Ask an Astrophysicist

• What's it like being an astronomer?
• Can you tell me about the different aspects of your job as an astronomer?
• How much math do astronomers use?
• Are there more men or women astronomers?
• Where can I find information on how to become an astronomer?
• What is the annual salary of an astrophysicist?
• Are there still jobs available in astronomy?
• Who, other than NASA, employs high-energy astrophysicists?
• Which institutions offer the best programs in astrophysics?
• Where would you go to study astrobiology?
• I have a new theory about astrophysics. Can I get it copyrighted?
• A student from India wants know how to become an astronomer.
• Do you have advice for one who wants to be a Theoretical Physicist?
• What does it take to work for NASA?
• How much of a social life do scientists have?
• Can you give me suggestions about becoming a robotics engineer?

• What is Cygnus X-1?
• What is the cause of X-ray bursts?
• Do companion stars survive SN events in binary star systems?
• What is the smallest nova ever found?
• What is an accretion disk in a binary star system?
• Why are binary stars interesting?
• How do binary stars get detected when you can't see them?
• What percentage of the stars are binary systems?
• Could planets exist in stable orbits around binary stars?
• Why are there so many binary and multiple star systems?
• How are binary star systems formed?

• How many black holes are currently known?
• Where is, and how far is the nearest known Black Hole?
• Is it true that time stops at the Event Horizon?
• If light has no mass, how can it get trapped in a Black Hole?
• Will black holes consume everything in the universe?
• Will the Large Hadron Collider produce Earth-destroying black holes?
• Could the Big Bang have been a Black/White Hole?
• Are black holes flat?
• Do white holes exist?
• Could Black Holes be connected to White Holes?
• Can black holes/worm holes transport you to other worlds?
• Who was the first person to discover a black hole and what was the date?
• How has it been demonstrated that black holes are real?
• Have X-rays been used to confirm the existence of black holes?
• What evidence is there for a black hole at the center of our Galaxy?
• What is known about Sagittarius A*, the center of our galaxy?
• Are there any pictures of black holes or of the edge of the Universe?
• How would a black hole look, if one came in front of a star field?
• What is the volume of a black hole?
• How does a black hole move through Spacetime?
• Could there be more than four dimensions in a Black Hole?
• What is the difference between stellar and galactic black holes?
• What properties define a black hole?
• How could I model a black hole for a science project?
• What would happen to Earth's orbit if the Sun became a black hole?
• How can a black hole only 2 to 3 kilometers big eat a star?
• What happens when you orbit a black hole outside the Event Horizon or fall into a black hole?
• What would happen if a black hole passed through a star?
• What would happen if a star were launched into a black hole?
• Do black holes ever collide?
• What would happen if two Black Holes merged?
• What happens to the material absorbed into black holes?
• What is the name for the center of a black hole?
• Is the singularity in M87 the same volume as a stellar one?
• What happens to the accreted matter once it has collapsed into the singularity?
• How can a Black Hole have zero volume and infinite density?
• How can a black holes singularity have zero volume?
• When light enters a black hole does it curve or is it bent?
• If time comes to a standstill in a black hole, where does time began again out side the black hole?
• How do black holes emit X-rays?
• Why does accretion of matter onto black holes make them luminous?
• Is it possible that high speed (close to c) particles are flying around a neutron star/black hole?
• Why are there bipolar jets associated with black holes?3a
• Can black holes be used as a power source?
• Are there any sub-atomic particles that are able to escape a hole's event horizon?
• How is it possible for black holes to emit matter even if their gravity field is so intense?
• Will black holes evaporate?
• Can you explain Hawking Radiation in more detail?
• What is the temperature of a black hole?
• How are black holes formed by supernovae?
• What force causes the compression of matter to a singularity?
• Can black holes be formed from lower mass stars?
• Are supermassive black holes and host galaxy sizes related?
• How are medium sized Black Holes formed?
• What is gravity's effect on itself?
• Does the gravitational field of a black hole pull objects in faster than the speed of light?
• What is Quantum Gravity and how does it relate to Black Holes?
• How does gravity escape from black holes?
• What are the meaning of the letters in the "BKZS Limit"?
• Can you explain what a Kerr Black Hole is?

