The search for signs of life in outer space has caused astronomers to continuously search for habitable worlds such as moons, planets within the Solar System, and exoplanets. Astrobiologists recently reported the discovery of 24 exoplanets that are "superhabitable" and may even be better than Earth.
A team from Washington State University had their research published in the journal Astrobiology. What makes Earth unique as humanity's home planet is its biosphere and geosphere—conditions not found elsewhere until recently.
While there had been signs of life on other planets and moons, their current harsh conditions cannot accommodate Earth's creatures. For example, traces of water vapor have been detected on Jupiter's moon, Europa.
Signs of Life in Space
Planetary scientist Lucas Paganini shared that elements required for life, such as carbon, hydrogen, and nitrogen, are found all over the Solar System. However, liquid water has near impossible to detect outside of Earth, although scientists have detected other forms of water such as vapor or salt from evaporated oceans.
Observations from NASA's James Web Space Telescope, the European Space Agency's Planetary Transits and Oscillations (PLATO) space telescope, and others have determined 24 superhabitable planets more than 100 light-years away from Earth. Future telescopes such as the Wide-Field Infrared Survey Telescope, which is expected to launch by 2025, will make further observations of the exoplanets.
Exoplanets are cosmic bodies that do not orbit the Sun. Astronomers have discovered nearly 4,000 exoplanets and are yet to confirm about 1,000 more. Among the exoplanets, scientists are also determining which ones may be habitable.
READ: Two Newly-Discovered 'Super Earth' Exoplanets Are Habitable
Defining Habitability
The authors wrote that "habitability is usually understood as a planet's potential to develop and maintain environments hospitable to life." Exoplanets may also be habitable but are lifeless because it did not host the origin of life.
Alongside the Max Planck Institute for Solar System Research and Villanova University, the team analyzed the 4,500 known exoplanets for possible candidates of superhabitability. Planets that orbited within the host star's liquid water habitable zone were considered as worthy candidates.
Moreover, the planets were detected to have warmer temperatures with an average surface temperature of about eight degrees Fahrenheit. The warmth and moisture in these exoplanets could mean biodiversity, similar to tropical rain forests on Earth.
The habitability of another world could also host extraterrestrial life while unable to host human life or lifeforms from Earth. For years, scientists have explored other factors, such as radiation levels, water activity, atmospheric pressure, and the weather of other worlds.
Professor Dirk Schulze-Makuch from the Technical University Berlin shared that it is a difficult concept to grasp that other planets may be superhabitable "because we think we have the best planet" for its numerous lifeforms and diverse environments. Scientists have to be "careful to not get stuck looking for a second Earth because there could be planets that might be more suitable for life than ours," he said.
READ: Scientists Find Previously "Lost" Planet in Search of Habitable Worlds
Check out more news and information on Exoplanets on Science Times.
