Unlike the Earth-like aqua-planets, terra-planets do not support life as we know it on Earth. This is because they are so massive that their atmosphere is too thin and their climate too dry to support life. However, they do have a larger habitable zone than the aqua-planets. Let’s look at these characteristics and how these characteristics affect the lives of humans. These are just a few of the benefits of terra-planets.
Earth-like terra-planets are too massive to support life like that of Earth
Some astronomers have speculated that the super-Earths of our Solar System are too massive to support life like that of our planet. While the masses of these planets are not specifically determined, most sources agree on the upper bound of 10 Earth masses, 69% of Uranus’ mass. The lower bound ranges from one to five. So, how can we be sure that Earth-like planets are common?
The Earth is a terrestrial planet, whereas gas giants are made up of hydrogen, helium, and iron. Terrestrial planets are solid and have a silicate surface. While gas giants have atmospheres that may be too inhospitable to support life, terrestrial planets lack those. This is the case with Jupiter, Saturn, and Mars. While all of these worlds may have moons, most do not have planetary rings.
Another factor affecting the habitability of planets is time. It took four billion years for Earth to evolve complex organisms. Over this period, rocks on Earth oxidized and built up an atmosphere rich in oxygen. This oxygen-rich atmosphere is essential for fast-moving macroorganisms to grow and evolve. This would prevent life from forming on other planets. The moon is a good example of a terra planet’s tidal flats.
If life was to evolve on a Terra planet, the surface conditions would be vastly different from Earth’s. The surface would have pressures of one to a thousand bars, the range of which is similar to the ocean’s trenches. Despite the pressures of this environment, the planetary surface would receive almost no sunlight. A more likely analogue of Earth’s complex life would be chemoautotrophic.
Kepler discovered hundreds of exoplanet candidates. Among them, Kepler-10b has a mass of three to four Earth masses and is 460 light-years away from Earth. The Kepler space telescope, launched in 2009, has made half of these discoveries. Astronomers have long dreamed of finding an alien Earth, and recent discoveries of exoplanets have shown there is an abundance of rocky worlds like ours in the galaxy.
There are two kinds of super-Earths. The low-density ones are believed to be ocean planets, and the intermediate-density ones are metallic. The highest density super-Earths may be rocky or metallic. They may also have water and ice as major constituents. If the latter is true, we could be facing an Earth-like superpower in the future.
In addition to being too massive to support life, massive planets may not be able to drive the carbon silicate cycle, which acts as a natural thermostat on Earth. In turn, these massive planets may turn into Venus-like planets with much higher volcanic activity and outgassed volatiles. There is no firm evidence that the first Earth-like planets had liquid water. And the next two planets may be too massive to support life like that of Earth.
They have a dry climate
The Terra planet has a dry climate due to its limited atmospheric access to water. The planet’s low obliquities limit water to high latitudes. Also, the planet’s water vapour feedback is muted, thereby reducing greenhouse warming. This feature also helps dry planets maintain habitability at high stellar fluxes. The dry atmosphere of the terra planet limits the number of hydrogen molecules, which is a key element of the runaway greenhouse effect.
They have a wider habitable zone than aqua-planets
Despite the vast differences in the size of the terra and aqua habitable zones, Earth-like planetary systems have a wider range of surface temperatures. This is due to their water-recycling mechanism, which allows the planet to return liquid water to its low-latitude atmosphere. This mechanism may also extend the habitable zone of terra planets at low obliquities.
In addition, the bistability of terra and aqua-planets suggests that such planets are likely to have a larger habitable zone. These characteristics are derived from observations on Earth and other terrestrial worlds. In addition to a wider habitable zone, land planets emit long-wave radiation and create a dry stratosphere. A planet’s obliquity can also limit the size of its habitable zone.
Giant planets influence the size of the habitable zone. They may facilitate the formation of planetary cores or modify the influx of asteroids toward terrestrial analogs. Giant planets may alter the orbits of terrestrial worlds and indirectly affect their climates. The presence of giant planets may reduce the chance of habitability of terrestrial worlds, while extending the habitable zone on smaller fractions of systems with high climate inertia.
Astronomers have confirmed that the TRAPPIST-1 system has three planets in the habitable zone. The Earth-sized planets GJ 581d and GJ 581g orbit the star in a habitable zone. Astronomers are using Kepler’s successor, TESS, to look for planets of Earth size within a few light-years. This enables quick observation from terrestrial telescopes and can confirm the discovery of a planet in September 2018.
There are over one billion Earth-sized worlds orbiting the familiar yellow sun-type stars. These planets have a habitable zone, and scientists believe that they may contain liquid water on their surfaces. However, some scientists still have reservations about Venus’ habitability. In the meantime, these planets are a good place to start a colony on another planet.
Class-M planets are relatively young. Their diameters range from ten to fifteen thousand kilometers. They are often in the outer edge of the solar system’s biozone. They are usually rocky, with high levels of water and atmospheres rich in oxygen and nitrogen. They are suitable for colonization and terraforming. But if you’re looking for the terra-planets of another solar system, you may want to look for Class-G planets.