• Why is the study of cosmic rays important?
• Who first discovered anti-matter?
• What is the effect of cosmic rays on other bodies? How do they get accelerated?
• Could ozone depletion be caused by cosmic rays?
• What are the different compositions and origins of Cosmic Rays?
• Where do extrasolar cosmic rays originate?
• How do cosmic rays produce Lithium?
• Is there a limit to how energetic cosmic rays can be?
• Are there any non-solar cosmic-ray cycles?
• Can Cosmic Rays be seen?
• What do Cosmic Rays tell us about potentially Earth-destroying black holes?

• Where in the Universe did the Big Bang originate?
• What was before the Big Bang?
• Was there time before the Big Bang?
• If all the distant galaxies are flying away from us, does that mean that we're in the center of the Universe?
• What is the Universe expanding into?
• What is at the edge of the Universe?
• If the universe is expanding like a balloon, is it hollow?
• How can we see light that should have already passed us?
• Could the Big Bang have been a Black/White Hole?
• Is it possible that there are many Universes?
• What does the evidence tell us about the origin of the Universe and what is the evidence that concludes this point?
• What was Friedman's theory on the expansion of the universe?
• What does the concept of relative time frames mean for the Universe's expansion?
• How much energy was released in the Big Bang?
• Where is the newest information on inflation theory?
• Doesn't faster than light inflation violate Relativity?
• Will the universe acceleration exceed the speed of light?
• Does time slow down in distant galaxies?
• Is the Universe rotating? With reference to what?
• What holds the Universe together? What holds us together?
• What is the longevity of light?
• How can galaxies merge in a expanding universe?
• Why dosen't the space in and between atoms also expand?
• If everything expands, how can we measure the expansion of the universe?
• How do you determine the age of the Universe?
• What is the Hubble Constant?
• How has the new Hipparcos data affected the Hubble constant and thus the estimated age of the Universe?
• How does Polaris being a Cepheid variable in a binary help us understand the expansion of the universe?
• What is the Sunyaev-Zeldovich Effect and can it be used to calculate the Hubble Constant?
• Do you have information on the Loh and Spillar test that can be used to determine the Hubble Constant?
• Is the expansion of the Universe slowing down or speeding up?
• Is the existence of a Cosmological Constant being considered?
• Is the Cosmological Constant real or not?
• The accelearted expansion of Space is not a constant.
• Is the Hubble Constant really a constant, if the Universe is expanding?
• Does the Universe have a dimension or size?
• Is the observable Universe not all of the Universe?
• Did WMAP results prove an infinite universe?
• How do you measure the size of the Universe?
• Is my conclusion about the Cosmic Particle Horizon correct?
• Can two areas of the Universe be so far away from each other that the light from area A can not reach area B?
• How can one estimate the size of the Universe if any part of it past this critical distance is forever cut off from our measurement?
• How do astronomers measure the mass of the cosmos?
• How do we find the mass of the visible Universe by finding the number of galaxies in the Universe and the mass of an average galaxy?
• What is the present accepted value of the density of the Universe?
• Can you tell me about the end of time?
• Is there enough matter in the Universe for a "Big Crunch"?
• Does the discovery of intergalactic hydrogen imply a Big Crunch?
• Will the Universe keep collapsing and re-expanding?
• Is a vacuum causing the acceleration of the universe edge?
• What is the known percentage of hydrogen in the Universe and where is it?
• If the Big Bang was pure energy, what made the matter?
• How serious is the hypothesis about anti-stars?
• Did the Big Bang also create anti-matter galaxies?
• If the Big Bang made equal amounts of matter and antimatter, where is all the antimatter?
• Can light be contained and how do we observe light from the Big Bang?
• Why is the CMB seen only in the microwave range?
• Does the CMB imply that the universe is not infinite?
• How did COBE measure the temperature of the Cosmic Background?
• What does it mean for the universe to become transparent?
• Why isn't the universe opaque after reionization?
• Shouldn't the CMB be uniform?
• Can we map the Universe before inflation?
• What is the structure of the Universe?
• Were there seeds for galaxy formation before atoms formed?
• What is the Great Attractor?
• Which formed first in the universe - galaxies or stars?
• What came first, black holes or galaxies?
• Did bigger stars in the early universe make more black holes?
• Can you explain Olbers' Paradox?
• Will a closed universe violate the 2nd law of thermodynamics?
• Will entropy increase with time as the Universe evolves?
• Could we compare the early Universe to a black hole?
• Could the Laws of Physics be different in another Universe?

