I believe Tom is mot likely suffering from the post traumatic stress disorder.Post traumatic stress disorder is the mental health condition that is triggered by a terrifying event-either experiencing it or witnessing it. Symptoms may include flashbacks, nightmares and severe anxiety, as well as uncontrollable thoughts about the event.
It can be confusing because it isn't specific enough. In astronomy, the big dipper is not a spoon. It is a bear. Scientists know it as Ursa Major rather than a dipper or bear.
Answer:
There are two primary factors: size and distance from the Sun. Gravity helps planets and moons to hold on to their atmospheres, so small planets/moons such as Mars and the Moon have thin atmospheres. The reason why the outer planets are larger is probably down to two major factors. The first is simply the amount of material available which may be accreted to a planet. Clearly, the further away from the Sun, the longer the orbit (twice as far means an orbit twice the physical length).
Explanation: