Discussion in 'Astronomy, Exobiology, & Cosmology' started by DaveC426913, Feb 27, 2017.

1. ### DaveC426913Valued Senior Member

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8,234
Thanks yeah.
Some of those comments I paraphrased from the announcement with little in the way of context.

3. ### nebelRegistered Senior Member

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998
no, I am looking at a simpler bode-like radius analisis, planets b, d,e,f,g and h are within ~4 % of a grid that has .0008 AU spacings. Planet c is within 6.7% of halfway between it's neighbours, and there is no planet in the last gap between g and h, so:
you have a pattern of a reasonable fit in the pattern of .0004 AU;-- b,c&d; .0008 AU: b,d,e,f,g,--; and .016 between g,f .*
* numbers are given as in the theoretical .004, .008 and .016 grid. namely .0118; .o201 .0282 .o365 .0446 .o61 AU in equal .008 AU spacings.
It looks clear on my measuring stick. and these simple orbital radius relations will translate into related velocities, timings.
Janus got it right with his/her avatar, it is 5 equally spaced circling planets, plus 1 in a half and another in a doubling spacing. octaves all the way.

5. ### nebelRegistered Senior Member

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998
In the solar system. Earth and Jupiter are the ones most closely conforming to a bode-type sequence.
in Trappist-1,
e,: .7 % has deviation
f,: 1.4 % "
g,: 1.6 % "
so if our home is any indication, life and stabilizing would be concentrated in those three, as Earth and Jupiter provide life and stability here.

Last edited: Mar 7, 2017

7. ### Janus58Valued Senior Member

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1,867
Here's a couple of images that give an idea of how outer planets could appear to someone on planets e, f and g.

The first one shows how the apparent sizes of the planets change over the course of a synodic period. The apparent sizes are shown how they change over equal time periods. The red lines represent the rising and setting horizons for someone at the center of the night-side. These would shift as you moved towards one day-night terminator or the other.
The first three line are Planets f,g and h as viewed from e. The time passage between images for each line is as follows:
f: 14.46 hrs (total synodic period 18.07 days)
g: 9.64 hrs (total synodic period 12.05 days)
h: 7.02 hrs (total synodic period 8.78 days)

The next two lines are g and h as viewed from f
g: 28.92 hrs (total synodic period 36.15 days)
h: 13.65 hrs (total synodic period 17.06 days)

Then we have h as viewed from g
h: 25.8 hrs (total synodic period 32.31 days)

Last, we have the Moon's apparent size as seen from the Earth for comparison.