What's happening to my grass? Alien life-force or other?

[LawnMystery]

In the true spirit of Mumsnet, I've attached a photo.

Over the course of several months this circle of dead grass has appeared in my garden - I've no clue what's caused it and speculation in this house is thinking perhaps it's a landing patch for an alien spaceship 👽

For full disclosure and to rule out some other suggestions - nothing has been placed over it, so no paddling pool/trampoline/whatever- its literally a boring grass front garden, not even a shrub in sight.

It's a mystery - whose up for solving it?

Aliens.

Definitely aliens. There's no other explanation.

Tiny alien spacecraft landing pad. Duh

It is probably related to the extreme dry weather. Maybe previous owners had something there that means that the root structure of the grass was not so good so it is more susceptible to stress. Maybe there is even concrete/gravel under that patch. We discovered loads of slabs under the grass at our old house. If you stick a fork in the ground can you get it all the way in?

Leather jackets? Or aliens?

Salt for slugs? Chemicals e.g. bleach in a bucket of cleaning water? A boiling kettle (or five) to sort out an ant's nest? All of these can kill grass.

It looks sort of square, could there be one of those square manhole cover grate things (forgot the proper name) under there?

You'll probably find there is concrete underneath as Sprig1 has said.

I'm going against the grain and voting dog pee