Astronomy Basics

Topic Page

Questions

• Why do astronomers use scientific notation to describe sizes?
• What is astronomy?
• What types of jobs are available for those who hold a degree in astronomy?
• What is the meaning of the word astronomy?
• How would you calculate the energy of a photon with a known frequency?
• What is the difference between astronomy and astrology?
• What schools are renowned for their astronomy programs?
• What is a meteor?
• What occupations are there in the astronomy field?
• How is the acceleration of gravity calculated for planets?
• What is the difference between astrophysics and astronomy?
• How are astronomy and chemistry related?
• What is a baseline in astronomy?
• How influential is the field of physics on astronomy?
• What are shockwaves in astronomy?
• How astronomy does affect our day to day lives?
• How does astronomy affect society?
• To what effect does astronomy have on nature?
• How is astronomy related to biology?
• How does astronomy relate to chemistry?
• Is geometry important when dealing with astronomy? Why?
• How important is the use of math in the subject of astronomy?
• Why is astronomy considered a branch of Earth Science?
• What is the difference between the study of astronomy and the study of cosmology?
• What do astronomers study?
• What is a galactic wind?
• How cold is an intergalactic void?
• What is the most recent galactic cannibalism event on record? Is it possible this could occur between Andromeda and the Milky Way?
• How many atoms are in the average cubic square of interstellar space?
• How cold is intergalactic space?
• What is he intergalactic star database?
• How does cosmology differ from astronomy?
• What does cosmology mean?
• How is cosmology related to geology?
• How does cosmology effect religion?
• How is cosmology similar to archaeology?
• Why is the study of cosmology important?
• What are the differences between astrophysics and cosmology?
• What is the difference between cosmology and theodicy?
• Is cosmology applicable to all world religions?
• How is cosmology linked to philosophy?
• What types of jobs are available to individuals with a degree in cosmology?
• Why is flatness a problem is cosmology?
• What is the difference between modern and ancient cosmology?
• What are some of the biggest current breakthroughs in cosmology?
• How do cosmologists use mathematics in their job duties?
• Difference between ontology and cosmology?
• How do you distinguish between astronomy, cosmology, and astrophysics? What are their links with physics?
• How are galaxies, stars, and planets formed? In what order are they typically formed?
• What is accretion as it relates to astronomy?
• If you are in the southern hemisphere where would you see Polaris?
• How do you find constellations in the sky?
• Where in the northern hemisphere sky is the constellation Persus?
• What are some star constellations that can only be seen from the southern hemisphere?
• How many galaxies are in Orion's arm?
• Are there intergalactic planets?
• What is the difference between interstellar and intergalactic? Which is larger?
• What is the distance from ground level to outer space?
• What is in empty space?
• In astronomy, what is a void?
• Who invented the word parsec and what does it mean?
• Is absolute zero possible? How does this relate to space?
• What lies beyond the universe?
• Why is outer space devoid of gases?
• How many clusters are in the universe?
• What is a cluster of galaxies?
• How is a planet classified a planet?
• What is the distance from land to outer space?
• What keeps galactic clusters together?
• Which galaxy has the least stars per unit volume?
• What is the edge of space?
• What this space is filled with?
• How many miles from the surface of the Earth does space begin?
• What is the difference between space and outer space?
• What evidence suggests that the Milky Way contains dark matter?
• How does convection work in space?
• What is convection and how does it relate to astronomy?
• What is convection, conduction and radiation and how do these work in space?
• What is the difference between eccentricity, obliquity, and precession?
• What distinguishes a star from a planet?
• How many types of seismic waves are there?
• What are the three types of seismic waves and how do they differ?
• What direction do the three different seismic waves travel?
• Compare and contrast primary (P) and secondary (S) waves. How are they used to determine the nature of the land?
• Do seismic waves change speed?
• How can seismic waves be detected?
• How are seismic waves measured?
• What is precession?
• What is procession of the equinoxes, and how does it relate to religion?
• How do you calculate the angular velocity of precession?
• What is the difference between precession and nutation in terms of the earth's rotation?
• What evidence do we have to support earth's precession?
• What is the precession of Venus?
• How often does earth's axis complete a precession?
• What causes the precession of the earth's axis? What causes this torque? Why is it a 26,000 year cycle? What force in the solar system causes this?
• What is precession cycle? What causes it?
• What is the precession of the equinoxes? Is it scientifically valid?
• What explains the precession of the equinoxes?
• Is precession the cause of global warming?
• How are the north and south celestial poles related to the earth's axis of rotation?
• What is the ecliptic, and why is it tilted with respect to the celestial equator?
