Intergalactic travel

Intergalactic travel is the term used for hypothetical manned or unmanned travel between galaxies. Due to the enormous distances between our own galaxy the Milky Way and even its closest neighborshundreds of thousands to millions of light-yearsany such venture would be far more technologically demanding than even interstellar travel. Intergalactic distances are roughly a hundred-thousandfold (five orders of magnitude) greater than their interstellar counterparts.[a]

The technology required to travel between galaxies is far beyond humanity's present capabilities, and currently only the subject of speculation, hypothesis, and science fiction.

However, theoretically speaking, there is nothing to conclusively indicate that intergalactic travel is impossible. There are several hypothesized methods of carrying out such a journey, and to date several academics have studied intergalactic travel in a serious manner.[1][2][3]

LH 95
Stars in the Large Magellanic Cloud, a dwarf galaxy. At a distance of 163,000 light-years, the LMC is the third closest galaxy to the Milky Way.

The difficulties of intergalactic travel

Due to the size of the distances involved any serious attempt to travel between galaxies would require methods of propulsion far beyond what is currently thought possible in order to bring a large craft close to the speed of light.

According to the current understanding of physics, an object within space-time cannot exceed the speed of light,[4] which means an attempt to travel to any other galaxy would be a journey of millions of earth years via conventional flight.

Manned travel at a speed not close to the speed of light, would require either that we overcome our own mortality with technologies like radical life extension or traveling with a generation ship. If traveling at a speed closer to the speed of light, time dilation would allow intergalactic travel in a timespan of decades of on-ship time.

Additional constraints include the variety of unknowns regarding the durability of a spaceship for such complex travel. Fluctuating temperatures as in the warm-hot intergalactic medium could potentially disintegrate future spacecraft if not properly shielded.

These challenges also mean a return trip would be very difficult. Therefore, all future studies on the risks and feasibility of intergalactic travel would have to include a wide range of simulations to increase chances of a successful payload.

Possible methods

Extreme long-duration voyages

Voyages to other galaxies at sub-light speeds would require voyage times anywhere from hundreds of thousands to many millions of years. To date only one design such as this has ever been made.[1]

Hypervelocity stars

Theorized in 1988,[5] and observed in 2005,[6] there are stars moving faster than the escape velocity of the Milky Way, and are traveling out into intergalactic space.[7] There are several theories for their existence. One of the mechanisms would be that the supermassive black hole at the center of the Milky Way ejects stars from the galaxy at a rate of about one every hundred thousand years. Another theorized mechanism might be a supernova explosion in a binary system.[8]

These stars travel at speeds up to about 3,000 km/second. However, recently (November 2014) stars going up to a significant fraction of the speed of light have been postulated, based on numerical methods.[9] Called Semi-Relativistic Hypervelocity Stars by the authors, these would be ejected by mergers of supermassive black holes in colliding galaxies. The authors think these stars will be detectable by forthcoming telescopes.[10]

These could be used by entering into an orbit around them and waiting.[11][12]

Artificially propelling a star

Another proposal is to artificially propel a star in the direction of another galaxy.[13][14]

Time dilation

While it takes light approximately 2.54 million years to traverse the gulf of space between Earth and, for instance, the Andromeda Galaxy, it would take a much shorter amount of time from the point of view of a traveler at close to the speed of light due to the effects of time dilation; the time experienced by the traveler depending both on velocity (anything less than the speed of light) and distance traveled (length contraction). Intergalactic travel for humans is therefore possible, in theory, from the point of view of the traveller.[15]

Accelerating to speeds closer to the speed of light with a relativistic rocket would allow the on-ship travel time to be drastically lower, but would require very large amounts of energy. A way to do this is space travel using constant acceleration. Traveling to the Andromeda Galaxy, 2 million light years away, would take 28 years on-ship time with a constant acceleration of 1g and a deceleration of 1g after reaching half way, to be able to stop.

Going to the Andromeda Galaxy at this acceleration would require 4 100 000 kg fuel per kg payload using the unrealistic assumption of a 100% efficient engine that converts matter to energy. Decelerating at the halfway point in order to stop dramatically increases the fuel requirements to 42 trillion kg fuel per kg payload. This is ten times the mass of Mt Everest required in fuel for each kg of payload. As the fuel contributes to the total mass of the ship, carrying more fuel also increases the energy required to travel at a certain acceleration and extra fuel added to make up for the increased mass would further contribute to the problem.[16]

The fuel requirements of going to the Andromeda Galaxy with constant acceleration means that either the payload has to be very small, the spaceship has to be very large or it has to collect fuel or receive energy on the way through other means (e.g. using a Bussard ramjet).

