All previously answered questions (in order of times viewed)

What's going to happen on December 21st 2012? (viewed 816498 times)
What color is each planet? (viewed 582932 times)
Is the Moon moving away from the Earth? When was this discovered? (viewed 381451 times)
How far is each planet from Earth? (viewed 352941 times)
How many stars are there in our Galaxy (Milky Way)? (viewed 301825 times)
At what speed does the earth move around the sun? (viewed 280595 times)
What is the universe expanding into? (viewed 259794 times)
How do I build a model rocket? (viewed 242031 times)
How do you measure the distance between Earth and the Sun? (viewed 239232 times)
Which planets have rings? (viewed 231152 times)
Why do the planets orbit the sun? (viewed 227065 times)
What is the life cycle of a star? (viewed 221130 times)
What color is Venus? (viewed 216450 times)
What is a white hole? (viewed 214390 times)
What is the largest star? (viewed 205906 times)
When will Halley's Comet return? (viewed 191601 times)
Why do stars twinkle? (viewed 178402 times)
How long does it take for the Sun's light to reach us? (viewed 177300 times)
Does the Moon rotate? Are there other moons that always keep one face toward their planet? (viewed 176310 times)
What are the names of the earth, moon, sun, and solar system? (viewed 167288 times)
What makes the Earth rotate? (viewed 153981 times)
What do astronauts eat in space? Can they grow food? (viewed 143128 times)
Why do planets rotate? (viewed 138591 times)
Is Pluto a planet? (viewed 130872 times)
Where did the name 'Earth' come from? (viewed 130828 times)
What are shooting stars? (viewed 127256 times)
Is the distance from the Earth to the Sun changing? (viewed 125371 times)
How many Earths fit into the Sun? (viewed 121102 times)
What is the largest galaxy? (viewed 115816 times)
Why are there both high and low tides? (viewed 112310 times)
How do we know the age of the Universe and the Earth? (viewed 111477 times)
How does the location of sunrise and sunset change throughout the year? (viewed 109406 times)
How many known galaxies are there? (viewed 107189 times)
How can we see the Milky Way if we are inside it? (viewed 106332 times)
Who named the planets and who decides what to name them? (viewed 105312 times)
What is that ring (or rainbow) around the moon? (viewed 105053 times)
Is the universe expanding faster than the speed of light? (viewed 101873 times)
What would happen if we did not have a Moon? (viewed 100062 times)
Will the sun go supernova in six years and destroy Earth (as seen on Yahoo)? (viewed 98165 times)
Can you hear sounds in space? (viewed 96020 times)
Is the Sun expanding? Will it ever explode? (viewed 93599 times)
What is at the end of the Universe? (viewed 92326 times)
How does the position of Moonrise and Moonset change? (viewed 91725 times)
When is the next comet due to arrive? (viewed 89304 times)
What was there before the Big Bang and what is there outside of our universe? (viewed 89001 times)
Why is a day divided into 24 hours? (viewed 87800 times)
What is the hottest time of day? (viewed 87605 times)
Will the magnetic field of the Earth reverse its direction in the future? Will this cause problems? (viewed 85708 times)
How can I find the star I have "bought"? (viewed 84906 times)
What direction do planets rotate? (viewed 82061 times)
What would happen if an impact caused Earth to stop rotating? (viewed 81783 times)
Can we feel the Earth spin? (viewed 81452 times)
How do stars move in the Galaxy? (viewed 80696 times)
Do stars move in the sky? (viewed 77623 times)
How critical is the Earth-Sun distance in maintaining our average temperatures on Earth? (viewed 77525 times)
Can I buy a star? (viewed 77143 times)
Does the Sun move around the Milky Way? (viewed 76157 times)
Are there telescopes that can see the flag and lunar rover on the Moon? (viewed 75378 times)
Have astronomers discovered Earth's second moon? (viewed 75372 times)
How many constellations are there? (viewed 73641 times)
What is apparent magnitude? (viewed 73314 times)
What happens when galaxies collide? (viewed 73145 times)
How are light and heavy elements formed? (viewed 72645 times)
What are the advantages and disadvantages of using a telescope in space? (viewed 71591 times)
How long does a solar eclipse last? (viewed 71292 times)
How do astronauts take baths and use restrooms in space? (viewed 70801 times)
If Mars is only about 35-60 million miles away at close approach, why does it take 6-8 months to get there? (viewed 70518 times)
How do rockets work? (viewed 70421 times)
What is the observational difference between a star and a planet? (viewed 70069 times)
Does the Sun rotate? (viewed 69617 times)
Does the Sun have a scientific name? (viewed 69416 times)
Can artificial gravity be created in space? (viewed 69023 times)
What will happen to life on Earth when the Sun becomes a red giant? (viewed 68814 times)
Why are the Moon and Sun sometimes orange or red? (viewed 68241 times)
What would happen if Earth had more than one moon? (viewed 68121 times)
How much money is spent on space exploration? (viewed 67996 times)
How much money do astronomers make? (viewed 67977 times)
What is the size of the Solar System? (viewed 67619 times)
What kind of rock is the moon made of? (viewed 67443 times)
How do you calculate the lifetime of the Sun? (viewed 67040 times)
What elements make up the Sun? (viewed 66611 times)
Which planet is most similar to Earth? (viewed 66405 times)
When was the last time all 9 planets were aligned? (viewed 66388 times)
Why do planets have elliptical orbits? (viewed 66209 times)
Why do airplanes take longer to fly West than East? (viewed 65897 times)
What would happen if an asteroid 10 kilometers across hit the Earth? (viewed 65595 times)
Did astronauts really go to the Moon, or is it a hoax? (viewed 65326 times)
Who has landed on the moon? (viewed 64829 times)
Who first measured the speed of light? (viewed 64752 times)
Does the Sun orbit the Earth as well as the Earth orbiting the Sun? (viewed 63905 times)
Considering the motion of the Earth, the solar system, and the galaxy, how fast am I moving while lying in bed asleep? (viewed 63665 times)
Why are stars and planets round? (viewed 62839 times)
What is the physical difference between a star and a planet? (viewed 62694 times)
Why hasn't NASA gone back to the moon? (viewed 61148 times)
What is a singularity? (viewed 61109 times)
Where does the name "Milky Way" come from? (viewed 60964 times)
Is there a proof that Earth moves? (viewed 59947 times)
Does your weight change between the poles and the equator? (viewed 59822 times)
Do black holes die? If so how? (viewed 59428 times)
What are RA and DEC? (viewed 59093 times)
Why aren't there any green stars? (viewed 57217 times)
Where did the Universe come from? (viewed 56538 times)
What is a nova? (viewed 56488 times)
How are galaxies formed? (viewed 56269 times)
How are black holes made? Could one be made close to us? (viewed 56043 times)
Since Earth is spinning, why do we land in the same place when we jump or fall? (viewed 55542 times)
Why is the Universe flat and not spherical? (viewed 55432 times)
When can I see the Moon through the hole in the Pantheon? (viewed 55414 times)
