Sky & Telescope - USA (2019-09)

p

SUPER-EARTHS &

MINI-NEPTUNES

1.5 – 2.5 RE

5 – 10 ME

p

NEPTUNE-SIZE

PLANETS

2.5 – 6.0 RE

10 – 50 ME

p

JUPITER-SIZE

PLANETS

6 RE and up

50 ME and up

752

181

25

12

11

7

1, 0 0 2

30

8

Is Anyone

There?

skyandtelescope.com • SEPTEMBER 2019 17

PLANETS: ISTOCK / GETTY IMAGES PLUS; STAR

TYPES: PANUWAT SRIJANTAWONG / THE NOUN

PROJECT (4); SUPERNOVAE: ANDRÉ LUIZ GOLLO

/ THE NOUN PROJECT; SOLAR MASS STAR

PLANETS: FLATART / THE NOUN PROJECT; GAL-

AXY: LUIZ CARVALHO / THE NOUN PROJECT;

ASTEROID: FLATART / THE NOUN PROJECT;

COMET: RALF SCHMITZER / THE NOUN PROJ-

ECT; SOLAR SYSTEM PLANETS: EUCALYP / THE

NOUN PROJECT

11

around

M dwarf

stars

14

around

K stars

5

around

G stars

1

around

F stars

Kepler and K2 found

31 potentially

habitable planets

2,

papers published

before 2019

(breakdown by

1,572 astrophysics

and 1,404 exoplanets)

9.

years in space

(8.4 years of full

science operations)

75,162,
Kepler light
curves

1, 2 0 6

potentially

rocky planets

2

missions

complete

12

kilograms

of fuel used

15 0

million

kilometers away

644

PLANETS THAT ORBIT

SUN-SIZE STARS

604 (Kepler), 40 (K2)

530,

STARS

200,038 (Kepler),

330,468 (K2)

268

ASTEROIDS

0 (Kepler),

268 (K2)

78,

GALAXIES

400 (Kepler),

78,348 (K2)

The (-est)

A few of the exoplanet

records set by Kepler/K

Closest worlds

detected:

Kepler-444 b, c, d, e, and f

116. 5 l i g h t- y e a r s

Farthest world

detected:

Kepler-40b

8,800 light-years

Shortest year: K2-317b

0.18 Earth day

Longest year: KIC 3558849b

1,322 Earth days

M

K

G

F

SOURCE: PLANETARY HABITABILITY LABORA-

TORY, UNIVERSITY OF PUERTO RICO, ARECIBO