A year ago, astronomers identified the first interstellar visitor to our solar system. 'Oumuamua was studied by nearly every telescope available, including the ultra-sensitive Spitzer infrared space telescope. Despite a whopping 33 hours of observation time, 'Oumuamua proved too faint for Spitzer to see. Nevertheless, this allowed the observation team to draw significant conclusions. Their analysis of the visitor was published online on Nov. 14 by The Astronomical Journal.
- Astronomical Journal