All previously answered questions (in order of times viewed)

What's going to happen on December 21st 2012? (viewed 2055686 times)
What color is each planet? (viewed 733089 times)
Is the Moon moving away from the Earth? When was this discovered? (viewed 451041 times)
At what speed does the earth move around the sun? (viewed 419792 times)
How far is each planet from Earth? (viewed 401932 times)
How many stars are there in our Galaxy (Milky Way)? (viewed 348899 times)
What is the universe expanding into? (viewed 313785 times)
Why do the planets orbit the sun? (viewed 295560 times)
How long does it take for the Sun's light to reach us? (viewed 290021 times)
Which planets have rings? (viewed 289075 times)
How do you measure the distance between Earth and the Sun? (viewed 282430 times)
When will Halley's Comet return? (viewed 279827 times)
How do I build a model rocket? (viewed 253289 times)
What color is Venus? (viewed 246078 times)
Why do stars twinkle? (viewed 245606 times)
Does the Moon rotate? Are there other moons that always keep one face toward their planet? (viewed 244841 times)
What is a white hole? (viewed 241279 times)
What is the life cycle of a star? (viewed 232682 times)
What is the largest star? (viewed 214573 times)
What are the names of the earth, moon, sun, and solar system? (viewed 197020 times)
What makes the Earth rotate? (viewed 180372 times)
What are shooting stars? (viewed 177712 times)
What do astronauts eat in space? Can they grow food? (viewed 175519 times)
Why do planets rotate? (viewed 168847 times)
What is that ring (or rainbow) around the moon? (viewed 163547 times)
Where did the name 'Earth' come from? (viewed 156448 times)
How many Earths fit into the Sun? (viewed 152270 times)
How do we know the age of the Universe and the Earth? (viewed 150987 times)
Is the universe expanding faster than the speed of light? (viewed 144414 times)
What would happen if we did not have a Moon? (viewed 141500 times)
How does the location of sunrise and sunset change throughout the year? (viewed 140157 times)
Is Pluto a planet? (viewed 139474 times)
Can you hear sounds in space? (viewed 138317 times)
How can we see the Milky Way if we are inside it? (viewed 137194 times)
Can artificial gravity be created in space? (viewed 136292 times)
Is the distance from the Earth to the Sun changing? (viewed 136183 times)
Who named the planets and who decides what to name them? (viewed 126743 times)
Why is a day divided into 24 hours? (viewed 125826 times)
Why are there both high and low tides? (viewed 122480 times)
What is the largest galaxy? (viewed 122155 times)
How many known galaxies are there? (viewed 117592 times)
How does the position of Moonrise and Moonset change? (viewed 117337 times)
What is at the end of the Universe? (viewed 117208 times)
Is the Sun expanding? Will it ever explode? (viewed 109886 times)
When was the last time all 9 planets were aligned? (viewed 108965 times)
How can I find the star I have "bought"? (viewed 108491 times)
Will the sun go supernova in six years and destroy Earth (as seen on Yahoo)? (viewed 105741 times)
What direction do planets rotate? (viewed 103140 times)
Can we feel the Earth spin? (viewed 101987 times)
Will the magnetic field of the Earth reverse its direction in the future? Will this cause problems? (viewed 101527 times)
Do stars move in the sky? (viewed 99712 times)
What is the hottest time of day? (viewed 99695 times)
When is the next comet due to arrive? (viewed 98696 times)
How do astronauts take baths and use restrooms in space? (viewed 98679 times)
Why do airplanes take longer to fly West than East? (viewed 97924 times)
Why are the Moon and Sun sometimes orange or red? (viewed 97486 times)
What was there before the Big Bang and what is there outside of our universe? (viewed 97420 times)
How do stars move in the Galaxy? (viewed 95032 times)
What would happen if an impact caused Earth to stop rotating? (viewed 92104 times)
Can I buy a star? (viewed 92063 times)
How long does a solar eclipse last? (viewed 91560 times)
Are there telescopes that can see the flag and lunar rover on the Moon? (viewed 91451 times)
What happens when galaxies collide? (viewed 91261 times)
How are light and heavy elements formed? (viewed 91079 times)
Does the Sun move around the Milky Way? (viewed 90765 times)
What are the advantages and disadvantages of using a telescope in space? (viewed 89153 times)
How many constellations are there? (viewed 88125 times)
What is the size of the Solar System? (viewed 88032 times)
How much money is spent on space exploration? (viewed 87836 times)
Does the Sun have a scientific name? (viewed 86816 times)
How do rockets work? (viewed 86605 times)
Does the Sun rotate? (viewed 86081 times)
What elements make up the Sun? (viewed 85189 times)
How much money do astronomers make? (viewed 84989 times)
Does your weight change between the poles and the equator? (viewed 84964 times)
Who first measured the speed of light? (viewed 84479 times)
How do you calculate the lifetime of the Sun? (viewed 84232 times)
What is apparent magnitude? (viewed 84225 times)
Why do planets have elliptical orbits? (viewed 83796 times)
What will happen to life on Earth when the Sun becomes a red giant? (viewed 83298 times)
What is the observational difference between a star and a planet? (viewed 82769 times)
How critical is the Earth-Sun distance in maintaining our average temperatures on Earth? (viewed 82367 times)
What is a nova? (viewed 82292 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 82196 times)
Have astronomers discovered Earth's second moon? (viewed 81004 times)
Do black holes die? If so how? (viewed 80687 times)
Why hasn't NASA gone back to the moon? (viewed 79366 times)
Why do all the planets orbit in the same plane? (viewed 79309 times)
Which planet is most similar to Earth? (viewed 77492 times)
What would happen if an asteroid 10 kilometers across hit the Earth? (viewed 77008 times)
Why are stars and planets round? (viewed 76202 times)
What is the physical difference between a star and a planet? (viewed 73489 times)
What would happen if Earth had more than one moon? (viewed 73338 times)
What kind of rock is the moon made of? (viewed 73062 times)
What is a singularity? (viewed 73041 times)
How many meteorites hit Earth each year? (viewed 73009 times)
Where does the name "Milky Way" come from? (viewed 72697 times)
Does the Sun orbit the Earth as well as the Earth orbiting the Sun? (viewed 72251 times)
Where did the Universe come from? (viewed 71859 times)
Considering the motion of the Earth, the solar system, and the galaxy, how fast am I moving while lying in bed asleep? (viewed 71470 times)
Is there a proof that Earth moves? (viewed 71382 times)
Did astronauts really go to the Moon, or is it a hoax? (viewed 70929 times)
Why do different stars appear with seasons? (viewed 70724 times)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (viewed 70684 times)
What makes the wind? (viewed 70642 times)
Who has landed on the moon? (viewed 69963 times)
What are RA and DEC? (viewed 69931 times)
Why is the Moon so bright? (viewed 69275 times)
Why is the Universe flat and not spherical? (viewed 69058 times)
