All previously answered questions (in order of times viewed)

What's going to happen on December 21st 2012? (viewed 311177 times)
What color is each planet? (viewed 279469 times)
Is the Moon moving away from the Earth? When was this discovered? (viewed 249209 times)
How far is each planet from Earth? (viewed 213244 times)
How do I build a model rocket? (viewed 210836 times)
What is the life cycle of a star? (viewed 183447 times)
How many stars are there in our Galaxy (Milky Way)? (viewed 173933 times)
How do you measure the distance between Earth and the Sun? (viewed 170498 times)
What is the largest star? (viewed 167504 times)
What is a white hole? (viewed 154139 times)
What color is Venus? (viewed 142806 times)
Why do the planets orbit the sun? (viewed 128400 times)
Which planets have rings? (viewed 123620 times)
At what speed does the earth move around the sun? (viewed 122631 times)
What are the names of the earth, moon, sun, and solar system? (viewed 108848 times)
Is the distance from the Earth to the Sun changing? (viewed 106404 times)
What makes the Earth rotate? (viewed 104590 times)
Why do stars twinkle? (viewed 100341 times)
What do astronauts eat in space? Can they grow food? (viewed 95200 times)
Is Pluto a planet? (viewed 95187 times)
What is the universe expanding into? (viewed 93361 times)
Does the Moon rotate? Are there other moons that always keep one face toward their planet? (viewed 91457 times)
How long does it take for the Sun's light to reach us? (viewed 85509 times)
Why do planets rotate? (viewed 84140 times)
Where did the name 'Earth' come from? (viewed 82051 times)
Will the sun go supernova in six years and destroy Earth (as seen on Yahoo)? (viewed 81991 times)
What are shooting stars? (viewed 79910 times)
What is the largest galaxy? (viewed 77018 times)
Who named the planets and who decides what to name them? (viewed 76813 times)
Why are there both high and low tides? (viewed 75370 times)
How many known galaxies are there? (viewed 74072 times)
How critical is the Earth-Sun distance in maintaining our average temperatures on Earth? (viewed 64982 times)
How do we know the age of the Universe and the Earth? (viewed 63991 times)
What was there before the Big Bang and what is there outside of our universe? (viewed 63931 times)
How does the location of sunrise and sunset change throughout the year? (viewed 63082 times)
Is the Sun expanding? Will it ever explode? (viewed 61094 times)
When is the next comet due to arrive? (viewed 59909 times)
Can you hear sounds in space? (viewed 58778 times)
How many Earths fit into the Sun? (viewed 58087 times)
What would happen if an impact caused Earth to stop rotating? (viewed 57900 times)
Will the magnetic field of the Earth reverse its direction in the future? Will this cause problems? (viewed 57397 times)
Are there telescopes that can see the flag and lunar rover on the Moon? (viewed 56964 times)
Have astronomers discovered Earth's second moon? (viewed 55645 times)
What is the hottest time of day? (viewed 55231 times)
Did astronauts really go to the Moon, or is it a hoax? (viewed 55164 times)
When will Halley's Comet return? (viewed 54650 times)
What kind of rock is the moon made of? (viewed 54291 times)
What is apparent magnitude? (viewed 53048 times)
What would happen if we did not have a Moon? (viewed 53002 times)
What will happen to life on Earth when the Sun becomes a red giant? (viewed 52884 times)
How does the position of Moonrise and Moonset change? (viewed 52779 times)
How do stars move in the Galaxy? (viewed 51564 times)
What is the observational difference between a star and a planet? (viewed 51432 times)
What is at the end of the Universe? (viewed 50846 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 50384 times)
Can I buy a star? (viewed 49720 times)
Does the Sun orbit the Earth as well as the Earth orbiting the Sun? (viewed 49148 times)
Who has landed on the moon? (viewed 48958 times)
Is the universe expanding faster than the speed of light? (viewed 48569 times)
What is the physical difference between a star and a planet? (viewed 47078 times)
How long does a solar eclipse last? (viewed 47063 times)
Why is a day divided into 24 hours? (viewed 47011 times)
Can we feel the Earth spin? (viewed 46885 times)
How do astronauts take baths and use restrooms in space? (viewed 45164 times)
Does the Sun have a scientific name? (viewed 45081 times)
What happens when galaxies collide? (viewed 44698 times)
What direction do planets rotate? (viewed 44621 times)
Why aren't there any green stars? (viewed 44515 times)
Does the Sun move around the Milky Way? (viewed 44426 times)
How do you calculate the lifetime of the Sun? (viewed 44227 times)
Does the Sun rotate? (viewed 44079 times)
What is that ring (or rainbow) around the moon? (viewed 43659 times)
Why are the Moon and Sun sometimes orange or red? (viewed 43308 times)
How can I find the star I have "bought"? (viewed 43168 times)
Is there a proof that Earth moves? (viewed 42868 times)
How do rockets work? (viewed 42493 times)
Why do planets have elliptical orbits? (viewed 42203 times)
What causes seasons? (viewed 42131 times)
Why are stars and planets round? (viewed 42043 times)
Can artificial gravity be created in space? (viewed 41874 times)
What are the "dog days of summer"? (viewed 41420 times)
What is a singularity? (viewed 41259 times)
Where does the name "Milky Way" come from? (viewed 41101 times)
How much money do astronomers make? (viewed 41022 times)
How can we see the Milky Way if we are inside it? (viewed 40524 times)
How many constellations are there? (viewed 40449 times)
What are the advantages and disadvantages of using a telescope in space? (viewed 40319 times)
Do stars move in the sky? (viewed 40289 times)
Since Earth is spinning, why do we land in the same place when we jump or fall? (viewed 40196 times)
What elements make up the Sun? (viewed 40102 times)
What would happen if an asteroid 10 kilometers across hit the Earth? (viewed 39972 times)
What is a nova? (viewed 39747 times)
How are black holes made? Could one be made close to us? (viewed 39716 times)
How does the Sun compare to other stars? (viewed 39529 times)
What is the mass of the Universe? (viewed 39487 times)
How are light and heavy elements formed? (viewed 39390 times)
What is the largest structure in the universe? (viewed 38947 times)
Why doesn't the earliest sunset occur on the shortest day of the year? (viewed 38635 times)
Where did the Universe come from? (viewed 38462 times)
Why do airplanes take longer to fly West than East? (viewed 38137 times)
What are RA and DEC? (viewed 37695 times)
When can I see the Moon through the hole in the Pantheon? (viewed 37650 times)
Is time travel possible? (viewed 37556 times)
Why doesn't the length of each day change much around the solstices? (viewed 37437 times)
Why does the Earth have only one moon? (viewed 37388 times)
Who first measured the speed of light? (viewed 37291 times)