How do astronomers use math in their jobs? (viewed 55323 times)
Why do different stars appear with seasons? (viewed 55256 times)
Why do all the planets orbit in the same plane? (viewed 54898 times)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (viewed 54207 times)
Why is the Moon so bright? (viewed 53905 times)
Why does the Earth tilt back and forward once a year? (viewed 53640 times)
What makes the wind? (viewed 53637 times)
What causes seasons? (viewed 53421 times)
What's the best college for astronomy? (viewed 52956 times)
What are constellations used for? (viewed 52850 times)
What are the "dog days of summer"? (viewed 52840 times)
What would you see from inside a black hole? (viewed 52719 times)
How does the Sun compare to other stars? (viewed 52693 times)
What are some of the effects of solar flares on Earth? (viewed 52526 times)
How many meteorites hit Earth each year? (viewed 52318 times)
Why doesn't the length of each day change much around the solstices? (viewed 52126 times)
Will the Sun become a black hole one day? (viewed 51705 times)
Is it possible to measure the temperature of the Sun? (viewed 51558 times)
What do astronauts do all day in the International Space Station? (viewed 51356 times)
What would happen if a supermassive black hole came close to the Earth? (viewed 51141 times)
How many stars are born and die each day? (viewed 51102 times)
Does gravity vary across the surface of the Earth? (viewed 50990 times)
What happens to a substance if its speed is more than the speed of light? (viewed 50593 times)
What kinds of jobs do astronomers do? (viewed 50484 times)
What is the largest structure in the universe? (viewed 50106 times)
What would happen if the gravity on Earth was suddenly turned off? (viewed 49995 times)
Why doesn't the earliest sunset occur on the shortest day of the year? (viewed 49910 times)
What is the mass of the Universe? (viewed 49784 times)
Do most astronomers believe in God based on the available scientific evidence? (viewed 49462 times)
How often does the Sun pass through a spiral arm in the Milky Way? (viewed 49401 times)
What is the density of a black hole? (viewed 48837 times)
What would happen to us if the sun went out for an hour? (viewed 48012 times)
Does the Moon rotate? (viewed 47996 times)
What is the shape of the universe? (viewed 47361 times)
Where are stars born? (viewed 47348 times)
How did the stars get named? (viewed 47278 times)
Are names given to black holes? (viewed 47273 times)
Could there be life in the galaxies nearest to the Milky Way? (viewed 47104 times)
What are black holes made of? (viewed 46862 times)
When the Sun converts mass to energy, do the orbits of the planets change? (viewed 46781 times)
Why does the Earth have only one moon? (viewed 46689 times)
How does the Moon stay "suspended" in the air? (viewed 46569 times)
Traveling at light speed, how long would it take to get to the nearest galaxy? (viewed 46567 times)
How do you measure a planet's mass? (viewed 46488 times)
Why do planets not twinkle? (viewed 46169 times)
How is astronomy impacted by trigonometry? (viewed 46086 times)
Can you fire a gun on the Moon? (viewed 46016 times)
How do astronomers measure the brightness of stars? (viewed 45963 times)
Why can't you see stars during the day? (viewed 45709 times)
How fast is the Universe expanding? (viewed 45514 times)
What is the difference between a "star" and a "sun"? (viewed 45375 times)
Where does the name "Moon" come from? (viewed 45155 times)
How do we know the mass of the Earth and the Moon? (viewed 45145 times)
How did asteroids form and what is the difference between an asteroid and a comet? (viewed 45124 times)
What are Altitude and Azimuth? (viewed 45060 times)
What are some astronomy science fair projects? (viewed 45034 times)
Can you see satellites? (viewed 44590 times)
Is time travel possible? (viewed 44263 times)
Are aliens or UFOs real? (viewed 44124 times)
If the universe is infinite does that mean there is an infinite number of "me"s? (viewed 44033 times)
Why do stars change colour when they twinkle? (viewed 43978 times)
Can moons have moons? (viewed 43972 times)
Why isn't the summer solstice the hottest day of the year? (viewed 43612 times)
Who discovered each planet? (viewed 43123 times)
How can the Universe expand faster than the speed of light during inflation? (viewed 43115 times)
How are elements heavier than iron formed? (viewed 43028 times)
If the Earth's rotation period is less than 24 hours, why don't our clocks fall out of sync with the Sun? (viewed 42944 times)
What is the size of a black hole? (viewed 42836 times)
How long would it take the Earth to fall into the Sun? (viewed 42741 times)
How do rockets move in space? (viewed 42554 times)
How can I measure the distance of a star? (viewed 42549 times)
How can a star burn with no oxygen? (viewed 42235 times)
How do you measure the mass of a star? (viewed 42214 times)
How do astronauts use math in their jobs? (viewed 42116 times)
How can I calculate the position or path of the Sun for a given time and location? (viewed 41731 times)
Can any galaxies be seen with the naked eye? (viewed 41730 times)
Is the speed of light constant? (viewed 41672 times)
Why do we see stars? (viewed 41386 times)
What's the difference between astronomy and astrology? (viewed 41321 times)
How does the parachute in a model rocket work? (viewed 41156 times)
Where, in relation to the entire universe, is the Milky Way located? (viewed 40959 times)
Why is it difficult to understand the expansion of the universe? (viewed 40936 times)
Are there any asteroids on a collision course with Earth? (viewed 40799 times)
How can I find the distance to the Sun on any given day? (viewed 40663 times)
What kind of schooling is necessary to become an astronomer? (viewed 40493 times)
Where did the matter in the universe come from? (viewed 40300 times)
Where is the nearest black hole? (viewed 40266 times)
What makes up most of the Universe? (viewed 40092 times)
Why does the Moon look big on the horizon? (viewed 39694 times)
How do we measure the size of the Moon and of the Sun? (viewed 39659 times)
How close was the Moon to the Earth when it formed? (viewed 39646 times)
Does evolution contradict the second law of thermodynamics? (viewed 39599 times)
How do you calculate the azimuth and altitude of an object? (viewed 39268 times)
Why is the moon in a different place every night? (viewed 39262 times)
How does light pollution affect astronomers? (viewed 39243 times)
If light has no mass, then what draws it into a black hole? (viewed 39118 times)
Does the Mediterranean sea have tides? (viewed 39022 times)
What is a star's "spectrum"? (viewed 38807 times)
What other careers involve Astronomy besides Astronomer? (viewed 38624 times)
Does quantum entanglement imply faster than light communication? (viewed 38592 times)
What is the biggest crater recorded on Earth? (viewed 38352 times)
Do dead stars still shine? (viewed 38219 times)
Would your weight change as you go underground? (viewed 38150 times)
Was the Sun made in a supernova? (viewed 37651 times)
Which constellation does our Sun belong to? (viewed 37587 times)
How long does the supernova stage of a star last? (viewed 37438 times)
What do I need to do to become an astronomer? (viewed 37075 times)