What do astronauts do all day in the International Space Station? (viewed 68752 times)
What are constellations used for? (viewed 68706 times)
Why isn't the sky bright at night if the universe has so many stars? (viewed 68498 times)
Why does the Earth tilt back and forward once a year? (viewed 68486 times)
Does gravity vary across the surface of the Earth? (viewed 68036 times)
How are galaxies formed? (viewed 66900 times)
Why aren't there any green stars? (viewed 66260 times)
How are black holes made? Could one be made close to us? (viewed 65451 times)
How do astronomers use math in their jobs? (viewed 65134 times)
How can a star burn with no oxygen? (viewed 64512 times)
Since Earth is spinning, why do we land in the same place when we jump or fall? (viewed 64255 times)
What would happen if a supermassive black hole came close to the Earth? (viewed 62950 times)
How many stars are born and die each day? (viewed 62899 times)
What would happen if the gravity on Earth was suddenly turned off? (viewed 62648 times)
Will the Sun become a black hole one day? (viewed 61612 times)
What are the "dog days of summer"? (viewed 61356 times)
What's the difference between astronomy and astrology? (viewed 60357 times)
When can I see the Moon through the hole in the Pantheon? (viewed 60258 times)
How often does the Sun pass through a spiral arm in the Milky Way? (viewed 60194 times)
Do most astronomers believe in God based on the available scientific evidence? (viewed 60100 times)
How does the Sun compare to other stars? (viewed 59858 times)
Can you fire a gun on the Moon? (viewed 59680 times)
What is the density of a black hole? (viewed 59649 times)
What are some of the effects of solar flares on Earth? (viewed 59611 times)
What causes seasons? (viewed 59525 times)
What happens to a substance if its speed is more than the speed of light? (viewed 59404 times)
Is it possible to measure the temperature of the Sun? (viewed 59213 times)
What would you see from inside a black hole? (viewed 59016 times)
What kinds of jobs do astronomers do? (viewed 58504 times)
How is astronomy impacted by trigonometry? (viewed 57311 times)
How do astronomers measure the brightness of stars? (viewed 57079 times)
Why can't you see stars during the day? (viewed 57076 times)
What's the best college for astronomy? (viewed 56924 times)
When the Sun converts mass to energy, do the orbits of the planets change? (viewed 56819 times)
Why doesn't the length of each day change much around the solstices? (viewed 56743 times)
What are black holes made of? (viewed 56516 times)
What kind of schooling is necessary to become an astronomer? (viewed 56055 times)
How do rockets move in space? (viewed 55955 times)
How does the Moon stay "suspended" in the air? (viewed 55933 times)
Why doesn't the earliest sunset occur on the shortest day of the year? (viewed 55833 times)
How do you measure a planet's mass? (viewed 55746 times)
Can moons have moons? (viewed 55524 times)
How do we know the mass of the Earth and the Moon? (viewed 55095 times)
How fast is the Universe expanding? (viewed 54773 times)
How can the Universe expand faster than the speed of light during inflation? (viewed 54733 times)
Does the Moon rotate? (viewed 54673 times)
How did the stars get named? (viewed 54636 times)
What is the mass of the Universe? (viewed 54590 times)
What would happen to us if the sun went out for an hour? (viewed 54316 times)
How did asteroids form and what is the difference between an asteroid and a comet? (viewed 54216 times)
What is the difference between a "star" and a "sun"? (viewed 54161 times)
Does evolution contradict the second law of thermodynamics? (viewed 54124 times)
If the universe is infinite does that mean there is an infinite number of "me"s? (viewed 53888 times)
Why do stars change colour when they twinkle? (viewed 53736 times)
How are elements heavier than iron formed? (viewed 53525 times)
Where does the name "Moon" come from? (viewed 53498 times)
What is the largest structure in the universe? (viewed 53363 times)
Traveling at light speed, how long would it take to get to the nearest galaxy? (viewed 53204 times)
Why do planets not twinkle? (viewed 52946 times)
What are Altitude and Azimuth? (viewed 52889 times)
Does quantum entanglement imply faster than light communication? (viewed 52511 times)
Where are stars born? (viewed 52244 times)
Could there be life in the galaxies nearest to the Milky Way? (viewed 52075 times)
Are there stars outside of galaxies? (viewed 52043 times)
What is the shape of the universe? (viewed 51861 times)
Does the Mediterranean sea have tides? (viewed 51842 times)
Why does the Earth have only one moon? (viewed 51834 times)
How long would it take the Earth to fall into the Sun? (viewed 51660 times)
Are names given to black holes? (viewed 51344 times)
How do you measure the mass of a star? (viewed 51117 times)
Why is the moon in a different place every night? (viewed 49965 times)
Can you see satellites? (viewed 49869 times)
How can I calculate the position or path of the Sun for a given time and location? (viewed 49615 times)
How does light pollution affect astronomers? (viewed 49544 times)
Where did the matter in the universe come from? (viewed 49337 times)
What is the evidence supporting the nebula theory of Solar System formation? (viewed 49262 times)
Can any galaxies be seen with the naked eye? (viewed 48820 times)
What is the origin of spiral structure in galaxies? (viewed 48630 times)
How does the parachute in a model rocket work? (viewed 48622 times)
What are the different kinds of astronomers? (viewed 48606 times)
Why isn't the summer solstice the hottest day of the year? (viewed 48570 times)
Why does the Sun's apparent path through the sky change throughout the year? (viewed 48526 times)
Are aliens or UFOs real? (viewed 48345 times)
What are some astronomy science fair projects? (viewed 48326 times)
Where, in relation to the entire universe, is the Milky Way located? (viewed 48258 times)
What are the requirements for being a planet? (viewed 48210 times)
How do astronauts use math in their jobs? (viewed 48200 times)
What is the size of a black hole? (viewed 48003 times)
Why do we not have eclipses every month? (viewed 47526 times)
What makes up most of the Universe? (viewed 47515 times)
How can I measure the distance of a star? (viewed 47509 times)
Is time travel possible? (viewed 47286 times)
Why do we see stars? (viewed 47006 times)
Is the speed of light constant? (viewed 46793 times)
What is a star's "spectrum"? (viewed 46688 times)
Who discovered each planet? (viewed 46547 times)
How close was the Moon to the Earth when it formed? (viewed 46516 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 46176 times)
What's the difference between dark matter and dark energy? (viewed 46126 times)
How do we measure the size of the Moon and of the Sun? (viewed 46058 times)
How can I find the distance to the Sun on any given day? (viewed 46048 times)
How do you calculate the azimuth and altitude of an object? (viewed 45777 times)
How long does the supernova stage of a star last? (viewed 45635 times)
What would happen if you took off your helmet in space? (viewed 45413 times)
Which constellation does our Sun belong to? (viewed 45401 times)
