There has been quite a bit of excitement in the public science sphere this week with NASA announcing the discovery of a series of exoplanets on Wednesday. The letter, sent to Nature, contains many of the more technical details that have been absent in many reports of the event. The star that these exoplanets have been found around is called TRAPPIST-1 and is very small even by the Sun’s standards being only 0.08 solar masses, about 1.6×1029 kg putting it in the dwarf star. This star is only 12 parsecs away, which is quite close astronomically speaking, but the real marvel comes from its satellites. Of the eight known planets that orbit this star seven are very similar to the Earth. Five of the planets have masses within 0.6 to 1.4 of the Earth’s mass with the final two being 0.41 Terra masses and an incalculable value. The surface temperatures of these planets are also very similar to the Earth’s 287 K with one planet actually being estimated at 288 K, an astonishing similarity. The other temperatures range range from 168 K (quite nippy) to 400 K (sweltering), although as these are just average calculated temperatures it is very possible liquid water could exist on all seven Earth like planets. The thing that should probably be noted is that these results are based on a preliminary glance over the system. Although the temperatures are believed to be accurate the masses have a percentage uncertainty averaging at 63.4% (I calculated it) which is really terrible. The letter itself talks about how predictive analysis can’t be performed because of this uncertainty. Overall it is quite clear why people can get very excited about discoveries like this. Apart from the massive galactic coincidence the idea that somewhere among the stars there is a place just like this is quite appealing.
Until tomorrow, goodnight.