Question

day 8 - evaluate: how do asteroid collisions affect the probability of life evolving?
objective:
can model how asteroid impacts influenced earths stability and argue whether life could exist elsewhere under similar
conditions.
the beginning of life on earth
this image shows the oldest rock that contains evidence of life. its striped pattern defines it as a stromatolite formation, a
type of rock formation created by microscopic organisms living in colonies. it comes from an ancient ocean, and has been
determined to have 59% of uranium - 238 remaining.
use the uranium - 238 dating curve below to determine the age of this rock.
how old is the sample, based on this curve?

Explanation:

Step1: Locate 59% on the y - axis

Find the point corresponding to 59% on the "Percent Uranium - 238 remaining" axis.

Step2: Draw a horizontal line to the curve

From the 59% point on the y - axis, draw a horizontal line until it intersects the Uranium - 238 Dating Curve.

Step3: Draw a vertical line from the intersection to the x - axis

From the intersection point on the curve, draw a vertical line down to the "Billions of Years" axis.

Step4: Read the value on the x - axis

The value on the x - axis where the vertical line meets it is the age of the rock.

Answer:

Based on the curve, the rock is approximately 3.25 billion years old.