1231: Habitable Zone

2015-01-15T00:30:59Z

Judestiel: /* Pedantic Comments */

{{comic
| number = 1231
| date = June 28, 2013
| title = Habitable Zone
| image = habitable zone.png
| titletext = They have a telescope pointed RIGHT AT US!
}}

==Explanation==
While searching for {{w|extrasolar planet}}s this gullible astronomer is very excited because he believes he has found a planet in a star's {{w|habitable zone}}, with oceans and visible weather. From these observations, he has determined that it is quite likely to have life on it, which would be a major groundbreaking discovery.

The caption explains, however, that someone has used a mirror as a prank to fool the astronomer, so he is in fact looking at a reflection of the Earth.

The title text goes on says that the astronomer would also be able to see the reflection of his telescope, which would convinces him that there definitely ''is'' intelligent life on the other planet, looking straight back at him no less!

===Pedantic Comments===
There are quite a number of issues (listed below) with the practical implementation of this prank, so in order to subscribe to the simplistic explanation, the viewer must either be ignorant of, or choose to ignore these issues. It could be that all jokes require suspension of disbelief, but the writers of this section do not understand this because they are egotists who seize on any opportunity to feel smarter than someone else, and take suspension of disbelief as ignorance, showing their own ignorance.

*The telescopes used for this type of research are designed to view faint, distant objects. In the images that they produce, objects the size of telescopes are not visible. Therefore, the astronomer would not see the reflection of the telescope.
*The telescopes have a motor that moves them to compensate for earth's rotation, so that they stay pointed on the same part of the sky. This means that the telescope would not stay pointed at the mirror. The prankster would have to move the mirror in a very precise way to maintain the illusion.
*For the astronomer to have ascertained that the planet is in a star's habitable zone means that the astronomer observed the planet to be the size of Earth and observed the distance between the planet (Earth) and its star (the Sun), and the approximate size of that star. However, in a mirror at any reasonable distance from the earth, up to several times the distance of the moon, the earth would appear to be larger than the sun.
*For the relative sizes of the earth and sun to be correct in the reflection, the mirror would have to be as far from earth as the mirror was from the sun. But even pointing to a mirror at a distance of the moon would require a real huge one, probably more than one hundred kilometers (sixty miles) in diameter.
*A professional astronomer should be able to realize nearly instantaneously that they're not looking at an Earth-like, extrasolar planet (as should anyone, in fact, who is familiar with even the basic arrangement of Earth's continents and oceans), but instead Earth itself.
*A telescope of this size, or indeed any one employing a solid mirror rather than a massive disk of dust in space, could never see an extrasolar planet with this level of detail without unsurmountable engineering issues.

==Transcript==
:[Cueball stands in front of a huge telescope, looking through the eyepiece.]
:Cueball: I've discovered an Earth-sized planet in a star's habitable zone! It even has oceans! And visible weather!
:To mess with an astronomer, put a mirror in the path of their telescope.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Science]]
[[Category:Exoplanets]]

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1231: Habitable Zone