Possible faster-than-light methods

The Alcubierre drive is a hypothetical concept that is able to impulse a spacecraft to speeds faster than light (the spaceship itself would not move faster than light, but the space around it would). This could in theory allow practical intergalactic travel. There is no known way to create the space-distorting wave this concept needs to work, but the metrics of the equations comply with relativity and the limit of light speed.[17]

See also


  1. ^ a b Burruss, Robert Page; Colwell, J. (September–October 1987). "Intergalactic Travel: The Long Voyage From Home". The Futurist. 21 (5): 29–33.
  2. ^ Fogg, Martyn (November 1988). "The Feasibility of Intergalactic Colonisation and its Relevance to SETI". Journal of the British Interplanetary Society. 41 (11): 491–496. Bibcode:1988JBIS...41..491F.
  3. ^ Armstrong, Stuart; Sandberg, Anders. "Eternity in six hours: intergalactic spreading of intelligent life and sharpening the Fermi paradox" (PDF). Future of Humanity Institute, Philosophy Department, Oxford University.
  4. ^ "Star Trek's Warp Drive: Not Impossible". 6 May 2009.
  5. ^ Hills, J. G. (1988). "Hyper-velocity and tidal stars from binaries disrupted by a massive Galactic black hole" (PDF). Nature. 331 (6158): 687–689. Bibcode:1988Natur.331..687H. doi:10.1038/331687a0.
  6. ^ Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Kurtz, Michael J. (2005). "Discovery of an Unbound Hypervelocity Star in the Milky Way Halo". Astrophysical Journal. 622 (1): L33–L36. arXiv:astro-ph/0501177. Bibcode:2005ApJ...622L..33B. doi:10.1086/429378.
  7. ^ "The Hyper Velocity Star Project: The stars". The Hyper-Velocity Star Project. 6 September 2009. Retrieved 20 September 2014.
  8. ^ Watzke, Megan (28 November 2007). "Chandra discovers cosmic cannonball". Newswise.
  9. ^ Guillochon, James; Loeb, Abraham (18 Nov 2014). "The Fastest Unbound Stars in the Universe". The Astrophysical Journal. 806: 124. arXiv:1411.5022. Bibcode:2015ApJ...806..124G. doi:10.1088/0004-637X/806/1/124.
  10. ^ Guillochon, James; Loeb, Abraham (18 Nov 2014). "Observational Cosmology With Semi-Relativistic Stars". arXiv:1411.5030 [astro-ph.CO].
  11. ^ Villard, Ray (24 May 2010). "The Great Escape: Intergalactic Travel is Possible". Discovery News. Retrieved October 18, 2010.
  12. ^ Gilster, Paul (26 June 2014). "Intergalactic Travel via Hypervelocity Stars". Retrieved 16 September 2014.
  13. ^ Gilster, Paul (27 June 2014). "Stars as Stellar Engines". Retrieved 16 September 2014.
  14. ^ Gilster, Paul (30 June 2014). "Building the Bowl of Heaven". Retrieved 16 September 2014.
  15. ^ Gilster, Paul (25 June 2014). "Sagan's Andromeda Crossing". Retrieved 16 September 2014.
  16. ^ "The Relativistic Rocket". Retrieved 4 April 2018.
  17. ^ Alcubierre, Miguel (1994). "The warp drive: hyper-fast travel within general relativity". Classical and Quantum Gravity. 11 (5): L73–L77. arXiv:gr-qc/0009013. Bibcode:1994CQGra..11L..73A. doi:10.1088/0264-9381/11/5/001.


  1. ^ Between small galaxies, which are the majority of galaxies, distances are typically a few hundred thousand light-years. Between large galaxies like the Milky Way and M31, they are typically a few million light-years.

Agamemno is a fictional character, a supervillain in the DC Comics universe. He first appeared in Silver Age #1 (July 2000) during the Silver Age event (a series of Silver Age styled one-shots of which he was the chief antagonist). He was created by Mark Waid.

Andromeda (TV series)

Andromeda (formally titled Gene Roddenberry's Andromeda) is a Canadian/American science fiction television series, based on unused material by Gene Roddenberry, developed by Robert Hewitt Wolfe, and produced by Roddenberry's widow, Majel Barrett. It starred Kevin Sorbo as High Guard Captain Dylan Hunt. The series premiered on October 2, 2000, and ended on May 13, 2005.

