Sky & Telescope - December 2020 - 19

to keep the Geminids sufficiently stocked for an annual display of shooting stars. So, if Phaethon currently isn't spewing
enough dust to account for the Geminids, did it shed more
material in the past? No one knows. It's yet another mysterious chapter in the story of the enigmatic Geminids.

The End Is Nigh (Maybe)
Unlike a number of other meteor showers whose historical
records span centuries or even millennia, the first definitive
appearance of the Geminids dates back just to 1862, making this display the new kid on the block. Are these midDecember meteors only a fleeting moment in the history of
the solar system?
In the past, some theorists predicted that Earth would hit
the densest part of the Geminid stream during the mid- or
late-20th century, and thereafter the shower would start to
decline and completely vanish by the end of the 21st century.
But these studies were conducted before the discovery of
Phaethon, and so far (thankfully) their dismal forecasts have
yet to become reality as the Geminids continue to strengthen.
But how long can we expect them to last?
To answer this question, I've done my own study with an
orbit simulator. The Geminid stream intersects the ecliptic
at two locations, but only one of these points (the stream's
descending node) is in the vicinity of Earth's orbit. The
Geminid stream is currently inside our planet's orbital track,
but around 2080 the respective orbits of the stream and Earth
should coincide. That could be when the shower plateaus with
a ZHR easily topping 200!

Making It Count
If you'd like to be more than a casual spectator, check out
how to report a scientific meteor count. You'll need to follow
the International Meteor Organization's standardized procedures so that your counts can be meaningfully compared
with others. To learn more, visit imo.net/visual/major.

But after that, all bets are off.
Once Earth exits the debris stream Geminid activity might
end abruptly. However, if the amount of material left in the
wake of Phaethon is symmetrically distributed, the Geminids
would slowly diminish before finally disappearing completely
by the end of the 23rd century.
No matter what the future holds, we should consider ourselves fortunate to be living at a time when we can enjoy such
a wonderful celestial pyrotechnics display each December.
Think of the Geminids as nature's free holiday gift - one well
worth braving cold temperatures to receive!

¢ JOE RAO is an eight-time Emmy-nominated broadcast
meteorologist and has been an assiduous amateur astronomer
for more than 50 years. He has served as an associate and
guest lecturer at New York's Hayden Planetarium since 1986.
He dedicates this article to his aunt and uncle, Irma and Ron
Balzano, who allowed the young Joe to observe comets and
meteor showers under the once-dark skies of Mahopac, NY,
located 75 km north of New York City.

BRILLIANT BOLIDE
This huge Geminid
fireball was captured
streaking past the stars
of Orion on December
14, 2017, over Tucson,
Arizona by Eliot Herman.
He writes: "Amazing
night - many meteors
captured including quite
a few bright ones - this
being the best by far. A
photo of a lifetime."

