![A Picture of Jupiter's Moon Callisto](https://www.factsjustforkids.com/wp-content/uploads/callisto-moon.png)
- Moon Name: Callisto
- Formed: 4.5 billion years ago
- Discovered: January 7th 1610 by Galileo Galilei
- Distance from Jupiter: Between 1,161,342 miles (perigee) and 1,178,741 miles (apogee)
- Distance from the Sun: Around 484,000,000 miles
- Time to Orbit Around Jupiter: About 17 Earth days
- Total Surface Area: 73,004,909 square miles
18 Callisto Facts for Kids
- Callisto formed about 4.5 billion years ago.
- Callisto was discovered by Galileo Galilei on January 7th, 1610, using a telescope.
- Callisto is one of Jupiter’s seventy-nine known moons.
- Callisto is the third largest moon in our Solar System.
- Callisto has a light atmosphere that contains carbon dioxide.
- Callisto has a radius of about 1,497 miles.
- The closest Callisto gets to Jupiter is 1,161,342 miles (perigee).
- The farthest Callisto gets from Jupiter is 1,178,741 miles (apogee).
- It takes Callisto about 17 Earth days to orbit the planet Jupiter.
- Callisto is almost the exact same size as Mercury, 99% to be exact, but only contains one third of the mass.
- Callisto is large enough to be considered a planet, but because it orbits Jupiter and not the Sun it’s considered a moon.
- Callisto has had a violent history; it has more impact craters on the surface than any other object in our Solar System.
- Scientists speculate that Callisto could contain or once contained life in its subsurface ocean.
- In 1973, Pioneer 10 was the first spacecraft to flyby and take close-up pictures of Callisto.
- In 1974, the Pioneer 11 spacecraft came within 488,700 miles of Callisto and was able to determine its mass.
- Between 1996 and 2001 the Galileo spacecraft had 12 encounters with Callisto; it indicated that Callisto had an atmosphere and potentially detected an underground ocean.
- In December 2000, the Cassini spacecraft took some awesome pictures of Callisto.
- In February 2007, the New Horizons spacecraft flyby of Jupiter allowed it to take pictures of Callisto.
Pictures of Jupiter’s Moon Callisto
![A photo of two images of Callisto taken by New Horizons Long Range Reconnaissance Imager.](https://www.factsjustforkids.com/wp-content/uploads/two-photos-of-callisto-moon-capture-by-new-horizons-long-range-reconnaissance-imager.png)
Two images of Callisto via the New Horizons Long Range Reconnaissance Imager.Credit: NASA
![A color of Jupiter's moon Callisto taken by NASA Galileo spacecraft in May 20](https://www.factsjustforkids.com/wp-content/uploads/a-color-photo-of-callisto-taken-by-NASA-galileo-spacecraft-in-may-2001.png)
A color of Jupiter’s moon Callisto taken by NASA Galileo spacecraft in May 20Credit: NASA
![A wonderful rendering of what the internal structure of Callisto could look like.](https://www.factsjustforkids.com/wp-content/uploads/rendering-of-the-possible-internal-structure-of-callisto-moon-by-nasa.png)
A wonderful rendering of what the internal structure of Callisto could look like.Credit: NASA
Additional Resources on Jupiter’s Moon Callisto
- In Depth | Callisto – NASA Solar System Exploration – A breath taking in depth view of Callisto on the NASA Solar System Exploration website.
- Callisto Photo Jounrnal at NASA – Look at some awesome pictures taken of Callisto by spacecraft and telescopes over the years.
- Callisto Moon – Wikipedia – Discover more amazing information about Jupiter’s moon Callisto on the Wikipedia website.