Are there any asteroids on a collision course with Earth? (viewed 45342 times)
What other careers involve Astronomy besides Astronomer? (viewed 44601 times)
Why does the Moon look big on the horizon? (viewed 44364 times)
Why is it difficult to understand the expansion of the universe? (viewed 44331 times)
How does astronomy benefit humankind? (viewed 44149 times)
Would your weight change as you go underground? (viewed 43668 times)
What happens to a bullet fired on the moon? (viewed 43643 times)
What can we learn from the color of a star? (viewed 43627 times)
If light has no mass, then what draws it into a black hole? (viewed 43498 times)
What is a graviton? (viewed 43474 times)
Where is the nearest black hole? (viewed 43093 times)
How do we weigh objects in space? (viewed 42997 times)
How long has there been water on Earth? (viewed 42976 times)
What would happen if the Moon fell out of its orbit around Earth? (viewed 42847 times)
Can we look back far enough in time to see the Big Bang? (viewed 42828 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 42752 times)
Do dead stars still shine? (viewed 42613 times)
What is the difference between nutation and precession of the Earth? (viewed 42085 times)
Which hemisphere has the best view of the Milky Way? (viewed 41845 times)
What do I need to do to become an astronomer? (viewed 41578 times)
Why is the sky blue and not blue & purple? (viewed 41357 times)
If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths? (viewed 41172 times)
Are meteorites hot or cold when they hit Earth? (viewed 40929 times)
Will we get sucked into the black hole at the center of the Milky Way? (viewed 40824 times)
How do gravitons escape black holes to tell the universe about their gravity? (viewed 40813 times)
Why is twilight short near the equator? (viewed 40650 times)
Are the planes of solar systems aligned with the plane of the Galaxy? (viewed 40649 times)
What is the biggest crater recorded on Earth? (viewed 40551 times)
What do a galaxy's colors mean? Are they its true colors? (viewed 40546 times)
Why does Barnard 68 appear dark? (viewed 40516 times)
Why can't we see Venus at night when it is an inner planet? (viewed 40240 times)
How are black holes discovered? (viewed 40163 times)
Was the Sun made in a supernova? (viewed 40131 times)
How do galaxies collide in an expanding universe? (viewed 40010 times)
What's the difference between astronomy and astrophysics? (viewed 39963 times)
Do supermassive black holes cause galaxy rotation? (viewed 39742 times)
What skills do astronomers need? (viewed 39632 times)
Why do the size and brightness of the full moon change? (viewed 39538 times)
How is the time of sunrise calculated? (viewed 39503 times)
Why is looking out into space the same as looking back in time? (viewed 39027 times)
Can I buy land on the Moon? (viewed 38890 times)
Is the Moon hollow? (viewed 38830 times)
What's the biggest meteorite? (viewed 38788 times)
How do the astronauts communicate in space if sound cannot travel in a vacuum? (viewed 38648 times)
What is time dilation? (viewed 38488 times)
Is the Earth slowly getting larger? (viewed 38469 times)
What happens when two black holes get too close? (viewed 38328 times)
Where did all the water in the universe come from? (viewed 38236 times)
What is a wormhole? (viewed 38202 times)
Why are there stars? (viewed 38195 times)
How much longer will the Earth last? (viewed 38149 times)
Why doesn't dark matter fall into a black hole? (viewed 38019 times)
What is the most distant known galaxy? (viewed 37956 times)
What color would Mars be if you were standing on it? (viewed 37786 times)
Has there been an experiment that measured speed faster than the speed of light in vacuum? (viewed 37644 times)
Can I calculate the size of the Universe by converting light years to kilometres? (viewed 37504 times)
Why does the location of sunrise change? (viewed 37231 times)
The Moon slows the Earth's rotation, but how fast was it spinning billions of years ago? (viewed 37021 times)
How would the weather on Earth be different if it were a cube? (viewed 36830 times)
How can two moons of Saturn share the same orbit? (viewed 36810 times)
Why does the Earth only see one side of the Moon? (viewed 36796 times)
Why do pictures of distant galaxies have higher resolution than those of nearby planets? (viewed 36564 times)
How long would it take for a mini-black hole to eat the Earth? (viewed 36458 times)
Why does the Sun appear larger on the horizon than overhead? (viewed 36428 times)
Can terrestrial planets have rings? (viewed 36277 times)
What happens to spacetime inside a black hole? (viewed 36167 times)
Does Mt. Everest cast a shadow on the moon? (viewed 36143 times)
How many Astronauts have been in space? (viewed 36022 times)
What can I use for fuel in my homemade rocket? (viewed 35938 times)
Could the Universe have expanded faster than the speed of light at the Big Bang? (viewed 35871 times)
Are Kuiper Belt Objects asteroids? Are large Kuiper Belt Objects planets? (viewed 35871 times)
How do we know what other planets (and stars, galaxies, etc.) are made of? (viewed 35842 times)
What is the difference between the "Doppler" redshift and the "gravitational" or "cosmological" redshift? (viewed 35803 times)
How big is the universe? (viewed 35581 times)
Are there eclipses on other planets? (viewed 35566 times)
Could someone travel the universe in his or her own lifetime? (viewed 35554 times)
Is the Great Wall the largest galaxy cluster? (viewed 35485 times)
What is the speed of gravity? (viewed 35276 times)
How does night and day work? (viewed 35253 times)
How does Astronomy involve Chemistry? (viewed 35201 times)
Where is the supernova remnant that led to our solar system? (viewed 35019 times)
Is there a "South Star"? (viewed 34891 times)
Is there really a 10th planet? (viewed 34295 times)
What is the typical size of a visible shooting star? (viewed 34264 times)
What is the best way to see the Milky Way? (viewed 34228 times)
What is Earthrise over the Moon? (viewed 34165 times)
How do I tell which planet is which? (viewed 34052 times)
How much can the location of sunset differ from due West? (viewed 34048 times)
What are "blue stragglers" in globular clusters? (viewed 34021 times)
Can I communicate faster than light? (viewed 34017 times)
If a white dwarf is a "dead" star, why is it so hot? (viewed 33997 times)
What if the Earth rotated twice as fast? (viewed 33835 times)
What is a dimension? (viewed 33834 times)
How many stars can I see? (viewed 33821 times)
Why is sea water salty, and not lake water? (viewed 33817 times)
Can a person go into a black hole and come out alive? (viewed 33807 times)
What would happen to the Earth if an asteroid hit the Moon? (viewed 33585 times)
Is it possible to see the full Moon and the Sun simultaneously in high northern latitudes when the Sun doesn't set? (viewed 33355 times)
Why do people draw stars with five points? (viewed 33330 times)
How do we know that nuclear fusion is still going on in the Sun? (viewed 33315 times)
How long could life on Earth survive if the Sun stopped shining? (viewed 33279 times)
Why don't people walk upside-down on the bottom of the Earth? (viewed 33197 times)
