All previously answered questions (in order of times viewed)

What's going to happen on December 21st 2012? (viewed 331735 times)
What color is each planet? (viewed 285228 times)
Is the Moon moving away from the Earth? When was this discovered? (viewed 251303 times)
How far is each planet from Earth? (viewed 215348 times)
How do I build a model rocket? (viewed 211671 times)
What is the life cycle of a star? (viewed 184508 times)
How many stars are there in our Galaxy (Milky Way)? (viewed 177228 times)
How do you measure the distance between Earth and the Sun? (viewed 171419 times)
What is the largest star? (viewed 168585 times)
What is a white hole? (viewed 155538 times)
What color is Venus? (viewed 144331 times)
Why do the planets orbit the sun? (viewed 130251 times)
Which planets have rings? (viewed 125887 times)
At what speed does the earth move around the sun? (viewed 124666 times)
What are the names of the earth, moon, sun, and solar system? (viewed 109946 times)
Is the distance from the Earth to the Sun changing? (viewed 106861 times)
What makes the Earth rotate? (viewed 105657 times)
Why do stars twinkle? (viewed 102111 times)
What do astronauts eat in space? Can they grow food? (viewed 96538 times)
Is Pluto a planet? (viewed 95810 times)
What is the universe expanding into? (viewed 94803 times)
Does the Moon rotate? Are there other moons that always keep one face toward their planet? (viewed 92934 times)
How long does it take for the Sun's light to reach us? (viewed 86504 times)
Why do planets rotate? (viewed 85200 times)
Where did the name 'Earth' come from? (viewed 83281 times)
Will the sun go supernova in six years and destroy Earth (as seen on Yahoo)? (viewed 82397 times)
What are shooting stars? (viewed 80735 times)
What is the largest galaxy? (viewed 78006 times)
Who named the planets and who decides what to name them? (viewed 77411 times)
Why are there both high and low tides? (viewed 76709 times)
How many known galaxies are there? (viewed 74847 times)
How critical is the Earth-Sun distance in maintaining our average temperatures on Earth? (viewed 65276 times)
How do we know the age of the Universe and the Earth? (viewed 64757 times)
What was there before the Big Bang and what is there outside of our universe? (viewed 64648 times)
How does the location of sunrise and sunset change throughout the year? (viewed 63837 times)
Is the Sun expanding? Will it ever explode? (viewed 61951 times)
When is the next comet due to arrive? (viewed 61025 times)
Can you hear sounds in space? (viewed 59423 times)
How many Earths fit into the Sun? (viewed 59301 times)
Will the magnetic field of the Earth reverse its direction in the future? Will this cause problems? (viewed 58695 times)
What would happen if an impact caused Earth to stop rotating? (viewed 58567 times)
Are there telescopes that can see the flag and lunar rover on the Moon? (viewed 57244 times)
When will Halley's Comet return? (viewed 56801 times)
Have astronomers discovered Earth's second moon? (viewed 56032 times)
What is the hottest time of day? (viewed 55489 times)
Did astronauts really go to the Moon, or is it a hoax? (viewed 55357 times)
What kind of rock is the moon made of? (viewed 54668 times)
What would happen if we did not have a Moon? (viewed 53902 times)
What is apparent magnitude? (viewed 53459 times)
How does the position of Moonrise and Moonset change? (viewed 53439 times)
What will happen to life on Earth when the Sun becomes a red giant? (viewed 53287 times)
How do stars move in the Galaxy? (viewed 52059 times)
What is the observational difference between a star and a planet? (viewed 51692 times)
What is at the end of the Universe? (viewed 51658 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 50825 times)
Can I buy a star? (viewed 50349 times)
Does the Sun orbit the Earth as well as the Earth orbiting the Sun? (viewed 49456 times)
Who has landed on the moon? (viewed 49351 times)
Is the universe expanding faster than the speed of light? (viewed 49258 times)
Why is a day divided into 24 hours? (viewed 47632 times)
Can we feel the Earth spin? (viewed 47540 times)
How long does a solar eclipse last? (viewed 47515 times)
What is the physical difference between a star and a planet? (viewed 47272 times)
How do astronauts take baths and use restrooms in space? (viewed 45761 times)
Does the Sun have a scientific name? (viewed 45553 times)
What happens when galaxies collide? (viewed 45497 times)
What direction do planets rotate? (viewed 45230 times)
Does the Sun move around the Milky Way? (viewed 44931 times)
Why aren't there any green stars? (viewed 44794 times)
How do you calculate the lifetime of the Sun? (viewed 44733 times)
Does the Sun rotate? (viewed 44517 times)
What is that ring (or rainbow) around the moon? (viewed 43883 times)
How can I find the star I have "bought"? (viewed 43842 times)
Why are the Moon and Sun sometimes orange or red? (viewed 43841 times)
How do rockets work? (viewed 43271 times)
Is there a proof that Earth moves? (viewed 43145 times)
Why do planets have elliptical orbits? (viewed 42628 times)
Why are stars and planets round? (viewed 42440 times)
Can artificial gravity be created in space? (viewed 42417 times)
What causes seasons? (viewed 42330 times)
What is a singularity? (viewed 41729 times)
What are the "dog days of summer"? (viewed 41563 times)
How much money do astronomers make? (viewed 41461 times)
Where does the name "Milky Way" come from? (viewed 41458 times)
How can we see the Milky Way if we are inside it? (viewed 41211 times)
How many constellations are there? (viewed 41012 times)
Do stars move in the sky? (viewed 40836 times)
What elements make up the Sun? (viewed 40752 times)
What are the advantages and disadvantages of using a telescope in space? (viewed 40752 times)
Since Earth is spinning, why do we land in the same place when we jump or fall? (viewed 40517 times)
What would happen if an asteroid 10 kilometers across hit the Earth? (viewed 40443 times)
What is a nova? (viewed 40286 times)
How are black holes made? Could one be made close to us? (viewed 40203 times)
How are light and heavy elements formed? (viewed 40008 times)
How does the Sun compare to other stars? (viewed 39833 times)
What is the mass of the Universe? (viewed 39728 times)
What is the largest structure in the universe? (viewed 39251 times)
Where did the Universe come from? (viewed 38838 times)
Why doesn't the earliest sunset occur on the shortest day of the year? (viewed 38837 times)
Why do airplanes take longer to fly West than East? (viewed 38812 times)
When can I see the Moon through the hole in the Pantheon? (viewed 38617 times)
What are RA and DEC? (viewed 38092 times)
Who first measured the speed of light? (viewed 37780 times)
What is the size of the Solar System? (viewed 37760 times)
Why doesn't the length of each day change much around the solstices? (viewed 37745 times)
Is time travel possible? (viewed 37708 times)