• Concerning precession of earth, is it possible that in 13,000 years it will be summer in December in the northern hemisphere? Or do we artificially change the definition of the length of the year to ensure this never happens?
• Why does the tilt of the earth's axis relative to its orbit cause the seasons as the earth revolves around the sun?
• Does precession effect seasons?
• What is precession, and how does it affect our view of the heavens?
• Which type of eclipse, lunar or solar, have most people seen? Why?
• How do we know about precession?
• How do we know precession is happening?
• How does precession affect earth?
• How does precession affect the earth's rotation and revolution?
• How does precession affect the north star?
• Is it safe to watch a solar eclipse without eye protection? A lunar eclipse?
• How does precession work?
• How is precession calculated?
• What are interstellar planets?
• What is orbital radius?
• A stellar object is emitting radiation at 1670 nm. If the detector is capturing 9 * 10^7 photons per second at this wavelength, what is the total energy of the photons detected in one hour?
• How do astronomers measure the distance of planet, stars, and galaxies?
• What does astronomy mean?
• What is an astronomical observatory?
• What does apparent and absolute motion mean in astronomy?
• What is axial tilt?
• What is multiwavelength astronomy?
• What is hydrogen shell fusion?
• How is Pythagoras's theorem used in astronomy?
• What is a Primary Atmosphere regarding a planet?
• What is the name given to the path of the Earth as seen from the sun?
• If you were to go outside and look at the sky at intervals of exactly one solar day how would the position of the sun and stars change, during daytime and during night?
• Is astronomy an earth science?
• What information about a star can be inferred from its Doppler shift?
• What are the main properties of a planet?
• What does declination mean?
• Moon rocks contain small amounts of uranium-238, which decays into lead with a half-life of 4.5 billion years. In one rock, you determine that 60% of the original uranium-238 remains, while the other 40% has decayed into lead. How old is the rock?
• What is the celestial dome?
• What is an envelope of gas surrounding a body in space?
• What does 'planetary differentiation' mean?
• What do astronomers mean by declination and ascension?
• What is the difference between a synodic period and a sidereal period? What is the difference between a synodic month and a sidereal month?
• In astronomy, what are called bolides?
• What is azimuth, altitude and declination in astronomy?
• Why is the North Star called the North Star?
• What does one light year equal in kilometers?
• What is an astronomical unit?
• When is the astronomical unit used?
• What is 1 Astronomical Unit?
• How are astronomical units, light years, and parsecs related?
• What are the units of astronomical measurement?
• How is distance measured in astronomical units?
• How do you use astronomical units and light years as measures of distance between the sun, stars and earth?
• What is the difference between an astronomical unit and a light year?
• How many AU are there in 1.00 light year?
• What is the speed of light in AU/h?
• How and when do scientists use astronomical units versus a light-year?
• How do you convert Astronomical units to parsecs?
• How do you convert light years to parsecs?
• Is an astronomical unit is larger than a light-year?
• Why are astronomical units used?
• How and why light-years are used to measure distances in the universe?
• What is a simple definition of a Parsec?
• How do we know that distance between earth and sun is 1 astronomical unit ?
• How is an astronomical unit defined?
• A new planet is discovered. Planet X is observed to orbit the sun every 300 years. What is the semi-major axis of Planet X's orbit in AU?
• When at closest approach to Earth, Planet X is observed to be 3.8 arcseconds in diameter. What is Planet X's diameter in meters?
• What are the stars we see in the sky?
• Can you see other galaxies from Earth?
• What is the probability that there is life in the universe aside from earth?
• Are there planets in other galaxies?
• Are any of the stars in the night sky actually galaxies?
• What is the possibility that there is life in the galaxy Andromeda?
• Aside from the Milky Way, what are the most studied galaxies in the universe? Why are they focused on over other galaxies?
• Why can we not see stars in other galaxies?
• What is the difference between a galaxy and a nebula? How do astronomers tell them apart?
• Can we see individual stars from other galaxies?
• Do black holes lead to other galaxies?
• How can we see other galaxies?
• How can we see other galaxies from earth?
• How can we take pictures of other galaxies?
• How do we detect other galaxies?
• How are galaxies detected?
• How do astronomers know about other galaxies?
• How do we know other galaxies exist?
• How do elliptical, irregular, and spiral galaxies differ from each other?
• How far are other galaxies from earth?
• How are other galaxies found?
• What are some examples of spiral galaxies?
• What is the name of the nearest star (excluding the sun)?
• What is the nearest star to earth called?
• Do we call other stars "suns," or is that just the name we gave to our star in our solar system?
• What planet is closest to the moon in the night sky?
