1887: Two Down, One to Go

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Two Down, One to Go

Title text: The third row will probably have to wait until 2034, and maybe longer. If I see a daytime supernova, I'll replace the meteor storm with that and consider it 3/3.

Explanation

In this comic, Randall lists three of the most spectacular astronomical sights: a total solar eclipse, an aurora (Aurora Borealis in the northern hemisphere and Aurora Australis in the south), and a meteor storm. In 2017, the first two of these phenomena happened within weeks of each other for observers in much of the US - a coincidence that Randall celebrates.

• Total solar eclipse: The total solar eclipse of August 21, 2017 was the first seen for decades in the contiguous United States. Randall already made several comics about this eclipse and had traveled to Missouri to witness this for himself as shown in this comic: 1880: Eclipse Review.

• Aurora: The aurora borealis is rarely visible from the continental USA. Randall bemoaned the fact he'd never seen one back in 1302: Year in Review in 2013 - which also mentioned the 2017 eclipse. Randall likely finally saw it due to the giant solar flares in the week leading up to this comic probably without any need of traveling.

• Meteor storm: A meteor storm is more than just a shower - while the best (or worst, depending on how you look at it) typical shower gives you a meteor or two per every minute, a storm gives you meteors every few seconds or better (or worse). The Great Meteor Storm of 1833 produced hundreds of thousands of meteors per hour.

In the title text, Randall suggests the next meteor storm could be 2034, probably because this is predicted to be a good year for Leonids.

Randall then continues by saying that if he manages to see a supernova during the daytime, he will drop the goal for the meteor storm and call it 3 of 3. This is because such an event is so unlikely that he hasn't even included it in his bucket list, and he would be happy to switch between the two types of events if he had the chance. A few stars, when they turn supernova, could be so bright that they can be seen during the day time here on Earth. The brightest supernova recorded in human history was SN 1006 which was sixteen times brighter than Venus but still not bright as the full moon. SN 1054 is an other example. When such an extremely rare event might happen is impossible to predict. There is a (very small) chance that the giant star Betelgeuse will go supernova within Randall's lifetime, allowing him to tick this off the list too. Randall even mentioned that this could not happen soon enough in 1644: Stargazing. Note that if you could see it during the day time, it would be one of the brightest objects in the night sky after the Moon. Also keep in mind that if Betelgeuse were to go supernova in Randall's lifetime, he wouldn't see it since it's over 600 light years away. For Randall to see it during his lifetime, it must have already gone supernova some 600 odd years ago, and we won't know that until we actually see it 613-881 years after it happened.

Astronomical backgrounds

• This particular aurora borealis happened because the coronal mass ejection (CME) headed directly toward Earth causing Northern Lights spreading more south than common. That solar flare was first detected by the Solar Dynamics Observatory (SDO) just eight minutes after it happened at the Sun. This animation shows what the probe SDO has seen on Sept. 4, 2017 in the early evening. While light, and x-rays as well, travel at light speed the mass ejected did only move at a speed of 500-1,000 km/s. It was first detected by DSCOVR two days later, still 1,5 Mio. to reach Earth or just 30 minutes before the --non critical-- impact. And at this aurora forecast the prediction showed that the northern United States were lucky.

• Betelgeuse is estimated to be in a range between 613 and 881 light-years from Earth, which means that its light takes more than 600 years to reach Earth. That incident must have already happened when it should reach us in the next few decades. But since all information cannot travel faster than light^{[actual citation needed]} there is no way to find this out.
• Something about the brightness of celestial objects:
  • The Sun is the brightest object at a magnitude of −26.74
  • The next object is the full moon at −12.90
  • Venus is at −4.89 on maximum brightness, bright enough to be (barely) visible in the daytime
  • The mentioned supernovae SN 1006 and SN 1054 were at −7.50 and −6.00 respectively
  • The brightness of the supernova from Betelgeuse is hard to predict. Because it's closer than both the other supernovae it could become brighter than Venus but definitely not than the full moon.

Transcript

[There are three rows equally filled with squares and above are year dates beginning from 2002 until 2017. The first year (2002) is cut on the left and the color is light gray. It fades in to black, which it becomes in in 2005. To the left of the three rows the text reads:]

Total eclipse

Aurora

Meteor storm

[Below the year 2017 the squares in the first two rows are checked.]

