I now discover that Lord Rayleigh already has two craters named after him. Here's a picture of the lunar crater Rayleigh . It's on the edge of the Moon , as seen from Earth- so it's hard to see it. It's quite big though - 107 km across.
And here's a picture of the Martian crater Rayleigh. It's quite near the Martian south pole , and even has some frost in it sometimes. It's bigger than the lunar crater - 153 km across.