'Oumuamua Gets Unexpected Speed Boost - and Reclassification

An illustration of 'Oumuamua speeding toward the edge of the solar system. Image Credits: NASA/ESA/STScl

Unless you've been living under a space rock, you've probably heard about 'Oumuamua - the first known interstellar object to travel through our solar system. Its odd shape, wobbly rotation and rapid trajectory are dead giveaways that this object did not originate in our solar system, undoubtedly creating excitement among scientists.

After analyzing a recent unexpected speed boost, an international team of scientists led by Marco Micheli of the European Space Agency (ESA) have confirmed that 'Oumuamua is actually a mildly active comet.

“Our high-precision measurements of ′Oumuamua’s position revealed that there was something affecting its motion other than the gravitational forces of the Sun and planets," said Micheli.

It was determined by Davide Farnocchia of the Center for Near Earth Object Studies (CNEOS) that the speed boost was due to jets of gaseous material being expelled from its surface, a characteristic behavior of comets. Its new classification as 1I overturned its previous designation as asteroid A/2017 U1 and introduced "I" to begin classifying Interstellar objects.

'Oumuamua - despite being less than a half a mile in length - continues to be a provocative source of data from distant worlds.