Some weeks ago I talked about the incredible variety of exoplanets, which we have just began to discover. I have also mentioned what we normally find and we can expect to find according to astrophysics, including the most coveted targets – i.e., planets in the HD, the habitable zone. From now on, I will start dealing more specifically with that variety, and presenting some weird things in the sample…all good for SF scenarios.
Pick of the week: Methuselah – the oldest planet
Yes, but how old? To have an idea of the age of celestial objects, it’s good to remember that year zero, aka the Big Bang, is about 13.78 GY (billion years) ago, give or take a few millions, according to the standard Lambda-CDM model of cosmology. The age of our Milky Way is estimated to be 13.2 GY, but its stellar population contains system far younger than that. The Solar System, for example, it’s just 4.6 billion years ago and planets are about the age of our Earth, 4.54 billion or so.
Enter Methuselah.
Discovered in 1994, this planet (not to be confused with the star HD140283, same moniker but different location), is known among astronomers as PSR B1620-26 b. Estimate age: 12.7 billion years. With a mass of two or more Jupiters, this gas giant is located 5,600 LY away from our system in a old, globular cluster in the Scorpio Constellation. It orbits a binary star formed by a white dwarf star and a pulsar; and considering its age, it’s highly possible that supernovae and other violent stellar events have affected its evolution. Difficult to imagine life over there, of whatever form and shape – SF writers are welcome to try.
In case this one has put you in a good mood for old stuff, you can also check out the already mentioned, recently discovered HD140283 – an apparent paradox, and a weird object in its own right. This video is a good starting point:
Fancy youngsters instead? Try LkCa 15 b, allegedly less than one million years. Cosmically speaking, just a baby.
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