Physics & Astronomy
Europa
100%
ice
57%
oceans
45%
solar system
37%
comets
36%
delivery
25%
Halley's comet
21%
exobiology
21%
electric power
18%
clathrates
18%
organic solids
18%
amino acids
17%
Earth rotation
17%
natural satellites
15%
explosions
15%
coma
15%
asteroids
15%
mars
14%
irradiation
13%
heating
12%
hydrocarbons
12%
extraterrestrial oceans
11%
planetary protection
10%
crusts
10%
Earth atmosphere
10%
plutonium 239
10%
meteorite collisions
10%
homopolar generators
10%
Jupiter (planet)
10%
water
10%
Earth mantle
9%
charged particles
9%
energy sources
9%
salinity
9%
induction heating
9%
Poynting theorem
9%
unified field theory
8%
Enceladus
8%
loss of coolant
8%
planetary surfaces
8%
Earth surface
8%
whales
8%
aldehydes
8%
thermal emission
8%
estimates
8%
infrared spectra
8%
magnetic induction
8%
hypervelocity
7%
critical mass
7%
habitability
7%
magnetic fields
7%
space exploration
7%
spores
7%
chemical energy
7%
extraterrestrial life
7%
lightning
7%
planetary systems
7%
information theory
6%
Hubble Space Telescope
6%
abrasives
6%
hydrates
6%
eclipses
6%
Joule heating
6%
radar
6%
Lorentz force
6%
energy conservation
6%
alkanes
6%
molecules
6%
hazards
6%
superconducting magnets
6%
causes
6%
synthesis
6%
bombardment
6%
ambiguity
5%
embedding
5%
uranium
5%
gravitational fields
5%
erosion
5%
alkenes
5%
carbon
5%
extraterrestrial environments
5%
atmospheres
5%
contamination
5%
relativity
5%
meteorites
5%
liquids
5%
infrared spectroscopy
5%
conductors
5%
Earth & Environmental Sciences
Europa
82%
ice
34%
comet
33%
solar system
31%
origin of life
26%
early Earth
24%
ocean
22%
heating
18%
clathrate
16%
amino acid
14%
irradiation
14%
Moon
13%
shell
13%
energy source
12%
Mars
12%
meteorite
10%
energy
9%
oxidant
9%
planetary satellite
9%
exobiology
9%
particle
8%
Enceladus
8%
racemization
8%
Jupiter
8%
impactor
8%
planetary surface
7%
organic matter
7%
saltation
7%
obliquity
6%
treaty
6%
hydrocarbon
6%
planetary atmosphere
6%
disequilibrium
6%
infrared spectroscopy
6%
mantle
6%
lightning
5%
RNA
5%
crust
5%
spore
5%
persistence
5%
dust
5%
aldehyde
5%