What is the origin of spiral structure in galaxies? (viewed 36783 times)
What is a graviton? (viewed 36761 times)
What is the evidence supporting the nebula theory of Solar System formation? (viewed 36653 times)
How are black holes discovered? (viewed 36565 times)
Why does Barnard 68 appear dark? (viewed 36554 times)
Is the Moon seen as a crescent (and not a "boat") all over the world? Is the same phase of the moon visible from the Northern and Southern hemispheres? (viewed 36492 times)
Why can't we see Venus at night when it is an inner planet? (viewed 36324 times)
How long has there been water on Earth? (viewed 36298 times)
Will we get sucked into the black hole at the center of the Milky Way? (viewed 36285 times)
Can I buy land on the Moon? (viewed 36228 times)
Why do we not have eclipses every month? (viewed 36124 times)
Can we look back far enough in time to see the Big Bang? (viewed 35986 times)
What would happen if the Moon fell out of its orbit around Earth? (viewed 35876 times)
What happens to a bullet fired on the moon? (viewed 35730 times)
What happens when two black holes get too close? (viewed 35694 times)
What is time dilation? (viewed 35689 times)
What are the different kinds of astronomers? (viewed 35643 times)
What is the most distant known galaxy? (viewed 35442 times)
How do gravitons escape black holes to tell the universe about their gravity? (viewed 35394 times)
Is the Moon hollow? (viewed 35383 times)
What's the biggest meteorite? (viewed 35352 times)
How do galaxies collide in an expanding universe? (viewed 34976 times)
What can we learn from the color of a star? (viewed 34731 times)
What can I use for fuel in my homemade rocket? (viewed 34606 times)
Why do the size and brightness of the full moon change? (viewed 34533 times)
Why do pictures of distant galaxies have higher resolution than those of nearby planets? (viewed 34461 times)
What are the requirements for being a planet? (viewed 34433 times)
What's the difference between dark matter and dark energy? (viewed 34413 times)
Which hemisphere has the best view of the Milky Way? (viewed 34293 times)
Why does the Sun's apparent path through the sky change throughout the year? (viewed 34290 times)
What color would Mars be if you were standing on it? (viewed 34132 times)
How big is the universe? (viewed 33938 times)
Where did all the water in the universe come from? (viewed 33909 times)
Why does the Earth only see one side of the Moon? (viewed 33868 times)
Does Mt. Everest cast a shadow on the moon? (viewed 33858 times)
Can I calculate the size of the Universe by converting light years to kilometres? (viewed 33827 times)
Why is twilight short near the equator? (viewed 33692 times)
Why doesn't dark matter fall into a black hole? (viewed 33576 times)
How much longer will the Earth last? (viewed 33406 times)
How can two moons of Saturn share the same orbit? (viewed 33386 times)
Can terrestrial planets have rings? (viewed 33313 times)
Why does the location of sunrise change? (viewed 33306 times)
What's the difference between astronomy and astrophysics? (viewed 33180 times)
Is the Earth slowly getting larger? (viewed 33056 times)
What would happen if you took off your helmet in space? (viewed 32969 times)
Why are there stars? (viewed 32967 times)
Where is the supernova remnant that led to our solar system? (viewed 32791 times)
How does night and day work? (viewed 32789 times)
What skills do astronomers need? (viewed 32689 times)
Are meteorites hot or cold when they hit Earth? (viewed 32522 times)
How do we weigh objects in space? (viewed 32456 times)
How long would it take for a mini-black hole to eat the Earth? (viewed 32411 times)
Could someone travel the universe in his or her own lifetime? (viewed 32367 times)
Is the Great Wall the largest galaxy cluster? (viewed 32324 times)
How is the time of sunrise calculated? (viewed 32089 times)
What do a galaxy's colors mean? Are they its true colors? (viewed 32001 times)
What is the difference between nutation and precession of the Earth? (viewed 31966 times)
How many stars can I see? (viewed 31931 times)
How would the weather on Earth be different if it were a cube? (viewed 31868 times)
What is the speed of gravity? (viewed 31757 times)
Is there really a 10th planet? (viewed 31688 times)
How does astronomy benefit humankind? (viewed 31676 times)
How do I tell which planet is which? (viewed 31601 times)
Why is looking out the same as looking back in time? (viewed 31308 times)
How many Astronauts have been in space? (viewed 31247 times)
What would happen to the Earth if an asteroid hit the Moon? (viewed 31072 times)
What is Earthrise over the Moon? (viewed 31045 times)
Why is sea water salty, and not lake water? (viewed 30991 times)
Do the Sun's or Earth's magnetic field reverse? (viewed 30689 times)
Do supermassive black holes cause galaxy rotation? (viewed 30683 times)
What was that really big falling star that I saw? (viewed 30647 times)
The Moon slows the Earth's rotation, but how fast was it spinning billions of years ago? (viewed 30612 times)
Has there been an experiment that measured speed faster than the speed of light in vacuum? (viewed 30525 times)
Is Andromeda part of the Milky Way? Where can I find them in the sky? (viewed 30512 times)
If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths? (viewed 30476 times)
Can I communicate faster than light? (viewed 30462 times)
How do the astronauts communicate in space if sound cannot travel in a vacuum? (viewed 30437 times)
What is a dimension? (viewed 30430 times)
What is the typical size of a visible shooting star? (viewed 30352 times)
Could the Universe have expanded faster than the speed of light at the Big Bang? (viewed 30213 times)
Is there a "South Star"? (viewed 30204 times)
Why have star signs shifted by one constellation? (viewed 30153 times)
Can a person go into a black hole and come out alive? (viewed 30114 times)
Are Earth and the Moon "twin planets"? (viewed 29944 times)
What is the approximate GPA needed in High School in Math and Science to be an astronomer? (viewed 29831 times)
What is the difference between the "Doppler" redshift and the "gravitational" or "cosmological" redshift? (viewed 29804 times)
If a white dwarf is a "dead" star, why is it so hot? (viewed 29758 times)
How can I find my age on another planet? (viewed 29670 times)
Is it possible to see the full Moon and the Sun simultaneously in high northern latitudes when the Sun doesn't set? (viewed 29476 times)
When we look back to the Big Bang, why don't we see the universe as a tiny speck of matter? (viewed 29321 times)
What if the Earth rotated twice as fast? (viewed 29304 times)
Why don't astronomers use everyday units to measure distances (what is an AU or a pc)? (viewed 29265 times)
What happens to spacetime inside a black hole? (viewed 29233 times)
Does the Coriolis force determine which way my toilet drains? Does it affect black holes? (viewed 29087 times)
Can we colonize other planets? (viewed 28998 times)
Are Kuiper Belt Objects asteroids? Are large Kuiper Belt Objects planets? (viewed 28936 times)
Why is our solar system so different from all the others we've found? (viewed 28875 times)