Which planet is most similar to Earth? (viewed 37675 times)
Why does the Earth have only one moon? (viewed 37600 times)
What's the best college for astronomy? (viewed 37542 times)
How much money is spent on space exploration? (viewed 37122 times)
Is it possible to measure the temperature of the Sun? (viewed 36950 times)
Does your weight change between the poles and the equator? (viewed 36915 times)
What would happen if the gravity on Earth was suddenly turned off? (viewed 36721 times)
What would you see from inside a black hole? (viewed 36500 times)
Why is the Universe flat and not spherical? (viewed 36383 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 36347 times)
Will the Sun become a black hole one day? (viewed 35645 times)
How many stars are born and die each day? (viewed 35499 times)
What happens to a substance if its speed is more than the speed of light? (viewed 35473 times)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (viewed 35433 times)
What is the density of a black hole? (viewed 35409 times)
Traveling at light speed, how long would it take to get to the nearest galaxy? (viewed 35400 times)
How do astronomers use math in their jobs? (viewed 35312 times)
Where are stars born? (viewed 35261 times)
Could there be life in the galaxies nearest to the Milky Way? (viewed 35144 times)
How often does the Sun pass through a spiral arm in the Milky Way? (viewed 34964 times)
What are some astronomy science fair projects? (viewed 34922 times)
Do most astronomers believe in God based on the available scientific evidence? (viewed 34816 times)
What would happen if a supermassive black hole came close to the Earth? (viewed 34680 times)
When was the last time all 9 planets were aligned? (viewed 34158 times)
Do black holes die? If so how? (viewed 34157 times)
How do we know the mass of the Earth and the Moon? (viewed 34150 times)
How did the stars get named? (viewed 34102 times)
Does the Moon rotate? (viewed 34095 times)
How are galaxies formed? (viewed 34060 times)
If the universe is infinite does that mean there is an infinite number of "me"s? (viewed 33850 times)
Why isn't the summer solstice the hottest day of the year? (viewed 33648 times)
What is the shape of the universe? (viewed 33597 times)
What kinds of jobs do astronomers do? (viewed 33470 times)
How can I find the distance to the Sun on any given day? (viewed 33294 times)
How does the parachute in a model rocket work? (viewed 33126 times)
What makes the wind? (viewed 33047 times)
When the Sun converts mass to energy, do the orbits of the planets change? (viewed 32944 times)
Are names given to black holes? (viewed 32787 times)
What are constellations used for? (viewed 32256 times)
Are aliens or UFOs real? (viewed 32176 times)
Why do different stars appear with seasons? (viewed 31963 times)
What would happen to us if the sun went out for an hour? (viewed 31891 times)
Why do planets not twinkle? (viewed 31848 times)
Are there any asteroids on a collision course with Earth? (viewed 31841 times)
What are black holes made of? (viewed 31752 times)
Where does the name "Moon" come from? (viewed 31747 times)
Does gravity vary across the surface of the Earth? (viewed 31692 times)
Was the Sun made in a supernova? (viewed 31618 times)
Considering the motion of the Earth, the solar system, and the galaxy, how fast am I moving while lying in bed asleep? (viewed 31511 times)
What are Altitude and Azimuth? (viewed 31481 times)
Why is the Moon so bright? (viewed 31471 times)
What is the biggest crater recorded on Earth? (viewed 31393 times)
How do astronomers measure the brightness of stars? (viewed 31304 times)
How long would it take the Earth to fall into the Sun? (viewed 31255 times)
How can the Universe expand faster than the speed of light during inflation? (viewed 31233 times)
Why is it difficult to understand the expansion of the universe? (viewed 31162 times)
What do astronauts do all day in the International Space Station? (viewed 31140 times)
What can I use for fuel in my homemade rocket? (viewed 31079 times)
Who discovered each planet? (viewed 30999 times)
How did asteroids form and what is the difference between an asteroid and a comet? (viewed 30939 times)
Where, in relation to the entire universe, is the Milky Way located? (viewed 30841 times)
How does the Moon stay "suspended" in the air? (viewed 30807 times)
How can I measure the distance of a star? (viewed 30788 times)
If light has no mass, then what draws it into a black hole? (viewed 30749 times)
Why hasn't NASA gone back to the moon? (viewed 30630 times)
How do astronauts use math in their jobs? (viewed 30313 times)
How do we measure the size of the Moon and of the Sun? (viewed 30198 times)
How do you calculate the azimuth and altitude of an object? (viewed 30028 times)
What's the difference between astronomy and astrology? (viewed 29715 times)
How do you measure a planet's mass? (viewed 29683 times)
What kind of schooling is necessary to become an astronomer? (viewed 29598 times)
Where is the nearest black hole? (viewed 29493 times)
What is time dilation? (viewed 29448 times)
Can you fire a gun on the Moon? (viewed 29416 times)
Why does the Moon look big on the horizon? (viewed 29389 times)
How big is the universe? (viewed 29375 times)
Can you see satellites? (viewed 29340 times)
What is the size of a black hole? (viewed 29194 times)
Is the speed of light constant? (viewed 29126 times)
What happens when two black holes get too close? (viewed 28975 times)
What are some of the effects of solar flares on Earth? (viewed 28912 times)
What do I need to do to become an astronomer? (viewed 28844 times)
Do dead stars still shine? (viewed 28786 times)
How is astronomy impacted by trigonometry? (viewed 28722 times)
Why does the Earth tilt back and forward once a year? (viewed 28640 times)
What other careers involve Astronomy besides Astronomer? (viewed 28626 times)
What would happen if Earth had more than one moon? (viewed 28571 times)
How do you measure the mass of a star? (viewed 28181 times)
How fast is the Universe expanding? (viewed 28166 times)
Why can't you see stars during the day? (viewed 28123 times)
Where is the supernova remnant that led to our solar system? (viewed 28116 times)
Can I buy land on the Moon? (viewed 28038 times)
What makes up most of the Universe? (viewed 27801 times)
Why does Barnard 68 appear dark? (viewed 27753 times)
Why does the Earth only see one side of the Moon? (viewed 27680 times)
What is the origin of spiral structure in galaxies? (viewed 27594 times)
How do rockets move in space? (viewed 27547 times)
How do gravitons escape black holes to tell the universe about their gravity? (viewed 27369 times)
Does Mt. Everest cast a shadow on the moon? (viewed 27291 times)
Would your weight change as you go underground? (viewed 27256 times)
Why do all the planets orbit in the same plane? (viewed 27217 times)
Where did all the water in the universe come from? (viewed 27157 times)