sk yandtelescope.org * DECEMBER 2 02 0

19


http://www.imo.net/visual/major http://www.skyandtelescope.org

Sky & Telescope - December 2020

Table of Contents for the Digital Edition of Sky & Telescope - December 2020

Contents
Sky & Telescope - December 2020 - Cover1
Sky & Telescope - December 2020 - Cover2
Sky & Telescope - December 2020 - 1
Sky & Telescope - December 2020 - Contents
Sky & Telescope - December 2020 - 3
Sky & Telescope - December 2020 - 4
Sky & Telescope - December 2020 - 5
Sky & Telescope - December 2020 - 6
Sky & Telescope - December 2020 - 7
Sky & Telescope - December 2020 - 8
Sky & Telescope - December 2020 - 9
Sky & Telescope - December 2020 - 10
Sky & Telescope - December 2020 - 11
Sky & Telescope - December 2020 - 12
Sky & Telescope - December 2020 - 13
Sky & Telescope - December 2020 - 14
Sky & Telescope - December 2020 - 15
Sky & Telescope - December 2020 - 16
Sky & Telescope - December 2020 - 17
Sky & Telescope - December 2020 - 18
Sky & Telescope - December 2020 - 19
Sky & Telescope - December 2020 - 20
Sky & Telescope - December 2020 - 21
Sky & Telescope - December 2020 - 22
Sky & Telescope - December 2020 - 23
Sky & Telescope - December 2020 - 24
Sky & Telescope - December 2020 - 25
Sky & Telescope - December 2020 - 26
Sky & Telescope - December 2020 - 27
Sky & Telescope - December 2020 - 28
Sky & Telescope - December 2020 - 29
Sky & Telescope - December 2020 - 30
Sky & Telescope - December 2020 - 31
Sky & Telescope - December 2020 - 32
Sky & Telescope - December 2020 - 33
Sky & Telescope - December 2020 - 34
Sky & Telescope - December 2020 - 35
Sky & Telescope - December 2020 - 36
Sky & Telescope - December 2020 - 37
Sky & Telescope - December 2020 - 38
Sky & Telescope - December 2020 - 39
Sky & Telescope - December 2020 - 40
Sky & Telescope - December 2020 - 41
Sky & Telescope - December 2020 - 42
Sky & Telescope - December 2020 - 43
Sky & Telescope - December 2020 - 44
Sky & Telescope - December 2020 - 45
Sky & Telescope - December 2020 - 46
Sky & Telescope - December 2020 - 47
Sky & Telescope - December 2020 - 48
Sky & Telescope - December 2020 - 49
Sky & Telescope - December 2020 - 50
Sky & Telescope - December 2020 - 51
Sky & Telescope - December 2020 - 52
Sky & Telescope - December 2020 - 53
Sky & Telescope - December 2020 - 54
Sky & Telescope - December 2020 - 55
Sky & Telescope - December 2020 - 56
Sky & Telescope - December 2020 - 57
Sky & Telescope - December 2020 - 58
Sky & Telescope - December 2020 - 59
Sky & Telescope - December 2020 - 60
Sky & Telescope - December 2020 - 61
Sky & Telescope - December 2020 - 62
Sky & Telescope - December 2020 - 63
Sky & Telescope - December 2020 - 64
Sky & Telescope - December 2020 - 65
Sky & Telescope - December 2020 - 66
Sky & Telescope - December 2020 - 67
Sky & Telescope - December 2020 - 68
Sky & Telescope - December 2020 - 69
Sky & Telescope - December 2020 - 70
Sky & Telescope - December 2020 - 71
Sky & Telescope - December 2020 - 72
Sky & Telescope - December 2020 - 73
Sky & Telescope - December 2020 - 74
Sky & Telescope - December 2020 - 75
Sky & Telescope - December 2020 - 76
Sky & Telescope - December 2020 - 77
Sky & Telescope - December 2020 - 78
Sky & Telescope - December 2020 - 79
Sky & Telescope - December 2020 - 80
Sky & Telescope - December 2020 - 81
Sky & Telescope - December 2020 - 82
Sky & Telescope - December 2020 - 83
Sky & Telescope - December 2020 - 84
Sky & Telescope - December 2020 - Cover3
Sky & Telescope - December 2020 - Cover4