• What is dark energy, and what is dark matter?
• Is dark energy the same as vacuum energy?
• Is Dark Energy a relatively recent force?
• Isn't accelerating expansion an illusion?
• What areas are at the forefront of Milky Way Studies?
• Can you tell me how dark matter affects galactic spin?
• Has there been any research with empirical results proving the existence of 'Dark Matter'?
• What is the ratio of barionic to non-barionic matter in the cosmos?
• Could the missing mass be around as energy from the Big Bang?
• Could neutrinos be the missing Dark Matter?
• Could virtual WIMPS be the Dark Matter?
• How are WIMPS distributed in a galaxy?
• Could Dark Matter be Solitons and Instantons?
• Could mini-blackholes from the Big Bang be what Dark Matter is?
• Could dark matter be gravity from other dimensions?

• When is the Sun at it's highest point in the sky?
• What is the altitude of the Sun on Equinoxes and Solstices?
• What sequence of events is necessary for the completion of one month on our calendar?
• How did Gauss calculate the date Easter will fall on?
• How does the tilt of the Earth's axis affect the seasons?
• Why is winter colder than summer?
• What causes the time asymmetry of sunrises and sunsets?
• What is Sidereal time?
• When does the new millennium start?
• Can science confirm the missing day referred to in the Bible?
• Do eggs only balance on end during the Spring Equinox?
• Is there a source that one can peruse and purchase high altitude pictures of a particular area on earth?
• Why does the Earth spin on its axis?
• How fast does the Earth rotate?
• What is the direction of rotation of Earth? Of our galaxy?
• How fast does the Earth travel around the Sun? Why, when the Earth moves at such a high rate of speed, don't we feel it?
• What effect do the tides have on the Earth's rotation rate?
• Why is Earth the only planet with an ozone layer? And why is it the only one with life and water?
• What if the hole in the ozone layer of Earth got really big?
• What are meteorites?
• How many meteorites enter our atmosphere a day?
• Did an asteroid ever hit Earth?
• Are we going to be hit by an asteroid?
• What are the effects of the solar cycle on the earth?
• How do sunspots affect the Earth?
• Are aurorae caused by solar flares?
• Is there any great danger to Earth from Solar Flares?
• What is the cause of Geomagnetic Storms?
• Can you tell me about the radiation in the Van Allen Belt?
• What are the boundaries of the South Atlantic Anomaly?
• Does the South Atlantic Anomaly rotate?
• What causes the South Atlantic Anomaly?
• Why does the moon appear during the day?
• Is there any night time on the Moon?
• Is there a dark side of the Moon?
• Why is the Moon's revolution and rotation period the same?
• How often do lunar eclipses happen?
• What do the Moon rocks Apollo brought back tell us?
• Besides water, what else is in the ice found on the moon?
• What are some of the substances found on the Moon?
• Does the Moon have a molten core?
• Can you provide me with the latest theories on the origin of the Moon?
• Does the Moon's phase affect the crime rate?

• Can you tell me more about those new planets that were found?
• How common are planetary systems around other stars?
• Can you tell me about the new solar system that has been found?
• How are solar systems created?
• Can you tell me the differences between exoplanets and brown dwarfs?
• How can you separate multiple exoplanets in radial velocity measurements?

