On September 9, 2017, the visitor reached its perihelion, the point at which its trajectory took it closest to the Sun. Thereafter, it began to exit the solar system; its speed far away—relative to our star, it was moving at about 58,900 miles per hour—more than ensured its escape from the Sun’s gravity. It passed through Venus’s orbital distance from the Sun around September 29 and through Earth’s around October 7, moving swiftly toward the constellation Pegasus and the blackness beyond.