What is the size of the Solar System? (viewed 37226 times)
What's the best college for astronomy? (viewed 37118 times)
Which planet is most similar to Earth? (viewed 37104 times)
Does your weight change between the poles and the equator? (viewed 36549 times)
Is it possible to measure the temperature of the Sun? (viewed 36513 times)
What would happen if the gravity on Earth was suddenly turned off? (viewed 36442 times)
How much money is spent on space exploration? (viewed 36357 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 36196 times)
What would you see from inside a black hole? (viewed 36124 times)
Why is the Universe flat and not spherical? (viewed 35892 times)
Will the Sun become a black hole one day? (viewed 35292 times)
What happens to a substance if its speed is more than the speed of light? (viewed 35230 times)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (viewed 35204 times)
Traveling at light speed, how long would it take to get to the nearest galaxy? (viewed 35161 times)
How many stars are born and die each day? (viewed 35045 times)
What is the density of a black hole? (viewed 34956 times)
How do astronomers use math in their jobs? (viewed 34903 times)
Where are stars born? (viewed 34885 times)
Could there be life in the galaxies nearest to the Milky Way? (viewed 34866 times)
What are some astronomy science fair projects? (viewed 34720 times)
How often does the Sun pass through a spiral arm in the Milky Way? (viewed 34522 times)
Do most astronomers believe in God based on the available scientific evidence? (viewed 34520 times)
What would happen if a supermassive black hole came close to the Earth? (viewed 34270 times)
How do we know the mass of the Earth and the Moon? (viewed 33907 times)
Do black holes die? If so how? (viewed 33769 times)
How did the stars get named? (viewed 33754 times)
Does the Moon rotate? (viewed 33680 times)
If the universe is infinite does that mean there is an infinite number of "me"s? (viewed 33564 times)
Why isn't the summer solstice the hottest day of the year? (viewed 33510 times)
How are galaxies formed? (viewed 33375 times)
When was the last time all 9 planets were aligned? (viewed 33316 times)
What is the shape of the universe? (viewed 33164 times)
How can I find the distance to the Sun on any given day? (viewed 33122 times)
What kinds of jobs do astronomers do? (viewed 33116 times)
How does the parachute in a model rocket work? (viewed 32963 times)
What makes the wind? (viewed 32726 times)
When the Sun converts mass to energy, do the orbits of the planets change? (viewed 32666 times)
Are names given to black holes? (viewed 32365 times)
Are aliens or UFOs real? (viewed 31903 times)
What are constellations used for? (viewed 31781 times)
Are there any asteroids on a collision course with Earth? (viewed 31676 times)
Why do planets not twinkle? (viewed 31590 times)
Why do different stars appear with seasons? (viewed 31582 times)
What would happen to us if the sun went out for an hour? (viewed 31510 times)
Was the Sun made in a supernova? (viewed 31483 times)
Where does the name "Moon" come from? (viewed 31446 times)
What are black holes made of? (viewed 31414 times)
Does gravity vary across the surface of the Earth? (viewed 31350 times)
What are Altitude and Azimuth? (viewed 31228 times)
Considering the motion of the Earth, the solar system, and the galaxy, how fast am I moving while lying in bed asleep? (viewed 31211 times)
Why is the Moon so bright? (viewed 31156 times)
What is the biggest crater recorded on Earth? (viewed 31109 times)
How can the Universe expand faster than the speed of light during inflation? (viewed 31049 times)
How do astronomers measure the brightness of stars? (viewed 31029 times)
How long would it take the Earth to fall into the Sun? (viewed 31026 times)
What can I use for fuel in my homemade rocket? (viewed 30988 times)
Why is it difficult to understand the expansion of the universe? (viewed 30889 times)
Who discovered each planet? (viewed 30679 times)
What do astronauts do all day in the International Space Station? (viewed 30619 times)
Where, in relation to the entire universe, is the Milky Way located? (viewed 30581 times)
How did asteroids form and what is the difference between an asteroid and a comet? (viewed 30512 times)
If light has no mass, then what draws it into a black hole? (viewed 30511 times)
How can I measure the distance of a star? (viewed 30500 times)
How does the Moon stay "suspended" in the air? (viewed 30459 times)
Why hasn't NASA gone back to the moon? (viewed 30392 times)
How do astronauts use math in their jobs? (viewed 30040 times)
How do we measure the size of the Moon and of the Sun? (viewed 30026 times)
How do you calculate the azimuth and altitude of an object? (viewed 29847 times)
What's the difference between astronomy and astrology? (viewed 29522 times)
How do you measure a planet's mass? (viewed 29410 times)
What kind of schooling is necessary to become an astronomer? (viewed 29397 times)
What is time dilation? (viewed 29298 times)
How big is the universe? (viewed 29273 times)
Where is the nearest black hole? (viewed 29247 times)
Why does the Moon look big on the horizon? (viewed 29228 times)
Can you fire a gun on the Moon? (viewed 29092 times)
Can you see satellites? (viewed 29021 times)
What is the size of a black hole? (viewed 28863 times)
What happens when two black holes get too close? (viewed 28807 times)
Is the speed of light constant? (viewed 28792 times)
What do I need to do to become an astronomer? (viewed 28660 times)
Do dead stars still shine? (viewed 28584 times)
What other careers involve Astronomy besides Astronomer? (viewed 28446 times)
What would happen if Earth had more than one moon? (viewed 28369 times)
What are some of the effects of solar flares on Earth? (viewed 28366 times)
How is astronomy impacted by trigonometry? (viewed 28360 times)
Why does the Earth tilt back and forward once a year? (viewed 28260 times)
Where is the supernova remnant that led to our solar system? (viewed 28020 times)
How do you measure the mass of a star? (viewed 27877 times)
Can I buy land on the Moon? (viewed 27787 times)
How fast is the Universe expanding? (viewed 27777 times)
Why can't you see stars during the day? (viewed 27754 times)
Why does Barnard 68 appear dark? (viewed 27611 times)
Why does the Earth only see one side of the Moon? (viewed 27541 times)
What makes up most of the Universe? (viewed 27515 times)
What is the origin of spiral structure in galaxies? (viewed 27420 times)
How do rockets move in space? (viewed 27251 times)
How do gravitons escape black holes to tell the universe about their gravity? (viewed 27201 times)
Does Mt. Everest cast a shadow on the moon? (viewed 27134 times)
Would your weight change as you go underground? (viewed 27032 times)
Where did all the water in the universe come from? (viewed 26949 times)
