Earth's Vital Statistics ( Earth Science)

Age

: 4.543 billion years old

Equatorial circumference:

40,075 km

Equatorial radius:

: 6,378 km

Polar radius

6,356 km

Total mass:

: 5.972 x 10 24 kg

Total volume

1.08 x 10 12 km3

Total surface area:

5.10 x 10 8 km2

Average density

5.513 g/cm3

Atmosphere

The atmosphere is a collective layer of gas that envelopes the Earth. It can be further divided into different layers based on characteristics.

The atmosphere is essential to life on Earth because (1) It shields the Earth and its inhabitants from harmful ultraviolet (UV) radiation from the Sun;

(2) maintains the warmth of the Earth’s surface; and

(3) contains all of the essential gasses needed to support life. More about the atmosphere will be covered later on.

Hydrosphere

The hydrosphere refers to the bodies of water consisting of freely flowing bodies of water found on the surface of the Earth, as well as water reservoirs stored below the ground as groundwater.

This sphere covers nearly 71% of the Earth’s surface.

Nearly 97.4% of the water in the hydrosphere is composed of saline or salt water found in vast oceans covering the Earth. The remaining 2.6% is made up of fresh water, mostly stored in glaciers and ice caps and underground reservoirs.

Although freshwater makes up only a tiny fraction of the total, we and other Earth residents rely on it for surviva

Biosphere.

The biosphere refers to the narrow band on the Earth’s surface where all biological life resides. This could range from bustling cities, lush tropical rainforests, arid deserts, or even extreme environments like the bottom of the ocean floor

Geosphere

The __________ is the largest out of all the spheres— extending from the surface of the Earth down to its center. It is composed of external processes that we can observe on the surface and internal processes that happen deep within.