Astronomy FAQ
Frequently Asked Questions about Astronomy.
This FAQ about Astronomy was compiled and written by Joseph Lazio (jlazio@patriot.net) with numerous contributions by others.
01 Introduction (Astronomy)- sci.astro is a newsgroup devoted to the discussion of the science ...
- 02 Copyright (Astronomy)
- This document, as a collection, is Copyright 1995--2003 by T. ...
- 03 What are the sci.astro newsgroups about?
- Author: Philippe Brieu
,...
- 04 How do I subscribe to sci.astro?
- By Joseph Lazio
- 05 What are the guidelines for posting on astronomy (sci.astro) newsgroups?
- By Philippe Brieu
,...
- 06 What should I do if I see an article that doesn't follow these guidelines? (What about cranks?) (astronomy)
- By Philippe Brieu
,...
- 07 Can I get help on my homework from the Net? (astronomy)
- By Philippe Brieu
,...
- 09 How can I find contact addresses for astronomers/observatories?
- By Ralph Martin
- 10 Which observatories offer tours or public viewing? (Astronomy)
- By Joseph Lazio
- 11 Is there a list of astro jokes?
- Of course! Astronomy is not an entirely sirius subject. Rather than ...
- 12 What are good books on astronomy (especially for beginners)?
- By Hartmut Frommert
- 13 Are there other sources of information? (Astronomy)
- By Hartmut Frommert
- 14 How can I find an astronomy club?
- By Joseph Lazio
- 15 Where can I find out about public lectures or star parties?
- By Joseph Lazio
- 17 What are the largest telescopes?
- By Bill Arnett
- 18 What new telescopes/instruments are being built?
- By Bill Arnett
- 19 04 What is the resolution of a telescope?
- By Steve Willner
- 20 What's the difference between astronomy and astrology?
- By Phillippe Brieu
- 22 What about God and the creation?
- By Joseph Lazio
- 23 What kind of telescope should I buy?
- See the Purchasing Amateur Telescopes FAQ, posted regularly ...
- 24 What are the possessive adjectives for the planets? (Astronomy)
- By Steve Willner
- 27 Is it O.K. to look at the Sun or solar eclipses using exposed film? CDs?
- By Joseph Lazio
- 28 Can stars be seen in the daytime from the bottom of a tall chimney, a deep well, or deep mine shaft?
- By Michael Dworetsky
- 29 Why do eggs balance on the equinox?
- By Bob Riddle
- 30 Is the Earth's sky blue because its atmosphere is nitrogen and oxygen? Or could other planets also have blue skies?
- By Paul Schlyter
- 31 What are the Lagrangian (L) points?
- By Joseph Lazio
- 32 Are humans affected psychologically and/or physically by lunar cycles?
- By Joseph Lazio
- 33 How do I become an astronomer? What school should I attend?
- By Suzanne H. Jacoby
- 34 What was the Star of Bethlehem?
- By Mike Dworetsky
- 35 Is it possible to see the Moon landing sites?
- By David W. Knisely
- 37 What are all those different kinds of time? (Astronomy)
- By Paul Schlyter
- 38 How do I compute astronomical phenomena for my location?
- By Paul Schlyter
- 39 What's a Julian date? modified Julian date?
- By Edward Wright
- 40 Is 2000 a leap year?
- By Steve Willner
- 41 When will the new millennium start?
- By Steve Willner
- 42 When is Easter?
- By Jim Van Nuland
- 43 Can I calculate the date of Easter?
- By Bill Jefferys
- 44 What is a "blue moon?"
- By Steve Willner
- 45 What is the Green Flash (or Green Ray)?
- By Steve Willner
- 46 Why isn't the earliest Sunrise (and latest Sunset) on the longest day of the year?
- By Steve Willner
- 47 How do I calculate the phase of the moon?
- By Bill Jefferys
- 48 What is the time delivered by a GPS receiver?
- By Markus Kuhn
- 49 Why are there two tides a day and not just one?
- By Joseph Lazio
- 50 Do neutrinos have rest mass? What if they do?
- By Joseph Lazio
- 51 Have physical constants changed with time?
- By Steve Carlip
- 52 What is gravity?
- By Steve Carlip
- 53 Does gravity travel at the speed of light?
- By Steve Carlip
- 54 What are gravitational waves?
- Author: Bradford Holden
- 55 Can gravitational waves be detected?
- By Bradford Holden
- 56 Do gravitational waves travel at the speed of light?
