Sky & Telescope - September 2020 - 35

First Exomoons
A handful of scientists are attempting to discover the first moons outside our solar system -
a finding that would be transformative, yet remains elusive.

should exist in abundance throughout
the galaxy - perhaps
reaching numbers as
high as tens of
billions.

sk yandtelescope.org * SEP TEMBER 2 02 0

ILLUSTR ATIONS: LE AH TISCIONE / S&T

D

didate, a Neptune-size world that garnered much attention in
avid Kipping was almost shaking with excitement.
2018, has now slipped through astronomers' fingers.
He was staring at a plot on his computer screen with
And yet Kipping and a few others trudge onward, aware
a peculiar dip that kept reappearing no matter how
that the first discovery, though teasingly difficult, would be
he processed the data. It looked like the first glimpse of a
transformative - even Nobel prize-worthy.
moon beyond the solar system.
But first, they have to find one.
He left his desk and went for a walk. "I had to sit on a bench
and take deep breaths to try and center myself a bit because I
was just, like, crazily excited about it - thinking 'This is gonna
Attempting the Impossible
be amazing, this is gonna change my life,'" he says.
If our solar system is any guide, moons should exist in abunBut Kipping, then a postdoc at Harvard University, also
dance throughout the galaxy - perhaps reaching numbers
knew that his excitement might be clouding his judgment.
as high as tens of billions. To discover them, Kipping started
Once he had talked himself into being more objective, he
digging in 2011 through publicly available data from Kepler,
returned to his office. And after a few days, another astronoNASA's prolific exoplanet-finding spacecraft. But the search
mer helped him discover that the exomoon was nothing
has not been easy.
more than an artifact produced when the telescope vibrated a
Kepler launched in 2009 and watched 150,000 stars near
little. He was devastated.
the constellation Cygnus for four years in an effort to spot
Unfortunately, it wasn't the only heartache of Kipping's
transits: instances when a planet passes in front of its host
career - several exomoons have appeared on his computer
star and blots out a small fraction of starlight. That manifests
screen before vanishing into thin air.
as a recurring dip in a star's light curve, its brightness plotted
That appears to be a common trademark of alien satellites.
over time. The mission was a wild success, and the telescope
Even the few candidates that have managed to make it onto
glimpsed roughly 2,500 confirmed distant planets.
the pages of prominent journals have remained evasive.
If any of those happen to host moons, their presSigns of a volcanically active exomoon might be
ence should have a similar effect. If the exomoon
easily explained away. The same is true for one
passed in front of the star before or after
possibly floating freely through space with its
the planet, for example, there would be a
planet, as well as the satellite that might
second, tinier dip in the star's light curve.
If our solar system
have carved a gap in the rings around a
Alternatively, a massive moon could exert
is any guide, moons
Saturn-like exoplanet. Even the best cana gravitational tug strong enough to