Why do pictures of distant galaxies have higher resolution than those of nearby planets? (viewed 26877 times)
Why do all the planets orbit in the same plane? (viewed 26865 times)
What is the most distant known galaxy? (viewed 26757 times)
Can I calculate the size of the Universe by converting light years to kilometres? (viewed 26732 times)
Will we get sucked into the black hole at the center of the Milky Way? (viewed 26668 times)
Can we look back far enough in time to see the Big Bang? (viewed 26661 times)
How are elements heavier than iron formed? (viewed 26583 times)
Why is the moon in a different place every night? (viewed 26442 times)
How can two moons of Saturn share the same orbit? (viewed 26432 times)
What would happen if the Moon fell out of its orbit around Earth? (viewed 26402 times)
Why do the size and brightness of the full moon change? (viewed 26397 times)
Where did the matter in the universe come from? (viewed 26395 times)
Why do stars change colour when they twinkle? (viewed 26353 times)
How do galaxies collide in an expanding universe? (viewed 26325 times)
Can any galaxies be seen with the naked eye? (viewed 26092 times)
What is a star's "spectrum"? (viewed 25959 times)
Why do we see stars? (viewed 25930 times)
How many meteorites hit Earth each year? (viewed 25919 times)
What are the different kinds of astronomers? (viewed 25871 times)
What is a graviton? (viewed 25826 times)
What was that really big falling star that I saw? (viewed 25751 times)
How can I calculate the position or path of the Sun for a given time and location? (viewed 25727 times)
Why doesn't dark matter fall into a black hole? (viewed 25621 times)
What can we learn from the color of a star? (viewed 25539 times)
How are black holes discovered? (viewed 25519 times)
Is the Great Wall the largest galaxy cluster? (viewed 25434 times)
Why can't we see Venus at night when it is an inner planet? (viewed 25384 times)
What would happen to the Earth if an asteroid hit the Moon? (viewed 25353 times)
What is the difference between a "star" and a "sun"? (viewed 25322 times)
What's the biggest meteorite? (viewed 25314 times)
Why is sea water salty, and not lake water? (viewed 25205 times)
What is the speed of gravity? (viewed 25143 times)
How can a star burn with no oxygen? (viewed 25091 times)
How much longer will the Earth last? (viewed 25070 times)
How does light pollution affect astronomers? (viewed 24950 times)
Why is looking out the same as looking back in time? (viewed 24913 times)
Could someone travel the universe in his or her own lifetime? (viewed 24900 times)
How many stars can I see? (viewed 24844 times)
Do the Sun's or Earth's magnetic field reverse? (viewed 24843 times)
Why is twilight short near the equator? (viewed 24702 times)
Can terrestrial planets have rings? (viewed 24638 times)
Why does the location of sunrise change? (viewed 24464 times)
Which constellation does our Sun belong to? (viewed 24404 times)
How do I tell which planet is which? (viewed 24376 times)
Why are there stars? (viewed 24376 times)
What happens to a bullet fired on the moon? (viewed 24308 times)
How long has there been water on Earth? (viewed 24286 times)
How can I find my age on another planet? (viewed 24234 times)
What is the typical size of a visible shooting star? (viewed 24216 times)
Does quantum entanglement imply faster than light communication? (viewed 24212 times)
Is the Earth slowly getting larger? (viewed 24104 times)
What is Earthrise over the Moon? (viewed 24103 times)
Did life originate on Earth, or did it come from somewhere else? (viewed 24088 times)
Is the Moon hollow? (viewed 23984 times)
How does night and day work? (viewed 23956 times)
Is it possible to count the stars? (viewed 23934 times)
How can we estimate the number of Earth-like planets in the Galaxy? (viewed 23900 times)
Is time travel possible using merging black holes? (viewed 23896 times)
Why have star signs shifted by one constellation? (viewed 23861 times)
Is there really a 10th planet? (viewed 23856 times)
Do supermassive black holes cause galaxy rotation? (viewed 23848 times)
What is the evidence supporting the nebula theory of Solar System formation? (viewed 23795 times)
What's the difference between astronomy and astrophysics? (viewed 23764 times)
Is there a "South Star"? (viewed 23739 times)
How long does the supernova stage of a star last? (viewed 23706 times)
Why don't astronomers use everyday units to measure distances (what is an AU or a pc)? (viewed 23688 times)
Has there been an experiment that measured speed faster than the speed of light in vacuum? (viewed 23638 times)
What is the approximate GPA needed in High School in Math and Science to be an astronomer? (viewed 23625 times)
Is Andromeda part of the Milky Way? Where can I find them in the sky? (viewed 23625 times)
Does the Mediterranean sea have tides? (viewed 23617 times)
Does evolution contradict the second law of thermodynamics? (viewed 23571 times)
Which hemisphere has the best view of the Milky Way? (viewed 23560 times)
Does the Coriolis force determine which way my toilet drains? Does it affect black holes? (viewed 23257 times)
Why does the Sun's apparent path through the sky change throughout the year? (viewed 23251 times)
How close was the Moon to the Earth when it formed? (viewed 23208 times)
How can I calculate distances between stars? (viewed 23206 times)
Are meteorites hot or cold when they hit Earth? (viewed 23194 times)
Why is our solar system so different from all the others we've found? (viewed 23007 times)
Can moons have moons? (viewed 23007 times)
How would the weather on Earth be different if it were a cube? (viewed 22985 times)
Could the Universe have expanded faster than the speed of light at the Big Bang? (viewed 22931 times)
Is the Earth at the centre of the Universe? (viewed 22877 times)
Is it possible to see the full Moon and the Sun simultaneously in high northern latitudes when the Sun doesn't set? (viewed 22846 times)
When we look back to the Big Bang, why don't we see the universe as a tiny speck of matter? (viewed 22839 times)
What skills do astronomers need? (viewed 22749 times)
What is a dimension? (viewed 22709 times)
Can I communicate faster than light? (viewed 22691 times)
How long would it take for a mini-black hole to eat the Earth? (viewed 22638 times)
Can you see the future as you fall into a black hole? (viewed 22601 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 22577 times)
Which American colleges teach astronomy? (viewed 22556 times)
Why do we not have eclipses every month? (viewed 22495 times)
What are the closest and/or brightest stars? (viewed 22481 times)
Are all stars the same? (viewed 22374 times)
What is the pattern to the distances between each planet and the sun? (viewed 22343 times)
Why doesn't gravity change the speed of light? (viewed 22272 times)
If a white dwarf is a "dead" star, why is it so hot? (viewed 22235 times)
Is there any limitation to what a black hole can "suck" in? (viewed 22230 times)