Is there a simple formula to calculate solar eclipse timings from any position on Earth? (viewed 28789 times)
How can we estimate the number of Earth-like planets in the Galaxy? (viewed 28741 times)
Is it possible to count the stars? (viewed 28728 times)
Did life originate on Earth, or did it come from somewhere else? (viewed 28708 times)
Which American colleges teach astronomy? (viewed 28619 times)
If the universe is 15 billion years old, how can it be larger than 15 billion light years across? (viewed 28572 times)
Is the Earth at the centre of the Universe? (viewed 28530 times)
How can I calculate distances between stars? (viewed 28434 times)
Is time travel possible using merging black holes? (viewed 28380 times)
How does Astronomy involve Chemistry? (viewed 28318 times)
Are all stars the same? (viewed 28272 times)
Will the Moon be invisible in 500 million years? (viewed 28252 times)
What companies or businesses can astronomers work for? (viewed 28223 times)
How do we know that nuclear fusion is still going on in the Sun? (viewed 28156 times)
How dangerous are the asteroids? (viewed 28124 times)
Why do people draw stars with five points? (viewed 28074 times)
Are there eclipses on other planets? (viewed 27829 times)
What is the pattern to the distances between each planet and the sun? (viewed 27794 times)
Can we find the place where the Big Bang happened? (viewed 27782 times)
Can you see the future as you fall into a black hole? (viewed 27718 times)
How does the brightness of a star depend on its distance from us? (viewed 27705 times)
Who came up with the name "black hole"? (viewed 27686 times)
Where do planetary rings come from, and what are they made of? (viewed 27654 times)
How much can the location of sunset differ from due West? (viewed 27594 times)
How is it that we see farther out in space (farther back in time) than in the past? (viewed 27535 times)
What is happening just around the black hole in the center of the Milky Way? (viewed 27509 times)
Why doesn't gravity change the speed of light? (viewed 27455 times)
What is the significance of the second focus of elliptical orbits of planets in our Solar System? (viewed 27388 times)
What is a wormhole? (viewed 27315 times)
How long could life on Earth survive if the Sun stopped shining? (viewed 27280 times)
How can we distinguish a star's "real" color from the change in color that we observe due to the star's motion? (viewed 27177 times)
What are quasars made of? (viewed 27114 times)
Can a lunar and a solar eclipse happen in the same month? When will this happen next? (viewed 27066 times)
Why does the Sun appear larger on the horizon than overhead? (viewed 27038 times)
How do we define distance in an expanding universe? (viewed 27035 times)
Are time machines possible? (viewed 26821 times)
How many moles of stars are in the known universe? (viewed 26769 times)
Why don't people walk upside-down on the bottom of the Earth? (viewed 26608 times)
What's that dark spot on the Sun? (viewed 26604 times)
How fast does the Earth go at perihelion and aphelion? (viewed 26510 times)
Is there any limitation to what a black hole can "suck" in? (viewed 26428 times)
How do we determine the age of the universe? (viewed 26419 times)
How do we feel heat? (viewed 26418 times)
How do astronauts communicate with their families from space? (viewed 26392 times)
On which days can I see the Moon in the evening / morning and why is this so? (viewed 26339 times)
Why do constellations look the same after several years even though all the stars are moving? (viewed 26287 times)
Does the Sun have an iron surface? (viewed 26280 times)
How do we measure distances to other stars? (viewed 26262 times)
Could an astronaut or satellite fall into a black hole that we didn't know about? (viewed 26221 times)
Did the speed of light change over the history of the universe? (viewed 26199 times)
What is dark matter? (viewed 26122 times)
What would happen if two stars collided? (viewed 26118 times)
What are the closest and/or brightest stars? (viewed 26055 times)
How do we know what other planets (and stars, galaxies, etc.) are made of? (viewed 26022 times)
Why isn't the sky bright at night if the universe has so many stars? (viewed 25990 times)
Can we see dead stars with the naked eye? (viewed 25974 times)
Why is Uranus tipped on its side? (viewed 25837 times)
How do I make a scale model of the Solar System? (viewed 25836 times)
Why are Saturn's rings flat? (viewed 25801 times)
What is the best way to see the Milky Way? (viewed 25770 times)
How big a change in the Earth's orbit would be required to destroy all life? (viewed 25670 times)
Are there stars outside of galaxies? (viewed 25596 times)
How are galaxy distances inferred from their recessional velocities? (viewed 25575 times)
Has anyone made a map of the Milky Way? (viewed 25548 times)
Don't tachyons travel faster than light? (viewed 25500 times)
How can I tell if the rock I found is a meteorite? (viewed 25495 times)
Who (and when) discovered that the earth's axis is on a 23 degree tilt? (viewed 25365 times)
Was I hit by a meteorite? (viewed 25306 times)
What are the facts about the Star of Bethlehem? (viewed 25284 times)
Will we ever stop having solar eclipses because of the moon's motion away from the Earth? (viewed 25276 times)
How do we know the Milky Way is a spiral galaxy? (viewed 25234 times)
What are the atmospheres of Mars and Pluto like? (viewed 25201 times)
Did I see the Aurora Borealis as a child? (viewed 25196 times)
How do I become both an astronaut and an astronomer? (viewed 25183 times)
Will winter and summer constellations change due to abnormal warmth or cold on Earth? (viewed 25058 times)
How are galaxies named? (viewed 25004 times)
Can superheavy elements (such as Z=116 or 118) be formed in a supernova? Can we observe them? (viewed 24978 times)
How will the two black holes that are going to collide affect Earth? (viewed 24929 times)
Are the planes of solar systems aligned with the plane of the Galaxy? (viewed 24913 times)
Why do most moons orbit their planets at the equator? (viewed 24883 times)
Is the gravitational force exerted by the Earth on the Moon equal to the centripetal force acting on the Moon? (viewed 24825 times)
How are planets detected around other stars? (viewed 24711 times)
Is the Sun always up for exactly 12 hours at the equator? (viewed 24679 times)
Why do astronauts in space need to exercise? (viewed 24659 times)
What happens when an antimatter black hole collides with a matter blackhole? (viewed 24614 times)
Can life exist on the recently discovered extrasolar planets? (viewed 24550 times)
Why do humans want to go in space? (viewed 24500 times)
Have there been other Big Bangs before? (viewed 24483 times)
Why are there no craters on Earth? Did all the meteorites miss us? (viewed 24241 times)
Aren't jobs in astronomy scarce? (viewed 24204 times)
Why are most months 30 or 31 days long? (viewed 24199 times)
Why does the SETI project search for radio signals? (viewed 24171 times)
How close do you have to come to the Earth to be influenced by its gravity? (viewed 24168 times)
How can geometry be different in space? (viewed 24152 times)
What does the term "visible universe" mean? (viewed 24026 times)
Can astronauts produce water in space? (viewed 23946 times)
