Amalthea is one of the 79 confirmed moons of Jupiter. It has so many moons because of its strong gravitational pull.
Amalthea is neither the largest nor the tiniest moon of Jupiter, but it is no regular moon. Surprised?
Read a lot of stuff like mundane data and cool facts about Amalthea in our Amalthea Facts article. Let us begin…
Amalthea Facts 1-11
1. Amalthea was actually named Jupiter V. It was Camille Flammarion who suggested ‘Amalthea’ name for this moon. It was officially accepted in 1976 by International Astronomical Union (IAU).
2. It is the name of a nymph who raised Jupiter or Zeus, the King of Gods. Amalthea is depicted with a goat. It is believed that she raised Jupiter by giving goats’ milk.
3. It was discovered by E. E. Barnard on 9 September 1892.
4. It has a mass of (2.08±0.15) × 1018 kg and volume of (2.43±0.22) × 106 km.
5. It has a mean density of 0.857±0.099 g/cm, surface gravity of nearly 0.020 m/s2, and escape velocity of nearly 0.058 km/s.
6. It has a mean radius of 83.5±2.0 km and its dimensions are 250 × 146 × 128 km. Its average orbital speed is 26.57 kilometers.
7. It’s one orbit takes 11 hours, 57 minutes, and 23 seconds i.e., it takes 0.498 earth days to complete a single orbit. It takes 12 days to complete one spin.
8. Mean surface temperature of Amalthea is 120 K and maximum surface temperature is 165 K.
9. It orbits within the orbit of Io, another moon of Jupiter. Amalthea belongs to a group of four smaller moons. The other three small moons are Adrastea, Metis, and Thebe.
10. Amalthea, just like other three small moons of Jupiter, doesn’t have a spherical shape. It actually has a rectangular shape. Galileo spacecraft showed impact craters, valleys, and hills.
11. Of the four smaller moons – Amalthea is the largest.
Amalthea Facts 12-22
12. It is the reddest celestial object in our solar system. It seems that it emits more heat than it receives from the Sun.
13. Just like the moon of Earth, Amalthea keeps only one side of it towards the planet Jupiter. The other side of Amalthea is not seen from Jupiter.
14. Thebe and Amalthea are one of the sources for the material of Amalthea Gossamer ring.
15. The orbit of Amalthea is extremely close to Jupiter. It did not get pulled by Jupiter because of its small size. However, the orbit of Amalthea will decay and fall into Jupiter eventually.
16. It is third moon from its parent planet, Jupiter.
17. Usually, the moons are formed by the debris present near the area of its parent planet. However, Amalthea is a bit different.
18. It is made up of ice and other porous materials. It is thought to have formed far away from Jupiter and its heat.
19. Most of the astronomers think that Amalthea is actually an asteroid and while moving it was very close to Jupiter and eventually was pulled by Jupiter’s gravity.
20. It was the fifth moon of Jupiter to be discovered. Hence it was known Jupiter V. Amalthea is the last moon to be discovered by means of telescope. Later, the moons were discovered by digital images and photographs.
21. The moon couldn’t be clearly seen or explored properly because of its proximity to Jupiter. The planet and the moon are extremely bright.
22. However, thanks to Galileo orbiter, we could explore the moon properly. The Galileo orbiter observed that Amalthea has nine moonlets that orbited around it. We don’t know much about the moonlets as of now. Their size can be from a sand grain to a stadium.
Amalthea Facts 23-33
23. Edward Emerson Barnard used 36-inch refractor telescope present at Lick University.
24. It is the first satellite of Jupiter to be discovered after the discovery of Galileo’s discovery of the moons of Jupiter in 1610.
25. Amalthea’s images were taken from close range by Voyager 1 and 2 in 1970’s and Galileo orbiter in the 1990s.
26. It is one of the largest inner satellites of Jupiter.
27. The largest crater on Amalthea has a diameter of 100 kilometers. It is known as Pan. Pan is a Greek goat-God and son of Hermes and Amalthea. It is 8 kilometers deep.
28. The other crater present on Amalthea is Gaea. It has a diameter of 80 kilometers. Gaea is the Greek Earth Goddess who brought Jupiter to Crete. It is twice as deep as Pan.
29. It is the sixth largest and massive moon of Jupiter.
30. The largest bright spot on Amalthea is called Ida Facula. It has a diameter of 50 kilometers. Another bright spot is called Lyctos Facula which has a diameter of 25 kilometers.
31. Not just red, patches of green are also seen on big slopes of Amalthea. The nature and the reason for green color is not known.
32. It orbits its parent planet at a distance of 181,000 kilometers.
33. Amalthea is the setting of many works of science fiction like the stories of James Blish, Boris Strugatsky, Arthur C. Clarke, etc.