This artist's illustration shows the wayward interstellar visitor 'Oumuamua (pronounced oh-MOO-ah-MOO-ah) racing toward the outskirts of our solar system. The object, heated by the Sun (lower right), is venting gaseous material from its surface, as a comet would.

Researchers suggest this outgassing is one possible cause for 'Oumuamua's slight acceleration, as detected by several telescopes.

The irregularly shaped object is only a half-mile across. It is now farther from the Sun than Jupiter and traveling away at about 70,000 miles per hour. The orbits of the major planets are included for scale. The box-shaped constellation Corvus is in the background near image center, and the bright blue star Spica is at upper left of center, in the constellation Virgo. The stars at bottom left belong to the constellation Hydra.