Harry Clement Stubbs (May 30, 1922 – October 29, 2003), better known by the pen name Hal Clement, was an American science fiction writer and a leader of the hard science fiction subgenre. He also painted astronomically oriented artworks under the name George Richard.[2]

Hal Clement
14th WSFS 008 - Hal Clement.jpg
BornHarry Clement Stubbs
(1922-05-30)May 30, 1922[1]
Somerville, Massachusetts
DiedOctober 29, 2003(2003-10-29) (aged 81)
Milton, Massachusetts, US
Pen nameGeorge Richard (as artist)
  • Novelist
  • military pilot
  • science teacher
GenreScience fiction
Literary movementHard science fiction
Notable works

In 1998 Clement was inducted by the Science Fiction and Fantasy Hall of Fame[3][a] and named the 17th SFWA Grand Master by the Science Fiction and Fantasy Writers of America (presented in 1999).[4][5]


Harry Clement Stubbs was born in Somerville, Massachusetts on May 30, 1922.

He went to Harvard, graduating with a B.S. in astronomy in 1943. While there he wrote his first published story, "Proof", which appeared in the June 1942 issue of Astounding Science Fiction, edited by John W. Campbell; three more appeared in later 1942 numbers.[6] His further educational background includes an M.Ed. (Boston University 1946) and M.S. in chemistry (Simmons College 1963).

During World War II Clement was a pilot and copilot of a B-24 Liberator and flew 35 combat missions over Europe with the 68th Bomb Squadron, 44th Bomb Group, based in England with 8th Air Force. After the war, he served in the United States Air Force Reserve, and retired with the rank of colonel. He taught chemistry and astronomy for many years at Milton Academy in Milton, Massachusetts.

From 1949 to 1953, Clement's first three novels were two-, three-, and four-part Astounding serials under Campbell: Needle (Doubleday, 1950), Iceworld (Gnome Press, 1953), and Mission of Gravity (1954), his best-known novel, published by Doubleday's Science Fiction Book Club (established 1953). The latter novel features a land and sea expedition across the superjovian planet Mesklin to recover a stranded scientific probe. The natives of Mesklin are centipede-like intelligent beings about 50 centimeters long. Various episodes hinge on the fact that Mesklin's fast rotational speed causes it to be considerably deformed from the spherical, with effective surface gravity that varies from approximately 3 gn at the equator to approximately 700 gn at the poles.

Clement's article "Whirligig World" describes his approach to writing a science fiction story:

Writing a science fiction story is fun, not work. ... the fun ... lies in treating the whole thing as a game.... [T]he rules must be quite simple. They are; for the reader of a science-fiction story, they consist of finding as many as possible of the author's statements or implications which conflict with the facts as science currently understands them. For the author, the rule is to make as few such slips as he possibly can... Certain exceptions are made [e.g., to allow travel faster than the speed of light], but fair play demands that all such matters be mentioned as early as possible in the story...

Clement was a frequent guest at science fiction conventions, especially in the eastern United States, where he usually presented talks and slide shows about writing and astronomy.

Clement died in Massachusetts at the Milton Hospital on October 29, 2003 at age 81. He died in his sleep, most likely due to complications of diabetes.[7]

Awards and honorsEdit

Clement has been honored several times for his cumulative contributions including 1998 Hall of Fame induction, when Clement and Frederik Pohl were the fifth and sixth living persons[a] honored, and the 1999 SFWA Grand Master Award.[3][4][5]

For the 1945 short story "Uncommon Sense" he received a 50-year Retro Hugo Award at the 1996 World Science Fiction Convention. Mission of Gravity, first published as a serial during 1953, was named best foreign novel by the Spanish Science Fiction Association in 1994 and it was a finalist for a 50-year Retro Hugo Award in 2004.[5]

The Hal Clement Award for Young Adults for Excellence in Children's Science Fiction Literature is presented in his memory at Worldcon each year.[8]

Wayne Barlowe illustrated two of Clement's fictional species, the Abyormenites and the Mesklinites, in his Barlowe's Guide to Extraterrestrials.


