Jump to ratings and reviews
Rate this book

The Sentinel

Rate this book
Written in 1948 and first published in 1951 as Sentinel of eternity, this is the short story on which the 1968 movie 2001: A Space Odyssey was based, and the beginning of Clarke's Space Odyssey series.

The story deals with the discovery during an expedition of an artefact on Earth's Moon that will be a turning point for humanity.

16 pages, Unknown Binding

First published January 1, 1951

1 person is currently reading
65 people want to read

About the author

Arthur C. Clarke

1,647 books11.5k followers
Stories, works of noted British writer, scientist, and underwater explorer Sir Arthur Charles Clarke, include 2001: A Space Odyssey (1968).

This most important and influential figure in 20th century fiction spent the first half of his life in England and served in World War II as a radar operator before migrating to Ceylon in 1956. He co-created his best known novel and movie with the assistance of Stanley Kubrick.

Clarke, a graduate of King's College, London, obtained first class honours in physics and mathematics. He served as past chairman of the interplanetary society and as a member of the academy of astronautics, the royal astronomical society, and many other organizations.

He authored more than fifty books and won his numerous awards: the Kalinga prize of 1961, the American association for the advancement Westinghouse prize, the Bradford Washburn award, and the John W. Campbell award for his novel Rendezvous with Rama. Clarke also won the nebula award of the fiction of America in 1972, 1974 and 1979, the Hugo award of the world fiction convention in 1974 and 1980. In 1986, he stood as grand master of the fiction of America. The queen knighted him as the commander of the British Empire in 1989.

Ratings & Reviews

What do you think?
Rate this book

Friends & Following

Create a free account to discover what your friends think of this book!

Community Reviews

5 stars
40 (21%)
4 stars
83 (44%)
3 stars
52 (27%)
2 stars
9 (4%)
1 star
2 (1%)
Displaying 1 - 22 of 22 reviews
Profile Image for Mangrii.
1,127 reviews467 followers
September 7, 2018
4,5 / 5

Un cuento clave en la ciencia ficción y más en la obra de Arthur C. Clarke es El centinela. Famoso por haber sido ampliado y modificado tanto en la novela como la película 2001: Odisea en el espacio, nos cuenta una historia de lo más sencilla: el simple descubrimiento de un extraño artefacto en la Luna dejado hace eones por antiguos alienígenas. Un objeto piramidal rodeado por un campo de fuerza esférico. Nuestro narrador en primera persona, especulará sobre los misteriosos forasteros que lo habrán dejado allí. Serán sus hipótesis y afirmaciones las que dejan en el lector una sensación de misterio y tensión constante. Una sensación sobre la abrumadora infinidad del universo. Sin ninguna duda, la prosa de Arthur la que consigue brillar y realzar todo este impacto psicológico. Un pequeño cuento que invita a reflexionar sobre nuestra propia existencia y nos desafía a buscar sin conformarse nunca.

Escuchado a través del maravilloso audio radioficcionado de Noviembre Nocturno: https://www.ivoox.com/el-centinela-ar...
Profile Image for Aeryn.
638 reviews8 followers
March 12, 2025
Short but does give a reader pause to think about.
Profile Image for Joctan Galindo.
4 reviews1 follower
June 10, 2024
Jamás había escuchado de A.C.C. y este ha sido el primer libro suyo con el que me topo. Sus relatos son tan fáciles de leer a pesar de que te das cuenta de que hay mucha ciencia y que quien lo escribió es una persona que conoce del tema (Astronomía? Astrofísica?). Siempre presenta dilemas morales a los que no seríamos capaces de llegar si no dispusiéramos de tecnología avanzada. Mis favoritos son duda: Antes del Edén (Que me recordó a 'La Guerra de los mundos'), El muro de la oscuridad y La estrella (que me recordó a 'La torre de babel' y 'El infierno es la asucencia de Dios' ambos de Ted Chiang)
Profile Image for Veronica.
111 reviews11 followers
May 19, 2015
La scrittura di Clarke è sempre piena di magia. Mi perdo nelle sue descrizioni ricche e particolari.
197 reviews
June 30, 2025
Still my second favorite ACC short story. ('A Walk In the Dark is #1 for me).

Read it a couple of times as a teenager in the 70's because I loved the movie 2001: A Space etc. Since I'm older now I only listen to it as a audiobook. But that is at least 6 or 7 times. It always a nice guilty pleasure to come back to when I feel the need to just get away from this stupid world and just ... imagine and dream.

I love the way the story slowly, slowly unfolds before you slowly pulling you in to it's basic premise until, before you know it, you have become a believer in the tale.

Never really realized until this listening that all the forward action stops about halfway through the story. From then on, the story teller just talks, speculates and expands your mind with possibilities. Wonderfully written.

My favorite line:

"Until we destroyed it that machine was still fulfilling the purpose of the builders."

