3200 Phaethon has been shown to be the parent body of the Geminid meteor shower.. Image credit: NAOJ
Based on a new study of how near-Earth asteroid Phaethon reflects light at different angles, astronomers think that its surface may reflect less light than previously thought. This is an exciting mystery for the recently approved DESTINY+ mission to investigate when it flies past Phaethon.
The way an object reflects light depends not only on its albedo (the percentage of light it reflects) but also on the illumination angle. One particular effect that scientists are interested in is how the polarisation changes when sunlight reflects off the surface of an asteroid. Scientifically, light is referred to as electromagnetic waves; the waves create changes in the electric and magnetic fields. The directions of these changes can either be random or aligned. When the electromagnetic effects of light are aligned, the light is said to be polarised.
An international team, including astronomers from the National Astronomical Observatory of Japan (NAOJ), Seoul National University, Chiba Institute of Technology, and other institutes, used the 1.6-metre Pirka Telescope at Nayoro Observatory in Hokkaido, Japan to observe the near-Earth asteroid 3200 Phaethon. They studied the changes in the ...