BetaHedron

BetaHedrons are Kryptonian devices that were used as secondary sources of power on Krypton, specifically used to power probes that scientists sent to space. According to Kara, it is a "smaller" version of the Omegahedron, though it is still powerful enough to provide a near-unlimited power supply.

History
Krypton sent probes with knowledge about their planet, society and religion all across space, in order to teach other planets about themselves. These probes were powered up by BetaHedrons. One of these probes ended up on earth.

After he was saved by Supergirl, a person named Thomas Coville became quite obsessed with her. Somehow, he found the probe, and used the knowledge inside to create a religion similar to the kryptonian one, nicknamed the "Cult of Rao". In order to recruit more believers to the religion, he turned the BetaHedron unstable, causing it to become unstable and explode, counting on Supergirl to stop it. Fortunately, with the aid to her sister, Supergirl succeeded to contain the blast by pushing the probe into a deep hole. However, it was still powerful enough to cause a tremor that affected the the Legion's cruiser, resulting in the awake of Mon-El.