Why do pictures of distant galaxies have higher resolution than those of nearby planets? (viewed 27011 times)
What is the most distant known galaxy? (viewed 26965 times)
How are elements heavier than iron formed? (viewed 26942 times)
Can I calculate the size of the Universe by converting light years to kilometres? (viewed 26922 times)
Will we get sucked into the black hole at the center of the Milky Way? (viewed 26875 times)
Can we look back far enough in time to see the Big Bang? (viewed 26863 times)
Why do stars change colour when they twinkle? (viewed 26697 times)
Why is the moon in a different place every night? (viewed 26667 times)
Where did the matter in the universe come from? (viewed 26661 times)
What would happen if the Moon fell out of its orbit around Earth? (viewed 26589 times)
How do galaxies collide in an expanding universe? (viewed 26551 times)
How can two moons of Saturn share the same orbit? (viewed 26539 times)
Why do the size and brightness of the full moon change? (viewed 26508 times)
Can any galaxies be seen with the naked eye? (viewed 26487 times)
How many meteorites hit Earth each year? (viewed 26375 times)
What is a star's "spectrum"? (viewed 26271 times)
Why do we see stars? (viewed 26123 times)
What is a graviton? (viewed 26073 times)
What are the different kinds of astronomers? (viewed 26071 times)
How can I calculate the position or path of the Sun for a given time and location? (viewed 25948 times)
What was that really big falling star that I saw? (viewed 25873 times)
Why doesn't dark matter fall into a black hole? (viewed 25820 times)
How are black holes discovered? (viewed 25803 times)
What can we learn from the color of a star? (viewed 25722 times)
Is the Great Wall the largest galaxy cluster? (viewed 25614 times)
What's the biggest meteorite? (viewed 25568 times)
Why can't we see Venus at night when it is an inner planet? (viewed 25558 times)
What is the difference between a "star" and a "sun"? (viewed 25537 times)
What would happen to the Earth if an asteroid hit the Moon? (viewed 25455 times)
What is the speed of gravity? (viewed 25312 times)
Why is sea water salty, and not lake water? (viewed 25311 times)
How much longer will the Earth last? (viewed 25257 times)
How can a star burn with no oxygen? (viewed 25251 times)
How does light pollution affect astronomers? (viewed 25197 times)
Why is looking out the same as looking back in time? (viewed 25065 times)
Could someone travel the universe in his or her own lifetime? (viewed 25054 times)
How many stars can I see? (viewed 25025 times)
Do the Sun's or Earth's magnetic field reverse? (viewed 25010 times)
Why is twilight short near the equator? (viewed 24877 times)
Can terrestrial planets have rings? (viewed 24820 times)
Why does the location of sunrise change? (viewed 24645 times)
Which constellation does our Sun belong to? (viewed 24608 times)
Why are there stars? (viewed 24581 times)
How long has there been water on Earth? (viewed 24552 times)
How do I tell which planet is which? (viewed 24522 times)
What happens to a bullet fired on the moon? (viewed 24500 times)
Does quantum entanglement imply faster than light communication? (viewed 24424 times)
What is the typical size of a visible shooting star? (viewed 24364 times)
How can I find my age on another planet? (viewed 24336 times)
Is the Earth slowly getting larger? (viewed 24291 times)
Did life originate on Earth, or did it come from somewhere else? (viewed 24216 times)
What is Earthrise over the Moon? (viewed 24216 times)
How does night and day work? (viewed 24130 times)
Is the Moon hollow? (viewed 24128 times)
Is there really a 10th planet? (viewed 24083 times)
Is it possible to count the stars? (viewed 24053 times)
How can we estimate the number of Earth-like planets in the Galaxy? (viewed 24040 times)
Do supermassive black holes cause galaxy rotation? (viewed 24028 times)
What's the difference between astronomy and astrophysics? (viewed 24007 times)
Is time travel possible using merging black holes? (viewed 24003 times)
What is the evidence supporting the nebula theory of Solar System formation? (viewed 23960 times)
How long does the supernova stage of a star last? (viewed 23953 times)
Why have star signs shifted by one constellation? (viewed 23940 times)
Does the Mediterranean sea have tides? (viewed 23873 times)
Is there a "South Star"? (viewed 23854 times)
Why don't astronomers use everyday units to measure distances (what is an AU or a pc)? (viewed 23807 times)
Is Andromeda part of the Milky Way? Where can I find them in the sky? (viewed 23803 times)
Which hemisphere has the best view of the Milky Way? (viewed 23791 times)
What is the approximate GPA needed in High School in Math and Science to be an astronomer? (viewed 23790 times)
Does evolution contradict the second law of thermodynamics? (viewed 23782 times)
Has there been an experiment that measured speed faster than the speed of light in vacuum? (viewed 23778 times)
How close was the Moon to the Earth when it formed? (viewed 23475 times)
Does the Coriolis force determine which way my toilet drains? Does it affect black holes? (viewed 23442 times)
Why does the Sun's apparent path through the sky change throughout the year? (viewed 23412 times)
Are meteorites hot or cold when they hit Earth? (viewed 23375 times)
How can I calculate distances between stars? (viewed 23300 times)
Can moons have moons? (viewed 23190 times)
Why is our solar system so different from all the others we've found? (viewed 23149 times)
How long would it take for a mini-black hole to eat the Earth? (viewed 23127 times)
How would the weather on Earth be different if it were a cube? (viewed 23102 times)
Could the Universe have expanded faster than the speed of light at the Big Bang? (viewed 23068 times)
Is the Earth at the centre of the Universe? (viewed 23001 times)
Is it possible to see the full Moon and the Sun simultaneously in high northern latitudes when the Sun doesn't set? (viewed 22978 times)
When we look back to the Big Bang, why don't we see the universe as a tiny speck of matter? (viewed 22973 times)
What skills do astronomers need? (viewed 22906 times)
What is a dimension? (viewed 22898 times)
Can I communicate faster than light? (viewed 22865 times)
Can you see the future as you fall into a black hole? (viewed 22714 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 22705 times)
Which American colleges teach astronomy? (viewed 22701 times)
Why do we not have eclipses every month? (viewed 22688 times)
What are the closest and/or brightest stars? (viewed 22576 times)
Are all stars the same? (viewed 22514 times)
What is the pattern to the distances between each planet and the sun? (viewed 22449 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 22402 times)
If a white dwarf is a "dead" star, why is it so hot? (viewed 22388 times)
Why doesn't gravity change the speed of light? (viewed 22385 times)
