An interstellar asteroid might have just been spotted for the first time
The interloper could carry information about the makeup of alien planet systems
![A/2017 U1's trajectory](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2017/10/102617_LG_interstellar-comet_main.jpg?fit=860%2C460&ssl=1)
INTERSTELLAR INTERLOPER? The unusual trajectory of an asteroid, called A/2017 U1, suggests it came from outside the solar system and is now on its way out again.
JPL-Caltech/NASA