How does the brightness of a star depend on its distance from us? (viewed 22163 times)
Can a person go into a black hole and come out alive? (viewed 22147 times)
How many moles of stars are in the known universe? (viewed 22147 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 22120 times)
Are time machines possible? (viewed 22078 times)
How is the time of sunrise calculated? (viewed 22074 times)
Can we colonize other planets? (viewed 22070 times)
What is happening just around the black hole in the center of the Milky Way? (viewed 21874 times)
What is the difference between the "Doppler" redshift and the "gravitational" or "cosmological" redshift? (viewed 21865 times)
How do we define distance in an expanding universe? (viewed 21733 times)
What would happen if you took off your helmet in space? (viewed 21689 times)
How dangerous are the asteroids? (viewed 21611 times)
What is the significance of the second focus of elliptical orbits of planets in our Solar System? (viewed 21545 times)
What are the requirements for being a planet? (viewed 21541 times)
How is it that we see farther out in space (farther back in time) than in the past? (viewed 21505 times)
Can a lunar and a solar eclipse happen in the same month? When will this happen next? (viewed 21500 times)
If the universe is 15 billion years old, how can it be larger than 15 billion light years across? (viewed 21489 times)
What happens to spacetime inside a black hole? (viewed 21406 times)
What is the difference between nutation and precession of the Earth? (viewed 21390 times)
Is there a simple formula to calculate solar eclipse timings from any position on Earth? (viewed 21379 times)
What companies or businesses can astronomers work for? (viewed 21375 times)
How do we know that nuclear fusion is still going on in the Sun? (viewed 21360 times)
Could an astronaut or satellite fall into a black hole that we didn't know about? (viewed 21281 times)
What's that dark spot on the Sun? (viewed 21269 times)
How does astronomy benefit humankind? (viewed 21259 times)
Are Earth and the Moon "twin planets"? (viewed 21244 times)
Can we find the place where the Big Bang happened? (viewed 21198 times)
How do I make a scale model of the Solar System? (viewed 21196 times)
How long could life on Earth survive if the Sun stopped shining? (viewed 21165 times)
How are galaxy distances inferred from their recessional velocities? (viewed 21138 times)
What's the difference between dark matter and dark energy? (viewed 21129 times)
How do we measure distances to other stars? (viewed 21048 times)
How will the two black holes that are going to collide affect Earth? (viewed 21033 times)
Why do people draw stars with five points? (viewed 20984 times)
How are galaxies named? (viewed 20895 times)
What are the facts about the Star of Bethlehem? (viewed 20892 times)
Did the speed of light change over the history of the universe? (viewed 20892 times)
The Moon slows the Earth's rotation, but how fast was it spinning billions of years ago? (viewed 20885 times)
Don't tachyons travel faster than light? (viewed 20794 times)
What are the atmospheres of Mars and Pluto like? (viewed 20786 times)
Are Kuiper Belt Objects asteroids? Are large Kuiper Belt Objects planets? (viewed 20726 times)
Was I hit by a meteorite? (viewed 20723 times)
Has anyone made a map of the Milky Way? (viewed 20696 times)
Will the Moon be invisible in 500 million years? (viewed 20667 times)
How do we weigh objects in space? (viewed 20663 times)
If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths? (viewed 20660 times)
What are quasars made of? (viewed 20654 times)
Have there been other Big Bangs before? (viewed 20636 times)
How big a change in the Earth's orbit would be required to destroy all life? (viewed 20613 times)
What do a galaxy's colors mean? Are they its true colors? (viewed 20530 times)
Are there eclipses on other planets? (viewed 20434 times)
Why do constellations look the same after several years even though all the stars are moving? (viewed 20398 times)
Who came up with the name "black hole"? (viewed 20374 times)
Will winter and summer constellations change due to abnormal warmth or cold on Earth? (viewed 20352 times)
Can life exist on the recently discovered extrasolar planets? (viewed 20327 times)
Why do most moons orbit their planets at the equator? (viewed 20214 times)
Aren't jobs in astronomy scarce? (viewed 20197 times)
How much time do astronomers spend looking through telescopes? (viewed 20153 times)
What is dark matter? (viewed 20085 times)
How close do you have to come to the Earth to be influenced by its gravity? (viewed 20042 times)
Where do planetary rings come from, and what are they made of? (viewed 19920 times)
How do I become both an astronaut and an astronomer? (viewed 19890 times)
How far does a galaxy extend? (viewed 19754 times)
What if the Earth rotated twice as fast? (viewed 19743 times)
Can we see dead stars with the naked eye? (viewed 19737 times)
How can I tell if the rock I found is a meteorite? (viewed 19602 times)
What would happen if two stars collided? (viewed 19580 times)
Why do the explosions of Type Ia supernovae have a more predictable spectrum than those of regular Type II supernovae? (viewed 19516 times)
Why don't people walk upside-down on the bottom of the Earth? (viewed 19492 times)
Can superheavy elements (such as Z=116 or 118) be formed in a supernova? Can we observe them? (viewed 19441 times)
Is the gravitational force exerted by the Earth on the Moon equal to the centripetal force acting on the Moon? (viewed 19430 times)
How do the astronauts communicate in space if sound cannot travel in a vacuum? (viewed 19424 times)
How will a change in the speed of light affect the evolution of the Universe? (viewed 19387 times)
Can one star orbit another? (viewed 19383 times)
How fast does the Earth go at perihelion and aphelion? (viewed 19347 times)
Can "tired light theory" explain the observed redshifts of galaxies? (viewed 19325 times)
What is a Dyson Sphere? (viewed 19270 times)
Do we know everything about the Sun? (viewed 19184 times)
Wouldn't the Big Bang theory be considered a hypothesis and not a theory? (viewed 19184 times)
How do we know what parameters to use when simulating the collision of the Milky Way and Andromeda? (viewed 19183 times)
How can we measure distances to more stars? (viewed 19174 times)
Is the Milky Way a collision of two galaxies? (viewed 19144 times)
How do astronauts communicate with their families from space? (viewed 19121 times)
Did I see the Aurora Borealis as a child? (viewed 19095 times)
Do you believe in UFOs? (viewed 19082 times)
How much can the location of sunset differ from due West? (viewed 19064 times)
Is the Sun always up for exactly 12 hours at the equator? (viewed 19047 times)
Is infinite temperature possible? (viewed 19027 times)
Why are the compositions of comets and asteroids different? (viewed 18998 times)
