Krillitane craft

The Krillitane craft was a spacecraft used by the Krillitanes. It was saucer-shaped, and its movements in Earth's atmosphere were associated with the appearance of orange lights in the sky. (TS: Tardisode 3)

It was spotted by many people and was the first unite notified flying object to be seen by the human eye according to the whoniverse. This ship was amongst the many spaceships and races that came together to form the alliance. Although the krillitane were not spotted in the episode, they were obviously there.