However, this puzzle has a simple key. Life forms, such as seeds, present or yet to arrive on the soil's surface, require nutrients. To germinate, they require water, wherein they rely on the nutrients within the seed for their first tentative germination efforts. After establishing a minimal root, the germinating plant seeks not only water, but nutrients. Lacking either of these, the germinating seed dies.
Life is started, but starved early on.
In the case of the landing spot of spaceships from another dimension, the lack is not water, but the availability of nutrients. This is a concept unknown to Earth scientists at this time. However, it relates to density switching, a concept which they are also unfamiliar with. When moving into another density, as from the 4th Density to the 3rd, in order to appear within the consciousness of humans, several steps are required. One is to reserve a place in the density to be moved into.