They can do it many ways:
carbon dating
Age, weight, blood tests.
They see the height of growth of tge tree From Mr Hogge
Go into space and look at the amount of circles (just like what you do to a tree)
fossill
At age sixteen he started as a scientist.
he became a scientist at the age of 16
no
albert became a scientist at the age of 2yrs old
Probably Lucy, the hominid, or Sue, the T-Rex.
he became a scientist at the age of 16
Because it comes from other planets and earth is approx the same age as the other planets so they work it out bye the dust and how hot it is I think.