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Discussion

Worth noting that the Orionids are the last major shower of the year: https://www.timeanddate.com/astronomy/meteor-shower/orionid.html 108.162.246.215 (talk) (please sign your comments with ~~~~)

Venus is sometimes visible during the day. A daylight supernova need not be the second brightest object in the night sky.162.158.62.159 13:30, 8 September 2017 (UTC)

The Moon is also sometimes visible during the day. SN 1006 and SN 1054 were brighter than Venus at maximum brightness but still dimmer than the Moon. --Dgbrt (talk) 14:02, 8 September 2017 (UTC)

Randall is likely talking about the expected replenishment of the Leonids http://www.imo.net/50-years-ago-the-1966-leonid-meteor-storm/ 172.68.65.18 14:55, 8 September 2017 (UTC)

Aurora viewing in "perhaps parts of Maine"? Maine's northern limit is ~47.5 degrees. Most of the US/Canada border is at 49 degrees, which is still too far south for good aurora views, but being in Seattle gets you closer to the pole than Maine. 108.162.216.160 18:59, 8 September 2017 (UTC)

Auroras are centered on the Earth's geomagnetic poles, not the geographic poles. The geomagnetic pole is currently on Ellesmere Island and is closer to Portland, ME than Seattle, WA. The closest spot in the contiguous US to the geomagnetic north pole might be in northern Maine, Isle Royale, MI or the Northwest angle, depending on exactly which epoch is used for the location of the pole.162.158.62.159 00:22, 9 September 2017 (UTC)

Could Randal's mention of a supernova be interpreted to mean that our sun goes supernova and since that's the last thing he sees, he jsut closes off his bucket list? 108.162.221.58 22:55, 8 September 2017 (UTC)

Nice idea, and fits with Randall's sense of humor, but he knows that while it is possible that a nearby star will go supernova in his lifetime (though unlikely) our sun will never go supernova because it is too small. And the odds of our sun going nova anytime soon are meaningfully zero (on the same order of magnitude of the odds that every atom that makes up the clothing you are wearing suddenly quantum tunneling two feet to your left). 162.158.78.124 14:54, 9 September 2017 (UTC)

I always have to share my favorite song about Romance and Science: Judith Edelman: Magnetic. Read the lyrics at one of the first comments, "...Will the aurora borealis give us one last show?". --Dgbrt (talk) 20:31, 9 September 2017 (UTC)

Total Solar Eclipse: (16 times) check, Aurora (both northern and southern) check, Meteor Storm (1966) check, Naked eye visible supernova (SN 1987A) check, Transit of Venus: (2004 & 2012) check, Comet impact into a planet (Jupiter) check, Volcanic eruption (Mt. St. Helens, Kilauea, Mt. Erebus, etc.) check, Tsunami (Marshall Islands) check, Major Earthquake (Turkey, China, US) check, Hurricane (US, Virgin Islands, etc.) check, Tornado (several close up on the state of NM) check, Earth Poles, (North Geographic Pole, South Geographic Pole. North Magnetic, South Magnetic) check, World records (1980 and 1990 record book) check, .. still hoping to go into outer space, still hoping to see a naked eye Supernova in our galaxy, plus and a few other cool things: nevertheless, I'm well satisfied with my life so far. Chongo (talk) 09:08, 10 September 2017 (UTC)

FYI: There was no total solar eclipse in 2014, 2011, 2007, 2005, 2004, ... Chongo (talk) 09:26, 10 September 2017 (UTC)

I'm not the only one who can see 'Wave of Hurricanes' right? 108.162.238.83 12:27, 11 September 2017 (UTC)

Someone changed the image on this site. xkcd.com still shows the original with "Meteor Storm". If I knew how to fix this, I would. 108.162.238.95

It's corrected back to the original. But you must be patient to see it until the cache on the website is expired.--Dgbrt (talk) 14:23, 11 September 2017 (UTC)--Dgbrt (talk) 14:23, 11 September 2017 (UTC)

Someone has broken it again 172.68.65.18 15:53, 11 September 2017 (UTC)

No, and the cache on the server has expired. Press F5 and you will see the correct picture. --Dgbrt (talk) 19:59, 11 September 2017 (UTC)

There was a meteor storm back in 2014 that peaked at over 100,000 meteors per hour. It's a shame we were on the wrong planet. 108.162.210.106 21:44, 21 October 2017 (UTC)

https://www.cnet.com/news/supernova-iptf13dqy-spotted-hours-after-star-explosion-nature-physics/172.69.62.184 01:44, 1 June 2018 (UTC)

Spam by X. K. C. D.? 172.70.131.106 22:53, 3 May 2022 (UTC)

The reason why I added "^{[actual citation needed]}" to the figure: Remember that it is currently not unproven that light could travel instantaneously in one direction and half as fast in the other direction. The speed of light is in actuality just an average between the two outliers in speed. I also said this (exactly, word for word) in my edit summary. SilverTheTerribleMathematician (talk) 02:33, 22 December 2022 (UTC)

This happened again in 2024! 162.158.62.236 14:17, 3 June 2024 (UTC)