Radiant (meteor shower) move along the comet's wake, and when the Earth moves through such debris, a meteor shower results. Because all of the debris is moving in roughly the same direction, the meteors which strike the atmosphere all "point" back to the direction of the comet's path. As an exception, the Geminids are a shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid. The radiant is an important factor in observation. If the radiant point is at or below the horizon, then few if any meteors will be observed. This is because the atmosphere shields the
Geminids to 03:00 local time. Geminids were first observed in 1862, much more recently than other showers such as the Perseids (36 AD) and Leonids (902 AD). The meteors in this shower appear to come from the radiant in the constellation Gemini (hence the shower's name). However, they can appear almost anywhere in the night sky, and often appear yellowish in hue. Well north of the equator, the radiant rises about sunset, reaching a usable elevation from the local evening hours onwards. In the southern hemisphere, the radiant appears only around local midnight or so. Observers in the northern hemisphere will