How can geometry be different in space? (viewed 18928 times)
How does Astronomy involve Chemistry? (viewed 18912 times)
Does the Sun have an iron surface? (viewed 18908 times)
Can astronauts produce water in space? (viewed 18850 times)
Is there such a thing as hyperspace? (viewed 18850 times)
Why isn't the sky bright at night if the universe has so many stars? (viewed 18825 times)
Will we ever stop having solar eclipses because of the moon's motion away from the Earth? (viewed 18796 times)
What's so exciting about the new planet around 55 Cancri? (viewed 18793 times)
Why does the SETI project search for radio signals? (viewed 18735 times)
How many Astronauts have been in space? (viewed 18713 times)
What does the term "visible universe" mean? (viewed 18703 times)
Why do photos of space taken from space never show any stars? (viewed 18695 times)
How do asteroids, meteors and comets disappear? (viewed 18671 times)
Will the seasons change due to precession? (viewed 18663 times)
How do we know that superclusters are the largest structures in the universe? (viewed 18641 times)
Do you think it's possible to maintain life on other planets? (viewed 18604 times)
What type of energy does a black hole have? (viewed 18592 times)
Why are there active volcanos on Io? (viewed 18551 times)
Can you use an infinite line of reflectors to send light to the edge of the Universe? (viewed 18548 times)
What is the farthest Northern Latitude in which the Magellanic Clouds can be seen? (viewed 18537 times)
Do the magnitudes and colors of stars ever change? (viewed 18537 times)
What's the object I saw that moved across the sky and then got very bright? (viewed 18503 times)
When unmanned spacecraft accelerate in space, what causes them to slow down? (viewed 18489 times)
How big was the Sun when it first "fired up"? (viewed 18481 times)
Is it true that the Sun burns off a billion tons of gas every 5 seconds? (viewed 18471 times)
Was Stonehenge built to mark solar phenomena? (viewed 18469 times)
Are there any dark stars or dark galaxies made of dark matter? (viewed 18414 times)
What supernova created the Crab nebula? (viewed 18390 times)
Have gravitational waves been proven to exist? (viewed 18381 times)
When are there 5 Sundays in February? (viewed 18376 times)
How do scientists slow light down? (viewed 18375 times)
Why do clocks turn in the opposite direction from the Earth and Moon? (viewed 18372 times)
Do astronomers believe in astrology? (viewed 18357 times)
How do we determine the age of the universe? (viewed 18355 times)
Who (and when) discovered that the earth's axis is on a 23 degree tilt? (viewed 18332 times)
Why does the Sun appear larger on the horizon than overhead? (viewed 18326 times)
How do we know the Milky Way is a spiral galaxy? (viewed 18274 times)
Why are Saturn's rings flat? (viewed 18229 times)
What happens when an antimatter black hole collides with a matter blackhole? (viewed 18192 times)
How can we know that there are other galaxies if we cannot leave ours? (viewed 18170 times)
What process would bring about a quark star? (viewed 18168 times)
Is there a project I can do on black holes? (viewed 18140 times)
Why are most months 30 or 31 days long? (viewed 18098 times)
Can astronauts play musical instruments in space? (viewed 18042 times)
Did a giant impact cause the Dark Ages? (viewed 18026 times)
Why do we assume that the universe is homogeneous? (viewed 17939 times)
Why do we study black holes? (viewed 17911 times)
Why do astronauts in space need to exercise? (viewed 17910 times)
How are planets detected around other stars? (viewed 17861 times)
What caused Shoemaker-Levy 9 to split up? (viewed 17851 times)
Which way does the sun travel in the southern hemisphere? (viewed 17811 times)
Can supernovae hinder the formation of life in galaxies? (viewed 17783 times)
Why is the shadow on the Moon the shape it is? (viewed 17773 times)
What are "blue stragglers" in globular clusters? (viewed 17772 times)
How are galaxies and solar systems similar? (viewed 17738 times)
Is it worthwhile to continue the search for extraterrestrial life? (viewed 17706 times)
How is it proved that the Universe is expanding? (viewed 17686 times)
How do planets capture satellites? (viewed 17643 times)
Why are there no craters on Earth? Did all the meteorites miss us? (viewed 17587 times)
What is sidereal time? (viewed 17584 times)
Why are stars of different masses? (viewed 17576 times)
How close does a supernova need to be to damage the Earth's environment? (viewed 17573 times)
What are the names of the three stars in Orion's belt? (viewed 17560 times)
Is there a list of the sizes of different kinds of stars? (viewed 17521 times)
What is the solar cycle? (viewed 17501 times)
What's the best thing about being an astronomer? (viewed 17474 times)
Does Cerenkov radiation travel faster than light? (viewed 17421 times)
Would extraterrestrial civilizations know that there is life on Earth? (viewed 17418 times)
Why is Uranus tipped on its side? (viewed 17387 times)
What happens to the material that has been sucked into a black hole? (viewed 17380 times)
What calculations go into predicting eclipses? (viewed 17374 times)
How long does it take the Big Dipper to move in the sky? (viewed 17330 times)
What would happen if there was a collision between two white dwarfs? (viewed 17295 times)
How can we see galaxies if their stars are so faint? (viewed 17274 times)
Could we send a space mission to a comet? (viewed 17234 times)
Could a different theory of gravity explain the dark matter mystery? (viewed 17233 times)
Why do humans want to go in space? (viewed 17223 times)
Why is the Hubble Space Telescope in space? (viewed 17211 times)
Is there sound coming from the Sun? (viewed 17155 times)
Why doesn't light from distant galaxies reach us instantaneously? (viewed 17154 times)
Why do so many of the world's UFO sightings happen in America? (viewed 17151 times)
Can two lunar eclipses occur in the same month? (viewed 17137 times)
How do solar flares affect airline pilots? (viewed 17132 times)
What happens when you change the mass of a White Dwarf or Neutron Star? (viewed 17129 times)
Are there stars outside of galaxies? (viewed 17126 times)
How do we know that sunspots are associated with the Sun's magnetic field? (viewed 17087 times)
What will happen to the Milky Way in the future? (viewed 17085 times)
If we invented special suits could we ever go to the sun? (viewed 17047 times)
How do I explain to my children why the Moon has phases? (viewed 17040 times)
How do I polar align my telescope? (viewed 17039 times)
How can we compare dark matter and dark energy? (viewed 17039 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 17036 times)
Can you tell time by the Big Dipper? (viewed 17026 times)
How different would the night sky have looked in 40,000 B.C.? (viewed 17012 times)
What kind of eyepieces do I need to look at planets? (viewed 17007 times)
