Newfound Exoplanet Could Shed New Information on How Earth-like Planets Evolve

A new exoplanet similar to Earth in size has been discovered, and it may offer researchers new information.

Earth-Like Exoplanet K2-415B Discovered

An exoplanet that closely resembles our planet in size has been spotted orbiting a tiny star 72 light years away. The exoplanet called K2-415b could bring some new information on how Earth-like planets form and evolve in various ways, probably different from ours, Science Alert reported.

According to the international team of astronomers led by Teruyuki Hirano of the Astrobiology Center in Japan, small planets around M dwarfs are good workshop to explore the atmospheric diversity of rocky planets and the condition in which a habitable terrestrial planet can exist.

As one of the lowest mass stars known to host a transiting planet of Earth's size, K2-415 will be an intriguing target for additional follow-up observations, including radial velocity monitoring and transit spectroscopy, Hirano added.

The research has been accepted for publication in The Astronomical Journal and is available on arXiv.

How Exoplanets Could Help Deliver Answers in Finding Life

Earth is the only known place in the universe where life has emerged. There are a lot of questions about whether life exists on another planet somewhere in the universe, and exoplanets with similar composition, size and temperature as Earth are key things to explore to study planetary system architecture.

Earth-sized exoplanets orbiting the stars like K2-415b are the best candidate for characterizing an atmosphere. When they pass in front of the star, a fraction of the star's light will pass through the atmosphere, and some wavelengths on the spectrum will be absorbed or amplified by the atmosphere's elements.

According to Sky at Night magazine, an exoplanet is habitable if it has the key seven factors of habitability - the right distance from its star, more or less circular orbit, stable rotational axis, enough water, no hydrogen-rich atmosphere, tectonic plates, and magnetic field.

The exoplanet was first discovered in 2017 via the now-retired Kepler planet-hunting telescope. It also appeared in the data from TESS.

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K2-415b Vs. Planet Earth

K2-415b and our planet have similarities. For instance, they are close in size. The former is 1.015 times the radius of Earth and is orbiting one of the smallest red dwarf stars found to be hosting an Earth-sized world. Its star K2-415 is just 16% of the mass of the Sun.

However, K2-415b begins to diverge significantly from Earth in terms of its mass. Although the exoplanet is roughly the size of Earth, its mass is approximately three times Earth's. It indicates that K2-415b is also denser than Earth.

Also, it is significantly closer to its star: Its orbital period is four days. The habitable zone of a red dwarf star can indeed be much closer than the habitable zone of the Sun, with orbits measured in days rather than months, but even for a red dwarf, this is a bit too close for comfort.

Nonetheless, K2-415b is slightly located inside the habitable zone's rim. This could indicate that the atmosphere is still explorable.

Venus is just inside the habitable zone of the Solar System, and its atmosphere is a fascinating horror show. It is also possible that K2-415 is a multiple-planet system, which raises the possibility of an undiscovered exoplanet in the host star's habitable zone.

At this point, it is unlikely to detect signs of life on K2-415b. However, the system is an excellent target for exoplanet atmospheric characterization and subsequent searches for hidden, potentially life-supporting planets.