As it is with pretty much all religious / spiritual texts, there’s a direct and dogmatic way to read this chapter, and there’s a poetic and symbolic way to read this chapter. And as with our real world counterparts, the direct way will pretty much fall apart if you know anything about science. Thing is, even Tolkien knew that. He was never really happy with this one, but by his own admission, he did try to get it as close to reality as he could and still be fantasy because Arda is our own Earth, and he was not a science denier. At the same time, the biggest grudge Tolkien had with science is that it dismissed myth out of hand completely. This is where the professor makes his play to reconcile the two ideas. It’s not entirely successful in my mind, but I do appreciate the attempt all the same.
Following the death of the Trees, the Valar mourn, maintaining council, but mostly as a formality to allow themselves to grieve together. Then they are spurred back into action when they learn the Noldor have reached Middle-Earth. Attempts to revive the Trees fail, resulting only in one last flower from each of them, which are hallowed.
The Valar discuss open war upon Morgoth, but such a fight could greatly damage the world and possibly kill mortals, a concern since they suspect the arrival of Man is not long in coming. The vessels created for the last flowers of the Trees, they decide, will be placed in the sky as the Moon and the Sun. The entire process is done by teamwork.
The ship of the moon is steered by a Maia called Tilion, the Sun by Arien. They were given equidistant arcs to follow, but Tilion, attracted by the beauty of Arien, is unsteady in his course as he tries to get ever closer. The lights begin on a path from west to east, and back and forth, but the Valar change the course to allow the world to sleep and rest. The new lights can never rival the brilliance of the Trees.
Morgoth hates the lights. Of course he does. He tries to block it out with smoke, sends his agents to attack Tilion… nothing meets with success. He finds he is afraid of the power of Arien, and discovers that his agents combined, though they all draw their power from him, they do not have the power en masse to overtake her.
The attack on Tilion is seen by the Valar, and Valinor is secured. The Pelóri are raised even higher and become impassable. The Calacirya remains open for those Eldar who are loyal to Valinor, protected by towers and armies. Enchanted Isles are set in the sea to obscure the route to Aman.
It’s important to note that the Moon rises before the Sun, just as the silver Tree was lit before the golden Tree. There’s symmetry there. The Moon relates to the Elves, who even now are already fading. Their time is over. Seems like such a short time until we remember that three ages have passed, numbering thousands of years. The sun relates to the rising of Men who, in their ability to flourish in daylight, stand in contrast to the Elves (who flourish in starlight), the Dwarves (who dwell beneath the earth), and the agents of Morgoth who live by Darkness. It’s also important to note that Morgoth’s agents are also in a decline of power, as Morgoth himself is. As we will see, and as we have seen in both The Hobbit and The Lord of the Rings, strength in numbers is what most of them rely upon. It is the same weakness to light that we’ll see in both Orcs and Trolls, and indeed what we’ll see in Gollum as the One Ring works its malice upon him. And yet… the Sun is not as powerful as the Tree it sprang from, not by far.
With the ignition of the Moon and Sun, we begin in earnest the First Age (of the Sun).