The Internet and other information sources


sci.astro is a newsgroup devoted to the discussion of the science of astronomy. As such its content ranges from the Earth to the farthest reaches of the Universe.

However, certain questions tend to appear fairly regularly. This document attempts to summarize answers to these questions.

This document is posted on the first and third Wednesdays of each month to the newsgroup sci.astro. It is available via anonymous ftp, and it is on the World Wide Web at the sci.astro FAQ site and Internet FAQ Archives. A partial list of worldwide mirrors (both ftp and Web) is also available. (As a general note, many other FAQs are also available from

Questions/comments/flames should be directed to the FAQ maintainer, Joseph Lazio <>.

The Internet and other information sources

[Dates in brackets are last edit.]

  1. What are the sci.astro* newsgroups about? [1999-11-04]

  2. How do I subscribe to sci.astro*? [1998-02-28]

  3. What are the guidelines for posting on astronomy (sci.astro*) newsgroups? [2003-09-18]

  4. What should I do if I see an article that doesn't follow these guidelines? (What about cranks?) [1997-02-04]

  5. Can I get help on my homework from the Net? [1995-07-26]

  6. What are good Net sites for astronomy info and images? [2003-04-27]

  7. How can I find contact addresses for astronomers/observatories? [2003-01-17]

  8. Which observatories offer tours or public viewing? [1995-09-17]

  9. Is there a list of astro jokes? [1999-12-15]

  10. What are good books on astronomy (especially for beginners)? [1995-06-27]

  11. Are there other sources of information? [1996-01-24]

  12. How can I find an astronomy club? [1996-01-24]

  13. Where can I find out about public lectures or star parties? [1995-09-17]

A.01 What are the sci.astro* newsgroups about?

Philippe Brieu <>, Walter I. Nissen Jr. CDP <>, Steven Willner <>

There are eight groups in the sci.astro hierarchy:


Astronomy discussions and information


Amateur astronomy equipment, techniques, info, etc.


The Search for ExtraTerrestrial Intelligence (SETI)


Issues related to the Flexible Image Transport System


Processing Hubble Space Telescope data. (Moderated)


Discussion of planetariums


Forum in astronomy/astrophysics research. (Moderated)


Visual observing of artificial satellites

Each group except sci.astro has a charter that defines appropriate postings. You can get the full charters via anonymous ftp.

By default, everything that is related to astronomy/astrophysics and is not covered by one of the other sci.astro.* groups is acceptable for posting in sci.astro. If something belongs in one of those groups, then it does not belong in sci.astro and should NOT be (cross)posted there. In particular, this includes all amateur observations, hardware, software, and trade (see sci.astro.amateur).

The sci.astro hierarchy is not the appropriate forum for metaphysical discussions. There are other groups for that (e.g. alt.paranet.metaphysics). Neither is it the right group to discuss astrology (alt.astrology is), which has nothing to do with astronomy, or topics such as creationism ( for that). This is a science group, not one for religion, sociology, or philosophy (even of science).

In addition, a number of topics related to astrophysics are better suited for other groups. For instance, elementary particle physics should be discussed in sci.physics.particle (but discussions of astronomical consequences are welcome in astro groups). Likewise for photons and the speed of light (sci.physics). Finally, all space related issues (e.g. spacecraft and faster than light/time travel) have a home in the* hierarchy (but astronomical results from space missions are welcome).

A.02 How do I subscribe to sci.astro*?

Joseph Lazio <>

(I've answered this question offline enough times that I thought it would be worthwhile to include it here. The FAQ is distributed widely enough that people may happen upon it through non-Usenet channels.)

In order to access sci.astro, you need an internet service provider (ISP). This could be a large commercial provider, like AOL or Prodigy in the U.S., or a more local one (check your phonebook under "Computer Networks" or "Internet"). If you're enrolled at a college or university in the U.S. (or overseas?), talk to your computer center; many colleges and universities are now providing free Internet access to students. If you don't have an ISP, you'll have to choose one. If you're interested in reading the sci.astro groups, as you search for an ISP, you'll want to ask the various contenders if they provide access to Usenet and specifically to the sci. hierarchy. If they don't, or can't tell you, that's a bad sign.