- See sci.physics FAQ part 2,...
- 57 Why can't light escape from a black hole?
- By William H. Mook, Jr.
- 58 How can gravity escape from a black hole?
- By Matthew P Wiener
- 59 What are tachyons? Are they real?
- By William H. Mook, Jr.
- 60 What are magnetic monopoles? Are they real?
- Short answer is that magnetic monopoles are the magnetic equivalent ...
- 61 What is the temperature in space?
- By Steve Willner
- 62 Saturn's rings, proto-planetary disks, accretion disks---Why are disks so common?
- By Michael Richmond
- 63 How did the solar system form?
- By Joseph Lazio
- 64 Has anyone attempted to discern details of the star that went supernova and formed our local group of stars?
- By Joseph Lazio
- 65 What is the "Solar Neutrino Problem?"
- By Bruce Scott TOK
- 66 Could the Sun be part of a binary (multiple) star system?
- By Bill Owen
- 67 When will the Sun die? How?
- By Erik Max Francis
- 68 What happens to the planets when the Sun dies?
- By Joseph Lazio
- 69 Could the Sun explode?
- By Erik Max Francis
- 70 How are solar system objects and features named?
- By Bill Owen
- 71 Where can I find pictures and planetary data?
- See Part 1 of this FAQ, ...
- 72 Could Jupiter become a star?
- By Erik Max Francis
- 73 Is Pluto a planet? Is Ceres? Is Titan?
- By Andy Rivkin
- 74 Additional planets (Astronomy - Pluto)
- In addition to the questions answered here, addition info is ...
- 75 What about a planet (Planet X) outside Pluto's orbit?
- By Ron Baalke
- 76 What about a planet inside Mercury's orbit?
- By Paul Schlyter
- 77 Won't there be catastrophes when the planets align in the year 2000?
- By Laz Marhenke
- 78 Earth-Moon system
- Related questions include ...
- 79 Why doesn't the Moon rotate?
- By Laz Marhenke
- 80 Why does the Moon always show the same face to the Earth?
- By Laz Marhenke
- 81 Is the Moon moving away from the Earth? (and why is Phobos moving closer to Mars?)
- By Richard A. Schumacher
- 82 What was the origin of the Moon?
- By George Cummings
- 83 What's the difference between a solar and lunar eclipse? Where can I find more information about eclipses?
- By Joseph Lazio
- 84 What's the Oort Cloud and Kuiper Belt?
- By Joseph Lazio
- 85 Asteroid Impacts
- Much of the material in this section is drawn from the ...
- 86 What would be the effects of an asteroid impact on the Earth?
- By Joseph Lazio
- 87 What can we do about avoiding impacts?
- By Joseph Lazio
- 88 I heard that an asteroid was going to hit the Earth?!
- By Louis Strous
- 89 What's the difference between meteoroids, meteors, and meteorites?
- Briefly, a meteoroid is piece of cosmic debris in the solar system....
- 90 How do we know that meteorites are from the Mars? (or the Moon?)
- [This question comes up most frequently with reference to ALH 84001,...
- 91 What is life?
- By T. Joseph W. Lazio
- 92 Life in the Solar System
- Within the past 100--150 years, the conventional wisdom regarding ...
- 93 Is there life on Mars?
- Author: Steve Willner
- 94 Is there life in Jupiter (or Saturn)?
- Jupiter (and Saturn) has no solid surface, like the Earth. Rather ...
- 95 Is there life on Jupiter's moon, Europa?
- This article is adapted from NASA Press Releases....
- 96 Is there life on Saturn's moon Titan?
- By T. Joseph W. Lazio
- 97 What is the Drake equation?
- By John Pike
- 98 What is the Fermi paradox?
- By John Pike
- 99 Could we detect extraterrestrial life?
- By Steve Willner
- 100 How far away could we detect radio transmissions?
- By Al Aburto
- 101 What's a Dyson spheres?
- By Anders Sandberg
- 102 What is happening with SETI now?
- By Larry Klaes
- 104 Why do we assume that other beings must be based on carbon? Why couldn't organisms be based on other substances?
- By Joseph Lazio
- 105 Could life occur on an interstellar planet?
- By Joseph Lazio
- 106 What are all those different kinds of stars? General overview and main sequence stars
- By Steve Willner
- 107 What are all those different kinds of stars? White Dwarfs How are white dwarfs classified? What do the spectral types DA, DC, etc. mean?
