Universe of Spectroscopy

Author: Yukio Katsukawa

What would you like to introduce to readers in this series?

“There is no atmosphere on the moon.” This is something that is often written in popular books aimed at the general public. However, it turns out that Mercury and the moon do have very thin atmospheres. Furthermore, it seems that these atmospheres are not stable. Because these atmospheres exist in circumstances where they can escape from the restraint of gravity, they have to be continually supplied. Moreover, the origin of these thin atmospheres is still unknown. There is also the difficulty associated with detecting the atmosphere as a very weak, faint line close to the side of a very bright moon at the observation.

With respect to shooting stars, since it is impossible to predict each one’s exact appearance, this makes it very difficult to plan to carry out a spectroscopic observation. Theoretical research is also progressing, and in cases where the orbit of the parent comet is known, it has become possible to make quite an exact prediction of the peak time of certain meteor showers.

Spectroscopic observation data is also being accumulated along with such prediction of meteor showers. In this “Universe of Spectroscopy,” I would like to explain to you how to overcome difficulties associated with these kinds of observations.

My research field and current interests:

I have done observational research of small solar system bodies, such as comets and meteors. In future, I would also like to pursue studies of the evolution of the meteoroids. These are ejected from a parent comet as observed in the meteor shower, and evolve into the sporadic meteors that become impossible to recognize as a group. I am also interested in detecting meteors around other planets.


Jun-ichi Watanabe
Public Relations Center
Job Title
Field of Expertise
Planetary science