Andromeda was filmed in Vancouver, British Columbia, Canada and produced by Andromeda Productions, Tribune Entertainment, Fireworks Entertainment and MBR Productions. In Canada, the show was on Global TV (Fireworks' parent company) in Canada and syndicated in the United States on Tribune, Sinclair and other stations.

Andromeda is one of two TV series (to date) based on concepts Roddenberry had created as early as the 1960s and 1970s. The name Dylan Hunt had previously been used for the hero of two TV pilots Roddenberry had produced in the mid-1970s, Genesis II, and Planet Earth, all sharing a similar dystopian, post-apocalyptic premise.

Galaxy Express 999

Galaxy Express 999 (銀河鉄道999(スリーナイン), Ginga Tetsudō Surī Nain) is a manga written and illustrated in 1977 by Leiji Matsumoto, later adapted into a number of anime films and television series. It is set in a spacefaring, high-tech future in which humans have learned how to transfer their minds and emotions with perfect fidelity into mechanical bodies, thus achieving practical immortality.The manga won the Shogakukan Manga Award for shōnen in 1978. The anime series won the Animage Anime Grand Prix prize in 1981.

Matsumoto was inspired to create Galaxy Express 999 by the idea of a steam train running through the stars in the novel Night on the Galactic Railroad by Kenji Miyazawa.

Goalkeeper of the Galaxy

Goalkeeper of the Galaxy (Russian: Вратарь Галактики) is a 2019 Russian 3D science fiction superhero film directed by Dzhanik Fayziev and co-produced by Sergey Selyanov and Anton Zlatopolskiy.

The film is set in the future, a post-apocalyptic city in a world inhabited, due to the Galactic war, which took place in proximity to Earth, the Moon was destroyed and the planet's poles shifted. Now an enormous spaceship hovers over Earth. This is a stadium, which hosts sports events that resemble soccer but at mind-boggling speeds. The name of the game is cosmoball, with the fate of the planet depending on the result of the match between earthmen and aliens.

It stars Yevgeny Romantsov as Anton a goalkeeper to the national team, alongside Victoria Agalakova, Yevgeny Mironov, Elena Yakovleva, Mikhail Yefremov, Dmitry Nazarov and Svetlana Ivanova in supporting roles.Location filming began in 2017 and principal photography beginning that June at Mosfilm Studios are produced together with a team of professional stuntmen, masters of special effects and artists who promise the most technologically, with shots taking place at Mosfilmovskaya Street in Moscow, and will last until mid-September 2017.

The film required a wide use of computer-generated imagery to portray the alien races.

The film is known for the first premiere was January 2019 previously planned, it was postponed to October 17.

Goalkeeper of the Galaxy is scheduled to be released in Russia by STV Film Company on October 17, 2019, in 2D, RealD 3D and Nashe Kino.


Intergalactic may refer to:

Intergalactic space

Intergalactic travel, travel between galaxies in science fiction and speculation

"Intergalactic" (song), a song by the Beastie Boys

Interstellar (film)

Interstellar is a 2014 science fiction film directed, co-written, and co-produced by Christopher Nolan. It stars Matthew McConaughey, Anne Hathaway, Jessica Chastain, Bill Irwin, Ellen Burstyn, and Michael Caine. Set in a dystopian future where humanity is struggling to survive, the film follows a group of astronauts who travel through a wormhole near Saturn in search of a new home for humanity.

Brothers Christopher and Jonathan Nolan wrote the screenplay, which had its origins in a script Jonathan developed in 2007. Christopher produced Interstellar with his wife, Emma Thomas, through their production company Syncopy, and with Lynda Obst through Lynda Obst Productions. Caltech theoretical physicist Kip Thorne was an executive producer, acted as scientific consultant, and wrote a tie-in book, The Science of Interstellar. Paramount Pictures, Warner Bros., and Legendary Pictures co-financed the film. Cinematographer Hoyte van Hoytema shot it on 35 mm in anamorphic format and IMAX 70 mm. Principal photography began in late 2013 and took place in Alberta (Canada), Iceland and Los Angeles. Interstellar uses extensive practical and miniature effects and the company Double Negative created additional digital effects.

Interstellar premiered on October 26, 2014, in Los Angeles, California. In the United States, it was first released on film stock, expanding to venues using digital projectors. The film had a worldwide gross of over $677 million, making it the tenth-highest-grossing film of 2014. Interstellar received critical praise for its themes, visual effects, musical score, and acting. At the 87th Academy Awards, the film won the Academy Award for Best Visual Effects, and was nominated for Best Original Score, Best Sound Mixing, Best Sound Editing and Best Production Design.