- By Mike Dworetsky
- 108 What are all those different kinds of stars? Neutron Stars
- By Joseph Lazio
- 109 What are all those different kinds of stars? Black Holes
- By Joseph Lazio
- 110 Are there any green stars?
- By Paul Schlyter
- 111 What are the biggest and smallest stars?
- By Ken Croswell,...
- 112 What fraction of stars are in multiple systems?
- By John E. Gizis
- 113 Where can I get stellar data (especially distances)?
- By Steve Willner
- 114 Which nearby stars might become supernovae?
- By Steve Willner
- 115 What will happen on Earth if a nearby star explodes?
- A nice article by Michael Richmond
- 116 How are stars named? Can I name/buy one?
- By Kevin D. Conod
- 118 What happens to the planets when a planetary nebula is formed? Do they get flung out of the solar system?
- By Joseph Lazio
- 119 How far away is the farthest star?
- By Joseph Lazio
- 120 Do star maps (or galaxy maps) correct for the motions of the stars?
- By Joseph Lazio
- 121 How many stars, galaxies, clusters, QSO's etc. in the Universe?
- The various parts of this question will be considered separately....
- 122 How many galaxies in the Universe?
- By William Keel
- 123 How many globular clusters in the Milky Way?
- By William Keel
- 124 How many open clusters?
- By William Keel
- 125 Is there dark matter in the Universe?
- By Will Sutherland
- 126 Evidence for dark matter
- There are many independent lines of evidence that most of the ...
- 127 How much dark matter is there?
- A convenient way of quoting mass estimates is via Omega, the ratio ...
- 128 What is the dark matter?
- Since it's detected in a negative sense---not visible in gamma rays,...
- 129 Searches for Dark Matter
- There are many searches now underway for the dark matter. ...
- 130 What is the Hubble constant? What is the best value?
- By Steve Willner
- 131 How are galaxy distances measured?
- By Martin Hardcastle
- 132 When people speak of galaxies X billion light years away, does this mean they are that far away now or were that far away when the light left them?
- By William Keel
- 133 What are QSO's ("quasars")?
- By Martin Hardcastle
- 134 Are the QSO's really at their redshift distances?
- By Martin Hardcastle
- 135 What about apparent faster-than-light motions?
- By Martin Hardcastle
- 136 What's the Local Group?
- By Hartmut Frommert
- 137 What do we know about the properties of the Universe?
- There are three key facts we know about the properties of ...
- 138 Why do astronomers favor the Big Bang model of the Universe?
- The fundamental properties of the Universe, summarized above, one ...
- 139 Where is the center of the Universe?
- Often when people are told that galaxies are receding from us, ...
- 140 What do people mean by an "open," "flat," or "closed" Universe?
- These different descriptions concern the future of the Universe,...
- 141 If the Universe is expanding, what about me? or the Earth? or the Solar System?
- You, the reader, are not expanding, even though the Universe in ...
- 142 What is inflation?
- The inflationary scenario, developed by Starobinsky and by Guth,...
- 143 How can the Big Bang (or inflation) be right? Doesn't it violate the idea that nothing can move faster than light? (Also, can objects expand away from us faster than the speed of light?)
- In the Big Bang model the *distance* between galaxies increases, ...
- 144 If the Universe is only 10 billion years old, how can we see objects that are now 30 billion light years away? Why isn't the most distant object we can see only 5 billion light years away?
- When talking about the distance of a moving object, we mean ...
- 145 How can the oldest stars in the Universe be older than the Universe?
- Obviously, the Universe has to be older than the oldest stars ...
- 146 What is the Universe expanding into?
- This question is based on the ever popular misconception that ...
- 147 Are galaxies really moving away from us or is space-time just expanding?
- This depends on how you measure things, or your choice of coordinates....
- 148 How can the Universe be infinite if it was all concentrated into a point at the Big Bang?
- Only the *observable* Universe was concentrated into a point at ...
- 149 Why haven't the CMB photons outrun the galaxies in the Big Bang?
- Once again, this question assumes that the Big Bang was an ...
- 150 Can the CMB be redshifted starlight?
- No! The CMB radiation is such a perfect fit to a blackbody that ...
- 151 Why is the sky dark at night? (Olbers' paradox)
- If the Universe were infinitely old, infinite in extent, and ...
- 152 What about objects with discordant redshifts?
- A common objection to the Big Bang model is that redshifts do ...
- 154 There are different ways to measure distances in cosmology?
- By Joseph Lazio
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