Editing 2135: M87 Black Hole Size Comparison

{{comic
| number    = 2135
| date      = April 10, 2019
| title     = M87 Black Hole Size Comparison
| image     = m87_black_hole_size_comparison.png
| titletext = I think Voyager 1 would be just past the event horizon, but slightly less than halfway to the bright ring.
}}

==Explanation==
This comic shows the picture of the {{w|Messier_87#Supermassive black hole|M87 black hole}} by the {{w|Event Horizon Telescope}} that was published on the same day as this comic. Overlaid on the picture is a scale image of the Solar System, showing the Sun, Pluto (one of the most well-known {{w|dwarf planet}}s) and its orbital path, and {{w|Voyager 1}}, a deep-space probe and the current farthest probe from Earth. The comic is quite similar to [[1551: Pluto]], in which Randall overlaid annotations onto the recently-released first images of Pluto taken by the New Horizons spacecraft.

The point of the comic is to celebrate the release of this image by the Event Horizon Telescope, referenced two comics earlier, in [[2133: EHT Black Hole Picture]], as well as to indicate the hugeness of M87 and the awe-inspiring thing that space is.  This image has been widely publicized as being the first image ever of a black hole.  Science had no visual evidence of black holes at all [https://www.space.com/16411-black-hole-photo-nasa-telescope.html until 2012].

In the title text Randall hypothesizes that if the Sun were at the center of M87, Voyager would be outside the event horizon. This is confirmed by a 2015 [https://arxiv.org/abs/1505.03545 study] in which the Schwartzchild radius of M87* was found to be 5.9x10^-4 pc, as opposed to the distance of 7.04x10^-4 pc, at the time the comic was written, between Voyager 1 and the Sun.

The comic's scale seems to be slightly small; while the orbit of Pluto should be about 4.9 microarcseconds across, in the comic it's about 3.9 microarcseconds across.

Regardless of the title text and its apparent correctness, [[Randall]] has placed the dot denoting Voyager 1 just outside the dark region. This may be based on the misconception of the dark area being the "black hole" itself, while, as stated above, the actual event horizon is a much smaller part (120 AU or so) in the middle of the black shadow, indistinguishable from the surrounding darkness. Whether this is intended as an obscure joke or if it's an actual art error is currently unknown.

==Transcript==

:[Caption above the panel:]
:Size comparison:
:'''The M87 Black Hole'''
:and
:'''Our Solar System'''

:[Caption at top left of the panel:]
:EHT Black Hole Image
:Source: NSF

:[An image of the M87 black hole captured by the event horizon telescope on the day that this comic was published is shown, in the shape of a thick red-and-yellow ring on a black background.]

:[A white ring about 1/4 of the diameter of the central black portion of the image is labelled with an arrow:]
:Pluto

:[A small white circle at the center of the image is labelled with an arrow:]
:Sun

:[A small white dot on the right hand edge of the central black portion of the image is labelled with an arrow:]
:Voyager 1

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics with inverted brightness]]
[[Category:Astronomy]]
[[Category:Space]]