Surface Area Of The Moon

Jupiter's moon Ganymede is proving to be a fascinating earth. Not only is it the largest moon in our solar system, bigger than the planet Mercury and the dwarf planet Pluto, but NASA'due south Hubble Infinite Telescope has found the best evidence all the same for an surreptitious saltwater sea on Ganymede. The ocean is thought to have more water than all the water on World's surface. Ganymede'due south ocean is estimated to be 60 miles (100 kilometers) thick – 10 times deeper than Earth'due south bounding main – and is thought to be buried under a 95-mile- (150-kilometer-) thick chaff of generally ice. Identifying liquid h2o is crucial in the search for habitable worlds across Earth and in the search for life as we know it.

Hubble Aurora Belt — Hubble images of Ganymede's auroral belts (colored blue for analogy) are overlaid on a Galileo orbiter image of the moon. The corporeality of rocking of the moon'south magnetic field suggests that the moon has a subsurface saltwater ocean. Credit: NASA/ESA

Ganymede is the only moon known to have its own magnetic field – a discovery made by NASA's Galileo spacecraft in 1996. The magnetic field causes auroras, which are ribbons of glowing, hot, electrified gas, in regions circumvoluted the n and southward poles of the moon. Because Ganymede is close to Jupiter, its magnetic field is embedded in, or lies within, Jupiter's magnetic field.

When Jupiter's magnetic field changes, the auroras on Ganymede also modify, "rocking" back and forth. It was by watching the rocking motion of the two auroras, that a team of scientists led by Joachim Saur of the University of Cologne in Frg came upward with the idea of using the Hubble infinite telescope to learn more about the inside of the moon.

Ganymede Dark Side — This image of the nighttime side of Ganymede was obtained by Juno's Stellar Reference Unit navigation camera during its June 7, 2021, flyby of the moon. Credit: NASA/JPL-Caltech/SwRI | Full image and explanation

Ganymede has two distinct types of terrain: large, vivid regions of ridges, and grooves that piece across older, darker terrains. This suggests to scientists that Ganymede's crust has been nether tension from global tectonic processes. NASA'south Juno spacecraft took the most recent images of Ganymede'south surface during flybys in June 2021.

Ganymede was discovered by Italian astronomer Galileo Galilei on January. 7, 1610. The discovery, forth with his discovery of iii other large moons effectually Jupiter, was the first time a moon was discovered orbiting a planet other than Earth. The discovery eventually led to the understanding that planets in our solar system orbit the Lord's day, instead of our solar system revolving around Earth. (Jupiter now has 53 named moons and 26 provisional moons awaiting confirmation of discovery).

Namesake

In mythology, Ganymede ("GAN uh meed") was a beautiful young male child who was carried to Olympus by Zeus (the Greek equivalent of the Roman god Jupiter) disguised as an eagle. Ganymede became the cupbearer of the Olympian gods.

Potential for Life

A computer model of Ganymede's interior created in 2014 supported the idea that the development of primitive life might be possible there. The model indicated the icy moon'due south rocky ocean bottom might exist in contact with table salt h2o. Scientists think water and rock interacting are key for the development of life.

Size and Distance

Ganymede has a radius of 1,635 miles (ii,631 kilometers) and is the largest moon in our solar system. It's bigger than Mercury and Pluto. Ganymede is well-nigh 665,000 miles (1.07 meg kilometers) from Jupiter, which orbits about 484 million miles (778 million kilometers) from the Sun. Jupiter is 5.2 astronomical units away from the Sunday. One astronomical unit (abbreviated as AU) is the altitude from the Sunday to World. From this distance, it takes sunlight 43 minutes to travel from the Lord's day to the Jovian system.

Orbit and Rotation

Ganymede orbits Jupiter at a distance of 665,000 miles (one,070,000 kilometers), making it 3rd in distance from Jupiter among the Galilean satellites:

Io: 262,200 miles (422,000 kilometers)
Europa: 417,000 mi (671,000 kilometers)
Ganymede 665,000 miles (1,070,000 kilometers)
Callisto: 1,170,000 mi (1,883,000 kilometers)

Ganymede completes an orbit around Jupiter about every seven Globe days (seven.155). Ganymede orbits the Sun along with Jupiter and its other satellites every 12 Globe years.

