Scientists believe that some potentially habitable planets are tidally locked, with one side permanently facing their star. This means one hemisphere experiences eternal daylight, while the other is in perpetual darkness. Research on Earth’s organisms living in sun-deprived environments shows that the absence of sunlight doesn’t hinder life. Such creatures offer a glimpse into what alien life without a circadian rhythm might look like, according to Marie Cohen from the Open University in the UK. Researchers estimate that our Milky Way galaxy, which contains between 100 and 400 billion stars, hosts billions of potentially habitable planets. Around 70% of the stars in the Milky Way are red dwarfs, and about 40% of them have at least one planet orbiting within their habitable zone. This means these planets could potentially have liquid water on their surface, increasing the chances of life. However, rocky planets orbiting red dwarfs differ from Earth. Red dwarfs are cooler than the Sun, so their planets orbit closer, experiencing stronger gravitational forces. As a result, many of these planets are tidally locked, with one side always facing their star, similar to how the Moon always shows the same face to Earth. Unlike Earth, these planets would have no traditional day-night cycle or seasonal changes. On Earth, life is deeply influenced by circadian rhythms, which are attuned to the alternation of day and night. These rhythms regulate biochemistry, body temperature, cell regeneration, behavior, and more. Cohen suggests it’s still unclear how crucial periods of rest, like sleep, are for life. It’s possible that organisms evolving without cyclical time might not need rest, functioning continuously. On Earth, many organisms in sunless environments synchronize their biorhythms with non-light cues, such as temperature, humidity, or chemical changes. Some species even possess internal circadian clocks adapted to daily and seasonal shifts. What Could Alien Life Look Like? Cohen notes that recent studies suggest rocky planets orbiting red dwarfs may experience cycles that simulate days and seasons. Simulations indicate that the contrast between the eternally lit and dark sides of these planets likely creates fast-moving winds and atmospheric waves. If these planets harbor water, the day side could generate dense cloud formations with frequent lightning storms. The interaction between winds, clouds, and atmospheric waves could trigger climate shifts, resulting in temperature and humidity cycles. These cycles could last anywhere from tens to hundreds of Earth days, though they would not align with the planet’s rotation period. Even as the star remains stationary in the planet’s sky, environmental conditions would change. Life on these planets may develop biorhythms in sync with these environmental cycles, or evolution could come up with more unusual adaptations. For instance, aliens living on the day side might migrate to the night side for sleep and recovery. This glimpse into alien evolution highlights how life might adapt to the unique environments of tidally locked planets, where traditional day-night cycles are absent. The post The Impact of Constant Day or Night on Alien Evolution appeared first on Anomalien.com.