• Tell me more about efforts to detect gamma-rays from nuclear bombs tested in space and what was actually discovered.
• Exactly how energetic are Gamma-ray Bursts?
• What is "hypernova"?
• Could the Gamma-ray burst we are seeing be the effects of the formation of a new black hole?
• How can two merging Neutron Stars make a Gamma-Ray Burst?
• Could Gamma-ray Bursts (GRBs) be caused by evaporating mini black holes as suggested by Stephan Hawking?
• What did the optical afterglow light curve of GRB990510 tell us?
• What is the danger of a close GRB to Earth?
• Has the Earth evern been hit by a GRB in the past?
• Would a Gamma-ray burst from Eta Carina going Hypernova kill us?
• Do we only see a fraction of the GRBs because they are beamed?
• How are GRB distances measured?

• How large is the Milky Way galaxy?
• Where is the Solar System located in the galaxy?
• What is our Sun's rate of speed in relation to the center of our galaxy? Is our galaxy moving as well?
• What is the age of the Milky Way compared to the Universe?
• How many stars (or what percentage) in our galaxy are 4.5 billion years old (age of the Sun) or older?
• What is the proof that the Milky Way is a barred spiral?
• Do you have any pictures of the Milky Way Galaxy from above?
• Why are far away galaxies visible to telescopes, but not the center of ours?
• Do you know where I can find information about mapping the Milky Way at different wavelengths?)
• Are there more Pop I or Pop II stars in our galaxy?
• What do you know about the dwarf galaxy that is colliding with our own?
• Was the Milky Way galaxy once a Quasar?
• How many galaxies are there in the Universe?
• What is the closest other galaxy to the Milky Way?
• Are the Magellanic Clouds moving away faster than we thought?
• What happens when galaxies collide?
• Can galaxies lose mass when they interact?
• Who first discovered the nature of galaxies?
• How do astronomers estimate the distances to other galaxies?
• How accurate are the published distances to other galaxies?
• What is the most distant known galaxy in the observable universe?
• Do all galaxies have large black holes at their center?
• What will happen to the Central Black holes when galaxies collide?
• What different types of galaxies are there?
• What are lenticular galaxies?
• Why do galaxies have their different shapes?
• What type of galaxy is the most abundent?
• What is the average size of a galaxy?
• What are the sizes of the different types of galaxies?
• What is the nature of spiral arms in galaxies?
• How can elliptical galaxies exist soon after the Big Bang?
• How is a galaxy's size determined when it forms?
• What are Dark Galaxies?
• How are the Local Group of galaxies selected?
• Do we need teraflop and petaflop computers for calculating the evolution of clusters of galaxies?
• What is the Great Attractor?

• What is interferometry?
• How cold is it in space?
• What units are used to measure distance in astronomy?
• What is a light year?
• What are the ways that distances are measured in astronomy?
• Why do most celestial bodies rotate?
• Do the Laws of Motion apply in space?
• When a star (or light source) is moving away from you, does it emit blue or red light?
• Can you explain the gravitational potential well?
• What is a plasma?
• What are the four forces of nature?
• How many chemical elements are known to exist?
• How do our eyes see light? Is light a particle or wave?
• Which method is used for actually detecting neutrinos?
• How do you receive email about the latest Astronomical events?
• Are there any astronomy search engines?
• Where can I find children's Astronomy videos and other resources?
• How do I find specific astronomy information on the Internet?
• Can you recommend any good astronomy-related science fair projects?
• Can you give me a science fair idea that has to do with gravity or inertia?
• What are the scientific principles behind hot air balloons?
• Why did ancient civilizations consider astronomy to be important?
• What is the history of astronomy? What tools did ancient astronomers use?
• Who discovered that the Earth orbits the Sun?
• Who was the first person to prove that the Earth rotates?
• How did they measure planetary and stellar distances in antiquity?
• Is technology advancing too rapidly to be safe?
• What is the Big Bang? What do you believe?
• What should I tell my daughter about the creation of the Universe?
• Can you interpret an astronomical reference for me?

