At present, NASA is planning a mission to Europa, to try and assess its habitability. An argument might also be made for Enceladus, however. Let's imagine you had to pick one of those moons to send an uncrewed (i. e. robotic) mission to. The spacecraft will probably orbit the giant planet (Jupiter in the case of Europa, Saturn in the case of Enceladus), and make many flybys of the moon you're studying. Which moon would you pick, and why?

Jupiter

Explanation:

For this space trip, the distance to the planet must be taken into account, so Because Jupiter is much closer it should be the correct choice

.

It must also be taken into account that Saturn has a series of rings, for which the ship has a probability of colliding with one of these in one of its turns, therefore taking this into account, Jupiter must also be chosen.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.