OK, now this *is* interesting…
Wonderful Potentially Habitable Worlds Around TRAPPIST-1
Seems a full *seven* roughly Earth-mass/size planets have been detected around the terribly small, dim, cool star TRAPPIST-1 (so named because of the TRAPPIST telescope in Chile). And three or four of them are in roughly the “Goldilocks zone” where liquid water can exist.
TRAPPIST-1 is 12.1 parsecs away. Which means two things:
1) Go ahead and get those Kessel Run jokes out of your system
2) We won’t be sending crews there anytime soon.
At just 8% the mass of Sol, TRAPPIST-1 is a tiny little thing. The planets are tucked in *close…* closest is at 0.01 AU, the furthest at 0.06 AU. This will probably have two effects:
1) Tidal locking. Chances are good the planets will always keep on face to the star. Through the plaents are close enough to each other that some sort of resonance might be at play.
2) Depending on how well behaved TRAPPIST-1 is, the Goldilocks Zone might still be a nightmare region of solar flares and X-Ray bursts, as was recently shown with Proxima b. TRAPPIST-1 *seems* relatively well behaved, but the star itself was only recently discovered so there isn’t that much data on it long-term.
Planetary data from Wiki:
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.85±0.72 M⊕ | 0.01111 | 1.51087081 ± 0.00000060 | < 0.081 | 89.65 ± 0.25° | 1.086 ± 0.035 R⊕ |
| c | 1.38±0.61 M⊕ | 0.01522 | 2.4218233 ± 0.0000017 | < 0.083 | 89.67 ± 0.17° | 1.056 ± 0.035 R⊕ |
| d | 0.41±0.27 M⊕ | 0.021 ± 0.06 | 4.049610 ± 0.000063 | < 0.070 | 89.75 ± 0.16° | 0.772 ± 0.030 R⊕ |
| e | 0.62±0.58 M⊕ | 0.028 | 6.099615 ± 0.000011 | < 0.085 | 89.86 ± 0.11° | 0.918 ± 0.039 R⊕ |
| f | 0.68±0.18 M⊕ | 0.037 | 9.206690 ± 0.000015 | < 0.063 | 89.680 ± 0.034° | 1.045 ± 0.038 R⊕ |
| g | 1.34±0.88 M⊕ | 0.045 | 12.35294 ± 0.00012 | < 0.061 | 89.710 ± 0.025° | 1.127 ± 0.041 R⊕ |
| h | unknown M⊕ | 0.063+0.027 −0.013 |
20+15 −6 |
unknown | 89.80 ± 0.07° | 0.755 ± 0.034 R⊕ |
TRAPPIST-1 is about half a billion years old, which means that if life has arisen on one or more of its planets it *probably* hasn’t had time to evolve great complexity yet. But on the other hand, the star is so cool and slow burning that its lifespan is expected to be on the order of a *trillion* years. Long before this star reaches adolescence, the rest of the universe will have grown into a pretty dark, uninteresting place. Unless a Giant Green Space Hand swats it, TRAPPIST-1 will be one of the last stars burning in the universe.