We present a novel method that can enhance the detection success rate of interstellar objects. Interstellarobjects are objects that are not gravitationally bound to our solar system and thus are believed to haveoriginated from other planetary systems. Since the nding of two interstellar objects, 1l/`Oumuamua in2017 and 2l/Borisov in 2019, much attention has been paid to nding new interstellar objects. In thispaper, we propose the use of Heliospheric Imagers (HIs) for the survey of interstellar objects. In particular,we show HI data taken from Solar TErrestrial RElation Observatory/Sun Earth Connection Coronal andHeliospheric Investigation and demonstrate their ability to detect `Oumuamua-like interstellar objects. HIs are designed to monitor and study space weather by observing the solar wind traveling throughinterplanetary space. HIs provide the day-side observations and thus it can dramatically enlarge theobservable sky range when combined with the traditional night-side observations. In this paper, we rstreview previous methods for detecting interstellar objects and demonstrate that HIs can be used for thesurvey of interstellar objects.

Technosignature, previously known as SETI(search for extraterrestrial intelligence), is the scientic evidence of past or present extraterrestrial civilizations. Since NRAO's Project Ozma was performed in 1960, most of the noticeable technosignature searches have been done by radio telescopes, hoping to find strong and narrow bandwidth signals that cannot be explained by known natural processes. Recently, the Breakthrough Listen project has opened a new opportunity for technosignature by utilizing both optical telescopes, radio telescopes, and next-generation radio telescope arrays. In this review, mainly based on NASA Technosignatures Workshop (2018), we review the current trends of technosignature surveys, as well as other possible methods for detecting technosignature. Also, we suggest what the Korean community could contribute the technosignature research, including the new SETI project with Korea VLBI Network (KVN).

Since the farside of the moon is a place to avoid arti cial radio frequency interference (RFI) created byhuman civilization, it is a most suitable place for searching technosignature, which are signs of technolog-ical civilization in the universe, in the radio band. The RFI is a factor that makes the study of searchingtechnosignature quite complicated because it is di cult to distinguish between technological signals pro-duced by human and extraterrestrial civilizations. In this paper, we review why the farside of the moon isthe best place to detect technosignature and also introduce radio observatories on the farside of the moonthat have been proposed in radio astronomy. The SETI (Search for Extraterrestrial Intelligence) projecton the farside of the moon is expected to be one of the main candidates for international collaborationresearch topics on lunar surface observatory.

"Are we alone in the universe?" is the fundamental question of mankind. To search for the life signaturesin the universe, there have been a lot of researches and space explorations, especially in our solar system. In this review paper, we introduce the de nition and characteristics of the \biosignature". The currentsituations and future plans for searching for biosignatures in our solar system are reviewed, especially atVenus, Mars, and Ocean Worlds such as Europa and Enceladus where life signatures are more likely toexist than in other places in the solar system. Finally, we discuss the opportunities and strategies for theKorean scienti c society to participate in searching for biosignatures in the solar system.

Since interstellar objects like 1I/`Oumuamua and 2I/Borisov originate from exoplanetary systems, evenif we do not visit the exoplanetary systems,yby, rendezvous, and sample return missions of interstellarobjects can provide clues to solve the mysteries of cosmic life phenomena such as the origin of exoplanetarysystems, galactic evolution, biosignatures (or even technosignatures), and panspermia. In this paper, wereview space missions for interstellar object exploration in the stage of mission design or concept studysuch as Project Lyra, Bridge, Comet Interceptors, and LightcraftTM. We also review space missions,OSIRIS-REx and NEA Scout, designed for Near Earth Asteroids(NEA) explorations, to investigate thecurrent state of basic technologies that can be extended to explore interstellar objects in a velocity of~ 6AU/year. One of the technologies that needs to be developed for interstellar object exploration is aspacecraft propulsion method such as solar sail, which can catch up with the fast speed of interstellarobjects. If this kind of propulsion becomes practical for space explorations, interstellar object explorationswill mark a new era and serve as a driving force to provide evidences of cosmic life.

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.