Mankind has been tirelessly searching for planets that support or can support various forms of life, and Gliese 581 c is one of those few planets on that esteemed list. Certainly, scientists have not confirmed that this planet can sustain life, but having looked at the conditions, they have ascertained that Gliese 581 c is suitable enough to be deemed a “potentially habitable planet”. However, this does not mean that this celestial body has conditions even remotely similar to those on earth- quite the contrary, in fact.
Gliese 581 c, an exoplanet, is classified as a “super earth”, since it is five times more massive than our planet. All the same, it is the smallest exoplanet ever found, and completes a revolution around the star in a mere thirteen days. It is located only 20.5 light years away from the earth in the constellation Libra, and revolves around its star, Gliese 581, at a distance fifteen times closer than the distance of our planet from the sun. Like earth, it is the third planet from its host star, which is a red dwarf of a luminosity of about 1.3% of the sun; red dwarf stars are the smallest and most dim of stars, and burn at comparatively low temperatures (around 5000 degrees Fahrenheit– the sun, a yellow dwarf, can reach up to 27 million degrees Fahrenheit). So, even though this heavenly orb orbits at a very close distance from the host star, the dim light that is emanated by its red dwarf indicates that Gliese 581 c could fall safely within the star’s inhabitable territory! (A habitable zone is the orbital stretch around a star that possesses liquid water and can even harbor life)
However, it must be remembered that Gliese 581 is a red dwarf star- so, the sky of its revolving planets would be a bright, ghastly crimson. This low frequency, infrared spectrum arising from the red dwarf would have its consequences on any possible forms of vegetation that perform photosynthetic processes, by making the plants a terrifyingly black hue. Moreover, Gliese 581 c is a tidally locked planet, meaning that its one half always faces the star, whereas its other side is bathed in perpetual darkness, almost as if two points on their surfaces are connected by a thread or rod (just like the movement of the moon around the earth). Therefore, it has been hypothesized that the half facing the red dwarf is stifling enough to incinerate any form of life, whereas venturing into the other half would mean immediate freezing. Because of these horrendous circumstances, Gliese 581 c has even been dubbed “the planet from hell”.
But there is still a place in which life can theoretically exist- in a very narrow, vertical band, between the scorching and glacial sides. Scientists believe that water is an absolute prerequisite for life to originate and thrive, and it is in this tapered stretch, which has an atmosphere, that this precious water may exist. The temperature of this belt is almost exactly like the earth’s (from approximately 0 to 40 degrees Celsius). Also, it has been predicted that the surface of the planet is either rocky, like that on earth, or covered in oceans of water. Compared to the uncontrolled tempests and other perilous conditions that reign on other planets, the surface of Gliese 581 c resembles what we’re used to more than anything else. And as said by Xavier Delfosse, a study team member of Grenoble University, “On the treasure map of the universe, one would be tempted to mark [Gliese 581 c] with an X”
But despite these discoveries, it has been found that Gliese 581 c is likely to have a phenomenon known as the runaway greenhouse effect, which indicates that the greenhouse effect on this planet keeps increasing until all of its oceans ultimately boil away. This is the phenomenon that is said to have occurred in the history of Venus, and is the reason behind its utterly uninhabitable planetary conditions. And its temperatures have only been speculated, and definitely not corroborated by empirical evidence, which consequently sheds light on the fact that the temperatures in the narrow belt of Gliese 581 c may not be alike to those on earth at all.
Nevertheless, since Gliese 581 c is located relatively within reach of our space probes, this planet is a very exciting discovery for scientists seeking out new possible destinations that can nurture forms of life. The earth may be a safe and immaculate haven, but there is nothing more thrilling than a new possible source of life and future colonization. In fact, on 9 October 2008, a powerful radio signal called “A Message from Earth” was sent from the earth to Gliese 581 c, in the hope that an alien civilization might find our planet if we make ourselves known in the unending cosmos. And in the words of Alison Boyle, the curator of astronomy at London’s Science Museum, “of all the planets we’ve found around other stars, this is the one that looks as though it might have the right ingredients for life”.
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