LOCAL GROUP OF GALAXIES & EARTHS RELATIVE MOTION.

Astronomy is a strange science. The more we study it, the more philosophical we become and it males us realise that humans do not really count in the massive Universe. 

You know that our Galaxy is known as the Milky Way. But did you know that our galaxy is a part of the Galactic group known as the Local Group?

The Local group consists of over 134 Galaxies. They consist of Milky Way our home galaxy, the Andromeda Galaxy M31, the Triangulam Galaxy M33 and many others.  The Local Group has a total mass of 4*10³⁹ tons and a diameter of 17 million light years.

The 2 largest members of the Local group are the Milky Way Galaxy and the Andromeda Galaxy.

The Milky Way’s satellite system consists of the Large Megallanic Cloud & the Small Megallanic Cloud Galaxies & Sagittarius, Canis Major, Ursa Minor, Draco, Carina, Sextans, Sculptor, Formax, Leo1, Ursa Major all of which are Dwarf galaxies and other galaxies.  

The Adromeda’s (M31) Satellite system consists of M32, M110, NGC 147, Andromeda I, II, III V & VI, VII, VIII Dwarf galaxies & others.

Despite the expansion of the Universe, the local group is moving towards each other due to their mutual gravitational attraction. Due to this, the Milky Way galaxy and the Andromeda Galaxy are coming towards each other at a speed of 120 Km/Sec. In 400 to 500 crore years they would collide with each other and form into a merged super galaxy.

As a whole, the entire Local group is travelling through space at 630 Km/Sec. Galaxies within the local group are drawn towards the massive Virgo Cluster at a speed of 100 to 400 Km/Sec.  

In turn the entire region including the Virgo Cluster is being pulled in by the gravitational tug of the Shapely Super Cluster which is an extremely dense concentration of galaxies 750 million light years away.  

As we are being pulled towards the Shapely Super Cluster our motion towards it is accelerated by being pushed away from a massive under dense void of space called the Dipole Repeller.

Now look at the motions we undergo sitting on the Earth completely unknowingly.

1.       Earth rotates on its axis at a speed of about 0.5 Km/sec.

2.       Earth goes round the Sun at a speed of around 30 Km/Sec.

3.    The Sun itself along with the Solar System rotates around the Milky Way galaxy at a speed of 230 Km/Sec.

4.     The Milky Way Galaxy itself is moving towards the Andromeda galaxy at a speed of 120 Km/Sec.

5.    The entire Local Group of galaxies are moving towards the Shapely Super Cluster at a speed of 630 km/sec.

Now sitting on the Earth, humans once thought they were stationery before the arrival of Astronomy. See the above 5 speeds which drive us through the Universe. What can we say? We partake in all those multiple speeds, yet never feel them at all. I think that is extremely amazing.