1880: Eclipse Review

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Eclipse Review
I watched from a beautiful nature reserve in central Missouri, and it was--without exaggeration--the coolest thing I've ever seen.
Title text: I watched from a beautiful nature reserve in central Missouri, and it was--without exaggeration--the coolest thing I've ever seen.


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This comic is the fifth consecutive comic with a solar eclipse as the topic. On August 21, 2017, a total solar eclipse was visible within a band across the contiguous United States from west to east. The other comics are 1876: Eclipse Searches, 1877: Eclipse Science, 1878: Earth Orbital Diagram and 1879: Eclipse Birds. As the first XKCD written since the total solar eclipse, Randal is ready to provide his "review."

The comic is another comparison graph, like 1775: Things You Learn or 1701: Speed and Danger. It contrasts how cool something sounds and how cool it actually is. It has five points on it, planetary conjunction, supermoon, lunar eclipse, partial solar eclipse, and total solar eclipse.

While the four other things than total solar eclipse are relatively close to each other on the "how cool to see" scale, the graph is not even high enough to plot the total solar eclipse point as indicated by the dotted arrow showing that this point should be way higher up. This is as opposed to leaving the point out, as Randall did with the coconut in 388: Fuck Grapefruit, where it is only mentioned in the title text. This could be an indication that if the scale had been high enough to fit the total solar eclipse point, then the rest of the points would be on the x-axis without any indication of which would be cooler.

A total solar eclipse correctly sounds like it is the coolest of the five, but it is vastly cooler to see it in person by a wide margin. It seems like Randall is trying to convice those who missed the eclipse this time to go watch in seven years when another total solar eclipse is visible in the USA.

Planetary Conjunction

In a planetary conjunction two or more planets are visible in night sky nearby. This happens relatively often because all planets roughly lie in the same plane around the sun (the Sagittal ecliptic). This looks like two big stars close to each other, and isn't particularly exciting.


A supermoon is a full moon or a new moon that approximately coincides with the closest distance of the Moon on in its elliptic orbit around the Earth. This results in a larger-than-usual apparent size of the lunar disk, but a typical human doesn't recognize the difference. Nevertheless in the last years the press always announces this as an important astronomical event. The opposite is called a micromoon. A "supermoon" sounds very cool, but like a planetary conjunction it's almost indistinguishable in the average night sky (see 1394: Superm*n).

Lunar Eclipse

A lunar eclipse can occur at full moon and happens only, like at a solar eclipse, when the Moon is in the region where the orbital planes of the Moon and the Earth intersect. The Earth's shadow falls on the Moon and it appears in dark red because some light still reaches the Moon through the outer layers of the Earth's atmosphere. Lunar eclipses occur more often than solar eclipses and they can be viewed by much more people at the same time in the night sky. Only people on the day-side can't see it. A lunar eclipse looks noticably different from a usual full moon, making it fairly cool.

Partial Solar Eclipse

There are three types of partial solar eclipses. An annular eclipse occurs when the Sun and Moon are exactly in line with the Earth but the Moon is too far away and can not block the entire Sun. The Sun appears as a very bright ring, also called annulus. A partial eclipse occurs when the Sun and Moon are not exactly in line to the observer on Earth and thus the Sun can't be fully blocked by the Moon. A hybrid eclipse is a total and annular eclipse at the same time. At some locations on Earth it appears as a total eclipse, while at other locations it appears as annular. These mixed eclipses are comparatively rare. A large percentage of the continental United States experienced a partial eclipse along with the total solar eclipse on August 21st. A partial solar eclipse is quite cool, but nowhere near as dramatic as a sky-darkening total solar eclipse.

Total Solar Eclipse

The total solar eclipse is the topic of this and the four preceding comics. It can occur at new moon and happens only when Sun and Moon are exactly in line with the Earth. But unlike to the lunar eclipse only a small part of the Earth is in the totality zone, a disc with a diameter of approx. 100 km. The disc moves very fast over the Earth's surface and at a specific location it lasts only a few minutes in maximum. At locations outside of this shadow-disc, in a region over a few thousand kilometers, the eclipse is partial.

In the title text, Randall remarks that, without any exaggeration or hyperbole, the total solar eclipse was the coolest thing he has ever seen in his life.


