Sentences with phrase «vary over tens of thousands of years»
That's a rare bit of evidence of how much black - hole feeding can vary over tens of thousands of years.
https://www.newscientist.com/ Not exact matches
«There must have been regional climate and chemical conditions that varied in time and space,» he says, adding that this would occur as the tilt of Mars's spin axis changed over tens of thousands of years, a wobble caused by the lack of a massive moon to stabilise the planet.
The microbiota, which evolved over tens of thousands of years alongside their human hosts, constitutes a complex and diverse community whose exact composition varies from person to person.