Why is europa special

It also takes Europa 3. This means that a day on Europa takes the same length of time as one year on Europa. Like almost all moons in the solar system, Europa is tidally locked — locked by gravity — to Jupiter and the same side of the moon always faces the planet. This breaks those molecules into oxygen and hydrogen atoms. The hydrogen escapes the surface of Europa but the oxygen is left being — leaving a tenuous oxygen based atmosphere.

The discovery of Europa and the other Galilean moons lead to the discovery of a Sun-centred solar system. The moon is named after a Phoenician noblewoman who became queen of Crete in Greek mythology. Europa is the smoothest object in the solar system.

Europa is about 4. Radiation on Europa is high enough to kill a human being in one day. Europa has a liquid ocean of saltwater beneath its surface. Europa may have twice as much water on it as Earth. One day on Europa lasts as long as one year — 3. Europa is tidally locked to Jupiter. Europa has a very weak atmosphere. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. However, you may visit "Cookie Settings" to provide a controlled consent.

Read more on our privacy policy here. Register for a free account to start saving and receiving special member only perks. Europa — one of the four large satellites of Jupiter discovered by Galileo Galilei in Figures 1. In large part, this interest stems from the possibility that Europa may have substantial amounts of liquid water, possibly as a global-scale ocean buried beneath a surface layer of ice, 1 , 2 with liquid water being one of the primary requirements for the origin or continued existence of life as we can imagine it.

The interest in Europa extends beyond the scientific community, and the idea that a europan ocean might harbor life has become a part of popular culture. This is exemplified by Arthur C. Clarke's science-fiction novel, Odyssey II, 3 in which life-harboring Europa is declared off-limits to humans with a mysterious, preemptive warning — "All these world are yours except Europa, attempt no landings there.

Scientific and public interest has intensified as the Galileo spacecraft has revealed remarkable indications of geologically recent or ongoing activity in Europa's atmosphere, on its surface, and within its interior.

There is abundant evidence on its icy surface for relatively recent geologic activity, including resurfacing with fresh ice and tectonic movement of the ice. Above the surface is an atmosphere produced mainly by the bombardment of the icy surface by energetic particles interacting with the jovian magnetospheric environment.

The average density of Europa suggests that the interior, although not sampled or observed directly, is composed predominantly of a rocky material similar to that of Io or the Moon and has a dense core at its center. The outermost to km, however, consists of a layer composed predominantly of water.

Evidence for fairly recent geologic activity at the surface suggests that the combined heating produced by the decay of radiogenic isotopes, tidal flexing associated with its orbit around Jupiter, and resonant interactions with neighboring satellites is substantial. What makes Europa of special interest, however, is the potential that it may hold for the presence of liquid water within this surface layer and the associated possibility of life.

Internal heating may be sufficient to raise temperatures to the melting point of water ice at only a modest depth of a few to tens of kilometers.

Consequently, Europa may contain a global ocean of liquid water more than km thick and covered by only a thin layer of water ice. The presence of liquid water is suggested by Galileo images showing blocks of ice, some of which are several kilometers across, that appear to have "rafted" away from a larger mass, possibly on a liquid-water or slushy-ice layer that subsequently froze.

Moreover, Europa's relatively crater-free surface suggests that the rafting occurred in the recent geologic past i. The possible presence of liquid water, combined with the presumed availability of geochemical energy within its interior, creates the potential for life to have originated on Europa and perhaps even to exist today within a. Courtesy of the Mendillo Collection. In this elegant depiction of the heliocentric theory, Galileo's discovery shows Jupiter orbiting the Sun to be itself "a center of motion" The four Galilean moons are shown as star-like objects, equidistant from Jupiter.

It would be years before these "Medicean stars" would be shown to be the individual worlds of Io, Europa, Ganymede, and Callisto. Europa was discovered by Galileo in , along with the three other large satellites of Jupiter — lo, Ganymede, and Callisto. The four are now collectively called the Galilean satellites.

