This article is being considered for deletion in accordance with Wikipedia's deletion policy. Please share your thoughts on the matter at this article's deletion discussion page. |
Europa, the fourth-largest moon of Jupiter, is a subject in both science fiction and scientific speculation for future human colonization. Europa's geophysical features, including a possible subglacial water ocean, make it a possibility that human life could be sustained on or beneath the surface.
Europa as a target for human colonization has several benefits compared to other bodies in the outer Solar System, but is not without challenges.
On a flyby mission around Europa in 1979, Voyager 1 and Voyager 2 took relatively detailed photographs of the moon's surface. They noted several important characteristics including dark streaks across the surface, or lineae, and an otherwise remarkably smooth icy crust. The lineae are believed to be the result of icy tectonic plates moving over a submerged ocean. Moreover, the smooth crust is believed to be the result of its recent formation. [1] Submerged water may have risen to cover the older, more damaged surface and smooth it over. These surface features indicate the existence of a subsurface ocean. Given water's importance to life on Earth, it is considered to be a possible indicator of life on other celestial bodies.
The high radiation on Europa's surface is one of the environmental challenges to colonization. [2] Europa receives 5.4 Sv (540 rem) of radiation per day, [3] which is approximately 1,800 times the average annual dose experienced by a human on Earth at sea level. Humans exposed to this level of radiation for one day would have greater than a 50% mortality rate within 30 days.
Another problem is that the surface temperature of Europa averages around 90K, or -183 °C. [4]
Furthermore, the low gravity of Europa may also present challenges to colonization efforts. The effects of low gravity on human health are still an active field of study, but can include symptoms such as impaired eyesight and a diminished sense of balance. [5] Negative health effects can also include muscle deterioration and bone loss. Galactic cosmic radiation along the journey is likely to lead to an increased chance of developing Alzheimer's Disease. [6] [7] Astronauts in Earth's orbit have remained in microgravity for more than a year at a time and have had to develop countermeasures to address its negative effects. Experts have also hypothesized that children born and raised in low gravity would not be well adapted for life under the higher gravity of Earth. [8]
Moreover, experts have speculated that alien organisms may exist on Europa, possibly in the subsurface ocean under the moon's ice shell. [9] [10] If true, this would mean human colonists may come into contact with harmful microbes.
An unstable surface could also represent a potential problem as it has been shown that Europa is geologically active. With an outer crust experts believe is made of constantly shifting plate tectonics, Europa's surface would make it difficult to maintain the structural integrity of any long-term infrastructure. [11]
The transportation of humans to Europa would be one of the primary challenges to colonization. Since Jupiter is on average 630.4 million kilometers away from Earth at a given time, it would take at least 3 years just to get into Europa's orbit plus additional time to land. In an effort to develop transportation methods to Mars and other planets, NASA has announced a program called NextSTEP that will merge the efforts of public and private industry to begin the research and architectural design necessary to create an Environmental Control and Life Support (ECLS) system. [12] The ECLS is currently being designed for Martian operations, will be called the Deep Space Transport (DST) and will allow for missions up to 2.75 years long. The transport vehicle to Europa will be similar to the DST and the International Space Station (ISS), but will also be different in several key aspects. Most importantly, the transport vehicle for Europa would need to be completely self-sufficient so that all the nutritional supplies are included at the onset of the flight, along with the ability to repair any systems that malfunction or break on the voyage. The vehicle would also need to be resistant to radiation because the levels of radiation on this trip would be significantly higher than on Earth. The shielding around the ship would have to be increased to prevent exposure to harmful radiation. While these considerations are prohibitively expensive and require development of current technologies, it is not impossible that a continuation of the DST would meet the requirements necessary to eventually complete this journey.
