Astrobiology Popular Science

Among all currently known exoplanets, the planetary system orbiting TRAPPIST-1 has long been regarded as one of the most promising targets for studying Earth-like atmospheres. Within this system, TRAPPIST-1e stands out: its size and mass are close to Earth, and it lies within the star’s habitable zone, making it a strong candidate for maintaining liquid water on its surface. However, this possibility depends on a crucial prerequisite—the presence of an atmosphere. Without an

In the search for extraterrestrial life, it is often intuitively assumed that detecting Earth-like environmental features on distant planets—such as the simultaneous presence of oxygen, water, and methane—would constitute strong evidence for life. However, the true difficulty does not lie in whether our observational technology is sufficiently advanced, but rather in whether we possess a theoretical framework capable of distinguishing between phenomena produced by life and th

On Titan, the largest moon of Saturn, the atmosphere is filled with an orange-brown organic haze that has long been considered a potential source of molecular precursors for prebiotic molecules. These particles, formed from nitrogen, methane, and other gases under high-energy conditions, are chemically complex and contain a wide range of compounds related to biomolecules, including amino acids and nucleobases. However, Titan's surface is frequently subjected to impacts from c

With the advancement of space probes, robotic explorers, radio telescopes, and data analysis technologies, the amount of accessible information about the universe has increased dramatically. The integration of artificial intelligence has further enabled rapid organization and identification of complex cosmic signals and chemical data. Despite these developments, humanity has yet to confirm the existence of extraterrestrial life. However, a growing body of evidence from meteor

The present-day environment of Venus is extremely hostile, with an average surface temperature of approximately 750 K (476.9°C), far beyond the limits for any known life. However, this does not necessarily mean that Venus has always been uninhabitable. Over the course of Solar System history, Venus has undergone profound changes, and its early state may have been dramatically different from what we observe today. When the young Sun was significantly fainter, Venus was located

In recent years, research in astrobiology has increasingly recognized that the emergence of life is not solely determined by whether an environment can sustain life, but by whether it possesses the conditions necessary for life to begin. This concept is referred to as an origin of life event, and it is fundamentally distinct from the traditional notion of habitability. The former emphasizes the chemical, energetic, and environmental requirements for life to arise from non-lif

Enceladus, the sixth-largest moon of Saturn, has long been regarded as one of the most compelling ocean worlds in the Solar System. Its subsurface ocean is composed of water, and what truly draws scientific attention is the ice plume erupting from fractures near its south pole. These ice grains are not products of surface weathering; rather, they originate from the deep interior ocean and are transported upward through fractures before being expelled directly into space. Duri

In recent years, research on the origin of life has increasingly converged with planetary science, prompting scientists to reassess whether different planetary bodies possess the necessary conditions for life to emerge. Life may not have arisen by chance in an obscure corner, but instead developed step by step under specific physicochemical conditions following fundamental processes. Therefore, understanding plausible scenarios for the origin of life is not only essential for

When exploring life on exoplanets, the most intuitive approach is often to search for gases such as oxygen that are produced or consumed by living organisms. However, long before life itself emerges, a planet's atmosphere may already contain molecules essential for its origin. These substances are known as prebiosignature molecules. They are not products of life, but rather the chemical precursors that enable life to arise.

Life metabolizes, grows, responds to environmental stimuli, reproduces and transmits hereditary information. It possesses an intrinsic capacity for self-organization and, to some extent, the ability to replicate with variation, enabling evolution. These seemingly well-defined characteristics are, in fact, conclusions inferred from the particular form of life observed on Earth. The deeper question is not merely what life initially was on Earth, but what life could be within th

On August 15, 1977, the Big Ear radio telescope at Ohio State University detected a mysterious signal that has never been reproduced. Known as the Wow! Signal, it stood out because of three striking properties: a strong narrowband emission, a frequency near 1420 MHz corresponding to the 21 cm hydrogen line, and a duration of 72 seconds. These features made it a compelling candidate for a possible extraterrestrial transmission. Yet, despite decades of follow-up observations, n

TRAPPIST-1 system artist's impression（感謝NASA/JPL-Caltech提供）

Astrobiology, by definition, is the scientific field dedicated to the study of life in the universe. Its central objective is to determine whether life exists beyond Earth, and whether other celestial bodies could support human habitation. Researchers therefore focus on identifying environments that meet these criteria. Among these targets, planets have traditionally received the most attention, not only within the Solar System but also in distant star systems. However, plane

Mars（圖片來源：ESA & MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA，採用  CC BY-SA 3.0  授權） The habitable zone in the Solar System (Figure 1) includes not only Earth but also Mars. However, because the core of Mars has cooled and no longer generates thermal convection, its magnetic field has disappeared. As a result, Mars lacks an effective shield against solar wind, unlike Earth. This has allowed the Martian atmosphere to be gradually stripped away into space, leaving i