1249: Meteor Showers

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Meteor Showers
Remember, meteors always hit the tallest object around.
Title text: Remember, meteors always hit the tallest object around.

[edit] Explanation

This comic spoofs the way that astronomical events are often reported in the mass media — events are often tagged with undeserved superlatives or described as being more dramatic than they actually are. In some cases, outright misinformation is spread. This phenomenon occurs in part by the result of over-eager scientists, but mostly because of journalists with no deeper knowledge on the subject they write about.

Meteor showers typically occur regularly each year. It always happens at the same days because the Earth is crossing the dust path of a particular comet. Sometimes meteor showers are in fact likely to be relatively spectacular when the peak of the shower occurs while your part of the world is in darkness and there is little moonlight. However, even in these cases it must be understood that there is nothing unusual about the meteor shower itself. The shower just consist of small particles at a size about roughly one millimeter, only the high speed is the reason that is can be seen from Earth's surface. The names of the showers refer to the star constellation where they visually belong to.

Most of the meteor showers listed in the comic are real, but some are made up (and indicated as such below).

  • Quadrantids - January 4th - Bring pets inside during peak activity
While keeping pets inside may be reasonable on days when fireworks are let off in the beginning of a new year, no regular meteor shower poses much danger to pets.
  • (made-up) Tricuspids - January 21st - Not viewable in region 2 countries
Apparently a play on the tricuspid valve in mammalian hearts, or possibly on bicuspid teeth. The mention of "Region 2" is a reference to region locking, a digital rights management (DRM) scheme intended to restrict media to certain areas. DRM of course does not apply to natural events. But ironically, meteor showers are also geographically restricted, and the visible area might roughly coincide with a DRM region. Further irony is that "Region 2" is actually Europe, Middle East, Egypt, Japan, South Africa, Swaziland, Lesotho, Greenland, French Overseas departments and territories, meaning that it's not strictly geographical.
  • (Alpha / Theta) Centaurids - February 6th - Too faint to see without going outside
Since indoor lights and window glass make them harder to see, it would take a very bright meteor to be visible without going outside.
  • (made-up) Beta Aquariids - February 10th - Inverted shower converges toward Aquarius instead of radiating away
This fictional shower would collect shooting stars into the origin to prepare for the real Eta Aquariids meteor shower associated with Haley's comet and diverging from Eta Aquarii in Aquarius; the real shower peaks around May 6th.
Due to perspective, meteor showers appear to radiate outwards from a certain point in the sky. Meteor showers may be seen to converge on a point on the opposite side of the sky, but with the earth in the way there would only be a few visible going past the edge, seen as nearly parallel streaks overhead, so the convergence point would hardly be notable.
  • (made-up) Chelyabids - February 15th - Only one meteor per shower, but it's big.
A reference to the February 15, 2013, Chelyabinsk meteor whose explosion shattered windows within a large radius.
  • Lyrids - April 22nd - Meteors sometimes scream
A meteor large enough to reach the lower atmosphere could produce sound audible to observers on the ground, but this is very unusual.
This shower is mostly observed via its effects on radio and TV signals, and therefore a good target for conspiracy theorists responding to June's Invisible Meteors - NASA Science
  • June Boötids - June 27th - 50/50 mix of meteors and shooting stars
The "50/50 mix of meteors and shooting stars" is a joke, as "meteor" and "shooting star" are synonymous.
This is saying that they are indistinguishable from stars, or that the stars themselves are actually meteors.
  • (made-up) Dromaeosaurids - July 22nd - Fast, highly intelligent, can open doors
Dromaeosaurids are a family of dinosaurs containing the genus Velociraptor, well-known from the movie Jurassic Park in which they are presented as a deadly menace, fast and especially intelligent to the point of understanding how to open a door; this representation of Velociraptors is a recurrent topic in xkcd. When the comic was originally published, the date listed for this shower was June 12th, the date of the velociraptor attacks in the movie.
  • Perseids - August 12th - Instead of falling from sky, meteors erupt from ground
??? (apart from the fact that erupting from the ground is the funny inverse of falling from the sky, what meteor always do)
  • (made-up) Tau Pyramids - August 15th - Visible even when eyes are closed
Probably a reference to Pyramidal cells, a type of neuron. The "tau" reference has two possibilities. The "visible even when eyes are closed" could refer to the Tau particle, a heavy sibling of the electron. When they traveled outside of Earth's magnetosphere on their way to the Moon, Apollo astronauts saw flashes of light about every three minutes even with their eyes closed; these were caused by high energy particles (cosmic rays) penetrating their eyes and brain. The other possibility is that it refers to Tau protein, a normal structural protein within brain neurons. In Alzheimer's Disease, abnormal Tau proteins can aggregate within pyramidal cells to form insoluble skeins. The number of these "neurofibrillary tangles" roughly correlate with the severity of cognitive impairment.
  • Draconids - October 8th - Very slow, but follow you if you run
??? (maybe something to do with the fact that "draconids" etymologically means "of the dragon", which could make for a fearsome meteor shower)
  • Orionids - October 21st - Entire shower happens at once
As noted in comic 1020, the Orion constellation (in which the Orionids are located) has a 'dong'. Possibly a joke about a "golden" shower. Maybe.
  • Leonids - November 17th - In 1966, unusually active Leonid shower killed God
There was a very active Leonid shower (a "meteor storm") in 1966, and a precursor to it in 1965. The article Is God Dead? was published in Time Magazine on April 8 of 1966. Perhaps this suggests that the meteors killed God earlier in the year when they and He were further out in the solar system?
  • Geminids - December 13th - Can be deflected with tennis rackets
??? (apart from the simple funny idea of deflecting a meteor with a tennis racket) (what about a Baseball Bat?)