How much time do astronomers spend looking through telescopes? (viewed 23920 times)
Do astronomers believe in astrology? (viewed 23820 times)
What colors are visible through an amateur telescope? (viewed 23811 times)
When are there 5 Sundays in February? (viewed 23722 times)
Is the Milky Way a collision of two galaxies? (viewed 23715 times)
Is it true that the Sun burns off a billion tons of gas every 5 seconds? (viewed 23702 times)
How far does a galaxy extend? (viewed 23622 times)
Why do clocks turn in the opposite direction from the Earth and Moon? (viewed 23606 times)
How can we measure distances to more stars? (viewed 23562 times)
How long does it take the Big Dipper to move in the sky? (viewed 23530 times)
What are the names of the three stars in Orion's belt? (viewed 23513 times)
How do asteroids, meteors and comets disappear? (viewed 23508 times)
Is infinite temperature possible? (viewed 23491 times)
Why do we study black holes? (viewed 23478 times)
Why do the explosions of Type Ia supernovae have a more predictable spectrum than those of regular Type II supernovae? (viewed 23439 times)
Do we know everything about the Sun? (viewed 23435 times)
Can one star orbit another? (viewed 23377 times)
How can we know that there are other galaxies if we cannot leave ours? (viewed 23243 times)
Will the seasons change due to precession? (viewed 23230 times)
How can we see galaxies if their stars are so faint? (viewed 23221 times)
How will a change in the speed of light affect the evolution of the Universe? (viewed 23221 times)
Why are the compositions of comets and asteroids different? (viewed 23176 times)
Can "tired light theory" explain the observed redshifts of galaxies? (viewed 23060 times)
How are galaxies and solar systems similar? (viewed 23016 times)
Wouldn't the Big Bang theory be considered a hypothesis and not a theory? (viewed 23016 times)
Is there a project I can do on black holes? (viewed 22997 times)
Do you believe in UFOs? (viewed 22996 times)
How do scientists slow light down? (viewed 22986 times)
How do sunrise and sunset times change with altitude? (viewed 22870 times)
What is a Dyson Sphere? (viewed 22869 times)
How do we know what parameters to use when simulating the collision of the Milky Way and Andromeda? (viewed 22869 times)
Is there such a thing as hyperspace? (viewed 22841 times)
Why can we see the sun's image before sunrise and after sunset? (viewed 22804 times)
Was Stonehenge built to mark solar phenomena? (viewed 22780 times)
What type of energy does a black hole have? (viewed 22657 times)
What is the farthest in space that we have gone? (viewed 22626 times)
How do I explain to my children why the Moon has phases? (viewed 22565 times)
How do I polar align my telescope? (viewed 22558 times)
What happens when you change the mass of a White Dwarf or Neutron Star? (viewed 22553 times)
Is the universe really like an expanding balloon? (viewed 22544 times)
Which way does the sun travel in the southern hemisphere? (viewed 22532 times)
What supernova created the Crab nebula? (viewed 22512 times)
How close does a supernova need to be to damage the Earth's environment? (viewed 22507 times)
What kind of eyepieces do I need to look at planets? (viewed 22458 times)
Do you think it's possible to maintain life on other planets? (viewed 22456 times)
What's so exciting about the new planet around 55 Cancri? (viewed 22428 times)
Are there any dark stars or dark galaxies made of dark matter? (viewed 22378 times)
Is it worthwhile to continue the search for extraterrestrial life? (viewed 22289 times)
Have gravitational waves been proven to exist? (viewed 22229 times)
What's the object I saw that moved across the sky and then got very bright? (viewed 22225 times)
Did a giant impact cause the Dark Ages? (viewed 22225 times)
How do we know that sunspots are associated with the Sun's magnetic field? (viewed 22165 times)
Could you escape from a black hole if you were able to go faster than the speed of light? (viewed 22155 times)
Is there a list of the sizes of different kinds of stars? (viewed 22153 times)
What happens to the material that has been sucked into a black hole? (viewed 22118 times)
Why are there active volcanos on Io? (viewed 22108 times)
What is sidereal time? (viewed 22094 times)
What is the farthest Northern Latitude in which the Magellanic Clouds can be seen? (viewed 22042 times)
What's the best thing about being an astronomer? (viewed 22014 times)
Can astronauts play musical instruments in space? (viewed 22008 times)
Can you use an infinite line of reflectors to send light to the edge of the Universe? (viewed 21978 times)
Can two lunar eclipses occur in the same month? (viewed 21945 times)
What are "blue stragglers" in globular clusters? (viewed 21939 times)
When unmanned spacecraft accelerate in space, what causes them to slow down? (viewed 21901 times)
Why do we assume that the universe is homogeneous? (viewed 21891 times)
How big was the Sun when it first "fired up"? (viewed 21888 times)
What process would bring about a quark star? (viewed 21885 times)
Do the magnitudes and colors of stars ever change? (viewed 21838 times)
What will happen to the Milky Way in the future? (viewed 21822 times)
Is there any possibility that the Solar System or the Universe is in a black hole? (viewed 21775 times)
Why is the time between two successive full moons different from the lunar synodic month? (viewed 21732 times)
How do we know that superclusters are the largest structures in the universe? (viewed 21693 times)
What calculations go into predicting eclipses? (viewed 21669 times)
Could you tell me about the life cycle of galaxies? (viewed 21631 times)
Could we be seeing dead stars? (viewed 21623 times)
How do we know if the universe will keep expanding forever? (viewed 21606 times)
Is there sound coming from the Sun? (viewed 21575 times)
Is there a beginning and an end to a galaxy's life? (viewed 21556 times)
Why do so many of the world's UFO sightings happen in America? (viewed 21553 times)
Why do photos of space taken from space never show any stars? (viewed 21544 times)
Why is the Hubble Space Telescope in space? (viewed 21366 times)
Does Cerenkov radiation travel faster than light? (viewed 21259 times)
How can we compare dark matter and dark energy? (viewed 21228 times)
How many sunspots can the Sun have at once? (viewed 21218 times)
Can double stars have planets? (viewed 21203 times)
What caused Shoemaker-Levy 9 to split up? (viewed 21091 times)
How is it proved that the Universe is expanding? (viewed 21042 times)
Could we send a space mission to a comet? (viewed 21017 times)
How can the universe be "flat"? We're 3D! (viewed 20986 times)
Would extraterrestrial civilizations know that there is life on Earth? (viewed 20980 times)
If we invented special suits could we ever go to the sun? (viewed 20968 times)
How different would the night sky have looked in 40,000 B.C.? (viewed 20962 times)
Can supernovae hinder the formation of life in galaxies? (viewed 20957 times)
How do solar flares affect airline pilots? (viewed 20933 times)
Why is the shadow on the Moon the shape it is? (viewed 20846 times)
Can I see details on Venus? (viewed 20798 times)
Could a different theory of gravity explain the dark matter mystery? (viewed 20798 times)
