Poker hands are improved by Planet cards. These Planet cards are based on various planets and dwarf planets from our Solar system, each improving the score of a specific hand type. There is also Planet X, which is based on the speculated planet that is beyond Neptune. The most elusive Planet card, that appears rarely when opening Planet packs, is the Black Hole, which increases the score of all hand types.

Correction

Um actually … Even though it appears in Planet packs, Black Hole is not a Planet card. It is a spectral card, based on its card design and interaction with various Planet card based jokers such as Constellation.