The moon Amalthea is certainly one of Jupiter’s 53 named satellites; it was the primary to be found after the 4 Galilean moons, and it’s the fifth-largest general. When it comes to proximity to JupiterAmalthea is the planet’s third moon — it takes simply 12 hours to make a full orbit.
Amalthea: Fast information
Dimension: Imply radius of 51.88 miles (83.5 kilometers) ± 1.49 miles (2.4 kilometers)
Common distance from Jupiter: 112,717 miles (181,400 kilometers)
Orbit interval: 11 hours, 54 minutes
Temperature: 155 ± 15 Kelvin
Composition: Rocky, specifics unknown
Astronomer Edward Emerson Barnard found Amalthea on September 9, 1892, whereas astronomer Camille Flammarion instructed the identify Amalthea after the Greek mythological determine. Amalthea was the ultimate planetary satellite tv for pc within the photo voltaic system to be found by direct commentary — that’s, through a telescope somewhat than an imaging gadget like a satellite tv for pc or a probe.
Not a lot is understood about Amalthea, because it has solely been noticed by three spacecraft: voyager 1 different Voyager 2 in 1979, and the Galileo spacecraft in 2002. Whereas all three spacecraft took photographs of the moon, they’re comparatively low-quality. However what is understood about Amalthea is that it’s an irregularly formed celestial physique marked by massive impression craters, hills, and valleys, and it contributes to Jupiter’s faint outer Gossamer Rings.
What can we find out about Amalthea?
Amalthea stays one thing of an enigma inside the realm of Jupiter’s moons. Resulting from an absence of shut observations, there are few issues we find out about Amalthea with certainty. We do know it’s a potato-shaped, rocky physique with a imply radius of 51.88 miles (83.5 kilometers) ± 1.49 miles (2.4 kilometers) in keeping with NASA.
It orbits Jupiter at a distance of 112,717 miles (181,400 kilometers), taking 11 hours, 54 minutes to circle the planet — it’s the third closest moon to Jupiter, belonging to the “internal moon” group alongside Metis, Adrastea, and Thebe. In response to infrared photometry, Amalthea has a temperature of 155 Kelvin ± 15 Kelvin.
The invention of Amalthea
Astronomer Edward Emerson Barnard is credited with the invention of Amalthea; he noticed the moon on September 9, 1892, through the Lick Observatory’s 36-inch refractory telescope in California.
Barnard initially named the moon Jupiter V — it was the fifth Jovian moon to be found, 282 years after Galileo first noticed sure, Callisto, Europeand Ganymede — collectively generally known as the Galilean moons.
Unsurprisingly, Amalthea is the fifth largest Jovian moon, making it comparatively simple to identify in comparison with a few of the smaller moons. However Amalthea is much smaller than the smallest of the Galilean moons, Callisto, whose equatorial radius is almost 29 instances bigger than Amalthea’s.
How Amalthea received its identify
Astronomer Camille Flammarion instructed the identify Amalthea after the Greek mythological determine. Amalthea is a naiad (water nymph) who nursed an toddler Zeus (the Greek model of the god Jupiter) with goat milk in a collapse Crete. She is typically depicted as a goat.
Traits of Amalthea
Observations from the Galileo orbiter within the Nineteen Nineties point out that the moon has hills and valleys, and it’s pockmarked by impression craters — in keeping with Britannica. The biggest is known as Pan, and it has a diameter of 55 miles (90 kilometers), which is huge in relation to Amalthea’s dimension. It’s the reddest object in our photo voltaic system; Scientists imagine that colour could also be because of sulfuric compounds from close by Jovian moon Io, which is volcanically energetic.
Amalthea additionally contributes to one of many Gossamer Rings of Jupiter — the Amalthea Gossamer Ring — which is the faint innermost Gossamer ring of the planet. The Gossamer Rings are exterior the principle Jovian ring.
Mysteriously, Amalthea seems to radiate out extra warmth than it receives from the solar, which NASA suggests could also be because of Jupiter’s magnetic discipline or from tidal stresses. Amalthea is tidally locked to Jupiter in synchronous rotation — it all the time aligns with the planet alongside its lengthy axis.
Missions to Amalthea
Solely two missions have visited Amalthea: Voyager and Galileo. Each the voyager 1 and Voyager 2 spacecraft photographed the Jovian moon throughout their flybys in 1979. Then the Galileo spacecraft captured photographs of Amalthea on the flip of the twenty first century with its Strong State Imaging (SSI) experiment, revealing extra particulars in regards to the uncommon moon.
Galileo would have probably been capable of present much more information about Amalthea if its excessive achieve antenna had not malfunctioned. As a result of spacecraft needed to transmit information again to Earth through its low-gain antenna, much less data was returned from the mission.
The way forward for Amalthea
There aren’t any future missions deliberate to Amalthea, although NASA does intend to ship a probe to the Jovian moon Europa in 2024. NASA’s Europe clippers mission will observe Europa in nice element and examine whether or not it displays life-harboring situations, in keeping with NASA Jet Propulsion Laboratory.
NASA predicts that Amalthea will finally lose its orbit and crash into Jupiter.
You possibly can see pictures of Amalthea taken by Voyager 1 in 1979 on NASA’s Voyager 1 mission web pageand you’ll learn in regards to the spacecraft Galileo’s observations from its 2002 flyby on JPL’s Galileo web site.
Joseph A Burns et al. “Jupiter’s ring-moon system,” Jupiter. The planet, satellites and magnetosphere2004.
NASA, Photo voltaic System Science “Amalthea.”
PC Thomas et al. “The Small Internal Satellites of Jupiter,” Icarus, Quantity 135Situation 1, September 1998.