The Super Earths
01- K-11
02- Migrating Worlds
03- Gliese 581
04- Goldilocks
05- 51 Pegasi
06- Doppler Effect
07- Rhythmic Shift
08- Eccentric Giants
09- Transitters
10- Mu Arae
11- Intermediate World
12- Worlds Observed
13- Extra Solar Earths
14- Migrant Worlds
15- Accretion
16- Core Accretion
17- Disk Erosion
18- Planetary Embryos
19- The Protected Zone
20- Ecosphere
21- Ecosphere II
22- Beta Pictoris
23- Vanquishing Starlight
24- Red Edge / Earth Shine
25- Distant Continents
26- The Age of Stars
   

17 - Disk Erosion

Click here for enlarged diagram

 

Some theorists feel that the gas needed for Core Accretion may not linger in the disk long enough.

In the theory of ‘Gravitational Instability’, gravity causes the disk of gas and dust to collapse into dense clouds, which shrink and form solid cores within a few thousand years. The rest of the cloud contracting to form the gas giant around the core could take less than a million years.

If more giant extrasolar gas planets continue to be found, this would imply that they regularly win the race against this erosion of the disk.

 
  Alan Lambert 2011