Expert: Jayendra Upadhye - 5/2/2004

Question
Hello,

Did the rocky dust grains condense out of the solar nebula where the jovian planets are now found? or did they just condense anywhere?

Thanks

Answer
Hi,
Actually The rocky dust grains "condense" or "appear" out of exploding supernovas. The solar nebula in which the sun was formed was part of some stellar nursery - a collection of sun like stars in embryonic stage.
The nuresery itself may have been part of a huge nebula as seen in the orion.
The moment the expanding debris of the supernova cools sufficiently, rocky solds form rodlike or needle like "fingers".
When trapped in the whirling accretion disks of the proto-suns, they loose their momentum to surrounding gas and as a result are "pushed" inwards towards the center.
Also the heating from the embedded star causes the gas to move away from center. this causes a differential in the content of the accretion disk.
The inner regions have "more" rocky material, outer regions "more" gas.
In the end it is only a question of re-arrangement of matter due to the centrifuge effect, and central heating, that's all.
Jayen