35


http://www.skyandtelescope.org

Sky & Telescope - September 2020

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

Contents
Sky & Telescope - September 2020 - Cover1
Sky & Telescope - September 2020 - Cover2
Sky & Telescope - September 2020 - 1
Sky & Telescope - September 2020 - Contents
Sky & Telescope - September 2020 - 3
Sky & Telescope - September 2020 - 4
Sky & Telescope - September 2020 - 5
Sky & Telescope - September 2020 - 6
Sky & Telescope - September 2020 - 7
Sky & Telescope - September 2020 - 8
Sky & Telescope - September 2020 - 9
Sky & Telescope - September 2020 - 10
Sky & Telescope - September 2020 - 11
Sky & Telescope - September 2020 - 12
Sky & Telescope - September 2020 - 13
Sky & Telescope - September 2020 - 14
Sky & Telescope - September 2020 - 15
Sky & Telescope - September 2020 - 16
Sky & Telescope - September 2020 - 17
Sky & Telescope - September 2020 - 18
Sky & Telescope - September 2020 - 19
Sky & Telescope - September 2020 - 20
Sky & Telescope - September 2020 - 21
Sky & Telescope - September 2020 - 22
Sky & Telescope - September 2020 - 23
Sky & Telescope - September 2020 - 24
Sky & Telescope - September 2020 - 25
Sky & Telescope - September 2020 - 26
Sky & Telescope - September 2020 - 27
Sky & Telescope - September 2020 - 28
Sky & Telescope - September 2020 - 29
Sky & Telescope - September 2020 - 30
Sky & Telescope - September 2020 - 31
Sky & Telescope - September 2020 - 32
Sky & Telescope - September 2020 - 33
Sky & Telescope - September 2020 - 34
Sky & Telescope - September 2020 - 35
Sky & Telescope - September 2020 - 36
Sky & Telescope - September 2020 - 37
Sky & Telescope - September 2020 - 38
Sky & Telescope - September 2020 - 39
Sky & Telescope - September 2020 - 40
Sky & Telescope - September 2020 - 41
Sky & Telescope - September 2020 - 42
Sky & Telescope - September 2020 - 43
Sky & Telescope - September 2020 - 44
Sky & Telescope - September 2020 - 45
Sky & Telescope - September 2020 - 46
Sky & Telescope - September 2020 - 47
Sky & Telescope - September 2020 - 48
Sky & Telescope - September 2020 - 49
Sky & Telescope - September 2020 - 50
Sky & Telescope - September 2020 - 51
Sky & Telescope - September 2020 - 52
Sky & Telescope - September 2020 - 53
Sky & Telescope - September 2020 - 54
Sky & Telescope - September 2020 - 55
Sky & Telescope - September 2020 - 56
Sky & Telescope - September 2020 - 57
Sky & Telescope - September 2020 - 58
Sky & Telescope - September 2020 - 59
Sky & Telescope - September 2020 - 60
Sky & Telescope - September 2020 - 61
Sky & Telescope - September 2020 - 62
Sky & Telescope - September 2020 - 63
Sky & Telescope - September 2020 - 64
Sky & Telescope - September 2020 - 65
Sky & Telescope - September 2020 - 66
Sky & Telescope - September 2020 - 67
Sky & Telescope - September 2020 - 68
Sky & Telescope - September 2020 - 69
Sky & Telescope - September 2020 - 70
Sky & Telescope - September 2020 - 71
Sky & Telescope - September 2020 - 72
Sky & Telescope - September 2020 - 73
Sky & Telescope - September 2020 - 74
Sky & Telescope - September 2020 - 75
Sky & Telescope - September 2020 - 76
Sky & Telescope - September 2020 - 77
Sky & Telescope - September 2020 - 78
Sky & Telescope - September 2020 - 79
Sky & Telescope - September 2020 - 80
Sky & Telescope - September 2020 - 81
Sky & Telescope - September 2020 - 82
Sky & Telescope - September 2020 - 83
Sky & Telescope - September 2020 - 84
Sky & Telescope - September 2020 - Cover3
Sky & Telescope - September 2020 - Cover4
https://www.nxtbook.com/nxtbooks/aas/st_202405
https://www.nxtbook.com/nxtbooks/aas/st_202404_qr
https://www.nxtbook.com/nxtbooks/aas/st_202404
https://www.nxtbook.com/nxtbooks/aas/st_202403
https://www.nxtbook.com/nxtbooks/aas/st_202402
https://www.nxtbook.com/nxtbooks/aas/st_202401_aus
https://www.nxtbook.com/nxtbooks/aas/st_202401
https://www.nxtbook.com/nxtbooks/aas/st_202312_aus
https://www.nxtbook.com/nxtbooks/aas/st_202312
https://www.nxtbook.com/nxtbooks/aas/st_202311
https://www.nxtbook.com/nxtbooks/aas/st_202310
https://www.nxtbook.com/nxtbooks/aas/st_202309
https://www.nxtbook.com/nxtbooks/aas/st_202308
https://www.nxtbook.com/nxtbooks/aas/st_202307
https://www.nxtbook.com/nxtbooks/aas/st_202306
https://www.nxtbook.com/nxtbooks/aas/st_202305
https://www.nxtbook.com/nxtbooks/aas/st_202304
https://www.nxtbook.com/nxtbooks/aas/st_202304_qr
https://www.nxtbook.com/nxtbooks/aas/st_202303
https://www.nxtbook.com/nxtbooks/aas/st_202302
https://www.nxtbook.com/nxtbooks/aas/st_202301
https://www.nxtbook.com/nxtbooks/aas/st_202212
https://www.nxtbook.com/nxtbooks/aas/st_202211
https://www.nxtbook.com/nxtbooks/aas/st_202210
https://www.nxtbook.com/nxtbooks/aas/st_202209
https://www.nxtbook.com/nxtbooks/aas/st_202208
https://www.nxtbook.com/nxtbooks/aas/st_202207
https://www.nxtbook.com/nxtbooks/aas/st_202206
https://www.nxtbook.com/nxtbooks/aas/st_202205
https://www.nxtbook.com/nxtbooks/aas/st_202204
https://www.nxtbook.com/nxtbooks/aas/st_202203
https://www.nxtbook.com/nxtbooks/aas/st_202202
https://www.nxtbook.com/nxtbooks/aas/st_202201
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/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