If you already have an ISP, you'll have to read their documentation or talk to their tech help. Some ISPs provide Usenet access through a Web browser (like Mosaic, Netscape, or Internet Explorer), others provide access through a dedicated news reading program like tin, rn, or GNUS. There are many different possibilities.

A.03 What are the guidelines for posting on astronomy (sci.astro*) newsgroups?

Philippe Brieu <>, Walter I. Nissen Jr. CDP <>, Steven Willner <>

If you will follow this group for a month or so before posting here, you will greatly reduce the likelihood that you will participate in making the newsgroup less productive and friendly and then end up regretting it. If you are new here, it is likely that any question you have has already been asked. If so, its answer is probably in one of the FAQ files. Check out the newsgroups news.answers, sci.answers, and news.announce.newusers, or ask your local help file or administrator to point you toward the FAQs. Also, please check an Usenet archive like Google to see if somebody has posted a comment or query similar to yours recently. If you become really frustrated, pick on one of the more helpful posters here and send e-mail (not a post) politely asking for some help. Conversely, if your question is novel and not in a FAQ, readers will likely be intensely interested in considering it.

Certain topics repeatedly come up and lead to lengthy, loud-mouthed discussions that never lead anywhere interesting. Often these topics have extremely little to do with the science of astronomy. Experience also shows that when messages are cross-posted to other groups, followups very seldom are appropriate in sci.astro. It would also help if you would ask yourself a few simple questions before posting:

Is this post about the science of astronomy? Will many of the thousands and thousands of readers here, people interested in the science of astronomy, find it of personal benefit? Is it unique or has something similar been posted recently?

If you do ask a question, please consider writing up the answer for a FAQ file. New entries to the FAQ are always welcome!

There are also a number of common rules for all newsgroups. The following types of posts are not acceptable (see the newsgroup news.announce.newusers and its FAQs at for more details):

Also, please try to follow the following USENET guidelines when posting:

A.04 What should I do if I see an article that doesn't follow these guidelines? (What about cranks?)

Philippe Brieu <>, Walter I. Nissen Jr. CDP <>, Steven Willner <>

You may come to this newsgroup in search of information and productive discussion. Others may have different motives. Their posts are often pretty sophisticated in that they have been designed and tested to be effective in pushing your hot buttons. And please bear in mind that some of these people will come into possession of new identities and will post something that sure looks like it comes from a hapless newbie.


To reemphasize, you should NOT post anything in response to an inappropriate post in sci.astro. Other readers are probably as annoyed as you are by that post, and the last thing they/you want is to waste their/your time/disk space by adding more useless articles and fueling a useless discussion.

What should you do then? Ignore people you consider crackpots (sometimes a.k.a. cranks) altogether: do not send them e-mail, do not refer to their posts or even name in your messages. Just pretend they do not exist and they will go away! Why? Because attention and an opportunity to argue is all they are looking for. Ignoring them is the ONLY way to deal with them.

One particularly easy way to ignore people is to use a KILL file. KILL files allow you to specify that you do not want to see any articles on a certain topic or by a certain person. If used, they can increase your enjoyment of sci.astro considerably. The creation and maintenance depends upon the particular newsreader you use, but you may want to consult the KILL file FAQ (also available via anonymous ftp).

What about spams? Spams are the posting of a totally irrelevant (often commercial) message to several (often many) groups by people who are just trying to reach as many USENET readers as possible, indiscriminately. They do not target you personally, but rather all of USENET. The ONLY appropriate action is to send a message to their news administrator (usenet or complaining about it and asking for their account to be closed (be sure to include the full spam message with all headers). You can send a copy of your message to the posters so that they end up being "mailbombed" by readers (but do NOT mailbomb them by yourself!). There is no point in posting to the group because the spammers do NOT read it anyway!

If the post you read is inappropriate in another way, chances are it is not intentional. The poster was probably unaware of netiquette or rules for this particular hierarchy/group. Be understanding: do not flame them on the group. Instead, tell them politely what to do by private e-mail, and refer them to this FAQ. Of course, if it is a repeat offender, feel free to flame, but only by e-mail.

