Rain iron on the young Earth

1 · Explain the spared nitrogen

Beginner

Nitrogen likes metal more than hydrogen does, yet only 4% of it ends up in the core. Why?

It arrives later than hydrogen, after most of the iron rain has fallen It barely dissolves in the magma, out of reach of the falling metal The falling metal is already loaded with hydrogen and takes no more

2 · Double the iron's appetite

The study's limiting formula, for a gas fully dissolved in the magma and delivered before the planet reaches mass M₀: the share left outside the core is (M₀/M)^(D × core/mantle), where D measures the metal's appetite for that gas. Hydrogen delivered before 0.02 Earth masses, planet finished at 0.64, core 30% against 70% mantle, D = 1: about 23% remains.

Intermediate

What if iron liked hydrogen twice as much, D = 2?

About 11% About 23% About 5%

3 · Raise the hydrogen budget

The study sets its total hydrogen from what is thought to hide in today's core: the equivalent of 9 Earth oceans in the reference model, 45 in the high variant.

Expert

With 45 oceans instead of 9, what share of the hydrogen does the core swallow during pebble growth?

Less, about 44% Same, about 70% More, nearly all

4 · Dissolve twice as much CO

The solubility of carbon monoxide in magma is the most influential and least measured input. Suppose new experiments find it twice as large.

Expert

In the pebble scenario, the carbon left outside the core becomes…

Halved, or close to it Unchanged, or close to it Quartered, or close to it

Iron rain over

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