As fall fully sweeps into season, October's sky is host to several new players.

Our large gaseous planetary neighbor Jupiter is perfectly placed to shine brilliantly from the southern sky. Astronomers call this "opposition" since Jupiter is literally behind the Earth, but high enough to catch plenty of the sun's strong rays. Jupiter reaches this year's maximum brilliance Oct. 18, when the planet officially reaches opposition and is visible throughout the night.

Jupiter is getting some company. The new players include a seasoned veteran and a rookie: Venus returns later this month along with the recently discovered Comet Bradfield.

Venus is as beautiful as ever, twinkling brightly and briefly in the early evening sky late in the month. Back from a journey that took it behind the sun, Venus keeps a low profile in the western sky even though its magnitude reaches about -4 (very bright.)

Geoff Chester, of the Einstein Planetarium at the Smithsonian's Air & Space Museum, calls Comet Bradfield an "easy target with binoculars" as it rapidly grows bright by the end of the month. During the evening twilight, look high to the southwest in order to find it, says Chester, who last saw it at the end of September.

Comet Bradfield currently is invisible to the naked eye, but in a few weeks it should appear as a little blur. Comparable in brightness to Comet Halley, Chester says Comet Bradfield should be visible through Thanksgiving.

The discoverer of this comet, William Bradfield of Australia, now is recognized as this century's most prolific comet catcher. It's the 13th comet he's found.

The Orionids meteor showers peak on Oct. 21 and astronomers believe that these "shooting stars" will be more spectacular than August's Perseids meteor showers. With the moon all but gone, a dark sky will make shower watching nearly perfect.

Meteor showers occur when the Earth passes through a trail of comet debris -- in this case it's Comet Halley's trash -- giving the effect of meteors zipping through the night. To find them, pick a spot and look up.

Earth-bound events:

Oct. 10-11 -- Goddard Visitor's Center in Greenbelt will show two free NASA films: "Adventures in Research," a 1975 film shows how the space agency performs research in aeronautics, life sciences and advanced computation. "Moonflights and Medicine," a 1973 film, explains the medical spinoffs from lunar landings. The shows both days begin at 1 p.m. Admission is free.

Oct. 16 -- Meet Chuck Yeager, the man who broke the sound barrier 40 years ago, at the Air & Space Museum's Langley Theater. Admission is free, but there is a caveat: The museum is issuing only four tickets per person and tickets only will be given out that night. Ticket distribution begins at 5 p.m. Theater doors open at 6:30 p.m. Yeager's lecture starts at 7:30 p.m.

Oct. 24 -- Star Watch. Peek at Jupiter and Venus and perhaps other objects of October's night sky. Bring your own telescope or binoculars or use the instruments set up at the Goddard Visitor's Center in Greenbelt. 7-9 p.m. Free.

Oct. 27 -- Dr. John Huchra, a Harvard University astronomer, will discuss the latest theories on the universe in his lecture "Bubbles, Voids, Arcs and Strings." Einstein Planetarium at the Air & Space Museum. 8 p.m. Free.

Notice to Astronomers -- Amateurs still have time to submit proposals to look through the Hubble Space Telescope. The HST will be man's best view of the cosmos, once it gets into space. This is a unique opportunity to "get time" on the telescope. The deadline for proposals is next June. For information, write to the American Association of Variable Star Observers, 25 Birch Street, Cambridge, Mass. 02138.