063
What would happen if you took off your helmet in space? (Beginner) Mar 99 115771
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 42495
Why is it important to study meteorites? (Beginner) Mar 99 49071
Why does the Moon look big on the horizon? (Intermediate) Mar 99 69700
When was the last time all of the planets were aligned? (Beginner) Mar 99 377109
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 89525
How do we measure distances to other stars? (Beginner) Mar 99 44877
What are the requirements for being a planet? (Beginner) Mar 99 152338
If comets are boiling away, why are there any left? (Intermediate) Mar 99 56408
What is sidereal time? (Beginner) Mar 99 41453
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 77347
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 221611
How are elements heavier than iron formed? (Intermediate) Feb 99 120201
Are time machines possible? (Intermediate) Jan 99 44052
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 41156
What is a nova? (Beginner) Jan 99 176627
Who first measured the speed of light? (Intermediate) Jan 99 133011
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 75578
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 251246
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 316908
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 42953
Where are stars born? (Beginner) Jan 99 74717
Can you see satellites? (Beginner) Jan 99 69562
What kinds of star clusters are there? (Intermediate) Jan 99 33680
What is the life cycle of a star? (Intermediate) Jan 99 276655
How do I tell which planet is which? (Beginner) Jan 99 56459
Why do stars twinkle? (Beginner) Jan 99 376004
Can HST see the Oort cloud? (Intermediate) Jan 99 31835
What is the shape of the universe? (Intermediate) Jan 99 79149
How can geometry be different in space? (Intermediate) Jan 99 40708
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 58965
Why are there blue shifted galaxies? (Intermediate) Jan 99 56905
What is a dimension? (Intermediate) Jan 99 54689
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 73548
Can you tell time by the Big Dipper? (Beginner) Jan 99 37335
How powerful are quasars? (Intermediate) Jan 99 36184
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 48574
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 38468
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 60986
Why do planets not twinkle? (Intermediate) Jan 99 100842
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 108110
What are the boundaries of the constellations? (Beginner) Jan 99 35827
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 55164
How do distant galaxies differ from those nearby? (Advanced) Jan 99 34088
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 525308
Do electrons age? (Beginner) Jan 99 33168
What causes seasons? (Beginner) Jan 99 83622
What is time dilation? (Intermediate) Dec 98 64714

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