<span>One observation would be the physical size of Russia compared to other countries, despite a lack of visible borders from space. In addition, part of Russia's outline would likely be obscured by the various clouds and objects in the stratosphere; this would allow the astronaut to view potential cloud and weather patterns on earth. Also, an astronaut could see outlines of Russia's geography such as mountain ranges.</span>
Perhaps the answer is "physical characteristics". I am simply making an educated guess, however I do know early philosophers classified organisms into two groups, Plants and Animals, and identified them based on physical characteristics.
Answer:
1. Radiometric dating
2. Relative dating is used to determine the age of fossils or rock layers by by comparing it to similar rocks and fossils of known ages.
3. The youngest rock layers are at the top and the oldest are at the bottom, which is according to the law of superposition.
4. Tribolite and Pecten fossils
Fossils are used to determine the ages of rock layers. Index fossils are the most useful in determining relative aging. Index fossils are of organisms that lived for a short period of time. An index fossil allows a scientist to determine the age of the rock it is in. So if they are found in a particular age, it means they belong in that age.
5. Scientists commonly use radioactive dating methods by using radioactive decay cloak of certain elements such as potassium or carbon to date fossils or rocks.
6. Law of superposition because in terms of finding the age of the rock as an object, all that needs to be identified are the layers of the rock.
7. The nuclear decay of radioactive elements are a process that behaves in a clock-like fashion which makes it a useful tool for determining the exact age of fossils or rocks.
