Exoplanet Origins
Exoplanets form from gas and _________
Dust
These are rocky planets about the size of Earth or Mars.
terrestrial planets
Exoplanets orbit stars outside of this system.
Our solar system
All exoplanets are the same size.
False
This was the first confirmed exoplanet found around a Sun-like star.
51 Pegasi B
This process explains how tiny particles stick together and grow into planets.
Core Accretion
These are massive gas planets found very close to their stars.
hot Jupiters
Some exoplanets are so close to their star that this only lasts a few days
Orbit
Exoplanets can orbit more than one star.
True
This year marked the discovery of 51 Pegasi b.
1995
This faster process forms planets when parts of the disk collapse quickly.
gravitational instability
These are planets bigger than Earth but smaller than Neptune
super-Earths
Some exoplanets orbit this many stars at once.
two
Planets can form when gas and dust collapse together
True
This NASA telescope revealed that planets are more common than stars.
Kepler
This solar system is used as the model for how exoplanets form.
our solar system
These are planets with thick gas layers but smaller than Jupiter
mini-Neptunes
Exoplanets wandering alone with no star are called this
rogue (or sunless) planets
Rogue planets still orbit a star
False
According to Kepler data, there may be over this many planets in our galaxy.
1 trillion
Both core accretion and gravitational instability start with this material circling a star.
protoplanetary disk
This zone is where planets might have liquid water
habitable zone
These can be bigger than Jupiter or as small as Mars
the sizes of exoplanets
Exoplanets only form in other galaxies
False
Kepler showed that these kinds of planets are very common.
Earth Sized Planets