The title text refers to the folk wisdom that lightning strikes the tallest thing around. Randall expressed frustration over how "maddeningly inexact" that statement is, and elaborated on the problem mathematically, on his what if? blog post on lightning.

[edit] Transcript

The xkcd guide to meteor showers
Name Peak Notes
Quadrantids January 4th Bring pets inside during peak activity
Tricuspids January 21st Not viewable in region 2 countries
Centaurids February 6th Too faint to see without going outside
Beta Aquariids February 10th Inverted shower converges toward Aquarius instead of radiating away
Chelyabids February 15th Only one meteor per shower, but it's big.
Lyrids April 22nd Meteors sometimes scream
Daytime Zeta Perseids June 9th Likely a NASA hoax
June Boötids June 27th 50/50 mix of meteors and shooting stars
Southern Delta Aquariids July 19th Meteors very bright, but stationary
Dromaeosaurids July 22th Fast, highly intelligent, can open doors
Perseids August 12th Instead of falling from sky, meteors erupt from ground
Tau Pyramids August 15th Visible even when eyes are closed
Draconids October 8th Very slow, but follow you if you run
Orionids October 21st Entire shower happens at once
Leonids November 17th In 1966, unusually active Leonid shower killed God
Geminids December 13th Can be deflected with tennis rackets
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Discussion

The dates are not in order ‎99.108.140.97 (talk) (please sign your comments with ~~~~)

Maybe the tennis reference is to Bob and Mike Bryan, they are twins. 83.227.33.35 09:36, 9 August 2013 (UTC)

The date for Dromaeosaurids was originally June 12, but on the page displayed at 9:44 ET, is now July 22.

Lyrids: Scream because of the similarity to "Lyrics"? 74.125.57.36 15:08, 9 August 2013 (UTC)

I don't know if it's relevant, but pyramidal cells are needed in complex object recognition and in vision-guided motor function. By closing your eyes, you're basically not using much of your pyramidal cells' capabilities. They're also one of the largest neurones, but I doubt that's relevant. 83.173.97.36 15:28, 9 August 2013 (UTC)

When it comes to the Leonids, John Lennon (I know it's a stretch), made his "bigger than Jesus" comment in '66 12.1.208.178 (talk) (please sign your comments with ~~~~)

Or perhaps it's related to the film 300 where Leonidas says: "Even a god can bleed?"--129.215.124.225 21:50, 15 August 2013 (UTC)

For Draconids, are there any movies with dragons that would fit the given description? --Irino. (talk) 18:56, 9 August 2013 (UTC)

Reign Of Fire first came to mind as far as dragons are concerned, but unlike the Jurassic Park T-Rex (which might be an influence, given their co-billing alongside the 'Raptor threat) I don't think they were blind to the motionless (just had bad vision at sunset?) and neither were they were notably slow (far from it!). Various zombies (non-Rage ones) are slow but surprisingly good at catching people who trip, but I don't see any obvious connection there either. Maybe there's another Monster Movie which has the same sort of thing with dragons? I had also considered Komodo Dragons, which are often filmed lumbering about, although they've got a turn of speed on them when attacking so... Anyway, my thoughts, FWIW. 178.104.103.140 23:00, 9 August 2013 (UTC)

With regard to "daytime" meteor showers being a NASA hoax, would anyone be able to see a meteor shower during the daytime? Odysseus654 (talk) 00:12, 10 August 2013 (UTC)

Regarding Centaurids: You could look at a meteor shower from inside through a window. Glare or perhaps light absorbed by the glass could make it difficult or impossible to see a meteor shower unless it is bright enough. (I nearly lost my edit to Odysseus654 who posted just before me.) 76.106.251.87 00:15, 10 August 2013 (UTC)

Perseids (“Instead of falling from sky, meteors erupt from ground”) are named after Perseus, a well-known hero of Ancient Greek mythology. The Perseids line apparently refers to another Ancient Greek myth, about founding the Thebes city by another Ancient Greek hero, Cadmus, who, according to the story, sowed the dragon teeth into the ground, from where the fierce warriors have grown ("erupted"); these warriors then, after a couple of story twists, assisted Cadmus in building the city. Honeyman (talk) 01:03, 10 August 2013 (UTC

Geminids: how about Prince of Tennis? [1] 84.193.43.190 (talk) (please sign your comments with ~~~~)
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