Like historic colonies that were established on Earth, Europa's economic development would be critical to its continual growth and success. [13] One such economic driver could be its relatively close proximity to Jupiter, the asteroid belt, and the periphery of the solar system. Earth is, on average, almost 500 million miles from Europa. [14] To alleviate the time and distance required to travel, Europa can serve as a midway colony between Earth and the aforementioned locations. "Intermediary" colonies have historic precedents. For example, Cape Town, South Africa, was established as a safe harbor for long voyages between Asia and Europe. [15]
Europa is hypothesized to have a large subsurface ocean. Water makes it possible to grow fruits, vegetables, and grains as it is an essential pillar to agriculture. [16] However, reddish-brown materials whose composition is not yet known, but that experts believe to be salt and sulfur compounds that have been mixed with ice and modified by radiation, litter Europa's surface and could make Europa's surface unsuitable for agriculture. [17] Manure and other fertilizers could be an inter-Europa commodity as it will most likely be essential to delivering the nutrients required for farming and industrial agriculture. [16]
The true breadth of ethical consequences that come from the colonization of Europa cannot be known until such a colony is fully established. The United Nations Outer Space Treaty, ratified in 1967, states that no country may take claim to space or celestial bodies like Europa. [18] It is unclear exactly how ownership over Europa colonial lands would be distributed and whether colonists will have private land ownership once a colony is established. More human centered ethical questions may arise from how extended periods in outer space will impact colonists. Migration on Earth is a well established phenomenon but it carries its own set of psychological impacts like a decrease in mental well-being due to having to adjust to a new environment, set of norms, distress, and separation from family. [19] NASA scientists predict that an altered state of gravity and radiation coupled with isolation and confinement have the potential to pose real psychological hardships on a person. [20] Such negative impacts on colonists will increase as they spend more time in space. Ethical arguments can be made as to why any entity should finance the colonization of Europa when the program has a high risk of failure and could be detrimental to the colonists' health and well-being.
The environment within a Europa colony will inevitably be altered. Colonists will most likely want to terraform the moon to make its surface and climate better suited for their colony. [21] Arguments can be made as to what right humans have, as extraterrestrial visitors, to alter the natural environment. Parallels can also be found between the negative impacts that unmonitored resource exploitation has had on Earth and the potential of such a catastrophe on Europa.
If life is found to exist on Europa, the difference in the environments of Earth and Europa would likely mean terraforming would have adverse effects on the natural inhabitants of the moon. [22] Ethical considerations regarding how to preserve natural life, whether it be primitive or in the form of microorganisms may be necessary.
Galileo Galilei first discovered Europa along with four of Jupiter's other satellites on 7 January 1610. [23] However, he only realized they were moons, rather than stars, on 15 January of that year. [24]
Pioneer 10 and Pioneer 11 were flyby missions to Jupiter in 1972 and 1973 respectively. [25]
Voyager 1 and Voyager 2 were NASA space probes launched in 1977. During a flyby mission in 1979, the Voyager probes took relatively precise photographs of the moon's surface. [1]
Europa Clipper is a NASA mission planned for launch in 2024. [1] After it is launched, the spacecraft will study Europa on flybys as it orbits Jupiter. The mission's goal is to determine whether there is a liquid water ocean submerged under Europa's icy surface. Furthermore, NASA hopes to determine whether that ocean provides suitable conditions for life.
Space exploration is the use of astronomy and space technology to explore outer space. While the exploration of space is currently carried out mainly by astronomers with telescopes, its physical exploration is conducted both by uncrewed robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main sources for space science.
Space colonization is the use of outer space or celestial bodies other than Earth for permanent habitation or as extraterrestrial territory.
Callisto, or Jupiter IV, is the second-largest moon of Jupiter, after Ganymede. In the Solar System it is the third-largest moon after Ganymede and Saturn's largest moon Titan, and as large as the smallest planet Mercury, though only about a third as massive. Callisto is, with a diameter of 4821 km, roughly a third larger than the Moon and orbits Jupiter on average at a distance of 1883000 km, which is about six times further out than the Moon orbiting Earth. It is the outermost of the four large Galilean moons of Jupiter, which were discovered in 1610 with one of the first telescopes, being visible from Earth with common binoculars.
Europa, or Jupiter II, is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 95 known moons of Jupiter. It is also the sixth-largest moon in the Solar System. Europa was discovered independently by Simon Marius and Galileo Galilei and was named after Europa, the Phoenician mother of King Minos of Crete and lover of Zeus.
Ganymede, or Jupiter III, is the largest and most massive natural satellite of Jupiter as well as in the Solar System, being a planetary-mass moon. It is the largest Solar System object without an atmosphere, despite being the only moon in the Solar System with a magnetic field. Like Titan, it is larger than the planet Mercury, but has somewhat less surface gravity than Mercury, Io or the Moon.
