Significados de periastro en inglés

I think they'll be adequate for anything that happens at periastron.

Not yet, but we're well past periastron now.

There was a project to provide shelters for the periastron storms set up ten years ago.

Mean they always acted this way at periastron?

Three days before periastron, they experienced a small earthquake, a thud followed by rumbling and groaning for about twenty seconds.