13. Which of the following is not true of Mercury?Mercury rotates exactly three times for every two orbits it makes around the Sun.Mercury has essentially no atmosphere.Its surface is heavily cratered.Even on Mercury's night side, the temperature is hot enough to melt lead.14. Which of the following statements about Mars is not true?Its surface is frozen today, but evidence indicates it had flowing water in the distant past.We have landed robotic spacecraft on its surface.It has mountains that are taller than the tallest mountains on Earth.We could survive on Mars without spacesuits, as long as we brought oxygen in scuba tanks.15. Which moons of our solar system are sometimes called the Galilean moons?the two largest moons in the solar system: Ganymede and Titanthe moons orbiting Uranus, which was once named "planet Galileo"the four largest moons of Jupiter: Io, Europa, Ganymede, and Callistothe moons that orbit their planet "backward" compared to their planet's rotation, such as Neptune's moon Triton