What is the approximate GPA needed in High School in Math and Science to be an astronomer? (viewed 33095 times)
Can you see the future as you fall into a black hole? (viewed 32995 times)
Do the Sun's or Earth's magnetic field reverse? (viewed 32966 times)
What was that really big falling star that I saw? (viewed 32832 times)
Does the Coriolis force determine which way my toilet drains? Does it affect black holes? (viewed 32809 times)
Can we find the place where the Big Bang happened? (viewed 32732 times)
Is Andromeda part of the Milky Way? Where can I find them in the sky? (viewed 32686 times)
Where do planetary rings come from, and what are they made of? (viewed 32391 times)
Did life originate on Earth, or did it come from somewhere else? (viewed 32378 times)
Why have star signs shifted by one constellation? (viewed 32342 times)
How can I find my age on another planet? (viewed 32270 times)
Are all stars the same? (viewed 32232 times)
What companies or businesses can astronomers work for? (viewed 32232 times)
How do we feel heat? (viewed 32218 times)
Why are most months 30 or 31 days long? (viewed 32087 times)
What are the names of the three stars in Orion's belt? (viewed 31999 times)
If the universe is 15 billion years old, how can it be larger than 15 billion light years across? (viewed 31865 times)
Are Earth and the Moon "twin planets"? (viewed 31759 times)
On which days can I see the Moon in the evening / morning and why is this so? (viewed 31750 times)
When we look back to the Big Bang, why don't we see the universe as a tiny speck of matter? (viewed 31656 times)
How fast does the Earth go at perihelion and aphelion? (viewed 31544 times)
Is there a simple formula to calculate solar eclipse timings from any position on Earth? (viewed 31394 times)
Why don't astronomers use everyday units to measure distances (what is an AU or a pc)? (viewed 31385 times)
Does the Sun have an iron surface? (viewed 31295 times)
How can we estimate the number of Earth-like planets in the Galaxy? (viewed 31200 times)
How do we determine the age of the universe? (viewed 31165 times)
Can we colonize other planets? (viewed 31056 times)
Is there a beginning and an end to a galaxy's life? (viewed 31037 times)
Why are Saturn's rings flat? (viewed 30994 times)
Is the Earth at the centre of the Universe? (viewed 30947 times)
Which American colleges teach astronomy? (viewed 30936 times)
Who (and when) discovered that the earth's axis is on a 23 degree tilt? (viewed 30879 times)
Why is our solar system so different from all the others we've found? (viewed 30874 times)
Who came up with the name "black hole"? (viewed 30868 times)
Will the Moon be invisible in 500 million years? (viewed 30852 times)
What is the pattern to the distances between each planet and the sun? (viewed 30669 times)
How is it that we see farther out in space (farther back in time) than in the past? (viewed 30647 times)
How dangerous are the asteroids? (viewed 30562 times)
What would happen if two stars collided? (viewed 30429 times)
How does the brightness of a star depend on its distance from us? (viewed 30320 times)
How can I calculate distances between stars? (viewed 30311 times)
What is the significance of the second focus of elliptical orbits of planets in our Solar System? (viewed 30242 times)
How do we define distance in an expanding universe? (viewed 30224 times)
What are quasars made of? (viewed 30138 times)
Is time travel possible using merging black holes? (viewed 30085 times)
Is it possible to count the stars? (viewed 30039 times)
Why is Uranus tipped on its side? (viewed 29961 times)
How do astronauts communicate with their families from space? (viewed 29927 times)
Why do humans want to go in space? (viewed 29916 times)
Can a lunar and a solar eclipse happen in the same month? When will this happen next? (viewed 29841 times)
Why doesn't gravity change the speed of light? (viewed 29773 times)
What is happening just around the black hole in the center of the Milky Way? (viewed 29647 times)
How do we know the Milky Way is a spiral galaxy? (viewed 29414 times)
Do you think it's possible to maintain life on other planets? (viewed 29411 times)
Will we ever stop having solar eclipses because of the moon's motion away from the Earth? (viewed 29301 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 29195 times)
Is the Sun always up for exactly 12 hours at the equator? (viewed 29192 times)
How are planets detected around other stars? (viewed 29139 times)
Why can we see the sun's image before sunrise and after sunset? (viewed 28959 times)
Why do constellations look the same after several years even though all the stars are moving? (viewed 28903 times)
Did the speed of light change over the history of the universe? (viewed 28834 times)
Are time machines possible? (viewed 28654 times)
Is there any limitation to what a black hole can "suck" in? (viewed 28643 times)
How do I become both an astronaut and an astronomer? (viewed 28639 times)
How do we measure distances to other stars? (viewed 28628 times)
Why do clocks turn in the opposite direction from the Earth and Moon? (viewed 28615 times)
Can we see dead stars with the naked eye? (viewed 28605 times)
How many moles of stars are in the known universe? (viewed 28468 times)
How big a change in the Earth's orbit would be required to destroy all life? (viewed 28456 times)
What is dark matter? (viewed 28436 times)
Why do astronauts in space need to exercise? (viewed 28248 times)
What's that dark spot on the Sun? (viewed 28137 times)
Is the gravitational force exerted by the Earth on the Moon equal to the centripetal force acting on the Moon? (viewed 28060 times)
How are photons created and destroyed? (viewed 27975 times)
Can superheavy elements (such as Z=116 or 118) be formed in a supernova? Can we observe them? (viewed 27809 times)
Why are there no craters on Earth? Did all the meteorites miss us? (viewed 27729 times)
Could an astronaut or satellite fall into a black hole that we didn't know about? (viewed 27664 times)
How are galaxy distances inferred from their recessional velocities? (viewed 27631 times)
What are the closest and/or brightest stars? (viewed 27565 times)
How do I make a scale model of the Solar System? (viewed 27531 times)
What happens when an antimatter black hole collides with a matter blackhole? (viewed 27512 times)
Is it true that the Sun burns off a billion tons of gas every 5 seconds? (viewed 27496 times)
How can the universe be "flat"? We're 3D! (viewed 27396 times)
How do sunrise and sunset times change with altitude? (viewed 27375 times)
Did I see the Aurora Borealis as a child? (viewed 27349 times)
Has anyone made a map of the Milky Way? (viewed 27332 times)
Don't tachyons travel faster than light? (viewed 27328 times)
How can I tell if the rock I found is a meteorite? (viewed 27311 times)
What are the facts about the Star of Bethlehem? (viewed 27088 times)
What are the atmospheres of Mars and Pluto like? (viewed 27021 times)
Was I hit by a meteorite? (viewed 26883 times)
Why do most moons orbit their planets at the equator? (viewed 26852 times)
What kind of eyepieces do I need to look at planets? (viewed 26851 times)