Ganymede, Io, and Europa are in what is called a resonance – every time Ganymede orbits Jupiter once, Europa orbits twice, and Io orbits four times. This pattern in their orbits is called orbital resonance. (Jupiter's other large moon – Callisto – is not part of the orbital resonance, seemingly because it was too far away from Jupiter early on in the moons' history for its orbit to be pulled inward toward Jupiter.) Over fourth dimension, the orbits of most large satellites or planets tend to become circular, simply that isn't the case for these three. Their resonance forces their orbits to become slightly elliptical, or eccentric. The satellites line upward with one another at the same points in their orbits over and over, giving each other a small gravitational tug that keeps their orbits from becoming circular.

Ganymede is tidally locked, meaning that similar World's Moon, the same side of Ganymede always faces Jupiter. The other three Galilean moons are also tidally locked.

Moons

Ganymede does non accept moons.

Rings

Ganymede does non have rings.

Formation

Ganymede and Jupiter's other large moons (Io, Europa, and Callisto) probable formed from leftover fabric after Jupiter condensed out of the initial cloud of gas and dust surrounding the Sun, early in the history of our solar system. Ganymede is likely almost the same age equally the rest of the solar organisation – about iv.5 billion years one-time.

NASA'due south Juno spacecraft is currently orbiting Jupiter with the master goal of learning more than almost the origin and development of Jupiter and its satellites. Scientists think that understanding Jupiter will provide critical knowledge nearly our solar system, and the planetary systems being discovered around other stars.

Structure

Ganymede has three main layers: A metal iron cadre at its center, a spherical crush of rock (pall) surrounding the core, and a spherical crush of mostly ice surrounding the rock vanquish. The surface is the very top of the water ice vanquish. Scientists accept discovered irregular lumps beneath Ganymede's icy surface. These irregular masses may exist stone formations, supported past Ganymede's icy beat for billions of years.

Computer models evidence Ganymede might take water ice and oceans stacked upward in several layers like a order sandwich. Scientists kickoff suspected Ganymede had an underground body of water in the 1970s. The Galileo spacecraft discovered Ganymede's magnetic field in 1996, providing show to back up the theory.

NASA'southward Hubble Space Telescope has establish more evidence for an undercover saltwater ocean, and show of a thin oxygen atmosphere on Ganymede.

Surface

Spacecraft images of Ganymede show its surface is a mix of ii types of terrain. 40 percentage of the surface is covered by highly cratered dark regions, and the remaining sixty percentage is covered by a light grooved terrain, which forms intricate patterns across the moon. Some of the groove ridges are as high equally ii,000 feet (700 meters), and the grooves run for thousands of miles across Ganymede'south surface. The large craters on Ganymede are generally flat, probably due to settling in the soft icy surface. Both bright and dark rays of ejecta can exist seen around Ganymede's craters.

In 2004, scientists discovered irregular lumps below the icy surface of Ganymede. The irregular masses may be stone formations, supported past Ganymede'south icy beat for billions of years. This tells scientists that the water ice is probably strong enough, at least about the surface, to support such stone masses from sinking to the bottom of the ice. However, this anomaly could too be caused by piles of rock at the lesser of the water ice.

Temper

Atmosphere

Astronomers using the Hubble Space Telescope have found show of a sparse oxygen temper on Ganymede. The researchers think the oxygen is coming from Ganymede's icy surface. Ganymede is much colder than Earth, with daytime surface temperatures ranging from -297 to -171 degrees Fahrenheit (ninety to 160 Kelvin). Jupiter and its moons receive less than i/30th the corporeality of sunlight that the World does, and Ganymede doesn't have a dense atmosphere to trap estrus.

Magnetosphere

The Galileo spacecraft, the outset to orbit Jupiter, made the major discovery that Ganymede has its ain magnetosphere – a region of charged particles that surrounds many planets simply had never before been found around a moon. Galileo fifty-fifty captured sounds of whistling and static caused past Ganymede's magnetosphere.

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