Variation in meteoroid impacts with the Earth, illustration. The Earth's rotation is shown by the red arrow. The orbital motion of the Earth (towards right) is shown by the grey arrow. Sunlight illuminates the Earth from top, with mid-day at top and midnight at bottom. At lower centre, meteoritic particles are seen grazing the Earth's atmosphere. These meteoritic particles are rarely fast enough to catch up with the Earth (yellow tracks at left). In contrast, large numbers of meteoritic particles impact the Earth's atmosphere in the direction of its orbit (yellow tracks at right). This affects the timing, frequency, and types of meteorite impacts that are observed (grazing impacts are usually observed near midnight).