For values of “much younger” that are probably only meaningful to geologists.
New research suggests that previous estimates of the time needed for Earth to accrete may have been too short. It had been thought that the process would have taken about 30 million years, but an analysis of isotopes from meteorites seems to indicate that it may have taken as much as 100 million years.
One of the researchers is quoted in the article thusly:
“We estimate that makes it about 4.467 billion years old – a mere youngster compared with the 4.537 billion-year-old planet we had previously imagined.”
Um, yeah. I don’t know about you, but to me the difference between 4.537 billion years and 4.467 billion years seems kind of inconsequential when you’re talking about, y’know, billions of years.
(I also like Jesus and Mo’s take on the subject.)