Sky & Telescope - USA (2019-09)

AT A GLANCE by Shannon Hall and Terri Dubé

2,333 confi rmed planets discovered by Kepler

361 confi rmed planets discovered by K

p

MERCURY-SIZE

PLANETS

0.03 – 0.4 RE

10 -5 – 0.1 ME

Size cutoffs:

Planet sizes not to scale Mass cutoffs:

p

MARS-SIZE

PLANETS

0.4 – 0.8 RE

0.1 – 0.5 ME

p

EARTH-SIZE

PLANETS

0.8 – 1.5 RE

0.5 – 5 ME

592

6

3

2

57

0

0

6

0

35 COLD Planets

35 discovered by Kepler

0 discovered by K

Too far for liquid surface H 2 O

2,586 HOT Planets

2,229 discovered by Kepler

357 discovered by K

Too close for liquid surface H 2 O

73 WARM Planets

69 discovered by Kepler

4 discovered by K

Right place for liquid surface H 2 O

16 SEPTEMBER 2019 • SKY & TELESCOPE

TOTAL PLANETS

CONFIRMED as of June 2019

NASA’s Kepler space telescope found that exoplanets exist in troves.

Although the mission ended in 2018 when the telescope ran out of fuel,

discoveries from both Kepler (the mission’s fi rst leg) and K2 (second leg)

are still pouring in. The tallies don’t include planets detected with Kepler

but discovered with other facilities.

Kepler’s Discoveries

Kepler’s Field

of View

116 square degrees

2,

Astrophysical Targets

Kepler has proved to be a game-

changer for astrophysics as well. Its

data have enabled astronomers to

peer deep within stars, track superno-

vae, and image planets, moons, and

asteroids in our own backyard.

67

SUPERNOVAE

6 (Kepler),

61 (K2)

81

OBJECTS BEYOND

NEPTUNE

0 (Kepler), 81 (K2)

4

SOLAR SYSTEM

PLANETS

0 (Kepler), 4 (K2)

21

COMETS

0 (Kepler),

21 (K2)