• Who discovered the first pulsar?
• What is the difference between pulsars and neutron stars?
• Why do we study pulsars?
• Can you answer my many questions about pulsars?
• Why is a pulsar rotation axis and magnetic field not aligned?
• Are magnetars and pulsars related?
• How does a Magnetar form?
• Is a magnetar's mass greater than a normal neutron stars' mass?
• How far away is the nearest neutron star?
• How do you know the approximate weight of a neutron star?
• Is there a mass limit for neutron stars like there is for white dwarfs?
• What happens when a neutron star gets too massive?
• How long does a neutron star live?
• What is the "neutron star" state of matter?
• What is the news about a possible Strange Quark Star?
• How can neutron stars have a magnetic field if they are made out of neutrons?
• Is there evidence for the superfluid interior structure of neutron stars?

• What was the object I saw, which brightened and faded quickly?
• Why is the sky blue and why is the Sun red at sunrise and sunset?
• Why is space black?
• How would you recommend that I go about purchasing my first telescope?
• What magnification do telescopes need to photograph galaxies?
• How can you measure the amount of light pollution in the sky?
• Why do the stars appear to twinkle while the planets don't?
• Are there special names for the first full moon of each month?
• Why does the Moon looks much larger near the horizon (at moonset) than in the middle of the sky?
• Why does the Moon looks white in daytime while it is yellow at night?
• Why did the moon turn red during the last lunar eclipse?
• What causes a ring to appear around the moon?
• What are Sundogs and Moondogs?
• Are there planet charts?
• Would you know a place that I can find out the positions in degrees of the planets on a given day?
• How do you calculate the positions of planets from any point on Earth at any given time?
• Where can I get a chart of the Southern Skies?
• How do the stars move in the sky?
• What are the three brightest stars in the Summer Sky?
• How many stars are there, named and un-named, known to exist?
• Are the stars we see at night all from our own galaxy? How many stars are in our galaxy?
• How bright is Antares?
• Can you tell me about Fomalhaut?
• Could you give me the names of all the stars in the constellation Pegasus? What about other constellations?
• Was the present North Star Closer to the pole in 44 B.C.?
• Where are the Pleiades located in the sky and the myths that go along with them?
• What determines the starting point of the stellar magnitude scale?
• How did the stars get their names?
• What is the best way to learn how to find the constellations?
• Which constellation is directly behind the Sun when the Sun rises?
• Where can you find Sagittarius in the sky on winter and summer nights?
• What would the constellations look like if they were viewed from someplace other than Earth?
• What is a shooting star?
• What are the dates of annual meteor showers?
• How did the Milky Way get its name?
• What is the tale of the two lovers kept apart by the Milky Way?
• When is the best time to view a comet?
• Can you see satellites with the naked eye?
• Where can I find a list of all the visible satellites?

