Final answer:
You would be younger on Jupiter in Earth years, because a Jovian year is about 11.86 Earth years long and Jupiter takes longer to complete one orbit around the Sun.
Step-by-step explanation:
On Jupiter, you would be younger in terms of Earth years because Jupiter takes much longer to orbit the Sun. A single year on Jupiter is equivalent to about 11.86 Earth years, which is the time it takes for Jupiter to complete one orbit around the Sun. If an astronaut was 40 years old on Earth and spent 2 years traveling to Jupiter, they would be 42 in Earth years upon their return. However, because only a fraction of a Jovian year would have passed, they would be considerably younger in Jovian terms, with Jupiter barely completing a small segment of its orbit in that time frame.
The situation would seem different to the astronaut. Because motion is relative, the spaceship would seem to be stationary and the Earth would appear to move. If the astronaut looks out the window of the spaceship, she will see time slow down on the Earth by a factor of y = 30.0. To her, the Earth-bound sister will have aged only 2/30 (1/15) of a year, while she aged 2.00 years. The two sisters cannot both be correct.