Good Morning! Today we'll be visiting some of the Gliese discoveries, and then... well, we'll see if we have the time to visit anything else.
Our first visit is to Gliese 436b, which orbits that faint red dwarf you can probably see in the distance. Gliese 436b is about the size of Neptune, but has a small rocky core, surrounded by ice that makes up the majority of its size. And then 436b has a huge hydrogen cloud surrounding it, a cloud that is approximately 50 times the size of 436b proper. Like a comet, 436b exudes a 'tail' of this hydrogen as it orbits its sun. And finally, despite its icy exterior, this planet has an average temperature around 439 ⁰ C. Some people call this the 'burning ice planet'.
Here is Gliese 581c, which made headlines when its discovery was announced in 2007. This is a super-Earth, with a mass 5 times that of our own. So if you weigh 100 pounds on Earth, here you would weigh 500 pounds. Even so, this was one of the first to be announced as a potentially hospitable planet. However, further study revealed that it was 'tidally locked', meaning that one side always faces its parent star. That side would be blistering hot, and the opposite side unbelievably cold. The only possible location that might offer acceptable temperatures would be the 'twilight zone' between day and night, which I'm thinking would possibly experience a lot of wind. So, a fairly thin band of livable area with a lot of wind, and you weigh 5 times what you should. Surely we could find a better place to colonize?
Gliese 581e is in the same system. 581E used to hold the title as the smallest alien planet, but in January 2011, the announcement of Kepler 10b meant 581e lost that title.
Okay, we do have time for a couple more, so let's look at the WASP planets!
WASP 17b is the first planet discovered that orbits in the opposite direction as its host star's rotation. It also currently has the title of 'Most Puffy'. This is because it is the 2nd largest planet currently known, but its mass is half of Jupiter's. Sounds like a big ball of gas, right?
That brings us to our final system for the day, WASP 47. This is a compact multi-planet system, the only one known to hold a 'hot Jupiter' with close companions.
Now, sit back and relax. We'll be back at the station in a jiffy.