This week's question comes from Morning Brief reader Mark: "I recently saw a video of upward lightning in Oregon. How and why does that happen? How rare is it?"

Most of us think about lightning striking downward from the clouds. But lightning can also strike upward from the ground, or even upward from clouds into the top of the atmosphere. 

In tall storm clouds, strong winds push water drops up high where they freeze into ice, and the ice pieces bump together to make positive and negative charges. 

Once these charges are separated, electricity has to make the connection from the cloud to the ground to release energy. This occurs through the path of least resistance. Electricity takes steps from the ground and from the cloud toward each other like a game of tag. When these channels meet, lightning is released. 

With upward lightning, it is often triggered by tall objects like wind turbines, skyscrapers or radio towers. These metal objects bring the ground closer to the sky and have an easier time launching electricity channels that will be caught by clouds.   

Upward lightning often looks like it is branching upward because of the numerous channels of charges trying to find their way to the cloud. When one of those channels meets a cloud, they often all light up. This process happens when lightning goes from cloud toward the ground, too, but they might be more visible in the upward direction because nothing is blocking your view and the distance between you and the lightning leaders is reduced.

There’s also lightning that strikes upward; sometimes these discharges of energy are seen on the distant horizon over Plains thunderstorms by storm chasers, airplane pilots or astronauts floating over the atmosphere. These strikes can stretch as much as 60 miles into the sky above thunderstorms and they come in a variety of colors from blood red to aquamarine blue. They are called sprites, elves or blue jets. You can read more about those here.