A.05 Can I get help on my homework from the Net?

Philippe Brieu <>, Steven Willner <>

A recurring subject of discussion is the posting of homework problems. Students should not ask readers to solve their homework problems in detail in this group because they are supposed to do it themselves in the first place, and readers are unlikely to be sympathetic to a lazy attitude. More importantly, answers are not guaranteed to be correct (far from that!), and instead of getting an answer, you may initiate a long and useless discussion on factors of two. Do not try to disguise homework: long time readers (there are many) will detect it and you will get flamed!

However, if there is a concept you do not understand in a problem and would like some guidance or some help getting started (not the solution), then feel free to ask. Or if you find conflicting sources, it's fine to ask about that. Basically, think of the net as a group of friends. You wouldn't ask your friends to do your homework for you, but you might well ask for help in the circumstances described. Of course it's up to you to evaluate the answers you get!

Please keep in mind that articles take anywhere from one hour to several days to propagate to other sites. Therefore, it is hopeless to get an answer for an assignment you have to turn in the next day, or after the weekend... USENET is not a last minute solution!

A.06 What are good Net sites for astronomy info and images?


This list is an attempt to compile the locations of the biggest sites and those with extensive cross-references. Please let me know other sites that fall into these categories or categories not included. The FAQ can't list everybody's favorite site, but it should list sites that cross-reference most people's favorites.


Data Archives and Catalogs

Images & Simulations

Societies, Institutions, Publishers

Related Usenet newsgroups (see also A.01)

Related FAQs

Many related newsgroups have FAQ's. Most can be obtained by anonymous ftp from

FAQ for sci.physics

available via anonymous ftp and on the Web from various mirrors including US West Coast mirror, European mirror, and Australia mirror.

FAQ for

available via anonymous ftp

Astro/Space Frequently Seen Acronyms

available via anonymous ftp

FAQ for sci.astro.planetarium

available via the Web

FAQ for sci.skeptic

available via anonymous ftp

FAQ for

available from the talkorigins Web site

FAQ for relativity

Usenet Relativity FAQ

FAQ for black holes

Black Holes FAQ

FAQ for calendars

Calendar FAQ

FAQ for supernovae and supernova remnants

Supernovae and Supernova Remnants FAQ

Lecture notes, essays, compilations, etc.

A.07 How can I find contact addresses for astronomers/observatories?

Ralph Martin <>, Luisa Rebull <>, Joseph Lazio <>

The first thing to try would be to visit your favorite search engine and enter the astronomer or observatory's name. Most astronomers and observatories today have Web sites. Although they may not be comprehensive, there are two astronomy-oriented Web sites with astronomer and/or observatory information. They are the Astronomy Search Engine (English site) or Astronomy Search Engine (German site) and the Star*s Family of Astronomy resources. The latter is part of the AstroWeb Consortium (see A.06).

A.08 Which observatories offer tours or public viewing?

Joseph Lazio <>

Many larger observatories do offer tours. If the observatory of interest has a Web page, that should provide a way to contact somebody at the observatory, see the FAQ "What are good Net sites for astronomy info and images?" and How can I find contact addresses for astronomers/observatories?.

A.09 Is there a list of astro jokes?

Of course! Astronomy is not an entirely sirius subject. Rather than try to explain how many astronomers change light bulbs, please see the Science Jokes Collection and Yahoo!'s science humor entries.

A.10 What are good books on astronomy (especially for beginners)?

Hartmut Frommert <>

Observing guides and images

A.11 Are there other sources of information?

Hartmut Frommert <>, Joseph Lazio <>

In general, do not underestimate your local library. It likely contains encyclopediae and other reference sources to answer many questions.

Pictures and/or other astronomical information

A.12 How can I find an astronomy club?

Joseph Lazio <>, Steve Willner <>

There are a few different ways to find astronomy clubs (listed in no particular order):

A.13 Where can I find out about public lectures or star parties?

Joseph Lazio <>

Very often public lectures and star parties are hosted by astronomy clubs. The list of ways to find astronomy clubs, given in the FAQ "How can I find an astronomy club?", can be exploited to find lectures and parties as well.

T. Joseph W. Lazio / <>