Is there any possibility that the Solar System or the Universe is in a black hole? (viewed 16976 times)
As the universe expands, why don't galaxies get stretched out? (viewed 16943 times)
Could we be seeing dead stars? (viewed 16943 times)
Can double stars have planets? (viewed 16940 times)
Why is the time between two successive full moons different from the lunar synodic month? (viewed 16912 times)
What colors are visible through an amateur telescope? (viewed 16867 times)
Are the properties of extrasolar planets known? (viewed 16845 times)
How do we feel heat? (viewed 16766 times)
Why does one side of Mars look more catastrophic than the other? (viewed 16737 times)
Do similar laws of physics throughout the Universe imply that all life must be like life on Earth? (viewed 16734 times)
How do sunrise and sunset times change with altitude? (viewed 16721 times)
How powerful are quasars? (viewed 16710 times)
How are asteroid compositions and classifications determined? (viewed 16683 times)
How do we know if the universe will keep expanding forever? (viewed 16680 times)
What month was it when Odysseus saw Orion in 1000BC? (viewed 16626 times)
What is a wormhole? (viewed 16603 times)
Could our position in the universe affect our perceptions of the expansion? (viewed 16600 times)
How many comets are currently orbiting our sun? (viewed 16558 times)
Do unmanned spacecraft like Voyager travel in straight lines? (viewed 16547 times)
Are the planes of solar systems aligned with the plane of the Galaxy? (viewed 16484 times)
Could you escape from a black hole if you were able to go faster than the speed of light? (viewed 16466 times)
Can I see details on Venus? (viewed 16441 times)
What kind of telescope should I use for astrophotography? (viewed 16405 times)
Does inflation allow for an infinite number of universes? (viewed 16400 times)
What happened to all the black holes that were around in the early universe? (viewed 16355 times)
Can a black hole come back to the visual universe through a "little bang"? (viewed 16327 times)
Can I see a quasar? (viewed 16294 times)
What equipment do I need for astrophotography? (viewed 16286 times)
Where does the kinetic energy of infalling bodies come from? (viewed 16279 times)
Can any comparison be made between spiral galaxies and hurricanes? (viewed 16269 times)
Can the theory of formation of the solar system explain all the observables? (viewed 16259 times)
How many sunspots can the Sun have at once? (viewed 16237 times)
What kind of instruments are used to detect extrasolar planets? (viewed 16172 times)
How does the Earth compare in size to the entire universe at the present epoch? (viewed 16156 times)
How do I become an astronomical artist? (viewed 16082 times)
Can other terrestrial moons be (or have been) stable? (viewed 16059 times)
How long do supernova remnants last? (viewed 16057 times)
Why did the Pioneer and Voyager take only 2 years to reach Jupiter, while Galileo and Cassini took more than 5 years? (viewed 16044 times)
Does a photon observe other photons moving past it at the speed of light? (viewed 16037 times)
Why search for only Earth-like life on other planets? (viewed 15948 times)
Why does the apparent density of galaxies drop off at larger distances? (viewed 15935 times)
Why can we see the sun's image before sunrise and after sunset? (viewed 15926 times)
Can I build an instrument to measure the size of the Sun and of the Moon? (viewed 15920 times)
How can you tell if a crescent moon is preceding or following a new-moon phase? (viewed 15901 times)
Why is the Cosmic Microwave Background not absorbed by interstellar hydrogen? (viewed 15900 times)
How are supernovae discovered? (viewed 15884 times)
Could there have been multiple Big Bangs at different places in the universe? (viewed 15866 times)
Would the biggest airplanes cause tsunamis if they crashed? (viewed 15861 times)
Did I really hear a meteor? (viewed 15845 times)
What makes a satellite geosyncronise itself with Earth's orbit? (viewed 15841 times)
Are there any new craters on the moon? (viewed 15810 times)
Which part of the sky did the famous 'wow' signal originate from? (viewed 15766 times)
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background? (viewed 15765 times)
If clocks run slow in a gravitational field, how can we know the true age of the Solar System and Universe? (viewed 15734 times)
Is it possible for amateurs to do optical interferometry? (viewed 15718 times)
Why are there blue shifted galaxies? (viewed 15709 times)
Is the universe really like an expanding balloon? (viewed 15708 times)
How was the starting point for the Julian Date system chosen? (viewed 15699 times)
Why do some eclipses take longer than others? (viewed 15695 times)
What is meant by "stopping down a telescope"? (viewed 15680 times)
How is the Cepheid yardstick validated? (viewed 15673 times)
Are planetary nebulae the result of supernovae? (viewed 15561 times)
Can you give me advice on buying a telescope? (viewed 15553 times)
Why was the Platonic year named after Plato? (viewed 15541 times)
Why doesn't NASA build rotating spacecraft to simulate gravity? (viewed 15499 times)
Is there a beginning and an end to a galaxy's life? (viewed 15473 times)
Will we discover an 11th planet? What would it be called? (viewed 15371 times)
Why doesn't the hydrogen on Jupiter explode? (viewed 15346 times)
Is it possible to build a cheap device to measure declination? (viewed 15322 times)
Would a planet near the galactic center have a brighter night sky? (viewed 15315 times)
Can you describe a day on the job as an astronomer? (viewed 15284 times)
What is the difference between homogeneity and isotropy? (viewed 15278 times)
Did time go slower just after the Big Bang? (viewed 15276 times)
How hot is each one of the layers of the sun? (viewed 15236 times)
What class of spiral galaxy is the Milky Way? (viewed 15230 times)
On which days can I see the Moon in the evening / morning and why is this so? (viewed 15201 times)
What is a Cepheid variable? (viewed 15194 times)
What would the Big Crunch look like to an observer on Earth? (viewed 15182 times)
If comets are boiling away, why are there any left? (viewed 15174 times)
Why don't astronauts sublimate in space? (viewed 15163 times)
How can we tell what the interiors of planets are like? (viewed 15143 times)
Could you tell me about the life cycle of galaxies? (viewed 15110 times)
Can the Space Shuttle abort and return to Earth before reaching orbit? (viewed 15098 times)
What happened to the girl who named Pluto? (viewed 15077 times)
How do astronomers come up with their facts? (viewed 15069 times)
How are sunspots formed? (viewed 15055 times)
Why is pressure broadening greater in low mass stars than in high mass stars? (viewed 15002 times)
Where can I find information on the moons of other planets? (viewed 14977 times)
Why aren't discoveries of extrasolar planets reported on the news? (viewed 14953 times)
