A Grand Problem is the first episode of Dragon Ball GT that aired on American television. It is a recap episode created by FUNimation Entertainment to work around the first 16 episodes of the series, as FUNimation did not think the more adventure oriented tone of those episodes would work well with western audiences.
The recap begins with J.T. Marsh traveling to Chaos to help dismantling the Pirate base there and witnesses it being attacked by presumably alien (see episode 2.25) vessels and disappearing into thin space. He then follows the aliens as they make their way to the Inner Planets.
Back on New Earth, Chris, Téa, and Serenity are admiring all 7 Chaos Emeralds in Chuck's lab when Bulma reseaches them. She tells the group that the Chaos Emeralds absorb the radio waves from the Alien transmitter that sending a signal into deep space, which apparently attracted the attention of a new, aggressive alien race known as "Insectoids."
In Dexter's Laboratory, the chickens powering Phineas and Ferb's invention.