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 80542
Do you believe in UFOs? (Beginner) Apr 99 59568
Why are there no craters on Earth? Did all the meteorites miss us? (Beginner) Apr 99 94938
Can life exist on the recently discovered extrasolar planets? (Beginner) Apr 99 64988
How can two moons of Saturn share the same orbit? (Intermediate) Apr 99 84688
How do you measure the mass of a star? (Beginner) Apr 99 146574
What direction do planets rotate? (Beginner) Apr 99 359961
Can you hear sounds in space? (Beginner) Apr 99 572952
How can we measure distances to more stars? (Intermediate) Apr 99 61679
Where did all the water in the universe come from? (Intermediate) Apr 99 114461
Why doesn't gravity change the speed of light? (Beginner) Apr 99 58121
How can you tell the difference between single and multiple extrasolar planets? (Intermediate) Apr 99 43300
Do you think it's possible to maintain life on other planets? (Beginner) Apr 99 70123
When unmanned spacecraft accelerate in space, what causes them to slow down? (Intermediate) Apr 99 63663
What are Altitude and Azimuth? (Intermediate) Apr 99 138276
Do dead stars still shine? (Beginner) Apr 99 92006
How does light pollution affect astronomers? (Intermediate) Apr 99 138239
Have gravitational waves been proven to exist? (Intermediate) Apr 99 60078
What is a Dyson Sphere? (Intermediate) Apr 99 51814
Why do we not have eclipses every month? (Beginner) Mar 99 302790
Do astronomers believe in astrology? (Beginner) Mar 99 74519
Which planets have rings? (Beginner) Mar 99 555600
What equipment do I need for astrophotography? (Advanced) Mar 99 62704
How are photons created and destroyed? (Advanced) Mar 99 132367
Why search for only Earth-like life on other planets? (Beginner) Mar 99 53117
How do we know the mass of the Earth and the Moon? (Advanced) Mar 99 165915
Why is twilight short near the equator? (Intermediate) Mar 99 172756
What kind of telescope should I use for astrophotography? (Beginner) Mar 99 54026
Does the shuttle worry about space junk? (Beginner) Mar 99 48605
Why do stars change colour when they twinkle? (Beginner) Mar 99 176083
How can I contribute to science as an amateur astronomer? (Advanced) Mar 99 60129
Can the theory of formation of the solar system explain all the observables? (Intermediate) Mar 99 72447
What do stellar classifications mean? (Beginner) Mar 99 54001
Could we be seeing dead stars? (Beginner) Mar 99 60008
Can one star orbit another? (Beginner) Mar 99 59980
Why can't you see stars during the day? (Beginner) Mar 99 199952
What would happen if you took off your helmet in space? (Beginner) Mar 99 235385
What makes a satellite geosyncronise itself with Earth's orbit? (Intermediate) Mar 99 72469
Why is it important to study meteorites? (Beginner) Mar 99 87367
Why does the Moon look big on the horizon? (Intermediate) Mar 99 88359
When was the last time all of the planets were aligned? (Beginner) Mar 99 689737
How did asteroids form and what is the difference between an asteroid and a comet? (Beginner) Mar 99 119399
How do we measure distances to other stars? (Beginner) Mar 99 64523
What are the requirements for being a planet? (Beginner) Mar 99 285734
If comets are boiling away, why are there any left? (Intermediate) Mar 99 73919
What is sidereal time? (Beginner) Mar 99 72388
Which hemisphere has the best view of the Milky Way? (Beginner) Mar 99 110065
Why do all the planets orbit in the same plane? (Intermediate) Mar 99 363383
How are elements heavier than iron formed? (Intermediate) Feb 99 212081
Are time machines possible? (Intermediate) Jan 99 59403
Are the asteroids the remains of a planet which broke apart? (Beginner) Jan 99 65230
What is a nova? (Beginner) Jan 99 222962
Who first measured the speed of light? (Intermediate) Jan 99 163045
How do gravitons escape black holes to tell the universe about their gravity? (Advanced) Jan 99 113567
How do we know the age of the Universe and the Earth? (Intermediate) Jan 99 308101
What is that ring (or rainbow) around the moon? (Beginner) Jan 99 395534
How could galaxies have gotten so far away in only 14 billion years? (Intermediate) Jan 99 66326
Where are stars born? (Beginner) Jan 99 96424
Can you see satellites? (Beginner) Jan 99 90398
What kinds of star clusters are there? (Intermediate) Jan 99 52968
What is the life cycle of a star? (Intermediate) Jan 99 320884
How do I tell which planet is which? (Beginner) Jan 99 92510
Why do stars twinkle? (Beginner) Jan 99 536808
Can HST see the Oort cloud? (Intermediate) Jan 99 48147
What is the shape of the universe? (Intermediate) Jan 99 106953
How can geometry be different in space? (Intermediate) Jan 99 57638
If the universe is 13.8 billion years old, how can it be larger than 13.8 billion light years across? (Advanced) Jan 99 79879
Why are there blue shifted galaxies? (Intermediate) Jan 99 80992
What is a dimension? (Intermediate) Jan 99 78151
Will we get sucked into the black hole at the center of the Milky Way? (Beginner) Jan 99 114147
Can you tell time by the Big Dipper? (Beginner) Jan 99 54853
How powerful are quasars? (Intermediate) Jan 99 51895
What happens when you change the mass of a White Dwarf or Neutron Star? (Intermediate) Jan 99 72259
What caused Shoemaker-Levy 9 to split up? (Advanced) Jan 99 57693
How do we know if the universe will keep expanding forever? (Intermediate) Jan 99 113577
Why do planets not twinkle? (Intermediate) Jan 99 148311
Can we find the place where the Big Bang happened? (Intermediate) Jan 99 195959
What are the boundaries of the constellations? (Beginner) Jan 99 54862
Why is our solar system so different from all the others we've found? (Intermediate) Jan 99 83133
How do distant galaxies differ from those nearby? (Advanced) Jan 99 54524
How long does it take for the Sun's light to reach us? (Beginner) Jan 99 683185
Do electrons age? (Beginner) Jan 99 49759
What causes seasons? (Beginner) Jan 99 113928
What is time dilation? (Intermediate) Dec 98 98624

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