Is there any limitation to what a black hole can "suck" in? (viewed 22347 times)
Can a person go into a black hole and come out alive? (viewed 22341 times)
How does the brightness of a star depend on its distance from us? (viewed 22319 times)
How many moles of stars are in the known universe? (viewed 22264 times)
How is the time of sunrise calculated? (viewed 22231 times)
Can we colonize other planets? (viewed 22220 times)
Are time machines possible? (viewed 22173 times)
What is the difference between the "Doppler" redshift and the "gravitational" or "cosmological" redshift? (viewed 22001 times)
What is happening just around the black hole in the center of the Milky Way? (viewed 22000 times)
What is the difference between nutation and precession of the Earth? (viewed 21922 times)
What would happen if you took off your helmet in space? (viewed 21868 times)
How do we define distance in an expanding universe? (viewed 21840 times)
How dangerous are the asteroids? (viewed 21786 times)
What are the requirements for being a planet? (viewed 21761 times)
What's the difference between dark matter and dark energy? (viewed 21685 times)
What is the significance of the second focus of elliptical orbits of planets in our Solar System? (viewed 21668 times)
If the universe is 15 billion years old, how can it be larger than 15 billion light years across? (viewed 21641 times)
How is it that we see farther out in space (farther back in time) than in the past? (viewed 21613 times)
Can a lunar and a solar eclipse happen in the same month? When will this happen next? (viewed 21612 times)
What happens to spacetime inside a black hole? (viewed 21586 times)
Is there a simple formula to calculate solar eclipse timings from any position on Earth? (viewed 21545 times)
What companies or businesses can astronomers work for? (viewed 21525 times)
How do we know that nuclear fusion is still going on in the Sun? (viewed 21493 times)
How does astronomy benefit humankind? (viewed 21437 times)
Could an astronaut or satellite fall into a black hole that we didn't know about? (viewed 21399 times)
What's that dark spot on the Sun? (viewed 21385 times)
Can we find the place where the Big Bang happened? (viewed 21368 times)
Are Earth and the Moon "twin planets"? (viewed 21366 times)
How long could life on Earth survive if the Sun stopped shining? (viewed 21296 times)
How do I make a scale model of the Solar System? (viewed 21294 times)
How are galaxy distances inferred from their recessional velocities? (viewed 21211 times)
Why do people draw stars with five points? (viewed 21149 times)
How do we measure distances to other stars? (viewed 21138 times)
How will the two black holes that are going to collide affect Earth? (viewed 21130 times)
The Moon slows the Earth's rotation, but how fast was it spinning billions of years ago? (viewed 21072 times)
Did the speed of light change over the history of the universe? (viewed 21023 times)
What are the facts about the Star of Bethlehem? (viewed 21001 times)
How are galaxies named? (viewed 20975 times)
Are Kuiper Belt Objects asteroids? Are large Kuiper Belt Objects planets? (viewed 20972 times)
If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths? (viewed 20924 times)
How do we weigh objects in space? (viewed 20920 times)
Don't tachyons travel faster than light? (viewed 20891 times)
What are the atmospheres of Mars and Pluto like? (viewed 20885 times)
Will the Moon be invisible in 500 million years? (viewed 20835 times)
Has anyone made a map of the Milky Way? (viewed 20830 times)
Was I hit by a meteorite? (viewed 20828 times)
What are quasars made of? (viewed 20813 times)
Have there been other Big Bangs before? (viewed 20763 times)
How big a change in the Earth's orbit would be required to destroy all life? (viewed 20735 times)
What do a galaxy's colors mean? Are they its true colors? (viewed 20734 times)
Are there eclipses on other planets? (viewed 20544 times)
Why do constellations look the same after several years even though all the stars are moving? (viewed 20541 times)
Who came up with the name "black hole"? (viewed 20524 times)
Will winter and summer constellations change due to abnormal warmth or cold on Earth? (viewed 20464 times)
Can life exist on the recently discovered extrasolar planets? (viewed 20443 times)
Aren't jobs in astronomy scarce? (viewed 20304 times)
What is dark matter? (viewed 20291 times)
Why do most moons orbit their planets at the equator? (viewed 20290 times)
How much time do astronomers spend looking through telescopes? (viewed 20243 times)
Where do planetary rings come from, and what are they made of? (viewed 20200 times)
How close do you have to come to the Earth to be influenced by its gravity? (viewed 20118 times)
How do I become both an astronaut and an astronomer? (viewed 20023 times)
What if the Earth rotated twice as fast? (viewed 19939 times)
Can we see dead stars with the naked eye? (viewed 19865 times)
How far does a galaxy extend? (viewed 19851 times)
What would happen if two stars collided? (viewed 19722 times)
How can I tell if the rock I found is a meteorite? (viewed 19716 times)
How do the astronauts communicate in space if sound cannot travel in a vacuum? (viewed 19680 times)
Why don't people walk upside-down on the bottom of the Earth? (viewed 19629 times)
Why do the explosions of Type Ia supernovae have a more predictable spectrum than those of regular Type II supernovae? (viewed 19615 times)
Can superheavy elements (such as Z=116 or 118) be formed in a supernova? Can we observe them? (viewed 19556 times)
Is the gravitational force exerted by the Earth on the Moon equal to the centripetal force acting on the Moon? (viewed 19530 times)
How fast does the Earth go at perihelion and aphelion? (viewed 19513 times)
How will a change in the speed of light affect the evolution of the Universe? (viewed 19489 times)
Can one star orbit another? (viewed 19460 times)
Can "tired light theory" explain the observed redshifts of galaxies? (viewed 19405 times)
What is a Dyson Sphere? (viewed 19357 times)
How do astronauts communicate with their families from space? (viewed 19327 times)
Wouldn't the Big Bang theory be considered a hypothesis and not a theory? (viewed 19286 times)
Do we know everything about the Sun? (viewed 19285 times)
How do we know what parameters to use when simulating the collision of the Milky Way and Andromeda? (viewed 19283 times)
How can we measure distances to more stars? (viewed 19271 times)
Is the Milky Way a collision of two galaxies? (viewed 19238 times)
How much can the location of sunset differ from due West? (viewed 19222 times)
Did I see the Aurora Borealis as a child? (viewed 19218 times)
Do you believe in UFOs? (viewed 19186 times)
Is the Sun always up for exactly 12 hours at the equator? (viewed 19155 times)
Is infinite temperature possible? (viewed 19129 times)
Why are the compositions of comets and asteroids different? (viewed 19099 times)
