Metric System

Metric System is in General Things.

Distance Metric System

Distances Greater Than a Metre


Gigametre. One thousand million metres. Abbreviation Gm.


Kilometre. One thousand metres. Abbreviation Km.

Mercury ...

is, on average, 0.39 AUs from the Sun.

has a diameter of 2440 Kms; around one third of the Earth.

has an eccentic orbit with the closest distance to the Sun being 47 million kilometers, and the farthest distance being 70 million kilometers.

has a year of 88 days.

spins on its axis every 59 days.

is tilted at 2 degrees.

formed around 4.5 Billion years ago.


is, on average, 0.67 AUs from the Sun.

has a diameter of 12.104 Kms; 95% of that of Earth.

has a year of 225 Days.

has a tilt of 3 degrees.

Is known as both the Morning Star and the Evening Star since it is brightest from the Earth at both sunrise and sunset.


Megametre. One million metres. Abbreviation Mm.


Metre. The standard unit of distance in the Metric System.

Mass Metric System


Gram. The standard unit of distance in the Metric System. Abbreviated as g.

Masses Greater Than a Gram


Exagram. One million million million grams.


Gigagram. One thousand million grams.


Kilogram. One thousand grams.


Megagram. One million grams.


Petagram. One thousand million million grams.


Teragram. One million million grams.


Yottagram. One million million million million grams.


Zettagram. One thousand million million million grams. It is abbreviated as Zgs, or, possibly g21.

Non-Metric Units

Non-Metric Distances

Astronomical Unit Length

Astronomical Unit Length. 149,597,870,700 metres ie 150 Gigametres. The average distance from the Earth to the Sun.

Light Year

Light Year. The distance travelled by light in one year. 9.46×1012 km.

The Milky Way Galaxy is one of many galaxies that form the Universe, each of which, on average, contains one hundred million stars. NASA has estimated there are 200 billion galaxies with the total number of stars being between 1019 and 1024 stars.

The Milky Way contains between 100 and 400 billion stars, and around the same number of planets. The Solar System is located 27,000 light-years from the centre of the Milky Way ie 255,420,000,000,000,000 Km.