How many comets are currently orbiting our sun? (viewed 20779 times)
How was the starting point for the Julian Date system chosen? (viewed 20747 times)
How do astronomers measure the radius of a star? (viewed 20746 times)
Can you tell time by the Big Dipper? (viewed 20675 times)
What do "homogeneity" and "isotropy" mean? (viewed 20666 times)
As the universe expands, why don't galaxies get stretched out? (viewed 20627 times)
What causes gamma ray bursts? (viewed 20593 times)
How do planets capture satellites? (viewed 20579 times)
What would happen if there was a collision between two white dwarfs? (viewed 20545 times)
Why doesn't light from distant galaxies reach us instantaneously? (viewed 20532 times)
Why are stars of different masses? (viewed 20471 times)
How are photons created and destroyed? (viewed 20453 times)
What happened to all the black holes that were around in the early universe? (viewed 20435 times)
How are sunspots formed? (viewed 20387 times)
How does the Earth compare in size to the entire universe at the present epoch? (viewed 20374 times)
What kind of instruments are used to detect extrasolar planets? (viewed 20338 times)
Are the properties of extrasolar planets known? (viewed 20283 times)
How long do supernova remnants last? (viewed 20268 times)
How are asteroid compositions and classifications determined? (viewed 20259 times)
Can you describe a day on the job as an astronomer? (viewed 20255 times)
How powerful are quasars? (viewed 20244 times)
What is the solar cycle? (viewed 20219 times)
Can I see a quasar? (viewed 20216 times)
What is the difference between homogeneity and isotropy? (viewed 20205 times)
Can any comparison be made between spiral galaxies and hurricanes? (viewed 20197 times)
How is the Cepheid yardstick validated? (viewed 20187 times)
Do similar laws of physics throughout the Universe imply that all life must be like life on Earth? (viewed 20164 times)
Why did the Pioneer and Voyager take only 2 years to reach Jupiter, while Galileo and Cassini took more than 5 years? (viewed 20088 times)
What equipment do I need for astrophotography? (viewed 20079 times)
Why are there blue shifted galaxies? (viewed 20074 times)
What month was it when Odysseus saw Orion in 1000BC? (viewed 19980 times)
Would the biggest airplanes cause tsunamis if they crashed? (viewed 19948 times)
Why doesn't NASA build rotating spacecraft to simulate gravity? (viewed 19895 times)
Do unmanned spacecraft like Voyager travel in straight lines? (viewed 19835 times)
If clocks run slow in a gravitational field, how can we know the true age of the Solar System and Universe? (viewed 19771 times)
Can the theory of formation of the solar system explain all the observables? (viewed 19757 times)
Why does one side of Mars look more catastrophic than the other? (viewed 19744 times)
Are there any new craters on the moon? (viewed 19722 times)
How can you tell if a crescent moon is preceding or following a new-moon phase? (viewed 19705 times)
How can we tell what the interiors of planets are like? (viewed 19691 times)
A line drawn perpendicular to a line through the tips of the horns of the crescent moon doesn't point to the Sun! Why not? (viewed 19676 times)
Can a black hole come back to the visual universe through a "little bang"? (viewed 19599 times)
What is our galaxy's halo made of, and how was it formed? (viewed 19593 times)
How do I become an astronomical artist? (viewed 19543 times)
What kind of telescope should I use for astrophotography? (viewed 19511 times)
Are planetary nebulae the result of supernovae? (viewed 19444 times)
Could our position in the universe affect our perceptions of the expansion? (viewed 19423 times)
Could there have been multiple Big Bangs at different places in the universe? (viewed 19406 times)
How are supernovae discovered? (viewed 19395 times)
Is there oxygen in the atmospheres of other planets? (viewed 19376 times)
Which part of the sky did the famous 'wow' signal originate from? (viewed 19364 times)
Why does the apparent density of galaxies drop off at larger distances? (viewed 19355 times)
Did I really hear a meteor? (viewed 19350 times)
How hot is each one of the layers of the sun? (viewed 19337 times)
Does inflation allow for an infinite number of universes? (viewed 19337 times)
Where does the kinetic energy of infalling bodies come from? (viewed 19335 times)
What is a Cepheid variable? (viewed 19331 times)
What happened to the girl who named Pluto? (viewed 19328 times)
Will we discover an 11th planet? What would it be called? (viewed 19323 times)
Can other terrestrial moons be (or have been) stable? (viewed 19290 times)
Does the Sun have any heavy elements? (viewed 19243 times)
Can I build an instrument to measure the size of the Sun and of the Moon? (viewed 19235 times)
What is the origin of the stellar classification system "OBAFGKM"? (viewed 19165 times)
Would a planet near the galactic center have a brighter night sky? (viewed 19164 times)
Did time go slower just after the Big Bang? (viewed 19161 times)
What makes a satellite geosyncronise itself with Earth's orbit? (viewed 19139 times)
Can you give me advice on buying a telescope? (viewed 19099 times)
Why is NASA shutting down the Hubble Space Telescope? (viewed 18995 times)
Why was the Platonic year named after Plato? (viewed 18956 times)
When did people discover that the Sun is a star? (viewed 18956 times)
Does a photon observe other photons moving past it at the speed of light? (viewed 18944 times)
Do galaxies orbit around anything? (viewed 18929 times)
Do asteroids hit the sun? (viewed 18914 times)
Why doesn't the hydrogen on Jupiter explode? (viewed 18892 times)
Is it possible for amateurs to do optical interferometry? (viewed 18889 times)
Can I listen to the SETI@home radio signal? (viewed 18837 times)
Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating? (viewed 18831 times)
What would the Big Crunch look like to an observer on Earth? (viewed 18807 times)
How are astronomy and poetry linked? (viewed 18799 times)
Why are there more maria on the near side of the Moon? (viewed 18783 times)
What is meant by "stopping down a telescope"? (viewed 18734 times)
Why do some eclipses take longer than others? (viewed 18674 times)
What class of spiral galaxy is the Milky Way? (viewed 18621 times)
Why search for only Earth-like life on other planets? (viewed 18588 times)
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background? (viewed 18473 times)
Where can I find information on the moons of other planets? (viewed 18410 times)
Why is the Cosmic Microwave Background not absorbed by interstellar hydrogen? (viewed 18409 times)
Do stars' orbits in galaxies obey Kepler's Laws? (viewed 18249 times)
Why are telescopes located in remote places? (viewed 18233 times)
Is it possible to build a cheap device to measure declination? (viewed 18205 times)
Do we see the same stars from above and below the equator? (viewed 18188 times)
What is the SU(3) quark model? (viewed 18170 times)
If the Universe was infinitely dense at the Big Bang, why didn't time stand still? (viewed 18152 times)
Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations? (viewed 18120 times)
