The following is a list of comets with a very high eccentricity (generally 0.99 or higher) and a period of over 1,000 years that do not quite have a high enough velocity to escape the Solar System. Often, these comets, due to their extreme semimajor axes and eccentricity, will have small orbital interactions with planets and minor planets, most often ending up with the comets fluctuating significantly in their orbital path. Some of these comets with orbital periods of millions of years come from the Oort cloud, a cloud of comets orbiting the Sun from ~10,000 to roughly 50,000 AU. The actual orbit of these comets significantly differs from the provided coordinates. A Solar System barycentric orbit computed at an epoch when the object is located beyond all the planets is a more accurate measurement of its long-term orbit.