What Do Exoplanets Mean For Humanity
February 25th 2018
In this episode of SkyTour Radio, we continue to discuss exoplanets; the possibilities they hold for humanity and what wonders may lie in wait.
We will take a look at prospects for alien life on these planets, what they may look like in each of these scenarios and the benefits and detriments they bring with them. We will be focusing on such star systems as Kepler 90, Kepler 452b and Gliese 667.
Kepler-90 is a G-type main sequence star located about 2,545 light-years from Earth in the constellation of Draco. It is approximately 120% the mass and radius of the Sun and has a surface temperature of 6080 K, and an estimated age of around 2 billion years.
It is notable for having a planetary system that has an equal number of observed planets to our Solar System, one of eight having a possibility as being in the habitable zone.
The star’s planetary companion was discovered by NASA’s Kepler Mission,which was a mission tasked with discovering planets in transit around their stars. The transit method that Kepler uses involves detecting dips in brightness in stars. These dips in brightness can be interpreted as planets whose orbits move in front of their stars from the perspective of Earth.
The name Kepler-90 derives directly from the fact that the star is the catalogued 90th star discovered by Kepler to have confirmed planets.
Kepler 452 b
Also known as Earth 2 or Earth’s twin, Kepler-452 is a G-type main-sequence star located about 1400 light-years away from Earth in the constellation of Cygnus. It has a similar temperature to that of the Sun, but it is 20 percent brighter, 3.7 percent more massive and is 11 percent larger. It is approximately six billion years old, 1.5 billion years older than the Sun.
Discovered in July 2015 by the Kepler spacecraft, this planet is mostly known for its characteristics similar to Earth, most notably its size, orbit and stellar flux. It is the first potentially rocky super-Earth planet discovered orbiting within the habitable zone of a star very similar to the Sun.
It may even have a surface temperature similar to that of Earth however its star is 6 billion years old and due to this, Kepler-452 is receiving roughly 10% more stellar radiation than the Earth does today.
If Kepler-452 is a rocky planet, it may be subject to a runaway greenhouse effect but due to its mass, it may be able to prevent succumbing to the runaway greenhouse for a limited amount of time (at most about 500 million years).
Gliese 667 is a star system with 6 planets in which three of which are in the habitable zone. This triple-star system in the constellation Scorpius lies at a distance of about 23.6 light years from Earth and all three of the stars have masses smaller than the Sun.
The largest star in the system, Gliese 667 A (GJ 667 A), is a K-type main-sequence star of stellar classification K3V. It has about 73% of the mass of the Sun and 76% of the Sun’s radius, but is radiating only around 12-13% of the luminosity of the Sun. The concentration of elements other than hydrogen and helium, is much lower than in the Sun with a relative abundance of around 26% solar
Like the primary, the secondary star Gliese 667 B (GJ 667 B) is a K-type main-sequence star, although it has a slightly later stellar classification of K5V. This star has a mass of about 69% of the Sun and it is radiating about 5% of the Sun’s visual luminosity.
Gliese 667 C is the smallest star in the system, with only around 31% of the mass of the Sun and 42% of the Sun’s radius, orbiting approximately 230 AU from the Gliese 667 AB pair. It is a red dwarf with a stellar classification of M1.5. This star is radiating only 1.4% of the Sun’s luminosity from its outer atmosphere at a relatively cool effective temperature of 3,700 K. This temperature is what gives it the red-hued glow that is a characteristic of M-type stars. It is It is known to have a system of two planets and claims have been made for up to seven but these may be in error due to failure to account for correlated noise in the radial velocity data. The red dwarf status of the star would allow any planets to receive minimal amounts of ultraviolet radiation.
On the next episode of Skytour Radio we look to science to help unravel some of the mysteries exoplanets hold in helping to solve what alien life form may look like, how they may move and what this could mean for the future of humanity and the pros and cons in planning for interstellar travel.
SkyTour Radio explores the Universe in a down to Earth manner explaining the science we know in fun and bite-sized terms. Science is for everyone and people shouldn’t require an advanced degree to understand as long as it is delivered in an easy to follow way. From Black Holes to Extraterrestrial Life, we will explore the Universe like never before. Join us to check out such things as how stars form, how they live and, how our fate is intertwined with theirs. On the extraterrestrial life front, we will be speaking to the UFO and science arena’s top researchers and bring UFOlogy into the 21st century.
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