Where are we going ?

From Exploration Files

From 2015 to 2025, many of the 150 stars with in the 20 light year range of Sol were investigated. Of them 15 had systems with earth-like planets and another 50 had planets or large moons that could be of some use.

 

The following is a list of the top locations for colonization. 

1. Top of the list was Teegarden's Star, 12.5 LY from Earth, a red dwarf discovered in 2003. Because the telescope data was so promising, 2 planets in the habitable zone, it was made a priority for Ranger missions. The data was confirmed in 2016 when the first scout visited the system. Both worlds being very close to Earth in size.

Tee-B was found to have an average equatorial temperature of +24c, and gravity of 0.8 G, native life included vegetation and animals, odd but understandable to the science team. No intelligence above the level of crows.

Tee-C was found to be much colder with an average -47c temperature, with a gravity of 0.6 G, native life was similar to the fungus and microbes found on Tee-B. There were no higher order plants or animals.

2. Proxima Centauri b, is a planet orbiting in the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of a triple star system. It is located about 4.2 light-years from Earth. PCB orbits the star at a distance of roughly 0.05 AU, very close. It has a mass of 1.3 times that of the Earth, with a gravity of 0.9G. 

The planet is subject to stellar wind pressures of more than 2,000 times those experienced by Earth, but the magnetic field does a good job of protecting it. Although it was expected to be tidally locked, it does rotate in retrograde, thus each day is actually 22 earth days long. This makes it very hot in the afternoon, up to +40c and very cold late at night down to -30c.

Scouts in 2015 found a wide range of life, some of which was only active during the day and hibernated during the night. While other creatures adapted to the cold came out at night and burrowed away during the day. The two main problems of this world are solar flares which occasionally scorch a sizable area of the world, and the extreme solar wind, that causes problems for any satellite in orbit. Because of its proximity to Earth colonization was put high on the priority list.

3. Tau Ceti, is a single star similar to the Sun, although it has only about 78% of the Sun's mass. At a distance of 12 light-years it is a relatively nearby G-class star that appears stable. Telescope data relieved it had two possible habitable worlds. Scouts visited it in late 2015.

Tau Ceti e, has an orbital distance of 0.55 AU just within the habital zone’s inner edge, with an orbital period of 168 days. It has a mass of 3.9 Earth’s and a radius of 1.8, its gravity is about 1.4G. TC-E has a surface temperature around 68 °C. It is almost perfect. A tropical paradise.

Tau Ceti f, has an orbital distance of 1.35 AU just at the far edge of the habitable zone, with an orbital period of 642 days. It has a mass of 3.8 Earth’s and a radius of 1.5, its gravity is about 1.6G. TC-F has a temperature average of 12 °C.

Both planets have a lot of good points, but there is no simple fix to the gravity issue. Planners aim at colonizing TC-F first as adapting to it will be somewhat easier.  

4. Gliese 832 c (named Glibbit) is a planet located 16 light-years away. It has a mass of 5.2 Earth's and a radius of 1.5 Earth. Interestingly the gravity is only 1.2G. Its temperature is relatively similar to Earth's, but subject to significant swings as it orbits its star. The planet has a relatively high eccentricity, taking it very near to the predicted inner edge of the habitable zone. The planet's temperature swings from (−40 °C) at apoastron to (17 °C) at periastron. However, because of its large mass and dense atmosphere, it much hotter with a equatorial surface temp around 33°C most of the time. 

Scouts in 2016 found there was an abundance of life, including a rabbit-like creature that was rather intelligent and friendly, but clearly not sentient and civilization building.   

5. Luyten b (AKA GJ 273b) is a rocky planet, orbiting within the habitable zone of the nearby red dwarf, at a distance of 12.2 light-years.  It is about 2.9 times the mass of Earth, with a gravity of 1.3G. It has an average orbital distance of 0.09 AU, but swings in a rather eccentric ellipse. Unlike many other planets this close to their star, it is not tidally locked. However the temperature does have some wild swings.From +44c to -30c. 

Scouts in 2017 reported; it was a nice place except for the volcanoes. There are plants and animals, which are mildly toxic, as is the soil, because of high sulfur.  The science team later confirmed that the planet is very active canonically, but there are several large areas of stability.

6. Gliese 667Cc, was discovered in 2011 orbiting a red dwarf in the Gliese 667 triple star system, 24 light years away. The planet’s mass is about 3.7 times the Earth’s, with a size roughly twice that of Earth and a gravity of 1.7G. It orbits at 0.125 AU, in the habitable zone of this star. 

The planet is tidally locked, with one side permanently facing towards the star, while the opposite side is shrouded in eternal darkness. Temperature on the light side averages 87c, while the night side averages -40c. This creates a temperate zone along the terminator line, which is extended by the atmospheric heat transference currents, providing a habitable zone with a temperature around 14c.

Scouts in 2020 found life, dangerous life. The 6 legged turtles looked harmless and slow, but they turned out to be very aggressive predators. But the main issue on Gliese CC for possible colonists is the gravity. 

7. Wolf 1061c, is a planet orbiting within the habitable zone of the red dwarf star Wolf 1061, about 13.8 light years away. The planet's orbital distance of 0.084 AU lies at the inner edge of its star's habitable zone. It is a rocky planet about 4.3 times the mass of Earth with a radius is of 1.5, it has a gravity of 1.6 times that on Earth. It is tidally locked, but the atmosphere does provide enough heat transference to made the habitable zone around the terminator line, with an average temperature of 36c, reasonably large. 