How does Astronomy involve Chemistry? (viewed 19085 times)
How can geometry be different in space? (viewed 19070 times)
Does the Sun have an iron surface? (viewed 19027 times)
How many Astronauts have been in space? (viewed 19022 times)
Can astronauts produce water in space? (viewed 19009 times)
Why isn't the sky bright at night if the universe has so many stars? (viewed 18986 times)
Is there such a thing as hyperspace? (viewed 18950 times)
Will we ever stop having solar eclipses because of the moon's motion away from the Earth? (viewed 18937 times)
What's so exciting about the new planet around 55 Cancri? (viewed 18886 times)
Why does the SETI project search for radio signals? (viewed 18858 times)
What does the term "visible universe" mean? (viewed 18827 times)
How do asteroids, meteors and comets disappear? (viewed 18801 times)
Why do photos of space taken from space never show any stars? (viewed 18770 times)
Will the seasons change due to precession? (viewed 18756 times)
How do we know that superclusters are the largest structures in the universe? (viewed 18728 times)
What type of energy does a black hole have? (viewed 18698 times)
Do you think it's possible to maintain life on other planets? (viewed 18686 times)
Can you use an infinite line of reflectors to send light to the edge of the Universe? (viewed 18643 times)
Why are there active volcanos on Io? (viewed 18627 times)
Do the magnitudes and colors of stars ever change? (viewed 18622 times)
What is the farthest Northern Latitude in which the Magellanic Clouds can be seen? (viewed 18607 times)
What's the object I saw that moved across the sky and then got very bright? (viewed 18580 times)
Is it true that the Sun burns off a billion tons of gas every 5 seconds? (viewed 18573 times)
Was Stonehenge built to mark solar phenomena? (viewed 18572 times)
When unmanned spacecraft accelerate in space, what causes them to slow down? (viewed 18557 times)
How big was the Sun when it first "fired up"? (viewed 18553 times)
How do we determine the age of the universe? (viewed 18537 times)
Are there any dark stars or dark galaxies made of dark matter? (viewed 18526 times)
Who (and when) discovered that the earth's axis is on a 23 degree tilt? (viewed 18525 times)
Why do clocks turn in the opposite direction from the Earth and Moon? (viewed 18496 times)
How do scientists slow light down? (viewed 18485 times)
Why does the Sun appear larger on the horizon than overhead? (viewed 18481 times)
Do astronomers believe in astrology? (viewed 18478 times)
What supernova created the Crab nebula? (viewed 18475 times)
Have gravitational waves been proven to exist? (viewed 18455 times)
When are there 5 Sundays in February? (viewed 18453 times)
Why are Saturn's rings flat? (viewed 18430 times)
How do we know the Milky Way is a spiral galaxy? (viewed 18425 times)
What happens when an antimatter black hole collides with a matter blackhole? (viewed 18345 times)
How can we know that there are other galaxies if we cannot leave ours? (viewed 18289 times)
Is there a project I can do on black holes? (viewed 18266 times)
What process would bring about a quark star? (viewed 18262 times)
Why are most months 30 or 31 days long? (viewed 18236 times)
Can astronauts play musical instruments in space? (viewed 18142 times)
Did a giant impact cause the Dark Ages? (viewed 18123 times)
Why do astronauts in space need to exercise? (viewed 18093 times)
Why do we assume that the universe is homogeneous? (viewed 18038 times)
Why do we study black holes? (viewed 18030 times)
How are planets detected around other stars? (viewed 18020 times)
Which way does the sun travel in the southern hemisphere? (viewed 17929 times)
What caused Shoemaker-Levy 9 to split up? (viewed 17928 times)
Can supernovae hinder the formation of life in galaxies? (viewed 17869 times)
What are "blue stragglers" in globular clusters? (viewed 17853 times)
How are galaxies and solar systems similar? (viewed 17843 times)
Why is the shadow on the Moon the shape it is? (viewed 17840 times)
How is it proved that the Universe is expanding? (viewed 17780 times)
Why are there no craters on Earth? Did all the meteorites miss us? (viewed 17773 times)
Is it worthwhile to continue the search for extraterrestrial life? (viewed 17770 times)
How do planets capture satellites? (viewed 17711 times)
How close does a supernova need to be to damage the Earth's environment? (viewed 17710 times)
What are the names of the three stars in Orion's belt? (viewed 17697 times)
What is sidereal time? (viewed 17691 times)
Why are stars of different masses? (viewed 17645 times)
Is there a list of the sizes of different kinds of stars? (viewed 17628 times)
What's the best thing about being an astronomer? (viewed 17570 times)
What is the solar cycle? (viewed 17567 times)
Why is Uranus tipped on its side? (viewed 17553 times)
Would extraterrestrial civilizations know that there is life on Earth? (viewed 17504 times)
Does Cerenkov radiation travel faster than light? (viewed 17493 times)
What happens to the material that has been sucked into a black hole? (viewed 17486 times)
What calculations go into predicting eclipses? (viewed 17464 times)
How long does it take the Big Dipper to move in the sky? (viewed 17458 times)
How can we see galaxies if their stars are so faint? (viewed 17401 times)
What would happen if there was a collision between two white dwarfs? (viewed 17369 times)
Why do humans want to go in space? (viewed 17360 times)
Could a different theory of gravity explain the dark matter mystery? (viewed 17337 times)
Could we send a space mission to a comet? (viewed 17321 times)
Are there stars outside of galaxies? (viewed 17298 times)
Why is the Hubble Space Telescope in space? (viewed 17290 times)
What happens when you change the mass of a White Dwarf or Neutron Star? (viewed 17262 times)
Is there sound coming from the Sun? (viewed 17260 times)
Why do so many of the world's UFO sightings happen in America? (viewed 17259 times)
Can two lunar eclipses occur in the same month? (viewed 17236 times)
Why doesn't light from distant galaxies reach us instantaneously? (viewed 17228 times)
How do we know that sunspots are associated with the Sun's magnetic field? (viewed 17225 times)
How do solar flares affect airline pilots? (viewed 17208 times)
What will happen to the Milky Way in the future? (viewed 17201 times)
How do I explain to my children why the Moon has phases? (viewed 17171 times)
How do I polar align my telescope? (viewed 17170 times)
If we invented special suits could we ever go to the sun? (viewed 17142 times)
How can we compare dark matter and dark energy? (viewed 17142 times)
Can you tell time by the Big Dipper? (viewed 17136 times)
How different would the night sky have looked in 40,000 B.C.? (viewed 17121 times)
What kind of eyepieces do I need to look at planets? (viewed 17107 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 17097 times)
