Friday, December 04, 2020

meteor outlook for next year

As the Earth tumbles through old dust and debris of comets and asteroids, we may enjoy meteors vapourising in our atmosphere. Most meteor showers "run" for days or weeks as the flotsam is big or wide. Meaning you might see some meteors on a night-by-night basis. A meteor shower peak occurs when our planet moves through the densest part of the trail. That's one night only and what I am focusing on below.

Here's my meteor showers assessment for 2021.

[ed: Revised on 12 Jan to downgrade the Ursids. ]

This list is tuned for observers in or near Ontario, Canada, factoring in the Sun's position at the shower peak. The dates and times are local too, for Ontario. The UTC dates and times are from the 2021 RASC Observer's Handbook.

New for 2021. To the table I added the Moon brightness and constellation the Moon is in so one can make a quick assessment as to the visibility. I determined the Moon information using Stellarium. If the Moon illumination number is high, our odds of seeing a good show go down. Full Moons are particularly bad. Also I added the day of the week so you can determine if it's a school night or not.

showerUTC d h *peakZHRSunMoolumconIR
Quadrantids3 Jan 15 *Sun 3 Jan-10 AM100151079Leo3
Lyrids22 Apr 12Thu 22 Apr-8 AM2016-2673Leo3
η Aquarids6 May 2Wed 5 May-10 PM60-14-5628Aqr2
δ Aquarids29 Jul 5Thu 29 Jul-1 AM30-261472Cet3
Perseids12 Aug 19 *Thu 12 Aug-3 PM90533720Vir2
Orionids21 Oct 12Thu 21 Oct-8 AM202599Ari3
S. Taurids5 Nov 12Fri 5 Nov-7 AM20-11-191Lib1
N. Taurids12 Nov 11Fri 12 Nov-6 AM15-12-5760Aqr3
Leonids17 Nov 18Wed 17 Nov-1 PM2025-2798Ari3
Geminids14 Dec 7 *Tue 14 Dec-2 AM120-591280Psc3
Ursids22 Dec 16Wed 22 Dec-11 AM155-2388Cnc3

  • "UTC d h *" is the date and hour in Coordinated Universal Time from the Handbook with the asterisk showing their emphasis
  • "peak" is the shower peak date and time, Eastern time zone
  • "ZHR" is the idealised zenithal hourly rate
  • "Sun" is the Sun's elevation at the moment of the shower peak in degrees (°)
  • "Moo" is the Moon's elevation at the peak
  • "lum" is the percentage (%) illumination of the Moon
  • "con" is the constellation the Moon is in
  • "IR" is the initial rating primarily based on time of day and Moon phase, 1 being good, and 3 being poor
other notes
  • the Quadrantids emanate from an area along the Boötes-Draco border
  • η refers to eta
  • δ refers to delta
  • for the Taurids, S refers to South and N is North
  • the Moon on 29 Jul lies in Cetus near the Pisces border
Ugh. You can see the Moon is over 50% lit for almost all the showers! If you eliminate all the others, you're left with η (eta) Aquarids, Perseids, and the South Taurids.

Now on dates where the peak technically occurs in daylight for us in Ontariariario, we need to roll into the night before or after, as close to the peak as possible...

Quadrantids - up to rating 2
Sundown on Jan 2 is around 5:30 PM. Should be fully dark around 6:30 PM. Bright Moon doesn't rise until 9 PM. Astro-twilight in the morning on Jan 3 begins around 6:30 AM. All that said, the meteors emanate from the north, from Boötes and Draco, with the radiant zone climbing toward zenith for the evening. The Moon is 65° away. So maybe there's a chance to see a few?

Lyrids - stay at 3
The bright Moon sets Apr 22 around 4:00 AM and the sky will remain fully dark until about an hour. Small window. The radiant between Lyra and Hercules is nearly at zenith.

Perseids - stay at 2
Both the Sun and thin Moon will have set by 10:30 PM on the Aug 12. This is 7 hours after the peak. The night before might be good given the thinner Moon. Sky will remain full dark until about 5 AM.

Orionids - stay at 3
A wash, methinks, with a full Moon. So either the Sun or the reflecting Moon is in the sky for the entire day and night.

Leonids - stay at 3
Same issue. If it's not the Sun, it's the bright Moon in the sky.

So, in the final analysis, it looks like the South Taurids will be the best meteor shower for the year. Others I rate as fair. There you have it. I'm calling the 2021 season a poor one for meteor showers.

South Taurids

η Aquarids

This may paint a bleak picture but I feel this is important to set expectations. Often the news outlets trumpet and soapbox these events and use phrases like "once of a lifetime" or "meteors will fill the sky" and that's just not right. Don't forget, they're trying to "sell newspapers." I'd rather people know the odds or percentage of visibility. I worry these repeated fantastic exclamations by the media is creating a crying wolf scenario where people will get jaded. People won't bother going out and looking up because they'll think, "I didn't see a thing the last time." If you waste people's time, they'll not try again. This blog post was inspired by past bad science reporting by magazines and newspapers.

Yes, outbursts can occur and it'd be a shame to miss it. So, if you are genuinely interested, and you can pause a Netflix binge-watch, get outside. I always say, any night looking at the sky is better than any TV.

See my annual meteor showers table on the lumpy companion for a longer list of showers, generally ones over 10 per hour. Note this shows when all the showers start and end, as well as their peak.

Also see my graphical presentation of meteor shower curves, emphasising the meteor "seasons" and that the peak date and time is kind of a big deal...

Also, visit the American Meteor Society or the International Meteor Organization for more information. In fact, consider them the official sources.


I didn't elucidate something in this piece. While I drew attention to the radiant area of some meteor showers, I don't want to make it sound like that's where one must look. put it well: "your best bet is to look 30° to 60° away from the radiant to see the longest meteor trails."

I was noting that in some situations for 2021 a bright Moon was in the radiant zone. That would suggest looking for meteor streaks there would be a bad idea. But normally amateur astronomers don't stare at that point. If fact, we don't look at any particular point. During meteor showers, get horizontal or supine and watch the whole sky.

No comments: