When galaxies collide – the enormity of space

Two Galaxies Collide

Amazing photo from Hubble space telescope depicts the enormity of space. When two galaxies pass through or close by each other the competing gravitational fields tear the galaxies apart. The upper left galaxy used to be a normal spiral galaxy until about 100 million years ago when the one on the right approached too close. You get an idea of the scale when you consider that each of the pin-pricks of light is an individual star with its own solar system.

Our own Milky Way galaxy contains between 100 billion and 400 billion stars, but even galaxies are dwarfed by massive superclusters. Fraser Cain at Universe Today explains:

The supercluster we live in is known as the Virgo Supercluster. It’s an enormous collection of more than a million galaxies, stretching across a region of space 110 million light-years across. Our Sun is just one member of the Milky Way, and the Milky Way is part of a collection of galaxies known as the Local Group. This contains three large spiral galaxies: the Milky Way, Andromeda, and the Triangulum Galaxy, as well as a few dozen dwarf galaxies. The Local Group is just one member of the Virgo Cluster. This is a collection of 1200-2000 galaxies that stretch across 15 million light-years of space. And then, the Virgo Cluster is just one cluster in the Virgo Supercluster.

……The Virgo Supercluster is just one of millions of superclusters across the Universe.

If the average galaxy is only 1/100th of the size of the Milky Way (i.e. between 1 and 4 billion stars) and the average supercluster contains a million galaxies, then the universe contains at least 1 Sextillion (or 10^18) stars.

See more photos at BuzzFeed: 18 Astounding Hubble Photos Released In 2012 | Donna Dickens

Tarantula Nebula in the Large Magellanic Cloud

The Tarantula Nebula in the Large Magellanic Cloud
Source: Hubblesite.org

Hubble Space Telescope composite image of a portion of the Tarantula Nebula’s central cavity. The flood of UV light and gusts of hot particles flowing freely from the young stars of 30 Doradus have hollowed out a bubble in the gaseous nebula. Only with Hubble’s exceptional resolution could the intricacy and three-dimensionality of these features be revealed.

The Hubble data have been combined with ground-based observations that trace hydrogen gas (in red) and oxygen (in blue). Together, this region can be appreciated as a microcosm of the larger nebula: a swirling palette of gas, dust, and stars in the midst of tumultuous upheaval.

Stars in the nebula number more than half a million.

Hat tip to Barry Ritholz.