Now we begin exploring the exo-planets that only appeared on 2 of the 4 lists. Does it seem like this series will never end? Cheer up; the process will get faster. The fewer lists that contained a particular planet, the less information I have to pass on to you. I’d like to get through several planets today, so let’s get started.
Earth Jr is only 20 light years away. It’s official name is Gliese 581d. Actually, there may be 2 planets around the same star, but only 581d is mentioned on both lists. 581g was a ‘shiny thing’ that briefly appeared in the same paragraph on the first list.
Gliese 581 is a red dwarf star located in the Libra constellation, and 581d sits on the outer edge of the Goldilocks zone, so it would be possible for water there to be liquid. In addition, the atmosphere produces a significant greenhouse effect, making it even more hospitable for life (more or less) as we know it. It is, however, 8 times the mass of Earth, so do you think any creatures living there would be Big and Strong? Or Short and Strong? I can’t decide, myself, and I assume it would depend - at least in part - on the biochemistry of the creatures.
If it exists, Gliese 581g sits in the middle of that same habitable zone. Some research says it does exist, other research says it doesn’t. This is only 20 light years away, so let’s go find out, shall we?
WASP-18b is 325 light years away. But since we don’t yet have light-speed travel, we aren’t likely to get there before it dies. Some scientists think it should have already died, before we ever got a glimpse of it. WASP-18b races around its sun in less than 24 hours, but its orbit is apparently degrading, so it’s getting closer and closer to its sun, and in 1 million years (or less?), it will plunge into that star.
WASP-12b is 870 light-years from us. I don’t think we’ll want to settle there, for it is rather warm - 4000°F or 2250°C. It sits only 2 million miles from its sun (Earth is 93 million miles from our sun), and takes just over 1 Earth day to make a complete orbit of that star. It’s also a gaseous planet, with 1.5 times the mass of Jupiter and about twice Jupiter’s size. Obviously, it’s less dense than Jupiter, right? So, even less chance that in all that gas there would be anyplace solid to build a new home. And can you imagine the air conditioning bill?