• Can you give me analogy to explain stars to young kids?
• Why do stars shine? (Middle School Level)
• Why do stars shine? (High School Level)
• Are there green stars?
• How are the temperatures of stars related to their colors?
• Can a particular star change color?
• What are the optimal wavelengths to view stars of differing spectral type?
• How do astronomers find the distances to stars?
• What is the nearest star other than the Sun?
• How many known stars are there within 100 light years of Earth?
• How many solar-type stars are within 50 light years of the Sun?
• Are stars only found in galaxies or globular clusters?
• How far is the furthest star visible from Earth
• How long does it take for the light from stars to be visible here on Earth?
• What keeps stars from crashing into one another?
• Are stars fixed or stationary?
• What are the different methods to weigh a star?
• Are there other ways to measure the mass of bodies in space rather than by gravitational means?
• How does the Sun compare to other stars, is it average?
• How long does it take a photon to leave the Sun?
• How do we know the core temperature of the Sun?
• When will the Sun become a red giant star?
• What is a red giant?
• Are there any clear pictures of red or blue giants?
• Are there stars larger than red giants? Are they candidates for black holes?
• How do red giant stars lose mass?
• What is a yellow giant?
• What is the largest known star and how big is it?
• Are there any stars larger than the Solar System in volume?
• What are R,N,C & S stars?
• How long does it take a Red Giant star to become a White Dwarf?
• Can you recommend an Internet site with information about white dwarfs?
• What is the surface temperature of a white dwarf star?
• What is a black dwarf?
• Can you explain the concept of degenerate gas pressure?
• Can a white dwarf really have a diamond core?
• What are the different types of stars?
• What are brown dwarfs?
• What kind of stars are the Cepheid variables?
• What are Wolf-Rayet stars?
• Were massive stars more common in the early Universe?
• Are there sunspots on non-solar type stars?
• Why do some Red Dwarf stars have such huge flares?
• How are stars formed, and how do they end up?
• How are large stars able to form?
• Inside a nebula, how big are the immense balls of dust and gas before they become stars?
• How can astronomers determine the age of a particular star?
• How long do stars live?
• What is the range of the lifetimes of red dwarf stars?
• What are the life cycles of the stars?
• What is the chemical composition of stars?
• Are we really made of stardust?
• What fraction of hydrogen in the universe has ever been in the stars
• Is hydrogen necessary to form a star?
• Does the chemical composition of a star have an effect on its luminosity and life span?
• What part do neutrinos play in the life cycles of stars?
• What is the cause of the Helium Flash in evolved stars?
• Why don't large mass stars become degenerate like some low mass stars?
• Do neutrinos come from only supernovae, or from all stars?
• What is a star cluster?
• Is it possible to determine the age of a star cluster?
• Were the Pleiades formed in the Orion Nebula?
• If Globular Clusters rotate, why are they still round?
• Can you tell us what the closest star to the Sun, Alpha Centauri, is made of, what its measurements are, and if it has any special assets?
• I need some information about Deneb, Rigel, Betelgeuse, and Antares.
• Can you tell me about Polaris?
• What are the evolutionary changes happening to Polaris?
• Can you tell me about Vega?

• Who discovered the quasar?
• What are Quasars? Is the Earth affected by them?
• Was the Milky Way galaxy once a Quasar?
• Can you give me detailed information about Quasars?
• How many quasars are known and how many are estimated to exist?
• Has anyone calculated the high and low limits of mass in the probable number of quasars?
• Why don't all Quasars show the nebulosity of host galaxies?
• Is the redshift of a Quasar a good indicator of its distance?
• How long is a Quasar's life and what happens when it dies?
• Why aren't there any quasars relatively close to us?
• Can you reconcile relativity and the superluminal jets from 3C273?
• What is an AGN (Active Galactic Nucleus)?
• What do some galaxies have active nuclei, while others don't?
• What is a blazar?
• What is the difference between a blazar a quasar?

• Can you recommend web sites that discuss space time?
• Have General Relativity and Special Relativity been proven?
• What evidence is there that supports the theory of curved space?
• Is gravity just warped space-time?
• Why is it not possible to travel at the speed of light?
• Can you answer my question about energy, space travelers, and relativity?
• Does anyone have an analysis of time dilation that I could read?
• Has time dilation been detected in controlled experiments?
• What is the Twin Paradox in Special Relativity and how is it resolved?
• Do photons have mass?
• If photons have no mass, how are they affected by gravity?
• If I were traveling at the speed of light, and turned on a flashlight, would it illuminate my console, or will the light "stall"?
• In gravitational lensing, why do off-centered objects appear as multiple images instead of ellipses?
• Why is the velocity of light the max speed despite its dependence on the permeability and dielectric constants?
• What do recent "faster than light" experiments imply for relativity?
• Are gravitational lenes achromatic?
• What does E=mc2 mean?
• Why is it impossible, at this point in time, to convert energy into matter?
• How fast do gravity waves travel?
• Could distant spacecrafts be used for gravity wave detection?
• How does antimatter react to gravity of normal matter?
• What is a graviton?
• If gravity is just warped space, why do we need gravitons?
• What are the experimental difficulties in 'discovering' gravitons?
• Does Quantum Uncertainty apply in Relativistic effects?
• Will humans ever be able to time travel?
• How can one prove the existence of tachyons and once proven, can they be implemented for space travel?
• Could you explain the relativity of theoretical travel through a worm hole?

