Brian W. Aldiss & Roger Penrose, White Mars, Or, The Mind Set Free (St. Martin’s 4/00) Aldiss takes his turn at colonizing Mars in this visionary ‘‘21st-Century Utopia’’ written in collaboration with noted physicist Penrose.

Gregory Benford, ed. Nebula Awards Showcase 2000 (Harcourt 4/00) Despite the name change, this is the 34th volume in the Nebula anthology series, with nine pieces of fiction (winning stories, some nominees, and an excerpt from the winning novel) plus pieces by Grand Master Hal Clement and Author Emeritus William Tenn, and extensive commentary on SF’s past and the state of the art in 1998.

Gregory Benford & George Zebrowski, eds. Skylife (Harcourt 4/00) Original and classic stories, along with articles by Larry Niven and Isaac Asimov, plus the editors’ own detailed introduction, give an impressive overview of SF and non-fiction speculation on the possibilities for life in space.

James Blish, Cities in Flight (Overlook 3/00) The out-of-print classic omnibus returns with the four SF novels of the ‘‘Okie’’ series about an exodus of flying cities from Earth, seeking work throughout the galaxy. A seminal mix of exciting plots with a serious examination of the cyclical nature of history.

Hal Clement, The Essential Hal Clement, Volume 2: Music of Many Spheres (NESFA 2/00) Stories from 1942 to 1987 give a welcome overview of the short fiction of the noted hard-SF writer named 1999 Nebula Grand Master of SF.

Dennis Danvers, The Fourth World (Avon Eos 3/00) Danvers uses SF concepts to explore the inequities between the rich and poor in this novel of a newsman attempting to reveal the horrors and injustice of life in Third World Mexico who uncovers a plot reaching all the way to a Fourth -- Mars.

Ellen Datlow & Terri Windling, eds., Black Heart, Ivory Bones (Avon 3/00) The sixth installment in Datlow & Windling’s celebrated anthology series of new fairy tales for adults, this brings together 17 stories and four poems from noted authors including Tanith Lee, Esther Friesner, Joyce Carol Oates, and Howard Waldrop.

Gardner Dozois, ed., Explorers: SF Adventures to Far Horizons (St. Martin’s Griffin 4/00) Dozois digs deep to unearth some classic SF tales, along with the cream of the current crop, for this anthology of 23 stories of exploration, by a stellar group of authors including Arthur C. Clarke, Cordwainer Smith, Ursula K. Le Guin, and John Varley.

Michael Flynn, Lodestar (Tor 3/00) Flynn returns to the near future of Firestar and Rogue Star about a half-generation later. Despite the success of an orbital factory, politics and personalities continue to block constructive efforts to prevent an asteroid strike on Earth. Though this is clearly a middle book in a series, striking characters and well-crafted hard SF keep this series compelling.

Daniel Keyes, Algernon, Charlie and I: A Writer’s Journey (Challcrest 2/00) Keyes reveals the inside story of the award-winning novelette ‘‘Flowers for Algernon’’ (included here), its adaptation into novel, TV movie, feature film, play, and even a failed Broadway musical -- telling a great deal about himself and the craft of writing in the process.

Fritz Leiber, The Big Time (Tor 4/00) A Hugo-winner long out of print returns in this classic SF short novel of the ‘‘Change War’’ with its battling time travellers and shifting realities.

Ricardo Pinto, The Chosen (Tor 3/00) A young man learns what it means to be a member of his world’s aristocracy in this opulent fantasy of cruel Masters bound by intricate protocols, and their treacherous maneuverings for power at court. A powerful first novel, the first in the series ‘‘The Stone Dance of the Chameleon’’.

Terry Pratchett, The Fifth Elephant (HarperCollins 3/00) In this 24th ‘‘Discworld’’ novel, a diplomatic mission drags the City Watch from the rough streets of Ankh-Morpork to the wilds of Uberwald, where the vampires and werewolves find they may have bitten off more than they can chew. Instant communications, oil-rights, gender gaps, and Wagnerian opera are among the many targets skewered by Pratchett’s sharp satire.

Sean Stewart, Galveston (Ace 3/00) Magic has returned to the world in this powerful near-future tale of magical realism, set in a town in Texas where the worst effects have been confined in a region of unending Carnival.

Michael Swanwick, Moon Dogs (NESFA 2/00) NESFA continues the tradition of providing quality collections for their convention Guests of Honor, this time for Boskone 37, with this sampling of Swanwick’s work, including seven stories (two original), six insightful essays, two speeches, and a play. Distinguished collaborators on some of the stories are Avram Davidson, Gardner Dozois, and Jack Dann. NESFA link.

James Tiptree, Jr., Meet Me at Infinity (Tor 2/00) Previously uncollected works by Tiptree -- eight stories and 35 non-fiction pieces, many autobiographical -- make this an important collection, particularly valuable for what it reveals of one of SF’s best authors, a fascinating character in her own right.