Journal of Astrobiology & Outreach

An Overview on Planetary Habitability

Ali Almer^* Department of Mechanical Engineering, Tafila Technical University, Tafila, Jordan
^*Correspondence: Ali Almer, Department of Mechanical Engineering, Tafila Technical University, Tafila, Jordan, Email:

Received: 04-Jan-2022, Manuscript No. JAO-2022-248; Editor assigned: 06-Jan-2022, Pre QC No. JAO-2022-248; Reviewed: 20-Jan-2022, QC No. JAO-2022-248; Revised: 24-Jan-2022, Manuscript No. JAO-2022-248; Published: 31-Jan-2022, DOI: 10.35248/2332-2519.22.10.248.

Description

Planetary habitability is the measure of a planet’s or a natural satellite’s potential to develop and maintain an environment hospitable to life. Life may be generated directly on a planet or satellite endogenously or be transferred to that from another body, through a hypothetical method called panspermia. Environments don’t need to contain life to be considered habitable nor are accepted habitable zones the only areas in which life may arise.

As the existence of life beyond Earth is unknown, planetary habitability is largely an extrapolation of conditions on Earth and also the characteristics of the Sun and solar system that seem favorable to life’s flourishing. An absolute requirement for life is an energy source, and also the notion of planetary habitability implies that several different geophysical, geochemical, and astrophysical criteria should be met before an astronomical body will support life. In its astrobiology roadmap, NASA has outlined the principal habitability criteria as “extended regions of liquid water conditions favorable for the assembly of complicated organic molecules, and energy sources to sustain metabolism”. In August 2018, researchers reported that water worlds might support life.

Habitability indicators and biosignatures should be understood in a planetary and environmental context. In determining the habitability potential of a body, studies aim at its bulk composition, orbital properties, atmosphere, and potential chemical interactions. Rocky, wet terrestrial-type planets and moons with the potential for Earth-like chemistry are a primary focus of astrobiological analysis, though a lot of speculative habitability theories often examine different biochemistries and different types of astronomical bodies.

The idea that planets beyond Earth may host life is an ancient one, although historically it was framed by philosophy as much as physical science. The late twentieth century saw 2 breakthroughs within the field. The observation and robotic spacecraft exploration of various planets and moons among the solar system has provided vital information on defining habitability criteria and allowed for substantial geophysical comparisons between the Earth and other bodies. The discovery of extrasolar planets, beginning in the early 1990s and accelerating thereafter, has provided additional data for the study of possible extraterrestrial life. These findings ensure that the Sun isn’t unique among stars in hosting planets and expands the habitability research horizon beyond the solar system.

The chemistry of life might have begun shortly after the Big Bang, 13.8 billion years ago, throughout a habitable epoch when the Universe was only 10-17 million years old. According to the panspermia hypothesis, microscopic life distributed by meteoroids, asteroids, and different tiny solar system bodies may exist throughout the Universe. However, Earth is the only place in the Universe noted to harbor life. Estimates of habitable zones around different stars, along with the discovery of thousands of extrasolar planets and new insights into the extreme habitats on Earth, recommend that there is also more in the places within the Universe than considered possible very recently. On 4 November 2013, astronomers reported, based on Kepler space mission information, that there can be as many as forty billion Earth-sized planets orbiting within the habitable zones of Sun-like stars and red dwarfs within the galaxy. Eleven billion of those estimated planets may be orbiting Sun-like stars. The closest such planet may be twelve light-years away, according to scientists. As of June 2021, a total of sixty potentially habitable exoplanets have been found. However, what makes a planet habitable could be a much more complicated question than having a planet situated at the proper distance from its host star in order that water can be liquid on its surface: various geophysical and geodynamical aspects, the radiation, and also the host star’s plasma environment will influence the evolution of planets and life if it originated.

A recent study suggests that cooler stars that emit more light in the infrared and near-infrared may actually host warmer planets with less ice and incidence of snowball states. These wavelengths are absorbed by their planets’ ice and greenhouse gases and stay warmer. In the solar system, the inner planets are terrestrial, and the outer ones are gas giants, however, discoveries of extrasolar planets recommend that this arrangement might not be at all common. However, present information for extrasolar planets is probably going to be skewed towards that kind (large planets in close orbits) because they’re far easier to identify; therefore, it remains to be seen which kind of planetary system is the norm, or indeed if there is one.