Doesn't that just wrap up the history of the human race in one sentence.
Profile Image for Miguel Garzón.
304 reviews14 followers
August 10, 2024
Evocador conjunto de breves relatos de ciencia ficción, más famoso porque el que da título al volumen es el preámbulo de la Odisea espacial en "2001". La ciencia ficción de décadas pasadas suele aparecer como el espejo más fiel de las épocas en que fue escrita, creo. Es normal que la escala temporal y tecnológica la arrolle en ocasiones, pero también que muestra una pureza y un espíritu de evasión, fantasía y maravilla difícil de encontrar en este tiempo más cínico en el que todo es sospecha y la ficción pura es dudosa si no añade cosmovisiones de la vida y el hombre alineadas con el sentir de la mayoría. O quizá, simplemente, los anhelos y temores de esa sociedad en ese tiempo me son completamente ajenos y no logro verlos.

Sea como fuere, es un soplo de aire fresco encontrar anhelos de lo maravilloso situados en años pasados y ser invitados a leer por el puro placer de imaginar y de volar muy lejos.
Profile Image for Glen Engel-Cox.
Author 4 books62 followers
November 16, 2023
A classic SF tale about finding a mysterious object on the moon and what that might mean. What’s strange about reading this story now is how it’s told: there is no dialogue, but just a long monologue by the protagonist. There’s action, sure, after a descriptive beginning, the story becomes one of exploration, then investigation, and ends in speculation. The time period covered is twenty years, from the discovery to the reflection on the discovery. And the last line is a killer. Recommended.
Profile Image for Mimi Dang.
149 reviews6 followers
February 2, 2025
3/5 (Finished 12.30.2024)

Short scifi story about how a group of human explorers stumbled upon a extremely high-tech mysterious object that was undoubtedly placed by other sentients ages ago as sentinel to watch for when other intelligent species from other planets would have evolved enough to discover this piece of technology on a far away planet.

Even though there was nothing that was outlandish or spectacular about this, I could have imagined what kinds of reactions this could have evoked in the readers when it was published a long time ago, as space exploration back then was much more nascent and more akin to that of a fantasy.
Profile Image for Richard.
756 reviews32 followers
November 9, 2018
The Sentinel is a short story Arthur C. Clarke wrote in 1948 for a BBC competition. There are many amazing things about this story - not the least of which is it didn't even place in the competition for which he wrote it.

In this thirteen page story, Clarke brings together all of the elements that made him a master of his genre: inventive story line, accurate and detailed visions of the future, hard science, interesting characters, and great writing. In just a few pages, Clarke puts together a story that stands on its own but also became, two decades later, the basis for movie 2001 which ushered in a new generation of science fiction movies.

Profile Image for Monika M..
159 reviews13 followers
January 27, 2021
A very short story about explorers in Moon finding an object, that was put here earlier than life itself began on Earth.
This story was an inspiration for Clarke and Kubrick to create "2001: The Space Odyssey".
It has more Lunar descriptions than story itself :) As it is told from first person perspective, we get some insights from the geologist who discovers the object, but the real purpose of it remains unknown... "To be continued"? Quite yes, go read 2001: A Space Odyssey!
Profile Image for Priscila Wood.
145 reviews4 followers
July 17, 2022
3/5

Confesso que não tenho costume de ler nada do gênero e que não me sinto qualificada a dar uma nota adequada para essa obra. Dito isso, ainda reservo o direito de ter alguma opinião sobre o que li rs. O que posso dizer é que é incrível que Arthur e Kubrick tenham feito algo tão maior a partir dessa pequena ideia (eles usaram também a ideia de outro conto para fechar o que se tornou 2001, mas vocês entenderam). Pequena mesmo.
Profile Image for Heidi.
720 reviews2 followers
October 29, 2020
4.5 stars

This is for the individual, single
short story only.

This 9 page SF short story
was first published in the Spring
1951 issue of 10 Story Fantasy.

This is a very well written SF
short story. The sheer originality
and creativity of this story just
astonishes me, particularly con-
sidering that it was written in 1951.
Profile Image for Vanessa Yeazel.
547 reviews
October 27, 2022
(4.5 stars) Read this for my sci-fi class, really enjoyed it, way more than I was expecting. The ending was left open, which I liked for this story. There was the possibility for exciting exploration or unsettling war. Another short but sweet science fiction story. I think it captures a lot of the sci-fi genre.
Profile Image for Wasi Rizvi.
Author 1 book4 followers
May 25, 2021
It was a fun experience reading the short story. Although my expectations may have been higher. I surely want to read more of Arthur C. Clarke.
Profile Image for Bash.
1,023 reviews24 followers
August 6, 2018
Thank goodness he went on to turn this into 2001: A Space Odyssey because on it's own it's sort of unfulfilling. But still an interesting read to see how the story progressed :)
Profile Image for Cailyn L.
236 reviews1 follower
May 2, 2022
Beautiful imagery and a haunting story.
Profile Image for Scott.
249 reviews2 followers
October 2, 2022
Going to be rewatching 2001 in the next few days and I decided it was about time I actually read the stories it's based on? Anyways, this is low level great, a very Clarke story.
Displaying 1 - 22 of 22 reviews

Can't find what you're looking for?

Get help and learn more about the design.