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 53071
Do you believe in UFOs? (Beginner) Apr 99 43199
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 51847
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 45643
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 63325
How do you measure the mass of a star? (Beginner) Apr 99 97954
What direction do planets rotate? (Beginner) Apr 99 223593
Can you hear sounds in space? (Beginner) Apr 99 448022
How can we measure distances to more stars? (Intermediate) Apr 99 42590
Where did all the water in the universe come from? (Intermediate) Apr 99 79949
Why doesn't gravity change the speed of light? (Beginner) Apr 99 43812
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 28491
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 54116
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 41827
What are Altitude and Azimuth? (Intermediate) Apr 99 91564
Do dead stars still shine? (Beginner) Apr 99 66966
How does light pollution affect astronomers? (Intermediate) Apr 99 99838
Have gravitational waves been proven to exist? (Intermediate) Apr 99 39941
What is a Dyson Sphere? (Intermediate) Apr 99 37182
Why do we not have eclipses every month? (Beginner) Mar 99 141152
Do astronomers believe in astrology? (Beginner) Mar 99 50465
Which planets have rings? (Beginner) Mar 99 391973
What equipment do I need for astrophotography? (Advanced) Mar 99 42649
How are photons created and destroyed? (Advanced) Mar 99 75945
Why search for only Earth-like life on other planets? (Beginner) Mar 99 36202
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 113549
Why is twilight short near the equator? (Intermediate) Mar 99 104364
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 37548
Does the shuttle worry about space junk? (Beginner) Mar 99 33020
Why do stars change colour when they twinkle? (Beginner) Mar 99 117555
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 40578
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 42011
What do stellar classifications mean? (Beginner) Mar 99 34523
Could we be seeing dead stars? (Beginner) Mar 99 39638
Can one star orbit another? (Beginner) Mar 99 42621
Why can't you see stars during the day? (Beginner) Mar 99 121718
What would happen if you took off your helmet in space? (Beginner) Mar 99 120341
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 43782
Why is it important to study meteorites? (Beginner) Mar 99 50599
Why does the Moon look big on the horizon? (Intermediate) Mar 99 70574
When was the last time all of the planets were aligned? (Beginner) Mar 99 392811
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 90903
How do we measure distances to other stars? (Beginner) Mar 99 45774
What are the requirements for being a planet? (Beginner) Mar 99 158436
If comets are boiling away, why are there any left? (Intermediate) Mar 99 57143
What is sidereal time? (Beginner) Mar 99 42418
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 79130
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 228365
How are elements heavier than iron formed? (Intermediate) Feb 99 123905
Are time machines possible? (Intermediate) Jan 99 44761
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 42168
What is a nova? (Beginner) Jan 99 178871
Who first measured the speed of light? (Intermediate) Jan 99 134096
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 77192
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 253759
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 319677
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 43923
Where are stars born? (Beginner) Jan 99 75662
Can you see satellites? (Beginner) Jan 99 70362
What kinds of star clusters are there? (Intermediate) Jan 99 34690
What is the life cycle of a star? (Intermediate) Jan 99 278714
How do I tell which planet is which? (Beginner) Jan 99 57587
Why do stars twinkle? (Beginner) Jan 99 378732
Can HST see the Oort cloud? (Intermediate) Jan 99 32497
What is the shape of the universe? (Intermediate) Jan 99 80487
How can geometry be different in space? (Intermediate) Jan 99 41413
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 59816
Why are there blue shifted galaxies? (Intermediate) Jan 99 58020
What is a dimension? (Intermediate) Jan 99 55611
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 75544
Can you tell time by the Big Dipper? (Beginner) Jan 99 38121
How powerful are quasars? (Intermediate) Jan 99 36919
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 49801
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 39315
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 62752
Why do planets not twinkle? (Intermediate) Jan 99 102825
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 113603
What are the boundaries of the constellations? (Beginner) Jan 99 36593
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 56335
How do distant galaxies differ from those nearby? (Advanced) Jan 99 34946
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 532727
Do electrons age? (Beginner) Jan 99 33968
What causes seasons? (Beginner) Jan 99 84858
What is time dilation? (Intermediate) Dec 98 66410

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