Cornfields specifically seem to attract this stuff way more than random chance would suggest. There's something about them - the height, the density, the way sound behaves differently around them - that either draws things in or just makes them easier to spot against the sky.
What was the size roughly? Like were we talking car-sized or bigger? And did it make any sound at all or was that the creepy part, the total silence? Because in my experience the silent ones are the ones that stick with you the longest. Noise you can rationalise. Silence just sits in your chest.
Also worth noting whether any animals were acting weird beforehand. Dogs especially. Had a shadow phenomenon near me a few years back outside Inverness and the neighbour's collie was going absolutely mental for about 20 minutes before anything visible happened. They always know first.
Post more details when you can, people here will actually engage with this properly rather than just telling you it was a drone or swamp gas or whatever.