The descent of an object (through our atmosphere) is affected by a number of factors:
- gravity: one of the most important factors controlling descent is the pull by the planet's surface. On a different planet (as compared to Earth), gravity may be different and hence an object may be pulled down with a different force
- air resistance: In the absence of air resistance, all objects will fall at the same rate. This also means that if descending from the upper atmosphere (where air is thin and hence resistance is low), different objects will fall with the same rate, as compared to the lower atmosphere. Air resistance decreases the descent rate.
- Properties of object: properties such as shape, size and density will affect the descent especially in conditions of air resistance. Smaller size means lower air resistance (due to lesser contact area), etc.
- wind velocity and direction will also affect the rate of descent of objects, especially lighter ones.