How are galaxies named? (viewed 26839 times)
Is the universe really like an expanding balloon? (viewed 26827 times)
Why does the SETI project search for radio signals? (viewed 26583 times)
Do astronomers believe in astrology? (viewed 26520 times)
How can geometry be different in space? (viewed 26371 times)
Will winter and summer constellations change due to abnormal warmth or cold on Earth? (viewed 26362 times)
Will the seasons change due to precession? (viewed 26328 times)
Aren't jobs in astronomy scarce? (viewed 26324 times)
Can astronauts produce water in space? (viewed 26294 times)
What does the term "visible universe" mean? (viewed 26269 times)
How will the two black holes that are going to collide affect Earth? (viewed 26227 times)
How can we know that there are other galaxies if we cannot leave ours? (viewed 26179 times)
What colors are visible through an amateur telescope? (viewed 26164 times)
What happens when you change the mass of a White Dwarf or Neutron Star? (viewed 26162 times)
How long does it take the Big Dipper to move in the sky? (viewed 26080 times)
When are there 5 Sundays in February? (viewed 26075 times)
Why are there blue shifted galaxies? (viewed 26034 times)
Can life exist on the recently discovered extrasolar planets? (viewed 25999 times)
Wouldn't the Big Bang theory be considered a hypothesis and not a theory? (viewed 25986 times)
Why do we study black holes? (viewed 25975 times)
What is the farthest in space that we have gone? (viewed 25968 times)
Have there been other Big Bangs before? (viewed 25962 times)
How much time do astronomers spend looking through telescopes? (viewed 25701 times)
How close do you have to come to the Earth to be influenced by its gravity? (viewed 25604 times)
How do asteroids, meteors and comets disappear? (viewed 25561 times)
How was the starting point for the Julian Date system chosen? (viewed 25526 times)
Is the Milky Way a collision of two galaxies? (viewed 25512 times)
Do you believe in UFOs? (viewed 25444 times)
Why are the compositions of comets and asteroids different? (viewed 25430 times)
Can you use an infinite line of reflectors to send light to the edge of the Universe? (viewed 25324 times)
How can we measure distances to more stars? (viewed 25230 times)
Do we know everything about the Sun? (viewed 25150 times)
How are galaxies and solar systems similar? (viewed 25149 times)
Is infinite temperature possible? (viewed 25122 times)
How can we see galaxies if their stars are so faint? (viewed 25089 times)
Could you tell me about the life cycle of galaxies? (viewed 25021 times)
How do scientists slow light down? (viewed 25002 times)
Why is the time between two successive full moons different from the lunar synodic month? (viewed 24998 times)
How far does a galaxy extend? (viewed 24948 times)
Is there a project I can do on black holes? (viewed 24908 times)
How do we know if the universe will keep expanding forever? (viewed 24906 times)
Could you escape from a black hole if you were able to go faster than the speed of light? (viewed 24893 times)
Is there such a thing as hyperspace? (viewed 24858 times)
How do I explain to my children why the Moon has phases? (viewed 24849 times)
Can one star orbit another? (viewed 24788 times)
What's the best thing about being an astronomer? (viewed 24766 times)
Why do the explosions of Type Ia supernovae have a more predictable spectrum than those of regular Type II supernovae? (viewed 24745 times)
Can "tired light theory" explain the observed redshifts of galaxies? (viewed 24740 times)
How close does a supernova need to be to damage the Earth's environment? (viewed 24726 times)
How do I polar align my telescope? (viewed 24674 times)
What do "homogeneity" and "isotropy" mean? (viewed 24649 times)
What happens to the material that has been sucked into a black hole? (viewed 24577 times)
How will a change in the speed of light affect the evolution of the Universe? (viewed 24492 times)
What is the farthest Northern Latitude in which the Magellanic Clouds can be seen? (viewed 24400 times)
Is it worthwhile to continue the search for extraterrestrial life? (viewed 24390 times)
Can two lunar eclipses occur in the same month? (viewed 24380 times)
What type of energy does a black hole have? (viewed 24358 times)
Do the magnitudes and colors of stars ever change? (viewed 24350 times)
What supernova created the Crab nebula? (viewed 24336 times)
How do we know what parameters to use when simulating the collision of the Milky Way and Andromeda? (viewed 24151 times)
What will happen to the Milky Way in the future? (viewed 24096 times)
What is sidereal time? (viewed 24049 times)
Can double stars have planets? (viewed 24046 times)
Which way does the sun travel in the southern hemisphere? (viewed 24041 times)
How do we know that sunspots are associated with the Sun's magnetic field? (viewed 23986 times)
What is a Dyson Sphere? (viewed 23979 times)
Can astronauts play musical instruments in space? (viewed 23960 times)
Was Stonehenge built to mark solar phenomena? (viewed 23922 times)
How hot is each one of the layers of the sun? (viewed 23910 times)
Why do so many of the world's UFO sightings happen in America? (viewed 23858 times)
How do astronomers measure the radius of a star? (viewed 23828 times)
What's so exciting about the new planet around 55 Cancri? (viewed 23763 times)
Are there any dark stars or dark galaxies made of dark matter? (viewed 23727 times)
Did a giant impact cause the Dark Ages? (viewed 23663 times)
Have gravitational waves been proven to exist? (viewed 23618 times)
Why do we assume that the universe is homogeneous? (viewed 23607 times)
What's the object I saw that moved across the sky and then got very bright? (viewed 23596 times)
Is there a list of the sizes of different kinds of stars? (viewed 23577 times)
Can you describe a day on the job as an astronomer? (viewed 23537 times)
What process would bring about a quark star? (viewed 23501 times)
What causes gamma ray bursts? (viewed 23463 times)
Why are there active volcanos on Io? (viewed 23386 times)
When unmanned spacecraft accelerate in space, what causes them to slow down? (viewed 23327 times)
What calculations go into predicting eclipses? (viewed 23217 times)
Is there sound coming from the Sun? (viewed 23195 times)
Is there any possibility that the Solar System or the Universe is in a black hole? (viewed 23178 times)
How different would the night sky have looked in 40,000 B.C.? (viewed 23170 times)
How many sunspots can the Sun have at once? (viewed 23127 times)
How big was the Sun when it first "fired up"? (viewed 23086 times)
If we invented special suits could we ever go to the sun? (viewed 23000 times)
Is there oxygen in the atmospheres of other planets? (viewed 22967 times)
Why did the Pioneer and Voyager take only 2 years to reach Jupiter, while Galileo and Cassini took more than 5 years? (viewed 22958 times)
Can I see a quasar? (viewed 22926 times)
Could we be seeing dead stars? (viewed 22921 times)
Why is the shadow on the Moon the shape it is? (viewed 22899 times)
Does Cerenkov radiation travel faster than light? (viewed 22873 times)
How can we tell what the interiors of planets are like? (viewed 22792 times)
