‘Lazarus comets’ returning to life after millions of years of dormancy …

August 3, 2013 by  
Filed under Wind Energy Tips

According to a news release from the Royal Astronomical Society, astronomers from the University of Anitoquia have found a graveyard of comets. Amazingly, these comets have come back from the dead after millions of years, convincing the astronomers to call them the “Lazarus comets.”

The Royal Astronomical Society notes that comets are among the tiniest objects in the Solar System, usually a few kilometers across and constructed of a mixture of rock and ices. If the comets journey close to the Sun, then some of the ices become gas, before being pushed back by the light of the Sun and the solar wind to create a tail of gas and dust.

A lot of comets have elliptical orbits, indicating that they almost never journey close to the Sun. In fact, some of these comets spend thousands of year completing each orbit around the Sun. In addition to these so-called long period comets, there are also approximately 500 short period comets, assembled when long period comets travel near Jupiter and are bounced off into orbits that last between 3 and 200 years. Occasionally, comets collide with Earth and may have played a key role in bringing water to our planet.

According to the Royal Astronomical Society, astronomers examined a third and well-defined region of the Solar System, the primary belt of asteroids between the orbits of Mars and Jupiter. This region holds more than one million objects varying in size from 1 meter to 800 kilometers.

Over the last ten years, 12 active comets have been found in this region. This discovery took the astronomers by surprise and they made a concerted effort to looked into their origin. After some careful analysis, Professor Ignacio Ferrin and his team members identified a reason for their surprising finding.

“We found a graveyard of comets,” said Ferrín. “Imagine all these asteroids going around the Sun for eons, with no hint of activity. We have found that some of these are not dead rocks after all, but are dormant comets that may yet come back to life if the energy that they receive from the Sun increases by a few per cent.”

According to the astronomers, this “return to life” can take place rather easily, as the revolutions of numerous objects in the asteroid belts are bumped by the gravity of Jupiter. The structure of their orbits can then alter, causing a decrease in the minimum distance between the object and the Sun and a small increase in average temperature.

The astronomers believe that millions of years ago the asteroid main belt was home to thousands of active comets. Eventually, their activity slowed down and this region became a graveyard of comets. The activity observed today is the residual activity from the comets’ active past.

“These objects are the ‘Lazarus comets,’ returning to life after being dormant for thousands or even millions of years,” Ferrín added. “Potentially any one of the many thousands of their quiet neighbors could do the same thing.”

The study’s findings are described in greater detail in the journal Monthly Notices of the Royal Astronomical Society.

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