Europa travels around Jupiter at an orbital distance of about 9. Europa's surface is highly reflective, and characteristic absorptions at certain wavelengths in the reflected sunlight, measured using ground-based telescopes beginning in the s, indicate the presence of water ice.

However, the mean density of Europa, about kg m -3 , is substantially higher than that of ice about kg m -3 and is lower than that of rock about kg m -3 , including the compression that occurs deep inside Europa's interior , implying that Europa consists of a mixture of water and rocky material. The Voyager spacecraft showed the surface to be relatively free of impact craters, suggesting that Europa's surface is younger than the surfaces of Ganymede and Callisto. In addition, Voyager data revealed that ice tectonics shapes Europa's surface geology and raised the possibility that liquid water might exist beneath its icy surface.

While it's not a unanimous opinion, it's certainly a tantalizing one. An ocean in our solar system, that has been in existence for billions of years? It is far, far out from the sun, and yet it's got this liquid-water ocean. But life needs more than water. It also needs hydrogen, carbon, and an energy source. Europa has them all, says Hand. But so far, this is all just theory. To get confirmation, we need more data, in the form of a longer, more focused mission.

One proposed mission is the Europa Clipper , named for the speedy and lightweight 19th-century ships. Its instruments would include radar to penetrate the frozen crust and determine the thickness of the ice shell, an infrared spectrometer to investigate the composition of Europa's surface materials, a topographic camera for high-resolution imaging of surface features, and an ion and neutral mass spectrometer to analyze Europa's trace atmosphere during flybys. Already a subscriber?

Monitor journalism changes lives because we open that too-small box that most people think they live in. We believe news can and should expand a sense of identity and possibility beyond narrow conventional expectations.

My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. If you were to come up with a punchline to a joke about the Monitor, that would probably be it. But you know what? We change lives.

We have a mission beyond circulation, we want to bridge divides. And we can prove it. Your subscription to The Christian Science Monitor has expired. That fantasy, however, may be grounded in reality. From ground-based telescopes, scientists knew that Europa's surface is mostly water ice, and scientists have found strong evidence that beneath the ice crust is an ocean of liquid water or slushy ice. In the two Voyager spacecraft passed through the Jovian system, providing the first hints that Europa might contain liquid water.

The team measured the vapor using a spectrograph at the Keck Observatory in Hawaii that measures the chemical composition of planetary atmospheres through the infrared light they emit or absorb. As the ice shell distorts and flexes from tidal forces, warmer and less-dense ice would rise, carrying the ocean samples to the surface where a spacecraft could analyze it remotely, using infrared and ultraviolet instruments, among others. Europa is named for a woman who, in Greek mythology, was abducted by the god Zeus — Jupiter in Roman mythology.

Life as we know it seems to have three main requirements: liquid water, the appropriate chemical elements, and an energy source. Astrobiologists — scientists who study the origin, evolution, and future of life in the universe — believe Europa has abundant water and the right chemical elements, but an energy source on Europa has been difficult to confirm. On Earth, life forms have been found thriving near subterranean volcanoes, deep-sea vents, and other extreme environments.

If we eventually find some form of life at Europa or Mars or Enceladus for that matter , it may look like microbes, or maybe something more complex. If it can be demonstrated that life formed independently in two places around the same star, it would then be reasonable to suspect that life springs up in the universe fairly easily once the necessary ingredients are present, and that life might be found throughout our galaxy and the universe.

If life were found at Europa, how might it change your view of the cosmos and our place in it? So if we replaced our Moon with Europa, it would appear roughly the same size in the sky as our Moon does, but brighter — much, much brighter. Europa orbits Jupiter at about , miles , kilometers from the planet, which itself orbits the Sun at a distance of roughly million miles million kilometers , or 5.

One AU is the distance from Earth to the Sun. Light from the Sun takes about 45 minutes to reach Europa.