Why do photos of space taken from space never show any stars? (viewed 22711 times)
How can we compare dark matter and dark energy? (viewed 22634 times)
Why is the Hubble Space Telescope in space? (viewed 22621 times)
What is "nothing", from a scientific point of view? (viewed 22603 times)
How do we know that superclusters are the largest structures in the universe? (viewed 22601 times)
How is it proved that the Universe is expanding? (viewed 22573 times)
Can any comparison be made between spiral galaxies and hurricanes? (viewed 22570 times)
What is the origin of the stellar classification system "OBAFGKM"? (viewed 22565 times)
What is the difference between homogeneity and isotropy? (viewed 22514 times)
What is a Cepheid variable? (viewed 22504 times)
How do solar flares affect airline pilots? (viewed 22494 times)
If clocks run slow in a gravitational field, how can we know the true age of the Solar System and Universe? (viewed 22488 times)
What equipment do I need for astrophotography? (viewed 22486 times)
How are sunspots formed? (viewed 22443 times)
What happened to all the black holes that were around in the early universe? (viewed 22385 times)
Why doesn't light from distant galaxies reach us instantaneously? (viewed 22369 times)
Do asteroids hit the sun? (viewed 22351 times)
How are asteroid compositions and classifications determined? (viewed 22318 times)
What caused Shoemaker-Levy 9 to split up? (viewed 22317 times)
Can I see details on Venus? (viewed 22298 times)
How powerful are quasars? (viewed 22288 times)
Could a different theory of gravity explain the dark matter mystery? (viewed 22275 times)
Could we send a space mission to a comet? (viewed 22254 times)
How long do supernova remnants last? (viewed 22221 times)
Which part of the sky did the famous 'wow' signal originate from? (viewed 22220 times)
How many comets are currently orbiting our sun? (viewed 22214 times)
As the universe expands, why don't galaxies get stretched out? (viewed 22203 times)
Would extraterrestrial civilizations know that there is life on Earth? (viewed 22200 times)
Can the acceleration of the Universe be analogous to apparent acceleration in a airplane? (viewed 22141 times)
Can you tell time by the Big Dipper? (viewed 22124 times)
What is our galaxy's halo made of, and how was it formed? (viewed 22070 times)
Can supernovae hinder the formation of life in galaxies? (viewed 22044 times)
How does the Earth compare in size to the entire universe at the present epoch? (viewed 22016 times)
When did people discover that the Sun is a star? (viewed 21907 times)
How is the Cepheid yardstick validated? (viewed 21831 times)
Is the Local Group expanding along with the entire Universe? (viewed 21823 times)
What would happen if there was a collision between two white dwarfs? (viewed 21820 times)
Are planetary nebulae the result of supernovae? (viewed 21813 times)
Why are there more maria on the near side of the Moon? (viewed 21785 times)
Would the biggest airplanes cause tsunamis if they crashed? (viewed 21784 times)
How do planets capture satellites? (viewed 21773 times)
Do we see the same stars from above and below the equator? (viewed 21751 times)
What happened to the girl who named Pluto? (viewed 21728 times)
Why are stars of different masses? (viewed 21727 times)
What kind of instruments are used to detect extrasolar planets? (viewed 21635 times)
Why are telescopes kept in cold conditions? (viewed 21624 times)
Can you give me advice on buying a telescope? (viewed 21600 times)
If the Universe was infinitely dense at the Big Bang, why didn't time stand still? (viewed 21576 times)
Can I build an instrument to measure the size of the Sun and of the Moon? (viewed 21553 times)
Why doesn't NASA build rotating spacecraft to simulate gravity? (viewed 21547 times)
Do unmanned spacecraft like Voyager travel in straight lines? (viewed 21476 times)
Are there any new craters on the moon? (viewed 21471 times)
Do similar laws of physics throughout the Universe imply that all life must be like life on Earth? (viewed 21470 times)
Are the properties of extrasolar planets known? (viewed 21424 times)
Where does the kinetic energy of infalling bodies come from? (viewed 21390 times)
Does the Milky Way spin counter-clockwise? If so, do all spiral galaxies spin in this direction and why? (viewed 21371 times)
How do I become an astronomical artist? (viewed 21251 times)
What month was it when Odysseus saw Orion in 1000BC? (viewed 21240 times)
Did I really hear a meteor? (viewed 21124 times)
What kind of telescope should I use for astrophotography? (viewed 21112 times)
Can the theory of formation of the solar system explain all the observables? (viewed 21112 times)
How can you tell if a crescent moon is preceding or following a new-moon phase? (viewed 21046 times)
Do galaxies orbit around anything? (viewed 21035 times)
What is the solar cycle? (viewed 21030 times)
Could there have been multiple Big Bangs at different places in the universe? (viewed 20963 times)
Did time go slower just after the Big Bang? (viewed 20957 times)
Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating? (viewed 20855 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 20848 times)
Why is NASA shutting down the Hubble Space Telescope? (viewed 20847 times)
Does the Sun have any heavy elements? (viewed 20818 times)
Will we discover an 11th planet? What would it be called? (viewed 20790 times)
Can I listen to the SETI@home radio signal? (viewed 20771 times)
Why does one side of Mars look more catastrophic than the other? (viewed 20769 times)
How are astronomy and poetry linked? (viewed 20765 times)
Why does the apparent density of galaxies drop off at larger distances? (viewed 20712 times)
What makes a satellite geosyncronise itself with Earth's orbit? (viewed 20642 times)
Can a black hole come back to the visual universe through a "little bang"? (viewed 20629 times)
How could galaxies have gotten so far away in only 15 billion years? (viewed 20575 times)
Can other terrestrial moons be (or have been) stable? (viewed 20550 times)
Would a planet near the galactic center have a brighter night sky? (viewed 20494 times)
What class of spiral galaxy is the Milky Way? (viewed 20486 times)
How are supernovae discovered? (viewed 20486 times)
Why is it important to study meteorites? (viewed 20482 times)
Does inflation allow for an infinite number of universes? (viewed 20456 times)
Why are telescopes located in remote places? (viewed 20423 times)
Why was the Platonic year named after Plato? (viewed 20392 times)
Is it possible for amateurs to do optical interferometry? (viewed 20359 times)
Could our position in the universe affect our perceptions of the expansion? (viewed 20340 times)
What would the Big Crunch look like to an observer on Earth? (viewed 20205 times)
What is meant by "stopping down a telescope"? (viewed 20098 times)
How can I contribute to science as an amateur astronomer? (viewed 20071 times)
Does a photon observe other photons moving past it at the speed of light? (viewed 20060 times)
Why doesn't the hydrogen on Jupiter explode? (viewed 20037 times)
Do the Earth's magnetic poles ever change places? (viewed 20000 times)
