Scientists are exploring and continuing to search for potentially habitable alien worlds
Since the first exoplanet orbiting a Sun-like star was confirmed in 1995, scientists have discovered more than 5,000 such distant worlds. More than half of these discoveries were made by NASA’s Kepler space telescope, launched in 2009 to determine the prevalence of Earth-like planets in the Milky Way galaxy. Kepler was decommissioned in 2018, having discovered more than 2,600 exoplanets.
Water is an inevitable consequence of planet formation and is much more common in the galaxy than scientists previously thought
The findings suggest that water may not be a rare cosmic coincidence, but rather an inevitable consequence of planet formation, making it far more common in the galaxy than scientists previously thought. Water is life, at least as we know it. All life on Earth uses liquid water, and researchers studying the origins of life believe that the complex chemistry of life likely originated either in a warm pool on the Earth’s surface or near a deep-ocean hydrothermal vent. Therefore, planetary scientists are particularly interested in extraterrestrial locations where liquid water exists. Based on existing exoplanet data, super-Earths and sub-Neptunes are considered the most common classes of planets in our galaxy, and some of them are likely water worlds. However, these planets are large, and the interactions between the water in their oceans and the rocks in their interiors will determine how habitable they might be.
Science fiction and the official scientific opinion on alien life
Many scientists are searching for extraterrestrial life on planets with conditions similar to Earth. For example, a habitable planet would likely have water. For liquid water, the planet would need to be at the perfect distance from its sun to prevent the water from freezing and turning into gas.
Scientists have linked the development of life with a magnetic field and concluded about magnetic fields on other planets
The weakening of the Earth’s magnetic field has led to a dramatic acceleration in the evolution of multicellular life. Fossil evidence has been found in Brazil and South Africa that the strength of the Earth’s magnetic field was about 30 times weaker than today’s values at the end of the Ediacaran period, about 590 to 560 million years ago. One of the defining features of the Earth is its magnetic field. It forms a protective shield against high-energy particles ejected by the Sun, and thus may have provided a safer place for life to grow into the complex array of organisms we see today.