According to the phylogenetic tree diagram, modern birds are most closely related to?
Does lightning travel from the earth to the sky, or from the sky downward? Lightning travels both ways. Lightning is a huge electrical discharge that results from vigorous motions that occur in thunderstorms. Lightning can travel from cloud to cloud, within the same cloud, or between the cloud and ground. In-cloud lightning discharges are more common than cloud-to-ground discharges and are not as hazardous. Cloud-to-ground is the best known type of lightning and it poses the greatest risk.
Lightning strikes occur most often during the climb and descent phases of flight at an altitude of 5,000 to 15,000 feet (1,524 to 4,572 meters). The probability of a lightning strike decreases significantly above 20,000 feet (6,096 meters). Seventy percent of all lightning strikes occur during the presence of rain.