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APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 4:05 am
by APOD Robot
Artistic Impression: The Surface of TRAPPIST-1f
Explanation: If you could stand on the surface of the newly discovered Earth-sized exoplanet TRAPPIST-1f, what would you see? Presently, no
Earthling knows for sure, but the
featured illustration depicts a reasoned guess based on observational data taken by
NASA's Sun-orbiting
Spitzer Space Telescope. In 2017, four
more Earth-sized planets were found by Spitzer, including
TRAPPIST-1f, in addition to
three discovered in 2015 from the ground. From the
planet's surface, near the mild
terminator between night and day, you might see water, ice, and rock on the ground, while water-based clouds might hover above. Past the clouds, the small central star
TRAPPIST-1 would appear more red than our
Sun, but angularly larger due to the close orbit. With
seven known Earth-sized planets -- many of which pass near each other -- the
TRAPPIST-1 system is not only a candidate to have life, but
intercommunicating life -- although a
preliminary search has found no
obvious transmissions.
[/b]
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 5:30 am
by RocketRon
APOD Robot wrote:is not only a candidate to have life, but intercommunicating life -- although a preliminary search has found no obvious transmissions
What are the odds of any extra-terrestrial life actually having any "communication" capability. ??
Life on earth has been going for how many millions/billions of years now, and its only in the past 150 odd years or so that human-based electromagnetic activity has been active.
Unless you include the flickering light of cooking fires, which extends the timespan somewhat.
We may already have been excluded from the search for "intelligent" life.
Missed us by that much.... ?
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 6:49 am
by Ann
It's an evocative illustration. I like it.
What are the chances that there is liquid surface water on a planet inside its star's habitable zone? Better than 50%? Worse than 50%?
Ann
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 7:20 am
by Boomer12k
They laughed at me back in the 70's... now they are finding them left and right...
Many even in the same system.... I'm
:---[===] *
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 9:04 am
by APODFORIST
This (artistic impressioned) sun looks scary. Probably the lifeforms are very religious - or - very good informed about astromomical laws by watching their nearby sister planets so close.
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 9:12 am
by douglas
RocketRon wrote:APOD Robot wrote:is not only a candidate to have life, but intercommunicating life -- although a preliminary search has found no obvious transmissions
What are the odds of any extra-terrestrial life actually having any "communication" capability. ??
https://en.wikipedia.org/wiki/Murasaki_(novel)
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 9:15 am
by douglas
The artist could have felt free to make the sun a bit redder, especially seeing as it's low on the horizon?!
Geez, if only these "artists" would check in with me first, such "sloppiness" .. or is it PR fatigue? maybe corporate "hysteria" fatigue?
![:) :ssmile:](./images/smilies/smile.gif)
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 10:59 am
by neufer
RocketRon wrote:APOD Robot wrote:
is not only a candidate to have life, but intercommunicating life
-- although a preliminary search has found no obvious transmissions
What are the odds of any extra-terrestrial life actually having any "communication" capability. ??
https://oeis.org/A287148 wrote:
Sequence A287148: Number of compositions (ordered partitions) of 2n-1 into
primes of form x2 + y2 (A002313). In other words: a(n) is the number of compositions of the n-th odd number into
primes of form x2 + y2.
0, 0, 1,
2, 3, 4, 6, 9, 15, 24, 37, 58, 92, 149, 243, 393, 629, 1004, 1603, 2564, 4106, 6571, 10508, 16807, 26895, 43060, 68952, 110392, 176696, 282798
Note that by definition a(4)..a(10) =
[2, 3, 4, 6, 9, 15, 24] is the number of compositions (ordered partitions) of
[7, 9, 11, 13, 15, 17, 19] respectively, into
primes of form x2 + y2. On the other hand a(4)..a(10) =
[2, 3, 4, 6, 9, 15, 24] is also the number of laps related to the orbital resonances of the seven Earth-sized planets
[h, g, f, e, d, c, b] in the planetary system of the TRAPPIST-1 star.>>
https://en.wikipedia.org/wiki/TRAPPIST-1 wrote:
<<The orbital motions of the TRAPPIST-1 planets form a complex chain with three-body Laplace-type resonances linking every member. The relative orbital periods (proceeding outward) approximate whole integer ratios of
24/24, 24/15, 24/9, 24/6, 24/4, 24/3, and 24/2, respectively, or nearest-neighbor period ratios of about 8/5, 5/3, 3/2, 3/2, 4/3, and 3/2 (1.603, 1.672, 1.506, 1.509, 1.342, and 1.519). This represents the longest known chain of near-resonant exoplanets, and is thought to have resulted from interactions between the planets as they migrated inward within the residual protoplanetary disk after forming at greater initial distances. The resonant chain has been shown to be necessary to keep the tightly packed system stable for long timescales, and the tight correspondence between whole number ratios in orbital resonances and in music theory has made it possible to convert the system's motion into music.>>
Re: APOD: Artistic Impression: The Surface of... (2017 Jun 26)
Posted: Mon Jun 26, 2017 11:16 am
by neufer
Ann wrote:
What are the chances that there is liquid surface water on a planet inside its star's habitable zone?
Better than 50%? Worse than 50%?
George Bailey:
What is it, a boy or a girl?
Mary: [nods enthusiasticly]
Mmmm-hmmm!