Planets created by Clement typically feature unique astronomical or physical aspects. They include:

  • Abyormen – A planet circling a dwarf star (Theer), which in turn circles a blue giant. This produces a hot and a cold season, each of 65 years' duration. The native intelligent life forms undergo a seasonal mass death. From Cycle of Fire.
  • Dhrawn – A high-gravity world settled by Mesklinites in Star Light.
  • Habranha - A planet that is tidally locked with its sun, such that the dark side is a mix of solid CO2, solid methane, and ice, and the sunlit side completely ocean, in Fossil.
  • Hekla – An ice-age planet in "Cold Front" (a short story in Astounding July 1946).
  • Kaihapa – An uninhabited ocean planet, twin of Kainui, in Noise.
  • Kainui – An inhabited ocean planet in Noise.
  • Mesklin — A planet with ultra-high gravity (up to 700 g) in Mission of Gravity. Clement later corrected his model of Mesklin and determined that the maximum surface gravity would be "only 250 gravities".
  • Sarr – An extremely hot planet with an atmosphere of gaseous sulfur, and little liquid (the natives occasionally need to drink a bit of molten copper chloride), in Iceworld
  • Tenebra – A high-gravity world with a highly corrosive atmosphere consisting mostly of water vapor near its critical point, in Close to Critical.
  • Enigma 88 - A small planet near η Carinae in Still River. The interior of the object is honeycombed with caves, due to evaporation of accreted ice-rich planetoids. Unusually for Clement, Enigma's structure is not fully consistent with the laws of physics.

Short stories, novelettes and novellasEdit

Editor Sam Merwin Jr. added 10,000 words to Clement's novella "Planetfall" for its publication in the February 1957 issue of Satellite Science Fiction as "Planet for Plunder"
Clement's short story "Hot Planet" took the cover of the August 1963 issue of Galaxy Science Fiction.


  • Needle (1950), ISBN 0-380-00635-9 (The first novel in the Needle series. Also published as From Outer Space. Published as young adult fiction although it includes abstract hard science fiction.)
  • Iceworld (1953), ISBN 0-345-25805-3
  • Mission of Gravity (1954), ISBN 0-345-31622-3 (first book in the Mesklin series).
  • The Ranger Boys in Space (1956) (for children)
  • Cycle of Fire (1957), ISBN 0-345-24368-4
  • Close to Critical (1958), ISBN 0-345-24508-3 (part of the Mesklin series. Magazine publication in 1958, book in 1964)
  • Natives of Space (1965), ISBN 0345219503 (three novelettes)
  • Small Changes (1969), ISBN 0709110006 (collection of 9 short stories)
  • Space Lash (1969), ISBN (reprint in paperback of Small Changes)
  • First Flights to the Moon (1970), ASIN B000BCHC4Y (anthology of short stories from others, edited by Hal Clement)
  • Star Light (1971), ISBN 0-345-02361-7 (part of the Mesklin series, sequel to Mission of Gravity. It also shares some characters with Close to Critical)
  • Ocean on Top (1973), ISBN 1-4510-1057-5 (magazine publications in 1967)
  • Left of Africa (1976), ISBN 0936414014 (historical novel for young adults, apparently limited to 750 copies[9])
  • Through the Eye of a Needle (1978), ISBN 0-345-25850-9 (the second and last novel in the Needle series)
  • The Best of Hal Clement (1979), ISBN 0345276892 (collection of 10 short stories, including all of Natives of Space and two from Small Changes: "Uncommon Sense" and "Dust Rag")
  • The Nitrogen Fix (1980), ISBN 0-441-58116-1
  • Intuit (1987), ISBN 0-915368-35-8 (complete collection of the 4 Laird Cunningham stories, edition limited to 820 copies)
  • Still River (1987), ISBN 0-345-32916-3
  • Fossil (1993), ISBN 0-88677-573-6 (set in Isaac Asimov's Universe)
  • Half Life (1999), ISBN 0-312-86920-7 (Humanity is going extinct due to disease, scientists are sent to Titan in the faint hope of finding biochemical clues to a cure)
  • The Essential Hal Clement, Volume 1: Trio for Slide Rule and Typewriter (1999), ISBN 1-886778-06-X (collection of the novels Needle, Iceworld and Close to Critical)
  • The Essential Hal Clement, Volume 2: Music of Many Spheres (2000), ISBN 1-886778-07-8 (collection of 17 short stories, including most from Small Changes and from The Best of Hal Clement)
  • The Essential Hal Clement, Volume 3: Variations on a Theme by Sir Isaac Newton (2000), ISBN 1-886778-08-6 (collection of all Mesklin stories except Close to Critical: Mission of Gravity, Star Light, "Lecture Demonstration" and "Under"; also the how-to-write-science-fiction article "Whirligig World")
  • Heavy Planet (2002), ISBN 0-7653-0368-X (reprint of The Essential Hal Clement, Volume 3)
  • Noise (2003), ISBN 0-7653-0857-6 (set on an ocean planet)
  • Men of the Morning Star/Planet for Plunder (2011), ISBN 978-1-61287-018-2 (two novellas, the first by Edmond Hamilton and the second by Hal Clement and Sam Merwin Jr.)
  • The Moon is Hell!/The Green World (2012), ISBN 978-1-61287-087-8 (two novellas, the first by John W. Campbell Jr. and the second by Hal Clement)
  • The Time Trap/The Lunar Lichen (2013), ISBN 978-1-61287-142-4 (two novellas, the first by Henry Kuttner and the second by Hal Clement)
  • Hal Clement SF Gateway Omnibus (2014), ISBN 978-0575110151 (collection of the novels Iceworld, Cycle of Fire and Close to Critical)

