Interesting properties characterize our corner of the galaxy

Sep 26, 2011 20:31 GMT  ·  By
This rendition shows the interactions between our solar system and the Local Bubble
   This rendition shows the interactions between our solar system and the Local Bubble

Currently, our solar system appears to be traveling inside a localized bubble of sorts. Astronomers believe that the star and all its planets, including Earth, are changing their position in the Milky Way through a series of interconnected cavities in the interstellar medium (ISM).

This medium plays a very important role in the Universe, since it underlies the transition between star system mediums and the intergalactic medium. Supernova explosions can create massive holes in the ISM, as the powerful blasts remove all matter from their surroundings.

Recent studies seem to confirm that the Sun is moving through such openings in the medium. Our own is called the Local Bubble, but is just one of countless others in the Milky Way and the Universe.

Usually, the ISM is made up of cosmic rays and dust, as well as ionic, atomic and molecular forms of gas, especially hydrogen. It spans the vast open spaces between stars in any galaxy. Planetary nebulae, stellar winds, and supernovae are responsible for replenishing this medium.

Its densest regions are usually the homes of stellar nurseries, which produce blue stars at a frantic pace. This is one of the reasons why the complex interactions between ISM and other stars can provide a decisive influence on the lifespan of entire galaxies.

After creating a map of the Sun's surroundings, spanning 1,500 light-years in every direction, astronomers figured out that our solar system is currently moving through a Local Interstellar Cloud (LIC), Daily Galaxy reports.

This LIC is located within the Local Bubble, which itself lies in the Milky Way's ISM. Understanding our neighborhood is critical for figuring out how life appeared on the planet. Nebulae, for example, are enormous chemical factories, producing a wide variety of chemicals.

Given that our galaxy is about 13.6 billion years old, these substances may have had sufficient time to assemble themselves into DNA-like structures long before the solar system appeared, some 4.6 billion years ago. The chemicals may have hitched rides of comets and asteroids in the mean time.

If the theory known as panspermia is taken into account, then this type of chemical development in the galaxy would have ensured that – given a hospitable environment like Earth's – life's seeds would develop extremely fast, bypassing billions of years of trial-and-error efforts.