Will I be able to see the shadow of the Moon streaking towards me in a total solar eclipse? (viewed 14950 times)
Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating? (viewed 14935 times)
What is the SU(3) quark model? (viewed 14915 times)
What is our galaxy's halo made of, and how was it formed? (viewed 14906 times)
Does the shuttle worry about space junk? (viewed 14864 times)
Can astronomers observe anything when the moon is full? (viewed 14787 times)
Can HST see the Oort cloud? (viewed 14768 times)
What is the origin of the stellar classification system "OBAFGKM"? (viewed 14768 times)
Can the acceleration of the Universe be analogous to apparent acceleration in a airplane? (viewed 14710 times)
Do galaxies orbit around anything? (viewed 14707 times)
How are astronomy and poetry linked? (viewed 14692 times)
What are the boundaries of the constellations? (viewed 14656 times)
Why is NASA shutting down the Hubble Space Telescope? (viewed 14649 times)
Does the Sun have any heavy elements? (viewed 14571 times)
What's new with the Big Bang? (viewed 14566 times)
Why do supernova remnants look like rings rather than spheres? (viewed 14533 times)
Why doesn't SETI concentrate its observations to the nearby stars and the solar systems that we are discovering? (viewed 14471 times)
Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations? (viewed 14456 times)
How could galaxies have gotten so far away in only 15 billion years? (viewed 14443 times)
How can we find galaxies behind the Milky Way? (viewed 14435 times)
Why are telescopes kept in cold conditions? (viewed 14386 times)
What is the best time of the year to see eclipses? (viewed 14368 times)
Can I listen to the SETI@home radio signal? (viewed 14325 times)
Did I find a rock that came from the Moon? (viewed 14299 times)
Where was the water in the big bang? (viewed 14294 times)
How can the Sun have such a strong gravitational field if it's made of gasses? (viewed 14292 times)
Could photons be dark matter? (viewed 14249 times)
Why are there more maria on the near side of the Moon? (viewed 14238 times)
How do astronomers measure the radius of a star? (viewed 14228 times)
Why can't relative velocities add up to more than the speed of light? (viewed 14214 times)
Is light of different colors affected differently by gravity? (viewed 14207 times)
How long is twilight on the Moon? (viewed 14177 times)
Do stars' orbits in galaxies obey Kepler's Laws? (viewed 14101 times)
Does the temperature of matter increase as it is accelerated to relativistic speeds? (viewed 14013 times)
How fast do particles travel in space? (viewed 13971 times)
How do bars form in spiral galaxies? (viewed 13963 times)
What would an "open geometry" for the universe look like? (viewed 13945 times)
What causes gamma ray bursts? (viewed 13943 times)
How long has humanity known that we live in a galaxy similar to others in the Universe? (viewed 13935 times)
How do we know what other planets (and stars, galaxies, etc.) are made of? (viewed 13918 times)
Do we see the same stars from above and below the equator? (viewed 13902 times)
What was that eclipse I saw in the sky? (viewed 13887 times)
What causes a particle to decay? (viewed 13863 times)
How much power is contained in a beam of light? (viewed 13772 times)
How do photons from distant objects maintain enough energy to reach us? (viewed 13763 times)
How do we find out about the star formation histories of galaxies? (viewed 13717 times)
Can we make a movie of the Milky Way galaxy's rotation? (viewed 13699 times)
Will the diameter of a cluster of galaxies change with redshift? (viewed 13665 times)
Will the next generation telescope OWL be able to detect an Earth like extrasolar planet? (viewed 13661 times)
Why is it important to study meteorites? (viewed 13634 times)
How do you classify galaxies? (viewed 13492 times)
Are the asteroids the remains of a planet which broke apart? (viewed 13479 times)
Can you tell me the characteristics of W, R, N and S type stars? (viewed 13472 times)
What are "curled" dimensions? (viewed 13466 times)
Why are accretion disks flat? (viewed 13450 times)
When did people discover that the Sun is a star? (viewed 13439 times)
What do "homogeneity" and "isotropy" mean? (viewed 13437 times)
What kinds of star clusters are there? (viewed 13389 times)
How can I contribute to science as an amateur astronomer? (viewed 13370 times)
Did the Sumerians measure precession? (viewed 13323 times)
Is there oxygen in the atmospheres of other planets? (viewed 13300 times)
How can we understand the meaning of large numbers like "a million million?" (viewed 13279 times)
Wouldn't the vast distances of space distort SETI signals into unintelligeble forms? (viewed 13187 times)
What kind of interference must astronomers contend with when observing? (viewed 13185 times)
Will the Leonid meteor shower go away? (viewed 13143 times)
How does interferometry work? (viewed 13122 times)
Do we have to worry about relativity when studying galactic objects? (viewed 13106 times)
Could we send a manned mission to the outer planets? (viewed 13038 times)
Why are telescopes located in remote places? (viewed 13037 times)
Do electrons age? (viewed 13029 times)
Why can we have solar eclipses? (viewed 13002 times)
What do stellar classifications mean? (viewed 12990 times)
How do distant galaxies differ from those nearby? (viewed 12894 times)
What is the best way to see the Milky Way? (viewed 12808 times)
What is the farthest in space that we have gone? (viewed 12801 times)
How do astronomers observe the Sun's interior? (viewed 12738 times)
How can I watch the Perseid meteor shower? (viewed 12705 times)
Why do spacecraft need heat shields coming back to Earth but not leaving? (viewed 12680 times)
How does melting a material reset its radioactive clock? (viewed 12662 times)
Will astronauts ever be able to go ice-skating on Europa? (viewed 12661 times)
How are astronauts trained for weightlessness? (viewed 12621 times)
What is the three-body problem? (viewed 12576 times)
How can I nominate myself for a Nobel Prize in Physics? (viewed 12507 times)
How can you tell the difference between single and multiple extrasolar planets? (viewed 12497 times)
How are photons created and destroyed? (viewed 12487 times)
How did Mars get so dusty? (viewed 12486 times)
Is cosmic expansion happening on microscopic scales? (viewed 12462 times)
Do we really observe the edges of galaxies at different epochs? (viewed 12367 times)
How does a star take mass from another star? (viewed 12332 times)
Where can I see Newton's original reflecting telescope? (viewed 12266 times)
How can I find out if the new moon has been sighted? (viewed 12081 times)
How can water be chemically trapped in rocks? (viewed 12042 times)
Why is the WMAP picture of the CMB an ellipse? (viewed 12006 times)
If the universe is "bounded" today, could it one day become "unbounded"? (viewed 11964 times)
