More than 5,000 exoplanets have been detected nowadays. One of the key motivations of exoplanet detection is to understand what physical/chemical conditions of exoplanets are suitable for harboring extraterrestrial life. Such conditions are called \habitability," and most modern studies assume the existence of liquid water as its key factor. In this paper, we review the current status of exoplanet and habitability studies, as well as some future (habitable) exoplanet survey plans, mostly from National Academies of Sciences, Engineering, and Medicine (2018, 2021). Also, we suggest several research items that the Korean astronomy and space science community could contribute to habitability.

The recent study of Chae et al. (2017) found a one-to-one correspondence between plasma blobs out owing along a ray formed after a coronal mass ejection (CME) and small X-ray ares. In the present work, we have examined the spatial conguration and the eruption process of the ares that are associated with the blobs by analyzing EUV images and magnetograms taken by the SDO/AIA and HMI. We found that the main are and the successive small ares took place in a quadrupolar magnetic conguration characterized by predominant magnetic elds of positive polarity, two minor magnetic fragments of negative polarity, and a curved polarity inversion line between them, which suggests that the formation process of the blobs may be similar to that of the parent CME. We also found that the successive ares resulted in a gradual change of the quadrupolar magnetic conguration, and the relevant migration of aring kernels. The three-dimensional geometry and the property of the current sheet, that is often supposed to be embedded in an observed post-CME ray, seem to keep changing because of mutual feedback between the successive ares and the temporal change of the magnetic eld conguration. Our results suggest that the observed post-CME rays may not re ect the characteristics of the current sheet responsible for the impulsive phase of the are.