Is there any possibility that the Solar System or the Universe is in a black hole? (viewed 17081 times)
Could we be seeing dead stars? (viewed 17057 times)
As the universe expands, why don't galaxies get stretched out? (viewed 17020 times)
Can double stars have planets? (viewed 17020 times)
Why is the time between two successive full moons different from the lunar synodic month? (viewed 17009 times)
What colors are visible through an amateur telescope? (viewed 16959 times)
How do we feel heat? (viewed 16933 times)
Are the properties of extrasolar planets known? (viewed 16925 times)
How do sunrise and sunset times change with altitude? (viewed 16828 times)
Do similar laws of physics throughout the Universe imply that all life must be like life on Earth? (viewed 16819 times)
How do we know if the universe will keep expanding forever? (viewed 16801 times)
Why does one side of Mars look more catastrophic than the other? (viewed 16799 times)
How powerful are quasars? (viewed 16793 times)
What is a wormhole? (viewed 16762 times)
How are asteroid compositions and classifications determined? (viewed 16735 times)
What month was it when Odysseus saw Orion in 1000BC? (viewed 16705 times)
Could our position in the universe affect our perceptions of the expansion? (viewed 16675 times)
How many comets are currently orbiting our sun? (viewed 16661 times)
Are the planes of solar systems aligned with the plane of the Galaxy? (viewed 16649 times)
Do unmanned spacecraft like Voyager travel in straight lines? (viewed 16620 times)
Could you escape from a black hole if you were able to go faster than the speed of light? (viewed 16592 times)
Can I see details on Venus? (viewed 16532 times)
What kind of telescope should I use for astrophotography? (viewed 16478 times)
Does inflation allow for an infinite number of universes? (viewed 16469 times)
What happened to all the black holes that were around in the early universe? (viewed 16460 times)
Can a black hole come back to the visual universe through a "little bang"? (viewed 16410 times)
Can I see a quasar? (viewed 16386 times)
How many sunspots can the Sun have at once? (viewed 16380 times)
Where does the kinetic energy of infalling bodies come from? (viewed 16376 times)
What equipment do I need for astrophotography? (viewed 16353 times)
Can any comparison be made between spiral galaxies and hurricanes? (viewed 16342 times)
Can the theory of formation of the solar system explain all the observables? (viewed 16338 times)
What kind of instruments are used to detect extrasolar planets? (viewed 16315 times)
How does the Earth compare in size to the entire universe at the present epoch? (viewed 16261 times)
How do I become an astronomical artist? (viewed 16170 times)
How long do supernova remnants last? (viewed 16140 times)
Can other terrestrial moons be (or have been) stable? (viewed 16135 times)
Why did the Pioneer and Voyager take only 2 years to reach Jupiter, while Galileo and Cassini took more than 5 years? (viewed 16121 times)
Does a photon observe other photons moving past it at the speed of light? (viewed 16102 times)
Why can we see the sun's image before sunrise and after sunset? (viewed 16056 times)
Why does the apparent density of galaxies drop off at larger distances? (viewed 16020 times)
Why search for only Earth-like life on other planets? (viewed 16011 times)
How can you tell if a crescent moon is preceding or following a new-moon phase? (viewed 15995 times)
Can I build an instrument to measure the size of the Sun and of the Moon? (viewed 15981 times)
Could there have been multiple Big Bangs at different places in the universe? (viewed 15966 times)
How are supernovae discovered? (viewed 15966 times)
Did I really hear a meteor? (viewed 15960 times)
Why is the Cosmic Microwave Background not absorbed by interstellar hydrogen? (viewed 15956 times)
Would the biggest airplanes cause tsunamis if they crashed? (viewed 15956 times)
What makes a satellite geosyncronise itself with Earth's orbit? (viewed 15922 times)
Are there any new craters on the moon? (viewed 15905 times)
Is the universe really like an expanding balloon? (viewed 15850 times)
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background? (viewed 15828 times)
If clocks run slow in a gravitational field, how can we know the true age of the Solar System and Universe? (viewed 15826 times)
Which part of the sky did the famous 'wow' signal originate from? (viewed 15826 times)
How was the starting point for the Julian Date system chosen? (viewed 15814 times)
Why are there blue shifted galaxies? (viewed 15806 times)
How is the Cepheid yardstick validated? (viewed 15796 times)
Is it possible for amateurs to do optical interferometry? (viewed 15783 times)
Why do some eclipses take longer than others? (viewed 15751 times)
What is meant by "stopping down a telescope"? (viewed 15734 times)
Are planetary nebulae the result of supernovae? (viewed 15646 times)
Can you give me advice on buying a telescope? (viewed 15634 times)
Why was the Platonic year named after Plato? (viewed 15629 times)
Is there a beginning and an end to a galaxy's life? (viewed 15597 times)
Why doesn't NASA build rotating spacecraft to simulate gravity? (viewed 15593 times)
Will we discover an 11th planet? What would it be called? (viewed 15448 times)
What is the difference between homogeneity and isotropy? (viewed 15432 times)
On which days can I see the Moon in the evening / morning and why is this so? (viewed 15420 times)
Why doesn't the hydrogen on Jupiter explode? (viewed 15419 times)
Would a planet near the galactic center have a brighter night sky? (viewed 15402 times)
Is it possible to build a cheap device to measure declination? (viewed 15392 times)
Can you describe a day on the job as an astronomer? (viewed 15392 times)
Did time go slower just after the Big Bang? (viewed 15384 times)
What class of spiral galaxy is the Milky Way? (viewed 15321 times)
How hot is each one of the layers of the sun? (viewed 15316 times)
What would the Big Crunch look like to an observer on Earth? (viewed 15291 times)
What is a Cepheid variable? (viewed 15289 times)
How can we tell what the interiors of planets are like? (viewed 15264 times)
If comets are boiling away, why are there any left? (viewed 15238 times)
Could you tell me about the life cycle of galaxies? (viewed 15232 times)
Why don't astronauts sublimate in space? (viewed 15223 times)
What happened to the girl who named Pluto? (viewed 15187 times)
How are sunspots formed? (viewed 15174 times)
Can the Space Shuttle abort and return to Earth before reaching orbit? (viewed 15151 times)
How do astronomers come up with their facts? (viewed 15134 times)
Why is pressure broadening greater in low mass stars than in high mass stars? (viewed 15070 times)
Where can I find information on the moons of other planets? (viewed 15037 times)
Why aren't discoveries of extrasolar planets reported on the news? (viewed 15028 times)