Do stars' orbits in galaxies obey Kepler's Laws? (viewed 19954 times)
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background? (viewed 19760 times)
Are the asteroids the remains of a planet which broke apart? (viewed 19687 times)
Where was the water in the big bang? (viewed 19679 times)
Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations? (viewed 19629 times)
What's new with the Big Bang? (viewed 19615 times)
Why do some eclipses take longer than others? (viewed 19555 times)
Did I find a rock that came from the Moon? (viewed 19534 times)
Can a human give birth in space? (viewed 19528 times)
What is the SU(3) quark model? (viewed 19526 times)
Why search for only Earth-like life on other planets? (viewed 19509 times)
Could we send a manned mission to the outer planets? (viewed 19485 times)
Is it possible to build a cheap device to measure declination? (viewed 19415 times)
Why are accretion disks flat? (viewed 19411 times)
How big is the Hubble Ultra Deep Field image? (viewed 19364 times)
Where can I find information on the moons of other planets? (viewed 19326 times)
Why can't relative velocities add up to more than the speed of light? (viewed 19304 times)
Could photons be dark matter? (viewed 19300 times)
Why is the Cosmic Microwave Background not absorbed by interstellar hydrogen? (viewed 19228 times)
Will I be able to see the shadow of the Moon streaking towards me in a total solar eclipse? (viewed 19199 times)
If comets are boiling away, why are there any left? (viewed 19122 times)
Why is pressure broadening greater in low mass stars than in high mass stars? (viewed 19117 times)
How do astronomers observe the Sun's interior? (viewed 19104 times)
How fast do particles travel in space? (viewed 19063 times)
How do astronomers come up with their facts? (viewed 19050 times)
Why aren't discoveries of extrasolar planets reported on the news? (viewed 19035 times)
What are the boundaries of the constellations? (viewed 19023 times)
What would an "open geometry" for the universe look like? (viewed 18983 times)
How can the Sun have such a strong gravitational field if it's made of gasses? (viewed 18895 times)
How can we find galaxies behind the Milky Way? (viewed 18895 times)
Can the Space Shuttle abort and return to Earth before reaching orbit? (viewed 18806 times)
How do bars form in spiral galaxies? (viewed 18780 times)
Why don't astronauts sublimate in space? (viewed 18731 times)
How do unmanned space probes avoid running into things? (viewed 18683 times)
Do electrons age? (viewed 18676 times)
How much power is contained in a beam of light? (viewed 18671 times)
Did the Sumerians measure precession? (viewed 18642 times)
Can HST see the Oort cloud? (viewed 18625 times)
Can we make a movie of the Milky Way galaxy's rotation? (viewed 18567 times)
What kinds of star clusters are there? (viewed 18532 times)
Does the shuttle worry about space junk? (viewed 18502 times)
Why do supernova remnants look like rings rather than spheres? (viewed 18470 times)
How do photons from distant objects maintain enough energy to reach us? (viewed 18390 times)
Why can we have solar eclipses? (viewed 18351 times)
How long is twilight on the Moon? (viewed 18345 times)
What is the best time of the year to see eclipses? (viewed 18254 times)
Why doesn't SETI concentrate its observations to the nearby stars and the solar systems that we are discovering? (viewed 18159 times)
How can water be chemically trapped in rocks? (viewed 18122 times)
Why do spacecraft need heat shields coming back to Earth but not leaving? (viewed 18114 times)
How do you classify galaxies? (viewed 18028 times)
Will the next generation telescope OWL be able to detect an Earth like extrasolar planet? (viewed 18027 times)
Where can I see Newton's original reflecting telescope? (viewed 18015 times)
What was that eclipse I saw in the sky? (viewed 17971 times)
Is light of different colors affected differently by gravity? (viewed 17860 times)
Why is the WMAP picture of the CMB an ellipse? (viewed 17806 times)
How can we understand the meaning of large numbers like "a million million?" (viewed 17800 times)
How long has humanity known that we live in a galaxy similar to others in the Universe? (viewed 17789 times)
What causes a particle to decay? (viewed 17787 times)
What are "curled" dimensions? (viewed 17765 times)
Can astronomers observe anything when the moon is full? (viewed 17731 times)
How did Mars get so dusty? (viewed 17717 times)
How does melting a material reset its radioactive clock? (viewed 17715 times)
How does interferometry work? (viewed 17595 times)
How do we find out about the star formation histories of galaxies? (viewed 17589 times)
Will the Leonid meteor shower go away? (viewed 17574 times)
How can I nominate myself for a Nobel Prize in Physics? (viewed 17534 times)
Will astronauts ever be able to go ice-skating on Europa? (viewed 17531 times)
Does the temperature of matter increase as it is accelerated to relativistic speeds? (viewed 17516 times)
How do distant galaxies differ from those nearby? (viewed 17423 times)
Can you tell me the characteristics of W, R, N and S type stars? (viewed 17257 times)
Do we really observe the edges of galaxies at different epochs? (viewed 17252 times)
Wouldn't the vast distances of space distort SETI signals into unintelligeble forms? (viewed 17223 times)
What do stellar classifications mean? (viewed 17111 times)
What kind of interference must astronomers contend with when observing? (viewed 16954 times)
Will the diameter of a cluster of galaxies change with redshift? (viewed 16925 times)
Why don't all neutron stars become pulsars? (viewed 16910 times)
How can I watch the Perseid meteor shower? (viewed 16853 times)
Why will fusion wait until hydrogen is gone before starting to fuse heavier atoms? (viewed 16839 times)
What is the three-body problem? (viewed 16650 times)
How are astronauts trained for weightlessness? (viewed 16635 times)
If the universe is "bounded" today, could it one day become "unbounded"? (viewed 16633 times)
Is cosmic expansion happening on microscopic scales? (viewed 16631 times)
Do asteroids ever do anything good in the Solar System? (viewed 16615 times)
How can I find out if the new moon has been sighted? (viewed 16611 times)
Do constellations looks the same from space? (viewed 16606 times)
Do we have to worry about relativity when studying galactic objects? (viewed 16554 times)
What would happen if you went back in time and killed your grandmother? (viewed 16392 times)
Why is it called astronomy when all the other sciences end in -ology? (viewed 16318 times)
Why aren't accretion disks around giant stars as hot as accretion disks around black holes? (viewed 16290 times)
How does a star take mass from another star? (viewed 16250 times)
What are collections of galaxies called? (viewed 16210 times)
How can you tell the difference between single and multiple extrasolar planets? (viewed 16020 times)
What kinds of cancer research have been done in space? (viewed 15975 times)
What would happen if a human were exposed to space without wearing a spacesuit? (viewed 15897 times)
Could neutrinos be dark matter? (viewed 15892 times)
What is Hot Dark Matter theory? (viewed 15752 times)