• How does a galaxy differ from a star?
• How does a galaxy differ from a constellation?
• When NASA releases images of objects that are light years away, are we viewing the image in real time?
• What is the difference between Astrophysics and Cosmology?
• Why does time slow down the faster you go?
• What is the difference between Cosmology and Theodicy?
• What do cosmologists work on during their day to day job?
• What are some specific examples of how a Cosmologist uses mathematics in his/her job?
• What is a singularity in cosmology?
• What is the difference between Cosmology and Epistemology?
• What are the different branches of cosmology?
• What is the difference between hot dark matter and cold dark matter? What difference does it make to cosmology?
• Why is Cosmic Microwave Background important to cosmology?
• How are theoretical physics, astrophysics, cosmology and string theory related to one another?
• The description of some cosmologies are very intricate and involved? Why might a culture have multiple layers and sections?
• What are the major theories of cosmology?
• What is the Anthropic Principle?
• What is the cosmology constant?
• What is the cosmological argument, the teleological argument and the ontological argument?
• Why is it important for astronomers to understand the distance to other stars?
• What type of galaxy has stars that are arranged in a disk with arms that surround a central bulge?
• Can we see other galaxies without the use of a telescope?
• How far apart are galaxies? How many stars are in a galaxy?
• How are galaxies, clusters, and nebulas different?
• What is the difference between a moon and a planet?
• Do astronomers classify planets?
• How are new planets discovered?
• Do astronomers have satellites orbiting other planets in our solar system?
• Why is the sky dark at night?
• How can we see stars that no longer exist?
• Which is the brightest star in our night sky?
• What are the most common elements found in the universe?
• How do physicists study the universe?
• What is the magnitude scale in astronomy?
• What are Galaxies classified by?
• What are galaxies?
• What are galaxies? How are they classified?
• What are the three shapes of galaxies?
• What is the difference between: a star, moon, planet, galaxy, universe, and a satellite?
• What percentage of stars in the sky are actually galaxies?
• How is the size of a galaxy measured?
• What are found at the centers of most galaxies?
• What characteristics do all galaxies share? What makes them different?
• What waves are produced by stars and galaxies?
• What are the 3 closest galaxies to ours? What are their names and do any of them have the required conditions to hold life?
• If gravity clumps matter together into galaxies, why are there separate galaxies? Wouldn't all matter in the universe be in one clump?
• What really holds galaxies together - Gravity or Dark energy?
• Are galaxies moving away from each other, or towards each other?
• How are galaxies and constellations alike?
• Why are all distant galaxies redshifted?
• Are galaxies visible in the night sky?
• How galaxies formed and classified?
• What are the differences between Elliptical, Spiral, and Irregular Galaxies?
• What are 6 major stars in the constellation Ursa Major?
• What method do scientists use to tell how far a galaxy is?
• Why are spiral galaxies the most commonly observed galaxies?
• What lies between galaxies?
• What give galaxies their different shapes?
• Are Elliptical galaxies made up of old stars, containing small amounts of gas?
• What is outside our galaxy?
• How many parsec are in one kilometer?
• How many parsecs are in one mile?
• How far is a parsec?
• Is a parsec a measurement?
• What is a parsec and why is it necessary when a light year measures distance as well?
• Star A has a parallax of 0.04 seconds of arc. Star B has a parallax of 0.02 seconds of arc. Which star is more distant from the sun? What is the distance to star A from the sun, in parsecs? thanks?
• What are the similarities and differences between a parsec and a light year?
• How do astronomers determine whether to use astronomical units, light years or parsecs?
• If a star has a parallax of 0.01 arcseconds what is its distance?
• If given 17.0, 1.4, 5.0 in parsecs (distance from earth) how do you find the parallax angle in arcseconds?
• How do scientists take pictures of our universe?
• How can we take pictures of our galaxy if we can not get outside of it to do so?
• How do we have images of our universe when everything the exists is inside it?
• What is at the center of the universe?
• What is the tallest known mountain in the universe?
• What is cosmic background radiation?
• What is cosmic background radiation? Is it dangerous?
• How are we able to detect cosmic background radiation?
• What is cosmic microwave background radiation composed of?
• What is background radiation in astronomy?
• What is one of the big puzzles about the properties and behavior of large clusters of galaxies?
• What is the meaning of astronomy?
• How is trigonometry used in astronomy?
• My Star has the temperature of 3000 Kelvins. How do you use Wein's Law to calculate the wavelength for which the intensity of the radiation emitted by your star is the greatest?
• An astronomer wishes to use a safety light in the observatory that will emit low-energy photons. What would be the best color of light to use?
