DEREK: I had submitted several versions of this puzzle to Will and Joel to the extent that they (kindly) nudged me in the direction of finding a collaborator.

I had worked with Sarah previously on a few puzzling endeavours, including a small diorama for a National Puzzlers' League convention event. It has always been very enjoyable working with her, a theme maven who doesn't let me get away with crummy entries, and again our collaboration worked out well.

I was particularly bogged down with chunky groups of black squares for the rays of the SUN, but she streamlined the layout of the whole grid and made everything fall into place.

I am indebted to her for helping make this puzzle come together. Thanks.

SARAH: This is our second New York Times collaboration. I met Derek, a successful new constructor, in 2008, at an NPL convention. We thought it would be fun to work on a puzzle together.

When collaborating, we always choose to work with wordplay themes as well as those that require unusual grids. This astrological theme was Derek's and Derek's alone. In my opinion, he is a grid master. In this venture, he combined circular THE WORLDs along with a SUNny central rebus.

We worked together on some grid manipulation to lessen the black square count as well to make the puzzle more pleasing to the eye. It was fun getting the puzzle publication-ready and is always fun working with Derek.

What a neat visual! Something so pretty about those four diagonals leading out to the four sets of circles. Eye-catching, artistic pattern.

We get THE WORLD circling in four places … that must mean "around THE WORLD"? ... with the SUN in the middle of the puzzle? It didn't all click for me, as I wasn't sure why around THE WORLD was circling … around what? And why were four worlds circling the SUN?

I'm sure my comics-ubergeek brother will clue me in, telling me about some fictional star system with four worlds circling the SUN. It'd be so awesome if it were called ETRURIA or ASASON!

Speaking of those, it's so tough to avoid obscure or esoteric entries when filling around so many circled letters. Although Derek and Sarah have a lot of flexibility in 1.) which way THE WORLD revolves and 2.) where to start it, it's highly likely that exactly zero of the 16 possibilities would have been easy to fill around.

I was all set to say how impressed I was with the NE corner, chock full of BATH TOY, PRELUDE, OODLES, and … ASASON? Oof. You can love someone like a son, you can think of someone as a son, but AS A SON by itself would be a puzzle-killer for me.

These types of heavily-constrained biggish corners tend to need entries with -ER and -EST additions, and/or RE- prefixes. The SW corner is a perfect example. EASIEST is a fine word, but ADORERS and LITHEST are both iffy.

It's common for these biggish, constrained corners to need short gluey bits, too. I don't mind an innocuous (and easily gettable) ESE. Maybe I should have known Jack SOO, one of the few Asian actors of his time? DIECI is … Italian for ten? Herb RITTS? Hmm.

This sort of puzzle with heavy constraints — so many letters fixed into place all over the grid — is so hard to pull off well. All in all, I would have liked a bigger payoff, something that made more sense of the rationale why four THE WORLDs were going around the SUN.

Still, what a great first impression the blank grid made on me.

ADDED NOTE: Astute reader Seth Cohen pointed out that THE WORLD rotates regularly, shifting two spots at each new position ... sort of how our world rotates as it revolves around the SUN. D'oh, can't believe I missed that. That does make much more sense now. I'm embarrassed to admit that I stared at everything for a good 10 minutes but couldn't piece together exactly what was going on.