• What are the types of rocket propulsion?
• What's in rocket fuel?
• What kind of fuel is used in spacecraft?
• Do today's rockets use the same fuel as the Apollo missions used in the late 60's and early 70's?
• How fast do our current spacecraft travel?
• Is a solar powered rocket possible?
• Can Helium particles push a solar sail better than sunlight?
• Is it possible for a satellite to piggy-back onto a comet?
• Can you tell me about new space propulsion systems?
• Tell me about ion propulsion.
• Is an anti-matter or nuclear propulsion drive possible?
• How many artificial satellites are there and who owns them?
• What is the altitude required for a geostationary orbit?
• What are the conditions and requirements for a Sun-synchronous satellite orbit?
• Where can I find information on the newest missions?
• Can you help me find information on two Soviet Satellites that reentered our atmosphere?
• Would you have any information on possible NASA projects to do astronomy from the Moon?

• How many times would the Earth fit into the sun?
• Does the Sun rotate?
• What manages to keep the Sun so hot all of the time? Could it burn out?
• Is the sunspot cycle and Jupiter's orbital period related?
• Are there any satellites currently studying the sun?
• What would happen to the Earth if the Sun was at Pluto's distance?
• How does the Sun just stay in one spot and how do all of the other planets stay on course/track?
• Why aren't the orbits of the planets circular?
• How can astronomers determine the Astronomical Unit (average Sun-Earth distance)?
• Did Venus and Earth ever swap orbits?
• Since Neptune and Pluto's orbits cross, will they eventually collide?
• Why is the orbit of Pluto so different than the other planets?
• How unique is the retrograde rotation of Venus?
• When will the next alignment of the planets be?
• Can an alignment of the planets affect the Earth?
• Do the moons of other planets have synchronous rotation?
• What keeps planetary rings in place?
• When were all the planets discovered?
• How large is the solar system?
• Why are the densest planets closest to the sun?
• Why do some planets have more moons than others?
• Why aren't the gas giant planets stars?
• What are some substances not found on Earth, but found on other planets or comets?
• Can you describe two or more aspects of the solar system that are not common knowledge?
• Where can I find Internet information on Planet X?
• Will Planet X end life on Earth in 2012?
• What will happen to the Solar System when the Sun evolves?
• What can you tell me about the Nemesis Star that supposedly had a hand in the extinction of the dinosaurs?
• When can I best view Mercury?
• Who discovered Venus, and when?
• When are the next transits of Venus?
• Do you have information about the oppositions of Mars?
• Is there water on Mars?
• Does Mars have precipitation?
• If all of the planets are named after Roman gods, why is it that the moons of Mars (the Roman god of war) are Deimos and Phobos (the sons of the Greek God of war)?
• Is the 'face on Mars' really only just a hill?
• Is the Jupiter referred to in the New Testament the planet or the Roman god?
• Can you walk on Jupiter? What causes its radioactivity?
• How big is Jupiter's Great Red Spot?
• How long will the Great Red Spot on Jupiter last?
• What is the average thickness of Saturn's rings?
• Do scientists still believe that diamonds can be found at the core of Uranus?
• Why are Uranus' moons named after Shakespearean characters rather than something related to Uranus?
• Is Pluto a Planet or Not?
• Are there pictures of the Asteroid Belt?
• Could the Asteroid Belt be a destroyed planet?
• When was the earliest known sighting of a comet?
• How can ice, which is a form of water and which has a finite vapor pressure, exist in the near vacuum of space?
• What happens if a comet is hit by a solar flare?
• Can you give me information about the instruments and measurements that are made of comet's tails?
• What are the remote indicators of life on Earth from space?
• Has evidence been found for life on Mars?
• What would an alien be like on Europa?
• Is there any other form of life out there?
• What are the chances of life existing outside our solar system?
• Where can I find information on extraterrestrial life?
• Could life based on an element other than carbon exist?

