B Earth may owe its birth to a solar eruption

[CygnusX-1]

Earth may have been born in a huge flare-up of the young sun

by Ken Croswell

It’s not easy to make Earth. Most of the explanations for how our planet formed have troubling problems. But if a new idea is right, we can thank a hyperactive young sun for Earth’s existence, plus solve a long-standing mystery about Mars.

Read more at New Scientist .

 

[mfb]

The explanation for Mars sounds odd. Sticking together is only relevant at sizes of at most a few kilometers (and most important before the http://www.mpia.de/~dullemon/group/overview.php), afterwards gravity takes over. Mars is larger than that, so something did form.

I had a look at the original research paper. Less sticky material would reduce the number of planetesimals and make the process of their formation slower. Both gives the remaining dust more chance to escape.

 

[rootone]

It seems to me that the reason why Mars is small is because Jupiter is big.
Mars sort of 'got lucky' to not end up not being just another moon of Jupiter,

 

[CygnusX-1]

As the New Scientist article states, the standard theory concerning Mars--going all the way back to 1755--is that the planet is small because of Jupiter.

But in the new theory, Mars is small because the solar flare-up didn't heat dust grains at its position much, so they didn't stick together much, so they could form only a planet much smaller than Earth.