• What impacts do astronomers make on society?
• What was one effect of Copernicus' theory of a sun-centered solar system?
• What is Radio Astronomy?
• Has the crust over which we live already been subjected to electron degeneracy pressure? What about planets like Jupiter, Saturn which are not as dense as the inner planets?
• What is a spectrum and how are spectra used in astronomy?
• What is revolution in astronomy?
• What is the math relationship between the earth's orbital and escape velocity?
• What is an ellipse?
• Why is the Doppler effect important for astronomy?
• Why is Polaris, even in historic times, not always the pole star?
• What are redshift and blueshift In Astronomy?
• What is gravitational lensing?
• In cosmology, what is the “inflationary period”?
• If there are an infinite number of stars and infinite number of galaxies, what fills space between two different galaxies?
• What is the most common colour in the universe?
• How we differentiate between galaxies in the universe?
• What is the electromagnetic spectrum? How is it used in astronomy?
• How did galaxies form in the early universe?
• How do galaxies exist in the universe?
• How do you convert 3.2 light years to parsecs?
• What is 3.2 light years equal to?
• How long is one light year?
• How are parsecs related to light years?
• How do scientists measure a lightyear?
• What does it mean when scientists say that a planet or star is a certain amount of light years away?
• What is the difference between light seconds, light minutes and light years?
• What is 1 lightyear in meters?
• How many earth years are in 1 light year?
• Can light years be converted into earth years?
• How many miles are in a light year?
• What is the approximate physical diameter in light-years in this problem?
• How far does light travel in one minute?
• How do you convert 4 light years to earth days?
• How many light days are in a light year?
• If the distance to the nearest star is 4.2 light-years, how far away is it in AU?
• How many kilometers are in a light year?
• How many feet are in a light year?
• What do we mean by the lookback time to a distant galaxy?
• What does it mean when something is 4 or 5 light years away from us?
• How many meters are in a light year?
• How many miles is 500 million light years?
• How many years are in a lightyear?
• How do astronomers define a light year?
• What defines a light year?
• Why do the stars, sun, moon and planets appear to move?
• What is the Goldilocks Zone?
• What is String Theory?
• When can you start noticing the effects of proper motion on constellations?
• What is a constellation?
• What are circumpolar stars?
• What is General Relativity and how does it relate to astronomy?
• Why are general and special relativity important to the field of astronomy?
• What is space made of? If there is an estimated one atom per cubic meter of space, what else is filling up space?
• Where is the origin of our universe?
• Is there anything beyond our Universe?
• What is on the outside of our universe? What is the term for it?
• What came before our Universe?
• What is in the center of our universe?
• How abundant is antimatter in our universe?
• How did our universe come into existence?
• How do scientists collect data about our universe?
• How do we observe our universe?
• How does relativity explain our universe?
• How do studies and discoveries about the universe affect our lives?
• Question #56ec8
• If the universe is an expanding sphere, what space is it expanding into?
• Is the universe a sphere?
• What is on the outside of our universe?
• What is the Universe made out of?
• Do all stars and planets rotate? Are there any that have been discovered that do not rotate?
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• Question #3bf09
• Is Astrology a science?
• I have some high resolution images of the sky around the constellation of Orion. I can determine the right ascension and declination of any object on the image. Which star and galaxy catalogues should I use to identify the objects?
• What is the magnitude scale?
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• Question #92de0
• Introducing 1 AAU (Areal Astronomical Unit) for the area of a circle of radius 1 AU, how do you find 4-sd values in AAU, fot the orbital areas of solar planets?
• What makes up most of interstellar matter?
• Galaxies are classed according to what?
• Do all stars have planets, and are all planets part of solar systems?
• What do astronomers mean by a constellation?
• What do astronomers mean when they say that we are all made of star stuff?
• What does it mean to say Kepler's laws are empiracle in nature?
• How are exponents used in astronomy?
• What does it mean when space is a vacuum?
• What is the difference between an astronomer, astronomist, astrologist and astronaut?
• What does 15 degrees above north mean?
• Why was retrograde motion important in astronomy?
• What is the universe made of?
• How are galaxies different from constellations?
• How are galaxies different from nebula?
• How do galaxies affect our understanding of the universe?
• What are the different galaxies in space?
• What are the different types of galaxies near the earth?
• What different shapes can galaxies have?
• What is a reason a theory cannot become a law?
• Question #a60dd
• How do I become an astronaut or an astronomer?
• What's the order of size of suns, planets, comets, asteroids and satellites? From smallest to largest?
• How are objects kept in orbit?
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• What is the nebular hypothesis?