Gliese 876
Natasha Oslinger
Conceptual Astronomy
7-11-16
You have each randomly selected a star (or stellar object) with one or more known exoplanets (with a couple of exceptions). You should write a description of the possibilities for life on planetary bodies around your star–don’t invent exotic lifeforms, but instead think about the necessities for life on Earth. What type of star did you pick? How is it different from our Sun? Does your planetary system resemble our own solar system? If not, how is it different? Please be as specific as you think necessary to fully address the question. Feel free to include illustrations if necessary.
Gliese 876 is a red dwarf star in the constellation Aquarius. This star is the third closest to our Sun, falling around 15 light years away from Earth. Gliese 876 has four exoplanets orbiting around it, two of which are believed to be a distance from Gliese 876 that would be considered habitable. Unfortunately, one of these planets is a gas giant and the other has too extreme weather, so they could not be occupied by any life known to Earth. The star itself is slightly smaller and less luminous than our Sun, it is considered a low mass star and is not visible from Earth without a telescope. The four planets that orbit Gliese 876 are named Gliese B, Gliese C, Gliese D, and Gliese E. B was the first to be discovered and E is the most recent, in addition, there are two planets, Gliese F and G, that although are unconfirmed, are believed to be in orbit as well.
Gliese B was discovered in 1998 and has an orbit of 61 days and about twice the mass of Jupiter. This planet would not be habitable for traditional Earth life considering its gaseous body, but, it's hypothetical moons are believed to possess surface water. Gliese C was discovered in 2001 and is thought to have rings similar to the rings of Saturn. This planet has a mass about half of that of Jupiter and an orbit of around 30 days. It is a Class II water cloud gas giant and much like Gliese B, if it was to have orbiting moons, they would likely have surface water. Gliese D was discovered in 2005, and like Earth, it is believed to be a rocky terrestrial planet. It has a mass around 5 times that of Earth, dubbing it the “Super Earth” of the Gliese system. Unfortunately, because of its close orbit, this planet is tidally locked and has an uninhabitable hot side of around 500 fahrenheit and a dark side that is extremely cold. Gliese D and C are considered to be in the “habitable zone” but, because of the individual properties of each planet, neither could support human life. The final planet in the Gliese 876 system is Gliese 876 E, which was discovered only recently in 2010. This planet takes 124 day to orbit its Sun and has a mass about the same as Uranus. This is the farthest planet away from Gliese 876, and much like the closest planet, would have a temperature too extreme to be habitable by traditional Earth Life.
There are specifically necessary conditions that must be fulfilled for traditional Earth life to inhabit a planet. Although it is possible for any conditions to fit some kind of unknown life, human and animal life from Earth ideally need extremely specific and mild conditions to thrive. For human life to exist on a planet, it needs to be terrestrial, not gaseous, and it has to be a comfortable distance from a star so that it is not too hot, but not too cold. Humans thrive best in conditions below around 115 degrees and above negative 10 degrees. Although it is possible for life in places out of this comfort zone, such as the Arctic or Death Valley, but, more mild conditions are preferred. The planet also needs to have a molten core for both a source of geothermal energy and a magnetic field to protect the planet’s inhabitants from outside radiation. There also needs to be a protective atmosphere to help hold in carbon dioxide and other gasses that insulate the planet. Finally, the planet needs to have some clean water source and some kind of sustenance that the inhabitants could live off of. Unfortunately, none of these conditions match any of those that exist in the Gliese planetary system. Because of this, the chances for human life are extremely dismal.
Natasha Oslinger
Conceptual Astronomy
7-11-16
You have each randomly selected a star (or stellar object) with one or more known exoplanets (with a couple of exceptions). You should write a description of the possibilities for life on planetary bodies around your star–don’t invent exotic lifeforms, but instead think about the necessities for life on Earth. What type of star did you pick? How is it different from our Sun? Does your planetary system resemble our own solar system? If not, how is it different? Please be as specific as you think necessary to fully address the question. Feel free to include illustrations if necessary.
Gliese 876 is a red dwarf star in the constellation Aquarius. This star is the third closest to our Sun, falling around 15 light years away from Earth. Gliese 876 has four exoplanets orbiting around it, two of which are believed to be a distance from Gliese 876 that would be considered habitable. Unfortunately, one of these planets is a gas giant and the other has too extreme weather, so they could not be occupied by any life known to Earth. The star itself is slightly smaller and less luminous than our Sun, it is considered a low mass star and is not visible from Earth without a telescope. The four planets that orbit Gliese 876 are named Gliese B, Gliese C, Gliese D, and Gliese E. B was the first to be discovered and E is the most recent, in addition, there are two planets, Gliese F and G, that although are unconfirmed, are believed to be in orbit as well.
Gliese B was discovered in 1998 and has an orbit of 61 days and about twice the mass of Jupiter. This planet would not be habitable for traditional Earth life considering its gaseous body, but, it's hypothetical moons are believed to possess surface water. Gliese C was discovered in 2001 and is thought to have rings similar to the rings of Saturn. This planet has a mass about half of that of Jupiter and an orbit of around 30 days. It is a Class II water cloud gas giant and much like Gliese B, if it was to have orbiting moons, they would likely have surface water. Gliese D was discovered in 2005, and like Earth, it is believed to be a rocky terrestrial planet. It has a mass around 5 times that of Earth, dubbing it the “Super Earth” of the Gliese system. Unfortunately, because of its close orbit, this planet is tidally locked and has an uninhabitable hot side of around 500 fahrenheit and a dark side that is extremely cold. Gliese D and C are considered to be in the “habitable zone” but, because of the individual properties of each planet, neither could support human life. The final planet in the Gliese 876 system is Gliese 876 E, which was discovered only recently in 2010. This planet takes 124 day to orbit its Sun and has a mass about the same as Uranus. This is the farthest planet away from Gliese 876, and much like the closest planet, would have a temperature too extreme to be habitable by traditional Earth Life.
There are specifically necessary conditions that must be fulfilled for traditional Earth life to inhabit a planet. Although it is possible for any conditions to fit some kind of unknown life, human and animal life from Earth ideally need extremely specific and mild conditions to thrive. For human life to exist on a planet, it needs to be terrestrial, not gaseous, and it has to be a comfortable distance from a star so that it is not too hot, but not too cold. Humans thrive best in conditions below around 115 degrees and above negative 10 degrees. Although it is possible for life in places out of this comfort zone, such as the Arctic or Death Valley, but, more mild conditions are preferred. The planet also needs to have a molten core for both a source of geothermal energy and a magnetic field to protect the planet’s inhabitants from outside radiation. There also needs to be a protective atmosphere to help hold in carbon dioxide and other gasses that insulate the planet. Finally, the planet needs to have some clean water source and some kind of sustenance that the inhabitants could live off of. Unfortunately, none of these conditions match any of those that exist in the Gliese planetary system. Because of this, the chances for human life are extremely dismal.