Usenet is a peer-to-peer network which came into being in late 1979. For installations which do not rely on telephone line links between machines, it has been superseded by the Internet. By 1981 Usenet was supporting a large volume of newsgroups, and this functionality has been carried over to the Internet. As of August 1994, an estimated 190,000 host machines have access to over 3100 newsgroups and about 7.1 million users at these sites are newsreaders. Not all sites receive the Usenet news, as this requires a site to find another site or organization that will agree to forward news (i.e., act as a ``feed''). The access software available to you on your system to access the newsgroup may be a command such as vnews, rn, trn, xrn, nn, GNUS, Gnews, notes, NNTP, etc.
A number of newsgroups are devoted to astronomical discussions, and many more are devoted to subjects in physics, chemistry, and computer science that might also be of interest to astronomers. Usenet sites include many of the universities, government research institutions, and observatories where most astronomers work. If you are at one of these sites, Usenet news is probably available to you. If not, you might want to look for someone who would allow you to access news on their system, or you might want to consider becoming a Usenet site yourself. For information about the latter, send e-mail to mail-server@pit-manager.mit.edu containing the message
send usenet/news.announce.newusers/How_to_become_a_USENET_site
Alternatively, this is available by anonymous FTP (see below in this section for further details on anonymous FTP) at the node pit-manager.mit.edu in the file
pub/usenet/news.announce.newusers/How_to_become_a_USENET_site
One key to effective use of Usenet is finding the right newsgroups. Newsgroups are arranged hierarchically by subject of interest. The top level ``big seven'' hierarchies are comp, sci, news (maintenance issues), misc, rec (recreational topics), soc (social), and talk (debate-oriented). Your system may not have all groups, since it is up to individual sites to decide which groups to carry. You may also find additional hierarchies for local or regional groups as well as hierarchies that are not really subject to Usenet ``rules'', including alt (eclectic), bionet, biz, gnu (Free Software Foundation GNU project), and vmsnet (VAX/VMS topics). There are more than 8000 newsgroups in the hierarchies mentioned here. For the big seven hierarchies, there is a formal mechanism for creating new newsgroups, and new groups appear regularly.
Of obvious interest to astronomers are the following newsgroups (a gateway is used here to allow Web access to them):
sci.astro: general astronomy discussions and information
sci.astro.fits: issues related to the FITS image storage standard
sci.astro.hubble: issues related to the Hubble Space Telescope
sci.astro.research: discussions of current professional research topics
sci.astro provides considerable discussion of amateur and popular astronomy questions, but it is read by many professional astronomers and is one possible forum for technical questions.
Other potentially useful newsgroups in the ``sci'' hierarchy include sci.chem, sci.image.processing, sci.optics, sci.physics, sci.space, and sci.space.news. There are many groups in the ``comp'' hierarchy that may be of interest, such as the comp.sys groups for various vendors of computer hardware, the comp.os group for your operating system, the comp.windows group for your windowing system (X11, Open Look, Motif, etc.), and if you are a programmer, the comp.lang group for the language of your choice. There are newsgroups for software that you might use in your research or for writing papers, such as: comp.graphics, comp.graphics.visualization, comp.emacs, comp.text.frame, comp.text.tex, and sci.math.symbolic.
A nice spin-off of Usenet newsgroups is that many individuals have taken it upon themselves to maintain FAQ (Frequently Asked Questions) files. Since these are often posted to the newsgroup approximately monthly, a good way to see if a FAQ exists is to subscribe to the newsgroup and ``listen in.'' As a condensation of the collective wisdom of the newsgroup (and admittedly signal-to-noise often leaves much to be desired) FAQs provide excellent all-round introductions to a topic, and comprehensive background information.
Update, Jan. 95: Many FAQs are available by anonymous ftp from rtfm.mit.edu:/pub/usenet/