The Jupiter Icy Moons Orbiter (JIMO) was a proposed NASA spacecraft designed to explore the icy moons of Jupiter. The main target was Europa, where an ocean of liquid water may harbor alien life. Ganymede and Callisto, which are now thought to also have liquid, salty oceans beneath their icy surfaces, were also targets of interest for the probe.
Many parts of the outer Solar System have been considered for possible future colonization. Most of the larger moons of the outer planets contain water ice, liquid water, and organic compounds that might be useful for sustaining human life.
The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of Pioneer 10 into the Jovian system in 1973, and, as of 2023, has continued with eight further spacecraft missions in the vicinity of Jupiter. All of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but two were flybys taking detailed observations without landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys. On 5 July 2016, spacecraft Juno arrived and entered the planet's orbit—the second craft ever to do so. Sending a craft to Jupiter is difficult, mostly due to large fuel requirements and the effects of the planet's harsh radiation environment.
The exploration of Uranus has, to date, been through telescopes and a lone probe by NASA's Voyager 2 spacecraft, which made its closest approach to Uranus on January 24, 1986. Voyager 2 discovered 10 moons, studied the planet's cold atmosphere, and examined its ring system, discovering two new rings. It also imaged Uranus' five large moons, revealing that their surfaces are covered with impact craters and canyons.
Io Volcano Observer (IVO) is a proposed low-cost, outer-planet mission to explore Jupiter's moon Io to understand tidal heating as a fundamental planetary process. The main science goals are to understand (A) how and where tidal heat is generated inside Io, (B) how tidal heat is transported to the surface, and (C) how Io is evolving. These results are expected to have direct implications for the thermal history of Europa and Ganymede as well as provide insights into other tidally heated worlds such as Titan and Enceladus. The IVO data may also improve our understanding of magma oceans and thus the early evolution of the Earth and Moon.
Laplace-P was a proposed orbiter and lander by the Russian Federal Space Agency designed to study the Jovian moon system and explore Ganymede with a lander.
The Jupiter Icy Moons Explorer is an interplanetary spacecraft that was launched on 14 April 2023 from Guiana Space Centre in the French Guiana by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission is planned to study Ganymede, Callisto, and Europa, three of Jupiter's Galilean moons. They are thought to have significant bodies of liquid water beneath their icy surfaces which would make them potentially habitable environments.
Europa Clipper is an interplanetary mission in development by NASA comprising an orbiter. Planned for launch in October 2024, the spacecraft is being developed to study the Galilean moon Europa through a series of flybys while in orbit around Jupiter.
Planetary oceanography also called astro-oceanography or exo-oceanography is the study of oceans on planets and moons other than Earth. Unlike other planetary sciences like astrobiology, astrochemistry and planetary geology, it only began after the discovery of underground oceans in Saturn's moon Titan and Jupiter's moon Europa. This field remains speculative until further missions reach the oceans beneath the rock or ice layer of the moons. There are many theories about oceans or even ocean worlds of celestial bodies in the Solar System, from oceans made of diamond in Neptune to a gigantic ocean of liquid hydrogen that may exist underneath Jupiter's surface.
Journey to Enceladus and Titan (JET) is an astrobiology mission concept to assess the habitability potential of Enceladus and Titan, moons of Saturn.
The Europa Lander is a proposed astrobiology mission concept by NASA to send a lander to Europa, an icy moon of Jupiter. If funded and developed as a large strategic science mission, it would be launched in 2027 to complement the studies by the Europa Clipper orbiter mission and perform analyses on site.
The future of space exploration involves both telescopic exploration and the physical exploration of space by robotic spacecraft and human spaceflight.
Trident is a space mission concept to the outer planets proposed in 2019 to NASA's Discovery Program. The concept includes flybys of Jupiter and Neptune with a focus on Neptune's largest moon Triton.
Planetary habitability in the Solar System is the study that searches the possible existence of past or present extraterrestrial life in those celestial bodies. As exoplanets are too far away and can only be studied by indirect means, the celestial bodies in the Solar System allow for a much more detailed study: direct telescope observation, space probes, rovers and even human spaceflight.
| Geology |
|  | ||||||
|---|---|---|---|---|---|---|---|---|
| Exploration |
| |||||||
| Other | ||||||||