[A scatter plot with five labeled dots is drawn. The x-axis reads "How cool it sounds like it would be" and the y-axis is labeled with "How cool it is to see in person".]
[Bottom left] Planetary conjunction
[Bottom middle] Supermoon
[Low left-center] Lunar eclipse
[Low-center middle] Partial solar eclipse
[Upper right, with a dotted arrow above it pointing up] Total solar eclipse

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The air temperature drop is greater during a total eclipse than during a partial eclipse, while the other two don't affect the air temperature at all. -- 10:31, 23 August 2017 (UTC)

A booklet I got on the eclipse said this: "If natural wonders were on a scale of 1 to 10, a partial solar eclipse might be a 7, but a total solar eclipse would be a 1,000,000!!!" They were right. I was there. That's right, Jacky720 just signed this (talk | contribs) 10:50, 23 August 2017 (UTC)

Yeah... That's quite a lot :) http://www.wolframalpha.com/input/?i=((1000000!)!)! (There should be 1 more "1" in the link, but it didn't catch it)kshksh (talk) 08:23, 24 August 2017 (UTC)

This is fun. 11:17, 23 August 2017 (UTC)

Is it worth having an "2017 Total Eclipse" tag for the 5 comics? 11:30, 23 August 2017 (UTC)

Yes. Be sure it includes the other comics that mentioned the eclipse, like 1868: Eclipse Flights. Dretler (talk) 12:37, 23 August 2017 (UTC)
And it should also be "2017 Total Solar Eclipse". -- Dretler (talk) (please sign your comments with ~~~~)
Here we go: Category:Total Solar Eclipse 2017. Any comic missing? --Dgbrt (talk) 14:41, 23 August 2017 (UTC)
Should probably get rid of Main page, which just shows the most recent comic, and add 1779: 2017, which mentions it directly, and 1302: Year in Review, which mentions the eclipse in the title text. I think that's it. Dretler (talk) 01:11, 24 August 2017 (UTC)
Both comics are updated by some IPs. The Main Page is only listed because of an embedded eclipse comic there, when the next is published and doesn't belong to this category it will be vanished. --Dgbrt (talk) 15:40, 24 August 2017 (UTC)

Here's a Whatif topic: What if the earth's orbit around the sun and the moon's orbit around the earth were in the same plane so that a solar eclipse happened every month. How would that affect tides, global temperature, animal behavior, etc? Would the orbits be stable or would the gravitational tugs destabilize the orbits? Rtanenbaum (talk) 13:27, 23 August 2017 (UTC)

Solar eclipse does not affect tides significantly more than the regular movement of the Moon and the Sun, those non-eclipse events where the Moon passes almost in front of the Sun actually make tides somewhat higher on that day, because forces sum up, but a fraction of angular degree misalignment which cases a "miss" does not make much difference for the tides. The effect of blocking the Sun's radiation during eclipse happens over a very small area and for a short time therefore it is too minuscule to affect temperature on Earth, normal Sun activity cycle creates a lot larger differences in the amount of energy reaching Earth. Animal behavior during eclipse might be a little different if it was a more frequent event, animals (including two-legged naked apes) would just get used to it. -- 14:25, 23 August 2017 (UTC)

SO. TRUE. (I saw it in Salem) SilverMagpie (talk) 13:54, 23 August 2017 (UTC)

Personal impressions on the 2017 eclipse or before

Maybe we can share some personal impressions from this eclipse or similar events. I personally was in the totality zone of the 1999 solar eclipse in Germany. Weather was bad, dark clouds obscured the sun, and I almost could see nothing of the Sun at all. I was so happy living in that zone and then this. That was really annoying. It got darker, but not that much as expected because of the scattered light from the damn clouds at the horizon. The nature went quiet and automatic lights switched on, but that was it. Nothing cool at all. A much better experience I had recently in 2015, a total eclipse at the Faroe Islands but still 80% at my location. Most of the Sun was blocked, it was getting darker, nature became silent, the temperature decreased and me and all my colleagues were impressed. But of course that also wasn't that cool like a total eclipse can be. So, after a missed total eclipse at home I still have to travel to get the real cool experience.--Dgbrt (talk) 15:17, 23 August 2017 (UTC)

saw Totality from nashville

No question there's a huge different betwen partial and total. Totality is awesome, I recommend anyone to chase one if you can. After the 2 minutes I wished I could rewind it. No video comes close to the IRL experience. (talk) (please sign your comments with ~~~~)

Also saw Totality from nashville

I have to echo the sentiment above. I've wanted to see a total eclipse ever since I was a small child and learned what they were, and the experience, however brief, DEFINITELY lived up to the years and years of anticipation. (talk) (please sign your comments with ~~~~)

Now that's interesting. I remember an eclipse from my childhood. I won't tell you what I didn't give about it (hint: it was flying) but much more interesting: It must have been around 1970+- but I don't find an eclipse in Germany. The only sensible explanation: My memory has been fabricated. 08:43, 28 August 2017 (UTC)

There was a partial eclipse on February 25, 1971 which was about 60% in northern Germany. The next possible eclipses (for Germany) were on May 11, 1975 and April 29, 1976. I also have some vague memories when my father was sooting a piece of glass which we used to gaze at the sun. This was probably 1971 because 1975 happened early in the morning on a Sunday and 1976 I've watched in school. But I'm still not sure to which eclipse my memories do belong.--Dgbrt (talk) 14:25, 29 August 2017 (UTC)