What is our galaxy's halo made of, and how was it formed? (viewed 15028 times)
Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating? (viewed 15021 times)
Will I be able to see the shadow of the Moon streaking towards me in a total solar eclipse? (viewed 15000 times)
What is the SU(3) quark model? (viewed 14986 times)
Does the shuttle worry about space junk? (viewed 14921 times)
Can HST see the Oort cloud? (viewed 14848 times)
Can astronomers observe anything when the moon is full? (viewed 14838 times)
What is the origin of the stellar classification system "OBAFGKM"? (viewed 14838 times)
Do galaxies orbit around anything? (viewed 14807 times)
How are astronomy and poetry linked? (viewed 14792 times)
Can the acceleration of the Universe be analogous to apparent acceleration in a airplane? (viewed 14784 times)
What are the boundaries of the constellations? (viewed 14734 times)
Does the Sun have any heavy elements? (viewed 14726 times)
Why is NASA shutting down the Hubble Space Telescope? (viewed 14722 times)
What's new with the Big Bang? (viewed 14651 times)
Why do supernova remnants look like rings rather than spheres? (viewed 14603 times)
Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations? (viewed 14540 times)
Why doesn't SETI concentrate its observations to the nearby stars and the solar systems that we are discovering? (viewed 14533 times)
How can we find galaxies behind the Milky Way? (viewed 14513 times)
How could galaxies have gotten so far away in only 15 billion years? (viewed 14512 times)
Why are telescopes kept in cold conditions? (viewed 14445 times)
Can I listen to the SETI@home radio signal? (viewed 14438 times)
What is the best time of the year to see eclipses? (viewed 14420 times)
Where was the water in the big bang? (viewed 14412 times)
Did I find a rock that came from the Moon? (viewed 14382 times)
Do electrons age? (viewed 14373 times)
How can the Sun have such a strong gravitational field if it's made of gasses? (viewed 14362 times)
How do astronomers measure the radius of a star? (viewed 14353 times)
Why are there more maria on the near side of the Moon? (viewed 14352 times)
Could photons be dark matter? (viewed 14335 times)
Is light of different colors affected differently by gravity? (viewed 14289 times)
Why can't relative velocities add up to more than the speed of light? (viewed 14284 times)
How long is twilight on the Moon? (viewed 14245 times)
Do stars' orbits in galaxies obey Kepler's Laws? (viewed 14189 times)
How do we know what other planets (and stars, galaxies, etc.) are made of? (viewed 14139 times)
What causes gamma ray bursts? (viewed 14133 times)
How fast do particles travel in space? (viewed 14075 times)
Does the temperature of matter increase as it is accelerated to relativistic speeds? (viewed 14061 times)
How do bars form in spiral galaxies? (viewed 14045 times)
What would an "open geometry" for the universe look like? (viewed 14044 times)
How long has humanity known that we live in a galaxy similar to others in the Universe? (viewed 14006 times)
Do we see the same stars from above and below the equator? (viewed 13974 times)
What was that eclipse I saw in the sky? (viewed 13949 times)
What causes a particle to decay? (viewed 13922 times)
How do photons from distant objects maintain enough energy to reach us? (viewed 13837 times)
How much power is contained in a beam of light? (viewed 13832 times)
Can we make a movie of the Milky Way galaxy's rotation? (viewed 13784 times)
How do we find out about the star formation histories of galaxies? (viewed 13775 times)
Will the next generation telescope OWL be able to detect an Earth like extrasolar planet? (viewed 13749 times)
Why is it important to study meteorites? (viewed 13724 times)
Will the diameter of a cluster of galaxies change with redshift? (viewed 13713 times)
What do "homogeneity" and "isotropy" mean? (viewed 13620 times)
How do you classify galaxies? (viewed 13570 times)
Are the asteroids the remains of a planet which broke apart? (viewed 13560 times)
When did people discover that the Sun is a star? (viewed 13560 times)
What are "curled" dimensions? (viewed 13557 times)
Can you tell me the characteristics of W, R, N and S type stars? (viewed 13537 times)
Why are accretion disks flat? (viewed 13526 times)
How can I contribute to science as an amateur astronomer? (viewed 13460 times)
What kinds of star clusters are there? (viewed 13459 times)
Is there oxygen in the atmospheres of other planets? (viewed 13433 times)
Did the Sumerians measure precession? (viewed 13419 times)
How can we understand the meaning of large numbers like "a million million?" (viewed 13350 times)
Will the Leonid meteor shower go away? (viewed 13268 times)
Wouldn't the vast distances of space distort SETI signals into unintelligeble forms? (viewed 13245 times)
What kind of interference must astronomers contend with when observing? (viewed 13234 times)
How does interferometry work? (viewed 13182 times)
Do we have to worry about relativity when studying galactic objects? (viewed 13166 times)
Why are telescopes located in remote places? (viewed 13151 times)
Could we send a manned mission to the outer planets? (viewed 13125 times)
Why can we have solar eclipses? (viewed 13087 times)
What do stellar classifications mean? (viewed 13080 times)
What is the best way to see the Milky Way? (viewed 13073 times)
How do distant galaxies differ from those nearby? (viewed 12968 times)
What is the farthest in space that we have gone? (viewed 12929 times)
How do astronomers observe the Sun's interior? (viewed 12876 times)
How can I watch the Perseid meteor shower? (viewed 12770 times)
Why do spacecraft need heat shields coming back to Earth but not leaving? (viewed 12758 times)
How does melting a material reset its radioactive clock? (viewed 12753 times)
Will astronauts ever be able to go ice-skating on Europa? (viewed 12732 times)
How are astronauts trained for weightlessness? (viewed 12688 times)
How are photons created and destroyed? (viewed 12633 times)
What is the three-body problem? (viewed 12630 times)
How can I nominate myself for a Nobel Prize in Physics? (viewed 12583 times)
How did Mars get so dusty? (viewed 12552 times)
How can you tell the difference between single and multiple extrasolar planets? (viewed 12546 times)
Is cosmic expansion happening on microscopic scales? (viewed 12533 times)
Do we really observe the edges of galaxies at different epochs? (viewed 12430 times)
How does a star take mass from another star? (viewed 12392 times)
Where can I see Newton's original reflecting telescope? (viewed 12355 times)
How can I find out if the new moon has been sighted? (viewed 12156 times)
How can water be chemically trapped in rocks? (viewed 12133 times)
Why is the WMAP picture of the CMB an ellipse? (viewed 12088 times)
Do asteroids hit the sun? (viewed 12058 times)
If the universe is "bounded" today, could it one day become "unbounded"? (viewed 12036 times)