https://www.nxtbook.com/nxtbooks/aas/st_202112
https://www.nxtbook.com/nxtbooks/aas/st_202111
https://www.nxtbook.com/nxtbooks/aas/st_202110
https://www.nxtbook.com/nxtbooks/aas/st_202109
https://www.nxtbook.com/nxtbooks/aas/st_202108
https://www.nxtbook.com/nxtbooks/aas/st_202107
https://www.nxtbook.com/nxtbooks/aas/st_202106
https://www.nxtbook.com/nxtbooks/aas/st_202105
https://www.nxtbook.com/nxtbooks/aas/st_202104
https://www.nxtbook.com/nxtbooks/aas/st_202103
https://www.nxtbook.com/nxtbooks/aas/st_202102
https://www.nxtbook.com/nxtbooks/aas/st_202101
https://www.nxtbook.com/nxtbooks/aas/skywatch_2021
https://www.nxtbook.com/nxtbooks/aas/st_202012
https://www.nxtbook.com/nxtbooks/aas/st_202011
https://www.nxtbook.com/nxtbooks/aas/st_202010
https://www.nxtbook.com/nxtbooks/aas/st_202009
https://www.nxtbook.com/nxtbooks/aas/st_202008
https://www.nxtbook.com/nxtbooks/aas/st_202007
https://www.nxtbook.com/nxtbooks/aas/st_202006
https://www.nxtbook.com/nxtbooks/aas/st_202005
https://www.nxtbook.com/nxtbooks/aas/st_202004
https://www.nxtbook.com/nxtbooks/aas/st_202003
https://www.nxtbook.com/nxtbooks/aas/st_202002
https://www.nxtbook.com/nxtbooks/aas/st_202001
https://www.nxtbook.com/nxtbooks/aas/st_201912
https://www.nxtbook.com/nxtbooks/aas/st_201911
https://www.nxtbook.com/nxtbooks/aas/st_201910
https://www.nxtbook.com/nxtbooks/aas/st_201909
https://www.nxtbook.com/nxtbooks/aas/st_201908
https://www.nxtbook.com/nxtbooks/aas/st_201907
https://www.nxtbook.com/nxtbooks/aas/st_201906
https://www.nxtbook.com/nxtbooks/aas/st_201905
https://www.nxtbook.com/nxtbooks/aas/st_201904
https://www.nxtbook.com/nxtbooks/aas/st_201903
https://www.nxtbook.com/nxtbooks/aas/st_201902
https://www.nxtbook.com/nxtbooks/aas/st_201901
https://www.nxtbook.com/nxtbooks/aas/st_201812
https://www.nxtbook.com/nxtbooks/aas/st_201811
https://www.nxtbook.com/nxtbooks/aas/st_201810
https://www.nxtbook.com/nxtbooks/aas/st_201809
https://www.nxtbook.com/nxtbooks/aas/st_201808
https://www.nxtbook.com/nxtbooks/aas/st_201807
https://www.nxtbook.com/nxtbooks/aas/st_201806
https://www.nxtbook.com/nxtbooks/aas/st_201805
https://www.nxtbook.com/nxtbooks/aas/st_201804
https://www.nxtbook.com/nxtbooks/aas/st_201803
https://www.nxtbook.com/nxtbooks/aas/st_201802
https://www.nxtbook.com/nxtbooks/aas/st_201801
https://www.nxtbook.com/nxtbooks/aas/st_201712
https://www.nxtbook.com/nxtbooks/aas/st_201711
https://www.nxtbook.com/nxtbooks/aas/st_201710
https://www.nxtbook.com/nxtbooks/aas/st_201709
https://www.nxtbook.com/nxtbooks/aas/st_201708
https://www.nxtbook.com/nxtbooks/aas/st_201707
https://www.nxtbook.com/nxtbooks/aas/st_201706
https://www.nxtbook.com/nxtbooks/aas/st_201705
https://www.nxtbook.com/nxtbooks/aas/st_201704
https://www.nxtbook.com/nxtbooks/aas/st_201703
https://www.nxtbook.com/nxtbooks/aas/st_201702
https://www.nxtbook.com/nxtbooks/aas/st_201701
https://www.nxtbook.com/nxtbooks/aas/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201611
https://www.nxtbook.com/nxtbooks/newtrack/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201610
https://www.nxtbook.com/nxtbooks/aas/st_201609
https://www.nxtbook.com/nxtbooks/aas/st_201608
https://www.nxtbook.com/nxtbooks/aas/st_201607
https://www.nxtbook.com/nxtbooks/aas/st_201606
https://www.nxtbook.com/nxtbooks/aas/st_201605
https://www.nxtbook.com/nxtbooks/aas/st_201604
https://www.nxtbook.com/nxtbooks/aas/st_201603
https://www.nxtbook.com/nxtbooks/aas/st_201602
