Our solar system is moving through the interstellar cloud - VIDEO PDF Print E-mail
Friday, 19 December 2014 15:47

Our solar system is moving through the so-called local interstellar cloud with very low density, an area the size of 30 light-years across. It is so sparsely that light year found only a small gasp of air - about one atom per three cubic centimeters of space. Earth and our Sun moves through the clouds from 40 000 to 150 000 years, and perhaps will move another 20 000 years. However, this is a moment for our orbit to 250 million years, which runs through the Milky Way.

Previous measurements of interstellar helium atoms spacecraft "Ulysses" have shown that the solar system may be out of the local cloud. However, recent data have discovered IBEX incoming atoms, which move at a slower speed, which means that the heliosphere is still inside the cloud.

In February 2012, the unit IBEX, mission cost 169 million dollars, which was to map the influence of the Sun, fixed atoms from interstellar space, flying towards the Earth, which differ in chemical composition from our solar system.

"Our solar system is different from the space that is outside that brings us to the two options, - says David McComas, principal investigator for IBEX. - Either the solar system evolved into a separate and oxygen-rich part of the galaxy in which we are currently, or most of the life-giving oxygen trapped in interstellar dust or ice pellets and can not move freely in space. "

"We directly measured four separate atoms from interstellar space, and composition just does not match with what we observe in the solar system - said Eric Christian, mission scientist IBEX. - IBEX observations shed light on the mysterious area in which the Solar System ends and interstellar space begins. "

Data hint at the fact that the region of interstellar space just outside the solar system may suffer from lack of oxygen compared to its abundance in the heliosphere - guttate bubble blown by the solar wind, which blocks most of the dangerous cosmic radiation, not letting it get to Earth.

IBEX satellite observed atoms of hydrogen, oxygen, neon and helium, which originated in interstellar space, trivial environment between the stars in the Milky Way, and found 74 oxygen atoms for every 20 neon atoms. For comparison, the solar system is found within 111 oxygen atoms for every 20 neon atoms. Most of the interstellar medium consists of hydrogen and helium. Heavy elements such as oxygen and neon distributed along with the explosion of the supernova at the end of the life cycle of stars.

"Local Bubble" is a network of cavities in the interstellar medium is likely to cut massive supernova explosions millions of years ago. The interstellar medium - a substance that exists in the space between star systems in the galaxy. This material includes a gas ion, the atomic and molecular form dust and cosmic rays. It fills interstellar space and smoothly into the surrounding intergalactic space.

The interstellar medium plays an important role in astrophysics precisely because of its role of mediator between the stellar and galactic scales, stars form in the densest regions of the interstellar medium, and matter, energy, planetary nebulae, stellar winds and supernovae fill it.

This interaction between the stars and the interstellar medium helps to determine the rate at which the galaxy is depleted gaseous terms, and thus the duration of the period of active star formation.

The image below shows how NASA astronomers see around us 1500 light years. The local interstellar cloud is shown in purple, it derives from the association of young stars Scorpius-Centaurus.

Local interstellar cloud is in the hole of the interstellar medium, low density, which is called the local bubble and shown in black. Nearby are the molecular clouds with a high density, including the Aquila Rift - region of active star formation, painted in orange color.

Gama Nebula, shown in green, - a region of hot ionized hydrogen. This complex nebula is thought to be a supernova remnant, exploded more than a million years ago. Inside the nebula are the remains of a supernova Gama Vela (pink), which expands and creates a fragmented portions of matter. Future observations will help astronomers learn more about the local galactic group and how it could affect the Earth's climate in the past.

More than 13 billion years ago, at least one of the domains of life could begin in the nebula clouds. If we restrict ourselves only to the Milky Way, whose age is 13.6 billion years old, the first chemical compounds could go all the way for billions of years to become self-replicating organisms with genomes of DNA, long before the formation of the Earth.

Cloud nebulae, are believed to be the most favorable environment for creating and promoting the evolution of molecules necessary for life. DNA building blocks can be created or merged in interstellar clouds, and she could be a part of the DNA molecule-protein-amino acid complex. Hydrogen, oxygen, carbon, calcium, sulfur, nitrogen and phosphorus, for example, is constantly irradiated with ions, and thus may form small organic molecules that evolved into larger and more complex organic molecules, which led to the formation of amino acids and other compounds.

Phosphorus, for example, is rarely found in our solar system, and in general can not exist on the young Earth. However, phosphorus is required for the production of DNA. Polarized radiation in the nebula clouds leads to the formation of proteins nUKleina, and then the DNA. The combination of hydrogen, carbon, oxygen, nitrogen, cyanide and other elements creates adenine, which is the major DNA and oxygen and phosphorous to form a ladder of DNA base pairs. Glycine also been detected in interstellar clouds.

If you fast-forward 4.6 billion years on Earth steps to create a random mixing of chemicals for the first nanoparticles probably would have taken hundreds of millions or even billions of years until it formed the first self-replicating molecule would. But even after billions of years, the first such molecules could not be DNA. Further research may shed light on the place of formation of the first molecules of life.



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