Mundane science fiction

Mundane science fiction is a subgenre of hard science fiction which is characterized by its setting on Earth or within the solar system, and a lack of interstellar travel, intergalactic travel or human contact with extraterrestrials.

Nova Corps

The Nova Corps is a fictional intergalactic military/police force appearing in American comic books published by Marvel Comics. Created by writer Marv Wolfman, the Corps first appeared in Fantastic Four #205 (April 1979). They have since appeared in numerous other Marvel stories set in outer space and media adaptations, such as the animated TV series The Super Hero Squad Show and the 2014 film Guardians of the Galaxy, the latter of which is set in the Marvel Cinematic Universe.

Oxygen equivalent

Oxygen equivalent compares the relative amount of oxygen available for respiration at a variable pressure to that available at SATP. As external respiration depends on the exchange of gases due to partial pressures across a semipermeable membrane and normally occurs at SATP, an oxygen equivalent may aid in recognizing and managing variable oxygen availability during procedures such as hyperbaric oxygen therapy or medical air transport.

It does so by expressing oxygen concentration as a ratio of the partial pressure of oxygen at a given altitude or pressure to Standard Atmospheric Pressure; rather than as a ratio of the PO2 at a given pressure to the total pressure of the gas mixture. The latter would generally be 0.2095, the atmospheric concentration by volume of O2, although FO2 and Patm vary for extraterrestrials. Calculations occur as follows:

Let O2E be oxygen equivalent, FO2 be the fractional concentration of oxygen, Patm (generally 760 mmHg, barring intergalactic travel), Pb be the barometric pressure, and dP be the change in pressure at a given altitude. Then,

O2E = FO2(Pb + dP)/ PatmIt is worthwhile to note that pressures may often be expressed in units of distance such as feet when diving. For this, note that descending 33 ft in salt water or 33.9 ft in fresh water results in a change of 1 atm, so distance and pressure are used interchangeably in this context.

Sleeper ship

A sleeper ship is a hypothetical type of crewed spacecraft in which most or all of the crew spends the journey in some form of hibernation or suspended animation. The only known technology that allows long-term suspended animation of humans is the freezing of early-stage human embryos through embryo cryopreservation, which is behind the concept of embryo space colonization.

The most common role of sleeper ships in fiction is for interstellar or intergalactic travel, usually at sub-light speed. Travel times for such journeys could reach into the hundreds or thousands of years, making some form of life extension, such as suspended animation, necessary for the original crew to live to see their destination. Suspended animation is also required on ships that cannot be used as generation ships.

Freezing the astronauts would probably involve whole-body vitrification and would, most likely, be frozen at 145 kelvins to reduce the risk of fracturing.Suspended animation can also be useful to reduce the consumption of life support system resources by crew members who are not needed during the trip, or by an author as a plot device, and for this reason sleeper ships sometimes also make an appearance in the context of purely interplanetary travel.

Space colonization

Space colonization (also called space settlement, or extraterrestrial colonization) is permanent human habitation off the planet Earth.

Many arguments have been made for and against space colonization. The two most common in favor of colonization are survival of human civilization and the biosphere in the event of a planetary-scale disaster (natural or man-made), and the availability of additional resources in space that could enable expansion of human society. The most common objections to colonization include concerns that the commodification of the cosmos may be likely to enhance the interests of the already powerful, including major economic and military institutions, and to exacerbate pre-existing detrimental processes such as wars, economic inequality, and environmental degradation.No space colonies have been built so far. Currently, the building of a space colony would present a set of huge technological and economic challenges. Space settlements would have to provide for nearly all (or all) the material needs of hundreds or thousands of humans, in an environment out in space that is very hostile to human life. They would involve technologies, such as controlled ecological life support systems, that have yet to be developed in any meaningful way. They would also have to deal with the as-yet unknown issue of how humans would behave and thrive in such places long-term. Because of the present cost of sending anything from the surface of the Earth into orbit (around $2,500 per-pound to orbit, expected to further decrease), a space colony would currently be a massively expensive project.

There are yet no plans for building space colonies by any large-scale organization, either government or private. However, many proposals, speculations, and designs for space settlements have been made through the years, and a considerable number of space colonization advocates and groups are active. Several famous scientists, such as Freeman Dyson, have come out in favor of space settlement.On the technological front, there is ongoing progress in making access to space cheaper (reusable launch systems could reach $10 per-pound to orbit), and in creating automated manufacturing and construction techniques.