Why aren't discoveries of extrasolar planets reported on the news? (viewed 18117 times)
Why is it important to study meteorites? (viewed 18100 times)
Where was the water in the big bang? (viewed 18098 times)
Did I find a rock that came from the Moon? (viewed 18053 times)
If comets are boiling away, why are there any left? (viewed 18045 times)
How do astronomers come up with their facts? (viewed 17997 times)
How could galaxies have gotten so far away in only 15 billion years? (viewed 17949 times)
Can the acceleration of the Universe be analogous to apparent acceleration in a airplane? (viewed 17927 times)
Why is pressure broadening greater in low mass stars than in high mass stars? (viewed 17927 times)
Can the Space Shuttle abort and return to Earth before reaching orbit? (viewed 17830 times)
Why don't astronauts sublimate in space? (viewed 17811 times)
What are the boundaries of the constellations? (viewed 17809 times)
Could photons be dark matter? (viewed 17784 times)
What's new with the Big Bang? (viewed 17778 times)
Can HST see the Oort cloud? (viewed 17753 times)
What would an "open geometry" for the universe look like? (viewed 17674 times)
How do bars form in spiral galaxies? (viewed 17635 times)
Do electrons age? (viewed 17594 times)
Does the shuttle worry about space junk? (viewed 17494 times)
How can we find galaxies behind the Milky Way? (viewed 17494 times)
Why do supernova remnants look like rings rather than spheres? (viewed 17472 times)
How can the Sun have such a strong gravitational field if it's made of gasses? (viewed 17415 times)
Why are accretion disks flat? (viewed 17366 times)
Will I be able to see the shadow of the Moon streaking towards me in a total solar eclipse? (viewed 17357 times)
Why doesn't SETI concentrate its observations to the nearby stars and the solar systems that we are discovering? (viewed 17224 times)
What is the best time of the year to see eclipses? (viewed 17216 times)
Could we send a manned mission to the outer planets? (viewed 17200 times)
Can we make a movie of the Milky Way galaxy's rotation? (viewed 17200 times)
What is "nothing", from a scientific point of view? (viewed 17193 times)
How do photons from distant objects maintain enough energy to reach us? (viewed 17193 times)
Why can't relative velocities add up to more than the speed of light? (viewed 17184 times)
Did the Sumerians measure precession? (viewed 17176 times)
How fast do particles travel in space? (viewed 17149 times)
What was that eclipse I saw in the sky? (viewed 17146 times)
Why can we have solar eclipses? (viewed 17101 times)
Why are telescopes kept in cold conditions? (viewed 17054 times)
How long is twilight on the Moon? (viewed 17020 times)
What kinds of star clusters are there? (viewed 17007 times)
Can astronomers observe anything when the moon is full? (viewed 16979 times)
Is light of different colors affected differently by gravity? (viewed 16969 times)
Are the asteroids the remains of a planet which broke apart? (viewed 16929 times)
How can I contribute to science as an amateur astronomer? (viewed 16888 times)
How do astronomers observe the Sun's interior? (viewed 16880 times)
Will the next generation telescope OWL be able to detect an Earth like extrasolar planet? (viewed 16754 times)
How long has humanity known that we live in a galaxy similar to others in the Universe? (viewed 16735 times)
How much power is contained in a beam of light? (viewed 16708 times)
How do you classify galaxies? (viewed 16601 times)
Does the temperature of matter increase as it is accelerated to relativistic speeds? (viewed 16597 times)
How do we find out about the star formation histories of galaxies? (viewed 16582 times)
What are "curled" dimensions? (viewed 16578 times)
What causes a particle to decay? (viewed 16429 times)
How does melting a material reset its radioactive clock? (viewed 16381 times)
How does interferometry work? (viewed 16331 times)
Will the Leonid meteor shower go away? (viewed 16287 times)
How can we understand the meaning of large numbers like "a million million?" (viewed 16273 times)
Can you tell me the characteristics of W, R, N and S type stars? (viewed 16261 times)
Will astronauts ever be able to go ice-skating on Europa? (viewed 16230 times)
Where can I see Newton's original reflecting telescope? (viewed 16098 times)
Will the diameter of a cluster of galaxies change with redshift? (viewed 16093 times)
How can I nominate myself for a Nobel Prize in Physics? (viewed 16087 times)
How do distant galaxies differ from those nearby? (viewed 16081 times)
Why do spacecraft need heat shields coming back to Earth but not leaving? (viewed 16056 times)
Why is the WMAP picture of the CMB an ellipse? (viewed 15939 times)
What do stellar classifications mean? (viewed 15915 times)
Wouldn't the vast distances of space distort SETI signals into unintelligeble forms? (viewed 15864 times)
How did Mars get so dusty? (viewed 15762 times)
Do the Earth's magnetic poles ever change places? (viewed 15687 times)
Do we have to worry about relativity when studying galactic objects? (viewed 15646 times)
How can water be chemically trapped in rocks? (viewed 15542 times)
What kind of interference must astronomers contend with when observing? (viewed 15520 times)
How can I watch the Perseid meteor shower? (viewed 15519 times)
How can I find out if the new moon has been sighted? (viewed 15446 times)
How are astronauts trained for weightlessness? (viewed 15445 times)
What is the three-body problem? (viewed 15437 times)
How do unmanned space probes avoid running into things? (viewed 15405 times)
Is cosmic expansion happening on microscopic scales? (viewed 15396 times)
Do we really observe the edges of galaxies at different epochs? (viewed 15396 times)
Why will fusion wait until hydrogen is gone before starting to fuse heavier atoms? (viewed 15319 times)
Can a human give birth in space? (viewed 15315 times)
How does a star take mass from another star? (viewed 15302 times)
If the universe is "bounded" today, could it one day become "unbounded"? (viewed 15294 times)
Why is the sky blue and not blue & purple? (viewed 15252 times)
Is the Local Group expanding along with the entire Universe? (viewed 15117 times)
Do asteroids ever do anything good in the Solar System? (viewed 15079 times)
How can you tell the difference between single and multiple extrasolar planets? (viewed 15059 times)
Why don't all neutron stars become pulsars? (viewed 14808 times)
How does libration allow us to see more than 50% of the Moon? (viewed 14685 times)
What would happen if you went back in time and killed your grandmother? (viewed 14645 times)
How big is the Hubble Ultra Deep Field image? (viewed 14593 times)
Why aren't accretion disks around giant stars as hot as accretion disks around black holes? (viewed 14520 times)
Do binary or triple star systems form together? (viewed 14506 times)
What is Hot Dark Matter theory? (viewed 14467 times)
What kinds of cancer research have been done in space? (viewed 14396 times)
Is light blueshifted when it is gravitationally lensed? (viewed 14363 times)
Why is it called astronomy when all the other sciences end in -ology? (viewed 14283 times)
How can observations of the distant universe prove that the expansion is accelerating *now*? (viewed 14231 times)