• What do I have to do to became an astronaut?
• What kind underwear do astronauts wear to keep warm?
• When astronauts are in space, do they get lonely?
• How do astronauts go to the bathroom in space?
• How would the unprotected human body react to the vacuum of outer space?
• What danger does solar or cosmic radiation pose to astronauts?
• How is it possible for manned space flights to survive the effects of the Van Allen Radiation Belt?
• How are the cosmonauts in MIR protected from Ultraviolet, X-Rays and Gamma-rays?
• Do you have web pages on Laika the Dog and the early Russian Space Program?
• Have bats ever flown on the Space Shuttle?
• How can I design an experiment to grow potatoes in space?
• Who was Valentina Tereshkova?
• Where can we find more information about John Glenn's spacecraft, Friendship 7?
• How long did it take to build the first space ship to the Moon?
• Can you help me find the picture of the Apollo 15 astronaut dropping the hammer and the falcon feather on the Moon?
• Was the Apollo 18 rocket flight of 1975 the last rocket to splash down?
• Do you have information on Skylab?
• Do you have any information on the Challenger?
• Where can I find information on the latest Space Telescope servicing mission?
• Do the astronauts have a hard time taking care of the Hubble Space Telescope? How is the film changed?
• What is the altitude at which the Space Shuttle orbits?
• What is the farthest a spacecraft has ever been from Earth?
• What is your opinion on exploring Mars with a vehicle capable of flight?
• What is Voyager doing now that it has left our solar system?
• Can you please tell me the facts about the launch of the Cassini Mission?
• Is crossing the asteroid belt a danger to spacecraft?
• Will space flight ever be possible for the average citizen?
• Is it possible to create artificial gravity?
• Is a manned trip to Mars and back possible very soon?
• Will we ever live on another planet?
• Within 50 years, will we be able to travel to the stars?

• Did I see a supernova?
• What is a supernova and how does it affect us?
• What is the difference between a nova and a supernova?
• Who discovered what a supernova is?
• What are the different types of supernovae?
• How long does a supernova last?
• Where does the energy for a supernova originate?
• How are supernovae detected and how can I find out when the last one occurred?
• When was the last supernova that could be seen without a telescope?
• Why aren't there as many supernovae in our galaxy as predicted?
• Are statements like "Most of the atoms of carbon, oxygen and nitrogen in our bodies came from supernovae." justified?
• How could an element heavier than iron be created?
• What is known about isotopic abundances in supernova remnants from X-rays and gamma-rays?
• Are there fewer heavy elements seen in older galaxies?
• How much do supernovae expand when they explode?
• What caused the ring around SN1987a?
• Does a newly found supernova remnant suggest a close supernova never seen?
• Can you refute claims that the Universe is only 10,000 years old?
• Is there any evidence of past extinctions from supernovae?
• Could the Earth be destroyed by a nearby supernova?
• Can we identify the SNR that helped make the Solar System?

• Where can I get a poster of the Electromagnetic Spectrum?
• Where could I find some pictures of UV radiation?
• What are the wavelengths and frequency ranges for the subdivisions of the EM Spectrum?
• What are X-rays and gamma-rays?
• Is there an upper limit to the Electromagnetic Spectrum?
• What is Space Astronomy?
• What are the limitations of ground-based astronomy?
• What is astrophysics? What is high energy astrophysics?
• How do X-rays work? (from a 5-year old)
• Who were some of the pioneers of X-ray astronomy?
• How does an X-ray Telescope work?
• What are the physical mechanisms that cause X-ray radiation?
• Did anyone analyze X-ray emission from Comet Hale-Bopp?
• How are X-rays and gamma-rays produced in space?
• What are the principle sources of X-rays and gamma-rays?
• Who discovered Gamma-rays?
• What do Gamma-ray Astronomers do?
• Do gamma-rays penetrate our atmosphere?
• I have questions about gamma-ray showers and Cerenkov detectors.
• Can gamma-rays react with CO2 in our atmosphere? If so, how?
• What happens to people who have been exposed to a lot of gamma-rays?
• Why are gamma-rays more dangerous than radio waves?
• Is it possible to have high-energy gamma-ray emission from de-excitation of nuclei?
• Does electron-positron annihilation always yields energy in the gamma-ray band?
• What is anti-matter?