Do binary or triple star systems form together? (viewed 11957 times)
Do asteroids hit the sun? (viewed 11883 times)
Is light blueshifted when it is gravitationally lensed? (viewed 11698 times)
How does libration allow us to see more than 50% of the Moon? (viewed 11697 times)
What percent of the time can astronomers observe without interference from the Moon? (viewed 11690 times)
Why will fusion wait until hydrogen is gone before starting to fuse heavier atoms? (viewed 11666 times)
Is the Local Group expanding along with the entire Universe? (viewed 11648 times)
No matter how fast the universe is expanding, shouldn't gravity eventually make it recollapse? (viewed 11413 times)
What color would Mars be if you were standing on it? (viewed 11412 times)
What kinds of cancer research have been done in space? (viewed 11353 times)
How do unmanned space probes avoid running into things? (viewed 11344 times)
If the Universe was infinitely dense at the Big Bang, why didn't time stand still? (viewed 11281 times)
What is "nothing", from a scientific point of view? (viewed 11271 times)
Do asteroids ever do anything good in the Solar System? (viewed 11265 times)
Why aren't accretion disks around giant stars as hot as accretion disks around black holes? (viewed 11136 times)
What is Hot Dark Matter theory? (viewed 11012 times)
How can observations of the distant universe prove that the expansion is accelerating *now*? (viewed 11002 times)
Why is it easier to see a star if you look slightly to the side? (viewed 10902 times)
What would happen if you went back in time and killed your grandmother? (viewed 10882 times)
Could matter-anti-matter repulsion power the expansion of the universe? (viewed 10841 times)
How can the universe be "flat"? We're 3D! (viewed 10730 times)
What do meteorites tell us about life on other planets? (viewed 10470 times)
What is the photoelectric effect? Why can't multiple low-frequency photons free an electron? (viewed 10418 times)
Why is it called astronomy when all the other sciences end in -ology? (viewed 10371 times)
Could neutrinos be dark matter? (viewed 10307 times)
Why don't all neutron stars become pulsars? (viewed 10306 times)
What are collections of galaxies called? (viewed 10286 times)
Are there any 'lonely galaxies'? (viewed 10189 times)
How are planets affected by the Hot Ionised Medium? (viewed 10125 times)
Can a human give birth in space? (viewed 10113 times)
What was different on Mars in the past to allow liquid water to be present? (viewed 9983 times)
What is the relationship between the width of a star trail on a photo and the star's intensity? (viewed 9929 times)
How can we discern different galaxies/clusters along the same line of sight? (viewed 9845 times)
During close approaches, can Mars appear in our sky as large as the Moon? (viewed 9766 times)
Why doesn't the ammonia and methane in Jupiter's atmosphere sink into the core? (viewed 9676 times)
Why was Mir burnt up in the atmosphere? (viewed 9608 times)
Do constellations looks the same from space? (viewed 9563 times)
What are the largest radio wavelengths observed from radio sources in the sky? (viewed 9304 times)
How does the color index of a star relate to its actual color? (viewed 8977 times)
Does lunar gardening really work? (viewed 8924 times)
Is it a coincidence that we can have total solar eclipses? Are there other planets which also have them? (viewed 8837 times)
Do the Earth's magnetic poles ever change places? (viewed 8723 times)
Why is the sky blue and not blue & purple? (viewed 8614 times)
How big is the Hubble Ultra Deep Field image? (viewed 8614 times)
How do we detect incoming meteorites? (viewed 8456 times)
Could the Universe's dark matter be made up of black holes? (viewed 8283 times)
Is the green flash real? (viewed 8116 times)
If nothing can escape a black hole, why do some black holes have jets? (viewed 7551 times)
If the sun went out and our atmosphere froze solid, what color would it be? (viewed 7508 times)
Does weightlessness affect hunger? (viewed 7466 times)
How do we know the density of some extrasolar planets? (viewed 6846 times)
Can we harvest H & O from space to make water? (viewed 6160 times)
Can the sun rise from the west on Mars? (viewed 6061 times)
What would happen if a human were exposed to space without wearing a spacesuit? (viewed 5850 times)
What is between the Oort cloud and the closest star? (viewed 5566 times)
Are black holes spherical? (viewed 5531 times)
Has anyone ever seen a star "turn on"? (viewed 5161 times)
Why don't skydivers burn up like meteors? (viewed 4697 times)
Did the Moon or planets form in a manner similar to that of Earth? (viewed 4545 times)
When measuring the expansion of the universe, do astronomers consider that they're seeing how galaxies moved long ago, not today? (viewed 4495 times)
What would happen if a nuclear-powered shuttle exploded? (viewed 4458 times)
Does the Milky Way spin counter-clockwise? If so, do all spiral galaxies spin in this direction and why? (viewed 4239 times)
Can we prove that the Moon isn't hollow? (viewed 4234 times)
When will Hale-Bopp return? (viewed 4146 times)
Could a planetary system survive if its star merged with another, or if its star went supernova? (viewed 4145 times)
Why are craters round? (viewed 3918 times)
Is it sensible to consider terraforming Mars? (viewed 3795 times)
Do planets radiate noise? (viewed 3682 times)
How do supernovae show us that the Universe's expansion is accelerating? (viewed 3643 times)
Can planets collide with one another? (viewed 3424 times)
If there are infinity universes, will every thing that is possible happen? (viewed 3176 times)
Are there solar tides? (viewed 3146 times)
When will humans travel to Mars and revisit the Moon? (viewed 3038 times)
Will the Pioneer and Voyager probes ever leave the Milky Way? (viewed 2317 times)
Where is the Spitzer Space Telescope? (viewed 2271 times)
If I were traveling through space, could I see distant galaxies with my own eyes? (viewed 2089 times)
Does the particles involved in a star's final core collapse travel faster than the speed of light? (viewed 1819 times)
Is Earth-moon tidal friction causing global warming? (viewed 1699 times)
Do more meteorites fall at low latitudes? (viewed 1623 times)
Is the moon spherical? (viewed 1370 times)
When is the best time to observe zodiacal light? (viewed 1259 times)
Why does Titan, in spite of being smaller than Mars, have an atmosphere more dense than Earth's? (viewed 1247 times)
The naming of Mars (viewed 1201 times)
Is the reddish dust of Mars biogenic? (viewed 1141 times)
Why does Mars have a dusty atmosphere? (viewed 1019 times)
What are the possible ends of the universe? (viewed 873 times)
Is dark energy affected by black holes? (viewed 643 times)
What color are meteors? (viewed 421 times)
How has light from 13 billion years ago not passed us by? (viewed 188 times)

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