What percent of the time can astronomers observe without interference from the Moon? (viewed 14199 times)
No matter how fast the universe is expanding, shouldn't gravity eventually make it recollapse? (viewed 14179 times)
Could neutrinos be dark matter? (viewed 14137 times)
Do constellations looks the same from space? (viewed 14002 times)
What are collections of galaxies called? (viewed 13869 times)
Could matter-anti-matter repulsion power the expansion of the universe? (viewed 13689 times)
How does the color index of a star relate to its actual color? (viewed 13616 times)
Why is it easier to see a star if you look slightly to the side? (viewed 13548 times)
What do meteorites tell us about life on other planets? (viewed 13433 times)
Are there any 'lonely galaxies'? (viewed 13387 times)
Could the Universe's dark matter be made up of black holes? (viewed 13253 times)
Does the Milky Way spin counter-clockwise? If so, do all spiral galaxies spin in this direction and why? (viewed 13072 times)
Is it a coincidence that we can have total solar eclipses? Are there other planets which also have them? (viewed 12916 times)
Why doesn't the ammonia and methane in Jupiter's atmosphere sink into the core? (viewed 12844 times)
During close approaches, can Mars appear in our sky as large as the Moon? (viewed 12839 times)
What is the photoelectric effect? Why can't multiple low-frequency photons free an electron? (viewed 12780 times)
How are planets affected by the Hot Ionised Medium? (viewed 12749 times)
Does lunar gardening really work? (viewed 12704 times)
If nothing can escape a black hole, why do some black holes have jets? (viewed 12635 times)
What was different on Mars in the past to allow liquid water to be present? (viewed 12577 times)
How can we discern different galaxies/clusters along the same line of sight? (viewed 12347 times)
Why was Mir burnt up in the atmosphere? (viewed 12098 times)
What is the relationship between the width of a star trail on a photo and the star's intensity? (viewed 12073 times)
What would happen if a human were exposed to space without wearing a spacesuit? (viewed 12000 times)
What are the largest radio wavelengths observed from radio sources in the sky? (viewed 11973 times)
Is the green flash real? (viewed 11666 times)
How do we detect incoming meteorites? (viewed 11512 times)
How do we know the density of some extrasolar planets? (viewed 11404 times)
Are black holes spherical? (viewed 11140 times)
If the sun went out and our atmosphere froze solid, what color would it be? (viewed 10882 times)
Can planets collide with one another? (viewed 10676 times)
Can we prove that the Moon isn't hollow? (viewed 10523 times)
Can the sun rise from the west on Mars? (viewed 10382 times)
Does weightlessness affect hunger? (viewed 10052 times)
Has anyone ever seen a star "turn on"? (viewed 9706 times)
When will Hale-Bopp return? (viewed 9527 times)
When measuring the expansion of the universe, do astronomers consider that they're seeing how galaxies moved long ago, not today? (viewed 9324 times)
What is between the Oort cloud and the closest star? (viewed 9185 times)
Can we harvest H & O from space to make water? (viewed 8637 times)
Could a planetary system survive if its star merged with another, or if its star went supernova? (viewed 8462 times)
Why don't skydivers burn up like meteors? (viewed 8345 times)
How do supernovae show us that the Universe's expansion is accelerating? (viewed 8259 times)
Why are craters round? (viewed 7996 times)
What would happen if a nuclear-powered shuttle exploded? (viewed 7685 times)
Are there solar tides? (viewed 7646 times)
Do planets radiate noise? (viewed 7625 times)
Did the Moon or planets form in a manner similar to that of Earth? (viewed 7551 times)
Is it sensible to consider terraforming Mars? (viewed 7140 times)
How has light from 13 billion years ago not passed us by? (viewed 7006 times)
Do more meteorites fall at low latitudes? (viewed 6732 times)
Why does Titan, in spite of being smaller than Mars, have an atmosphere more dense than Earth's? (viewed 6723 times)
If there are infinity universes, will every thing that is possible happen? (viewed 6664 times)
Where is everybody? (viewed 6583 times)
Is Earth-moon tidal friction causing global warming? (viewed 6578 times)
What are the possible ends of the universe? (viewed 6081 times)
Is the moon spherical? (viewed 5824 times)
When will humans travel to Mars and revisit the Moon? (viewed 5496 times)
Will the Pioneer and Voyager probes ever leave the Milky Way? (viewed 5399 times)
Is dark energy affected by black holes? (viewed 5348 times)
If I were traveling through space, could I see distant galaxies with my own eyes? (viewed 5095 times)
What color are meteors? (viewed 5088 times)
Where is the Spitzer Space Telescope? (viewed 5048 times)
The naming of Mars (viewed 4988 times)
Why does Mars have a dusty atmosphere? (viewed 4796 times)
Does the singularity in a black hole create a new Universe? (viewed 4676 times)
Does the particles involved in a star's final core collapse travel faster than the speed of light? (viewed 4536 times)
Why can't a plane fly slowly and let the Earth pass underneath? (viewed 4359 times)
Is the reddish dust of Mars biogenic? (viewed 4342 times)
When is the best time to observe zodiacal light? (viewed 4257 times)
Will Comet Elenin (C/2010 X1) affect the Earth on its close approach in Fall 2011? (viewed 4255 times)
The Moon and Sun are the same apparent size in the sky. The Moon is moving away from us at 3.8 centimeters/year. Isn't it improbable that we live in an epoch in which they appear the same size in the sky? (viewed 2322 times)
Wait, I'm still confused why information can't travel faster than the speed of light. (viewed 2094 times)
What happens to the helium formed in the sun? (viewed 2029 times)
Where are the protons and electrons in a Neutron Star? (viewed 1586 times)
What happens to the Earth as the moon gets farther away and will it ever go away entirely? (viewed 1581 times)
Can we hear sound on Titan? (viewed 1300 times)
How did a transit of Venus provide astronomers with the first measurement of the Earth-Sun distance? (viewed 1286 times)
Does the Moon look different in the northern and southern hemispheres? (viewed 1185 times)
Is the Moon always visible during winter on the North Pole? (viewed 815 times)
Why is the Moon higher in the sky in winter and lower in the summer? (viewed 758 times)
Does the direction of the moon's crescent change through the night? (viewed 685 times)
How likely is it for a planet to transit its star? (viewed 666 times)
Why do astronomers use telescopes? (viewed 554 times)
What do all the angles in a table for a planet's orbit mean? (viewed 486 times)
What causes the aurora? (viewed 348 times)
What time is sunrise/sunset or moonrise/moonset at my location? (viewed 194 times)
If photons have zero mass, why do they feel the effects of gravity? (viewed 178 times)

URL: http://curious.astro.cornell.edu/list.php
This page has been accessed 66919 times since September 25, 2002.
Last modified: November 28, 2003 3:53:21 PM

Legal questions? See our copyright, disclaimer and privacy policy.
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.