How so?
<{POST_SNAPBACK}>
Jupiter's moons
Saturn's moons
Io is volcanic, mainly due to its immediate proximity to Jupiter and its core being squeezed and elongated as it orbits:
IO
Io is a large, rocky, volcanically active moon of Jupiter. Its volcanoes spew out molten sulfur, making Io a very colorful moon. It is the innermost of Jupiter's four large moons and the third largest. It has a diameter of 1,942 miles (3,636 km), very close in size to our moon. Io's mean distance from Jupiter is 220,000 miles (422,000 km). It has a mass of 8.93x1022 kg. It takes Io 1.77 days to orbit Jupiter. There is a doughnut-shaped plasma cloud around Jupiter near Io's orbit (known as the "Io plasma torus") This torus is caused by Jupiter's strong magnetic field, which strips ions from Io as it rotates; Io acts like an electrical generator. Io was discovered by Galileo and Marius (independently) in 1610.
Speaking of Jupiter's magnetosphere: it is powerful enough to affect radio broadcasts here on Earth!
...
At aphelion (the place in its orbit where Jupiter is farthest from the Sun), Jupiter is 815,700,000 km from the Sun. At perihelion (the place in its orbit where Jupiter is closest to the Sun), Jupiter is 749,900,000 km from the Sun.
...
The Earth orbits, on average, 93 million miles (149,600,000 km) from the Sun. This distance is defined as one Astronomical Unit (AU). The Earth is closest to the Sun (this is called perihelion) around January 2 each year (91.4 million miles = 147.1 million km); it is farthest away from the Sun (this is called aphelion) around July 2 each year (94.8 million miles = 152.6 million km).
...
Europa has an atmosphere, surface water ice and Icecanos!
Titan has an atmosphere, as well:
Biggest moon of Saturn and second largest moon in Solar System (after Jupiter's Ganymede). It is larger than the planets Mercury and Pluto. Titan has a thick mostly nitrogen atmosphere (with some methane) and an atmospheric pressure of 1.6 bars (60 percent greater than the Earth's). This atmosphere with its heavy clouds obscures the moon's surface. It may rain liquid methane. The surface temperature is about -178