https://www.nxtbook.com/nxtbooks/aas/st_201601
https://www.nxtbook.com/nxtbooks/aas/st_201512
https://www.nxtbook.com/nxtbooks/aas/st_201511
https://www.nxtbook.com/nxtbooks/aas/st_201510
https://www.nxtbook.com/nxtbooks/aas/st_201509
https://www.nxtbook.com/nxtbooks/aas/st_201508
https://www.nxtbook.com/nxtbooks/aas/st_201507
https://www.nxtbook.com/nxtbooks/aas/st_201506
https://www.nxtbook.com/nxtbooks/aas/st_201505
https://www.nxtbook.com/nxtbooks/aas/st_201504
https://www.nxtbook.com/nxtbooks/aas/st_201503
https://www.nxtbook.com/nxtbooks/aas/st_201502
https://www.nxtbook.com/nxtbooks/aas/st_201501
https://www.nxtbook.com/nxtbooks/aas/st_201412
https://www.nxtbook.com/nxtbooks/aas/st_201411
https://www.nxtbook.com/nxtbooks/aas/st_201410
https://www.nxtbook.com/nxtbooks/aas/st_201409
https://www.nxtbook.com/nxtbooks/aas/st_201408
https://www.nxtbook.com/nxtbooks/aas/st_201407
https://www.nxtbook.com/nxtbooks/aas/st_201406
https://www.nxtbook.com/nxtbooks/aas/st_mars
https://www.nxtbook.com/nxtbooks/aas/st_201405
https://www.nxtbook.com/nxtbooks/aas/st_201404
https://www.nxtbook.com/nxtbooks/aas/st_201403
https://www.nxtbook.com/nxtbooks/aas/st_201402
https://www.nxtbook.com/nxtbooks/aas/st_201401
https://www.nxtbook.com/nxtbooks/aas/st_201312
https://www.nxtbook.com/nxtbooks/aas/st_201311
https://www.nxtbook.com/nxtbooks/aas/st_201310
https://www.nxtbook.com/nxtbooks/aas/st_201309
https://www.nxtbook.com/nxtbooks/aas/st_201308
https://www.nxtbook.com/nxtbooks/aas/st_201307
https://www.nxtbook.com/nxtbooks/aas/st_201306
https://www.nxtbook.com/nxtbooks/aas/st_201305
https://www.nxtbook.com/nxtbooks/aas/st_201304
https://www.nxtbook.com/nxtbooks/aas/st_201303
https://www.nxtbook.com/nxtbooks/aas/st_201302
https://www.nxtbook.com/nxtbooks/aas/st_201301
https://www.nxtbook.com/nxtbooks/aas/st_201212
https://www.nxtbook.com/nxtbooks/aas/st_201211
https://www.nxtbook.com/nxtbooks/aas/st_201210
https://www.nxtbook.com/nxtbooks/aas/st_201209
https://www.nxtbook.com/nxtbooks/aas/st_201208
https://www.nxtbook.com/nxtbooks/aas/st_201207
https://www.nxtbook.com/nxtbooks/aas/st_201206
https://www.nxtbook.com/nxtbooks/aas/st_201205
https://www.nxtbook.com/nxtbooks/aas/st_201204
https://www.nxtbook.com/nxtbooks/aas/st_201203
https://www.nxtbook.com/nxtbooks/aas/st_201202
https://www.nxtbook.com/nxtbooks/aas/st_201201
https://www.nxtbook.com/nxtbooks/aas/st_201112
https://www.nxtbook.com/nxtbooks/aas/st_201111
https://www.nxtbook.com/nxtbooks/aas/st_201110
https://www.nxtbook.com/nxtbooks/aas/st_201109
https://www.nxtbook.com/nxtbooks/aas/st_201108
https://www.nxtbook.com/nxtbooks/aas/st_201107
https://www.nxtbook.com/nxtbooks/aas/st_201106
https://www.nxtbook.com/nxtbooks/aas/st_201105
https://www.nxtbook.com/nxtbooks/aas/st_201104
https://www.nxtbook.com/nxtbooks/aas/st_201103
https://www.nxtbook.com/nxtbooks/aas/st_201102
https://www.nxtbook.com/nxtbooks/aas/st_201101
https://www.nxtbook.com/nxtbooks/aas/st_201012
https://www.nxtbook.com/nxtbooks/aas/st_201011
https://www.nxtbook.com/nxtbooks/aas/st_201010
https://www.nxtbook.com/nxtbooks/aas/st_201009
https://www.nxtbook.com/nxtbooks/aas/st_201008
https://www.nxtbook.com/nxtbooks/aas/st_201007
https://www.nxtbook.com/nxtbooks/aas/st_201006
https://www.nxtbook.com/nxtbooks/aas/st_201005
https://www.nxtbook.com/nxtbooks/aas/st_201004
https://www.nxtbook.com/nxtbooks/aas/st_201003
https://www.nxtbook.com/nxtbooks/aas/st_201002
https://www.nxtbook.com/nxtbooks/aas/st_201001
https://www.nxtbookmedia.com