Space travel

Space travel can refer to:

Spacefaring, the capability of and activity in the art of space travel

Spaceflight, the use of space technology to fly a spacecraft into and through outer space, which may include:

Human spaceflight

Interplanetary spaceflight

Interstellar travel

Intergalactic travel

Space Travel (video game), an early computer game


Stargate is a science fiction media franchise based on the film written by Dean Devlin and Roland Emmerich. The franchise is based on the idea of an alien Einstein–Rosen bridge device (the Stargate) that enables nearly instantaneous travel across the cosmos. The franchise began with the film Stargate, released on October 28, 1994, by Metro-Goldwyn-Mayer and Carolco, which grossed US$197 million worldwide. In 1997, Brad Wright and Jonathan Glassner created a television series titled Stargate SG-1 as a sequel to the film. This show was joined by Stargate Atlantis in 2004, Stargate Universe in 2009, and a prequel web series, Stargate Origins, in 2018. Also consistent with the same story are a variety of books, video games and comic books, as well as the direct-to-DVD movies Stargate: Children of the Gods, Stargate: The Ark of Truth, and Stargate: Continuum, which concluded the first television show after 10 seasons.

In 2011, Stargate Universe, the last Stargate program on television, ended its run. Brad Wright announced that there were no more plans to continue the same story in further productions. In 2016, comic publisher American Mythology acquired the rights to publish new Stargate Atlantis stories set within the established franchise canon. This was expanded in 2017 to include new Stargate Universe comics as well, resolving the cliffhanger that ended the show. The predominant story arc thus ran on television for 15 years, including 17 seasons (354 episodes) of programming, and 8 comic book issues as of July 2017. However, a variety of other media either ignore this main continuity or resets it, while maintaining essential elements that define the franchise (mainly, the inclusion of a Stargate device). These include the 2002 animated series Stargate Infinity.

In 2017, the franchise was revived with the announcement of a new prequel web series, Stargate Origins. Episodes premiered on a central "fan hub" for the franchise called Stargate Command, with a first season of ten 10-minute episodes.

Stargate Atlantis

Stargate Atlantis (often abbreviated SGA) is a Canadian-American adventure and military science fiction television series and part of MGM's Stargate franchise. The show was created by Brad Wright and Robert C. Cooper as a spin-off series of Stargate SG-1, which was created by Wright and Jonathan Glassner and was itself based on the feature film Stargate (1994). All five seasons of Stargate Atlantis were broadcast by the Sci-Fi Channel in the United States and The Movie Network in Canada. The show premiered on July 16, 2004; its final episode aired on January 9, 2009. The series was filmed in and around Vancouver, British Columbia, Canada.

The story of Stargate Atlantis follows the events of Stargate SG-1's seventh season finale episode "Lost City" and eighth season premiere episode "New Order", in which the cast of that series discovered an Antarctic outpost created by the alien race known as the Ancients. In the pilot episode "Rising", Stargate Command sends an international team to investigate the outpost, where Dr. Daniel Jackson discovers the location of Atlantis, the legendary city created by the Ancients, and Colonel Jack O'Neill visits the outpost after having been put in stasis and retrieved from it.

The series was a ratings success for the Sci Fi Channel, and was particularly popular in Europe and Australia. Although it received little critical response, Stargate Atlantis was honored with numerous awards and award nominations in its five-season run. After Stargate Atlantis was cancelled, the show's co-creators began working on the already-conceptualized Stargate Universe which the network had approved to have a bigger budget, be less mythology-dependent, and have more focus on character development; Stargate Universe premiered on October 2, 2009, and was cancelled after two seasons. Merchandise for Stargate Atlantis includes games and toys, print media, and an original audio series. With the cancellation of Stargate Universe, the intended direct-to-DVD Stargate Atlantis movie, entitled Stargate: Extinction, was also cancelled.

The Evil Marriage

The Evil Marriage is an upcoming fantasy live-action film, written and directed by Rana Abrar and produced by WBJ Media. The film is scheduled to be released in November 2019.

The Galaxy Being

"The Galaxy Being" is the first episode of the original The Outer Limits television series, originally broadcast on September 16, 1963. In it, Allan Maxwell, an engineer for a small radio station, somehow makes contact with a peaceful alien creature – the "Galaxy Being" – who is then transported to Earth by accident. The Galaxy Being inadvertently kills several people with its natural radiation, and is met with violence and hysteria from the people of Earth.

Human spaceflight
Space launch
Ground segment
Space agencies

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