Answer:
It hit Earth like a really long time ago, so many rocks and soil should have been piled on top of the crater because of wind, rain, etc.
Also, it is really deep and really old so when it is old, it gets less visible to the naked eye.
Answer:
15? I actually don't know
a. 46 m/s east
The jet here is moving with a uniform accelerated motion, so we can use the following suvat equation to find its velocity:

where
v is the velocity calculated at time t
u is the initial velocity
a is the acceleration
The jet in the problem has, taking east as positive direction:
u = +16 m/s is the initial velocity
is the acceleration
Substituting t = 10 s, we find the final velocity of the jet:
And since the result is positive, the direction is east.
b. 310 m
The displacement of the jet can be found using another suvat equation
where
s is the displacement
u is the initial velocity
a is the acceleration
t is the time
For the jet in this problem,
u = +16 m/s is the initial velocity
is the acceleration
t = 10 s is the time
Substituting into the equation,

Answer:
it appears to be farther away than it actually is, and therefore smaller then the object itself.