George and Gracie came to the attention and interest of Admiral Kirk, who had time traveled to 1986 in search for some of these whales. In the 23rd century, the powerful signal from a deep space probe had caused disruption of Earth's weather patterns, threatening the entire planet. Spock theorized that an alien species had sent the probe to Earth to determine why they had lost contact with humpback whales (which had become extinct in the 21st century).