How does libration allow us to see more than 50% of the Moon? (viewed 15567 times)
If nothing can escape a black hole, why do some black holes have jets? (viewed 15560 times)
How does the color index of a star relate to its actual color? (viewed 15424 times)
Do binary or triple star systems form together? (viewed 15339 times)
How can observations of the distant universe prove that the expansion is accelerating *now*? (viewed 15317 times)
Could the Universe's dark matter be made up of black holes? (viewed 15277 times)
Is light blueshifted when it is gravitationally lensed? (viewed 15214 times)
No matter how fast the universe is expanding, shouldn't gravity eventually make it recollapse? (viewed 15165 times)
What percent of the time can astronomers observe without interference from the Moon? (viewed 15127 times)
Are black holes spherical? (viewed 14753 times)
Could matter-anti-matter repulsion power the expansion of the universe? (viewed 14745 times)
Does lunar gardening really work? (viewed 14668 times)
Is it a coincidence that we can have total solar eclipses? Are there other planets which also have them? (viewed 14617 times)
What is the photoelectric effect? Why can't multiple low-frequency photons free an electron? (viewed 14543 times)
Why is it easier to see a star if you look slightly to the side? (viewed 14533 times)
Can planets collide with one another? (viewed 14513 times)
What do meteorites tell us about life on other planets? (viewed 14480 times)
Are there any 'lonely galaxies'? (viewed 14272 times)
Why doesn't the ammonia and methane in Jupiter's atmosphere sink into the core? (viewed 14130 times)
Is the green flash real? (viewed 13863 times)
How do we know the density of some extrasolar planets? (viewed 13845 times)
During close approaches, can Mars appear in our sky as large as the Moon? (viewed 13740 times)
How are planets affected by the Hot Ionised Medium? (viewed 13538 times)
What was different on Mars in the past to allow liquid water to be present? (viewed 13421 times)
How do we detect incoming meteorites? (viewed 13267 times)
If the sun went out and our atmosphere froze solid, what color would it be? (viewed 13139 times)
Can we prove that the Moon isn't hollow? (viewed 13124 times)
When measuring the expansion of the universe, do astronomers consider that they're seeing how galaxies moved long ago, not today? (viewed 13116 times)
How can we discern different galaxies/clusters along the same line of sight? (viewed 13074 times)
Why was Mir burnt up in the atmosphere? (viewed 12934 times)
What are the largest radio wavelengths observed from radio sources in the sky? (viewed 12903 times)
What is the relationship between the width of a star trail on a photo and the star's intensity? (viewed 12684 times)
Why can't a plane fly slowly and let the Earth pass underneath? (viewed 12516 times)
How do supernovae show us that the Universe's expansion is accelerating? (viewed 12178 times)
Has anyone ever seen a star "turn on"? (viewed 12133 times)
When will Hale-Bopp return? (viewed 12013 times)
Can the sun rise from the west on Mars? (viewed 12004 times)
Why don't skydivers burn up like meteors? (viewed 11799 times)
Can we harvest H & O from space to make water? (viewed 10901 times)
Why are craters round? (viewed 10843 times)
Does weightlessness affect hunger? (viewed 10754 times)
What is between the Oort cloud and the closest star? (viewed 10681 times)
How has light from 13 billion years ago not passed us by? (viewed 10282 times)
Could a planetary system survive if its star merged with another, or if its star went supernova? (viewed 10166 times)
Are there solar tides? (viewed 10005 times)
Why does Titan, in spite of being smaller than Mars, have an atmosphere more dense than Earth's? (viewed 9364 times)
Do planets radiate noise? (viewed 9306 times)
What would happen if a nuclear-powered shuttle exploded? (viewed 9140 times)
Does the Moon look different in the northern and southern hemispheres? (viewed 8938 times)
Is Earth-moon tidal friction causing global warming? (viewed 8795 times)
Did the Moon or planets form in a manner similar to that of Earth? (viewed 8581 times)
Is it sensible to consider terraforming Mars? (viewed 8231 times)
Is dark energy affected by black holes? (viewed 8125 times)
Do more meteorites fall at low latitudes? (viewed 8059 times)
Is the moon spherical? (viewed 8042 times)
If there are infinity universes, will every thing that is possible happen? (viewed 7932 times)
What happens to the helium formed in the sun? (viewed 7850 times)
Where is everybody? (viewed 7541 times)
If photons have zero mass, why do they feel the effects of gravity? (viewed 7536 times)
What are the possible ends of the universe? (viewed 7385 times)
Will Comet Elenin (C/2010 X1) affect the Earth on its close approach in Fall 2011? (viewed 7255 times)
Will the Pioneer and Voyager probes ever leave the Milky Way? (viewed 7113 times)
What color are meteors? (viewed 7006 times)
The naming of Mars (viewed 6594 times)
Why does Mars have a dusty atmosphere? (viewed 6591 times)
Does the singularity in a black hole create a new Universe? (viewed 6344 times)
If I were traveling through space, could I see distant galaxies with my own eyes? (viewed 6333 times)
When will humans travel to Mars and revisit the Moon? (viewed 6315 times)
Is the reddish dust of Mars biogenic? (viewed 6313 times)
Where is the Spitzer Space Telescope? (viewed 5921 times)
Wait, I'm still confused why information can't travel faster than the speed of light. (viewed 5829 times)
Why is the Moon higher in the sky in winter and lower in the summer? (viewed 5296 times)
Does the particles involved in a star's final core collapse travel faster than the speed of light? (viewed 5287 times)
What happens to the Earth as the moon gets farther away and will it ever go away entirely? (viewed 5265 times)
When is the best time to observe zodiacal light? (viewed 5218 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 5112 times)
Where are the protons and electrons in a Neutron Star? (viewed 5044 times)
Is the Moon always visible during winter on the North Pole? (viewed 4098 times)
How likely is it for a planet to transit its star? (viewed 3771 times)
What time is sunrise/sunset or moonrise/moonset at my location? (viewed 3238 times)
How did a transit of Venus provide astronomers with the first measurement of the Earth-Sun distance? (viewed 2938 times)
Can we hear sound on Titan? (viewed 2492 times)
Why do astronomers use telescopes? (viewed 2264 times)
Does the direction of the moon's crescent change through the night? (viewed 2005 times)
Cosmologists say the expansion of the universe is accelerating, what is driving this? (viewed 1899 times)
What causes the aurora? (viewed 1891 times)
What do all the angles in a table for a planet's orbit mean? (viewed 1874 times)
Can the Sun be closer to the Earth than any planet is to Earth? (viewed 1700 times)
How do I maximize my chances of seeing shooting stars? (viewed 690 times)
Are exoplanets real? (viewed 661 times)

URL: http://curious.astro.cornell.edu/list.php
This page has been accessed 1 time since June 19, 2013.
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.