Scouts in 2016 reported very few plants, mostly mosses but a wide range of small insect like creatures. The “wolf-spider” very similar to the Earth spider of the same name, seems to be the top predator. "It is very creepy and I would not want to live there." the captain said.  However the scientific data shows it is a very likely place to colonize. 

8. Kapteyn b, orbits within the habitable zone of the red sub-dwarf Kapteyn's star, located approximately 12.8 light-years from Earth. It has a mass 4.2 and radius 1.8 of Earth’s, gravity is 1.8G, It has a surface temperature of −48 °C. Too cold to support liquid water on the surface.

Scout in 2018 found that it is a good candidate for terraforming, having lots of C02 we can use to build up a green house effect to warm the planet. But the gravity issue puts it low on the list of places we want to settle on. 

Author's note;  The info here is based on real scientific data and some fictionalization.  For various story reasons I want habitable worlds that are similar to Earth to a bit different. As this is an early draft of the overall setting, some other worlds may be inserted and colonized as the story line demands. 

 

 

Part 2.

 

 

9. Eridani 82 is a star about 20 light years away from Earth in the constellation Eridanus. It is a main-sequence star with a stellar classification of G6 V, and it hosts a system of at least three planets and a dust disk. Planet 82 GE is a Neptune sized gas ball, orbiting at 0.5 AU, it has 3 moons, one of which is habitable. Gee Mouse, as the moon was named, is slightly larger than Earth’s moon, with a gravity of 0.4G the average temperature is 55c, making it uncomfortably hot but not unmanageable. Scouts report a jungle environment, with diverse plant and animal life.  

10. Beta Hydri is a yellow star slightly larger, but much brighter, than our sun, located about 24 light-years away. The third and forth planets are very Earth like. There is also a massive gas giant 4 times the size of Jupiter orbiting at 20 AU from the star, which has 4 moons that offer good potential for habitation. Scouts report BH-3 has a high carbon dioxide atmosphere, gravity of 0.9G and average temperature of 42c. BH-4 is much better for habitation with a mostly oxygen atmosphere, gravity of 0.8G and average temperature of 22c.  Both worlds have plant life.  

11. Ross 154, located 9.7 LY from Earth. It is a UV Ceti-type flare star, that unleashes a burst of high radiation every 2 days, thus making the inner system very hazardous.  However one of the moons of the outer gas giant, named Blinky, does support life. Slightly larger than Earth's moon, with 0.5G an average temperature of 18c and a breathable atmosphere, it is protected from the flares by the planet's strong magnetic field. Scouts reported Blinky was a near paradise, except that all electronics tended to malfunction frequently.

12. Barnard’s Star is a red dwarf about 6 light-years away from Earth. Its single planet was found at the outer edge of the habitable zone. It orbits at 0.4 AU every 233 days and has a mass of 3.2 of Earth. Gravity is 1.7G and atmosphere is thin but breathable, average temperature is -17c.  Its magnetic field is week, but offers reasonable protection.  Scouts report most of the world is frozen ice, but a sea of high salt water does exist at the equator. No life was found on land, but there is some in the ocean.  

13. Sigma Draconis also named Alsafi, is located 18.8 light-years from Earth. It has 85% of the Sun's mass, but the luminosity of this star is only 41% that of the Sun.  Alsafi-3 is a dry Mars like world, with gravity of 0.8G a thin but breathable atmosphere and average temperature of 51c. Scouts detected underground aquifers. The only surface water is around the mineral rich geysers that dot what once may have been a sea bed. Limestone, forms by organic sedimentary process, supports the theory that the world once was more lively. 

14. Epsilon Indi, approximately 12 light-years from Earth. It is a ystem of Indi A, an orange star and two brown dwarfs. There is a single gas giant, 3 times the size of jupiter, orbiting at the edge of the habitable zone of Indi A, called Yavin. Of its 9 moons, 3 are habitable and support life forms that are nearly identical. Scientists are very interested in the question of how this occurred; independent parallel evolution or some kind of cross pollination?

15. Delta Pavonis, is a yellow star about 19.9 light-years from Earth.  Its is a 95% match to our own sun, although slightly larger in radius. Although astronomic data looked promising,  scouts discovered that no planets in the system were habitable. DP-3 being a near mach for Earth was unfortunately highly radioactive.  

16. Lalande 21185 (AKA Gliese 411) is a bright red dwarf approximately 8.3 light-years away. About 46% of the mass of the Sun. It has 2 rocky planets and 1 gas giant. None are habitable. 

17. Wolf 359 is a red dwarf star located 7.9 light years from Earth. It is a flare star that can undergo sudden increases in luminosity for several minutes. These flares emit strong bursts of X-ray and gamma ray radiation. At only 9% of the Sun's mass, Wolf 359 is just above the lowest limit at which a star can perform hydrogen fusion. There are 2 planets, a gas giant orbiting at 1.8 AU and a rock ball at 2.2 AU. Neither is habitable. 

18. Luhman 16 is a binary brown-dwarf system approximately 6.5 light-years from Earth. The Luhman stars are each slightly smaller than Jupiter, they orbit a central pivot point at a distance of 3.5 AU.  There is an asteroid field at 5.2 AU and 3 rocky planets beyond this. None are habitable. 

19.  Altair is 16.7 light-years from the Sun and is one of the closest stars visible to the naked eye. Altair rotates rapidly, with a velocity at the equator of approximately 286 km/s. This is a significant fraction of the star's estimated breakup speed of 400 km/s. A study revealed that Altair is not spherical, but is flattened at the poles due to its high rate of rotation. Although it has several rocky planets, none are habitable.