About Hal ClementEdit

Articles and introductionsEdit

  • Probability Zero! (nov 1942). Published jointly with Malcolm Jameson, Harry Warner Jr., Dennis Tucker and P. Schuyler Miller in Astounding. About Probability Zero, Harry Harrison said in the John Campbell Memorial Anthology:[10]

"In the early 1940s, in Astounding, there was a small department called Probability Zero! that ran short-short stories. Or items. Or lies. Things. These things were usually funny and always impossible - echoing the description of the title."

See alsoEdit

Explanatory notesEdit

  1. ^ a b As living inductees Clement and Frederik Pohl were preceded in the Hall of Fame by A. E. van Vogt and Jack Williamson, Arthur C. Clarke and Andre Norton.[3]


  1. ^ "Henry Clement Stubbs". Archived from the original on July 20, 2008. Retrieved 2006-05-30.. Rosetta Books (rosettabooks.com). Archived 2008-07-20. Retrieved 2013-03-23.
  2. ^ "Hal Clement, 81, craftsman of sci fi novels". Tom Long. The Boston Globe. October 31, 2003.
  3. ^ a b c "Science Fiction and Fantasy Hall of Fame". Mid American Science Fiction and Fantasy Conventions, Inc. Retrieved 2013-03-23. This was the official website of the hall of fame to 2004.
  4. ^ a b "SFWA Grand Master". Science Fiction and Fantasy Writers of America (SFWA).
  5. ^ a b c "Clement, Hal". The Locus Index to SF Awards: Index to Literary Nominees. Locus Publications. Retrieved 2013-03-23.
  6. ^ Hal Clement at the Internet Speculative Fiction Database (ISFDB). Retrieved 2013-04-04.
  7. ^ Clute, John (31 October 2003). "Hal Clement: Writer From the Golden Age of Science Fiction". The Independent. Retrieved 13 March 2021.{{cite web}}: CS1 maint: url-status (link)
  8. ^ "Submission Guidelines". Golden Duck Awards (goldenduck.org). Archived 2008-05-25. Retrieved 2014-08-14.
  9. ^ "LEFT OF AFRICA by Hal Clement, Harry Clement Stubbs on L. W. Currey, Inc".
  10. ^ "Series:Probability Zero - ISFDB". isfdb.org.

External linksEdit