Do binary or triple star systems form together? (viewed 12029 times)
How does libration allow us to see more than 50% of the Moon? (viewed 11763 times)
Is light blueshifted when it is gravitationally lensed? (viewed 11757 times)
What percent of the time can astronomers observe without interference from the Moon? (viewed 11743 times)
Why will fusion wait until hydrogen is gone before starting to fuse heavier atoms? (viewed 11742 times)
Is the Local Group expanding along with the entire Universe? (viewed 11724 times)
What color would Mars be if you were standing on it? (viewed 11530 times)
No matter how fast the universe is expanding, shouldn't gravity eventually make it recollapse? (viewed 11484 times)
If the Universe was infinitely dense at the Big Bang, why didn't time stand still? (viewed 11455 times)
How do unmanned space probes avoid running into things? (viewed 11410 times)
What kinds of cancer research have been done in space? (viewed 11407 times)
What is "nothing", from a scientific point of view? (viewed 11391 times)
Do asteroids ever do anything good in the Solar System? (viewed 11361 times)
Why aren't accretion disks around giant stars as hot as accretion disks around black holes? (viewed 11213 times)
What is Hot Dark Matter theory? (viewed 11097 times)
How can observations of the distant universe prove that the expansion is accelerating *now*? (viewed 11070 times)
How can the universe be "flat"? We're 3D! (viewed 10975 times)
Why is it easier to see a star if you look slightly to the side? (viewed 10954 times)
What would happen if you went back in time and killed your grandmother? (viewed 10935 times)
Could matter-anti-matter repulsion power the expansion of the universe? (viewed 10908 times)
What do meteorites tell us about life on other planets? (viewed 10548 times)
Why is it called astronomy when all the other sciences end in -ology? (viewed 10461 times)
What is the photoelectric effect? Why can't multiple low-frequency photons free an electron? (viewed 10461 times)
Why don't all neutron stars become pulsars? (viewed 10452 times)
Could neutrinos be dark matter? (viewed 10403 times)
What are collections of galaxies called? (viewed 10348 times)
Can a human give birth in space? (viewed 10265 times)
Are there any 'lonely galaxies'? (viewed 10250 times)
How are planets affected by the Hot Ionised Medium? (viewed 10180 times)
What was different on Mars in the past to allow liquid water to be present? (viewed 10037 times)
What is the relationship between the width of a star trail on a photo and the star's intensity? (viewed 9992 times)
How can we discern different galaxies/clusters along the same line of sight? (viewed 9900 times)
During close approaches, can Mars appear in our sky as large as the Moon? (viewed 9823 times)
Why doesn't the ammonia and methane in Jupiter's atmosphere sink into the core? (viewed 9751 times)
Why was Mir burnt up in the atmosphere? (viewed 9676 times)
Do constellations looks the same from space? (viewed 9654 times)
What are the largest radio wavelengths observed from radio sources in the sky? (viewed 9369 times)
How does the color index of a star relate to its actual color? (viewed 9081 times)
Does lunar gardening really work? (viewed 9005 times)
Do the Earth's magnetic poles ever change places? (viewed 8958 times)
Is it a coincidence that we can have total solar eclipses? Are there other planets which also have them? (viewed 8923 times)
How big is the Hubble Ultra Deep Field image? (viewed 8717 times)
Why is the sky blue and not blue & purple? (viewed 8678 times)
How do we detect incoming meteorites? (viewed 8504 times)
Could the Universe's dark matter be made up of black holes? (viewed 8419 times)
Is the green flash real? (viewed 8180 times)
If nothing can escape a black hole, why do some black holes have jets? (viewed 7692 times)
If the sun went out and our atmosphere froze solid, what color would it be? (viewed 7584 times)
Does weightlessness affect hunger? (viewed 7518 times)
How do we know the density of some extrasolar planets? (viewed 6943 times)
Can we harvest H & O from space to make water? (viewed 6224 times)
Can the sun rise from the west on Mars? (viewed 6147 times)
What would happen if a human were exposed to space without wearing a spacesuit? (viewed 5974 times)
Are black holes spherical? (viewed 5647 times)
What is between the Oort cloud and the closest star? (viewed 5635 times)
Has anyone ever seen a star "turn on"? (viewed 5263 times)
Why don't skydivers burn up like meteors? (viewed 4782 times)
When measuring the expansion of the universe, do astronomers consider that they're seeing how galaxies moved long ago, not today? (viewed 4620 times)
Did the Moon or planets form in a manner similar to that of Earth? (viewed 4606 times)
What would happen if a nuclear-powered shuttle exploded? (viewed 4535 times)
Does the Milky Way spin counter-clockwise? If so, do all spiral galaxies spin in this direction and why? (viewed 4374 times)
Can we prove that the Moon isn't hollow? (viewed 4342 times)
When will Hale-Bopp return? (viewed 4273 times)
Could a planetary system survive if its star merged with another, or if its star went supernova? (viewed 4239 times)
Why are craters round? (viewed 4011 times)
Is it sensible to consider terraforming Mars? (viewed 3871 times)
Do planets radiate noise? (viewed 3760 times)
How do supernovae show us that the Universe's expansion is accelerating? (viewed 3733 times)
Can planets collide with one another? (viewed 3546 times)
If there are infinity universes, will every thing that is possible happen? (viewed 3279 times)
Are there solar tides? (viewed 3243 times)
When will humans travel to Mars and revisit the Moon? (viewed 3095 times)
Will the Pioneer and Voyager probes ever leave the Milky Way? (viewed 2382 times)
Where is the Spitzer Space Telescope? (viewed 2331 times)
If I were traveling through space, could I see distant galaxies with my own eyes? (viewed 2154 times)
Does the particles involved in a star's final core collapse travel faster than the speed of light? (viewed 1876 times)
Is Earth-moon tidal friction causing global warming? (viewed 1865 times)
Do more meteorites fall at low latitudes? (viewed 1684 times)
Is the moon spherical? (viewed 1493 times)
Why does Titan, in spite of being smaller than Mars, have an atmosphere more dense than Earth's? (viewed 1448 times)
When is the best time to observe zodiacal light? (viewed 1329 times)
The naming of Mars (viewed 1314 times)
Is the reddish dust of Mars biogenic? (viewed 1206 times)
What are the possible ends of the universe? (viewed 1155 times)
Why does Mars have a dusty atmosphere? (viewed 1114 times)
Is dark energy affected by black holes? (viewed 819 times)
What color are meteors? (viewed 535 times)
How has light from 13 billion years ago not passed us by? (viewed 522 times)

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