Plus, when such an object that is moving so (relatively) slowly approaches the planet, it will fall into the gravity well and pick up a lot of speed - the escape velocity of the planet, which for Earth is about 11.2km/s. So effectively there is a minimum speed at which an object can touch the planet's surface, if you disregard air resistance and assume that the object came from a long way away without doing anything funky like slingshots on its way in.