Η μεγαλύτερη διαστημική παρατήρηση στην ιστορία της Γης βρίσκεται σε εξέλιξη τα τελευταία 24ωρα λόγω της έλευσης ενός τεράστιου κομήτη που τρέχει με ταχύτητα 377 χιλιομέτρων το δευτερόλεπτο προς τον ήλιο. Ο κομήτης ISON που έχει όπως εκτιμάται διάμετρο έως 4,8 χιλιόμετρα (όσο ένα μικρό βουνό) δεν αποτελεί κίνδυνο για τη Γη αλλά αναμένεται να προσφέρει χάρη στη λαμπρότητα του ένα συγκλονιστικό υπερθέαμα αλλά και την ευκαιρία στην επιστημονική κοινότητα να συλλέξει σημαντικά δεδομένα και πληροφορίες για την nature and the descent of these heavenly bodies.
On November 28, the comet from the exotic Oort cloud, tens of trillions of kilometers away, will approach the sun at a distance of 1.159.000 kilometers and automatically the thermowineits a will explode at 2.760 degrees Celsius. If it survives this close pass by the sun, then ISON will surpass the Great Comet of 1680 in brightness.
In November of this year, an incredibly brilliant comet discovered by the German astronomer Gödfred Kirch with a telescope passed almost as close to the sun as ISON is expected to do, fearing the world that was running in the churches seeking ... forgiveness from God.
The Great Comet was visible and the day while the tail that left behind was appreciated much later that 150 was the milestone.
ISON was discovered in September 2012 by Russian amateur astronomers when it was 940 million kilometers from the sun. It was then 25.000 times fainter than it is today and was incredibly difficult to detect even with large telescopes.
But at the beginning of June, the telescopes were "arrested" for good when it was at a distance of 500 millions of kilometers. Carbon dioxide along with the dust released from its surface had already created a 300.000 queue.
"At that time, ISON emitted one million kilograms of carbon dioxide and 54,4 million pounds of powder each day," said Karei Lise of John Hopkins University's Applied Physics Laboratory.
The latest 24, space telescopes such as Hubble, SOHO A and B, or SDO, as well as large Earth observation devices, are turning to the ISON comet, following its rapid approach to the sun.
Even if the comet dissipates from the heat of the sun, the spectacle that it causes is expected to be shocking, while the information that telescopes will collect for this distant visitor will be most valuable.
"No matter what the comet's fate is, we are in the midst of an exciting opportunity," said Matthew Nate, an astronomer at the Lowell Observatory in Arizona.
"We are dealing with a celestial object that enters the Earth's trajectory after 4,5 billions of years in the cold. All eyes will be on it. "
Some time ago, a NASA-funded study conducted by Lowell Observatory and the Southwestern Research Institute in Texas, estimated that the comet is very likely to survive from its near-pass to the sun.
If this happens, then at 26 December, the comet will be at the nearest point of its path to the Earth and will depart from our planet 45 millions of kilometers, that is 1 / 3 of the distance that separates Earth from the sun.
As early as early December in the Northern Hemisphere, the comet will be particularly bright and easily visible with the naked eye. Even during the day it will be visible low on the horizon towards the end of the month and in early January it will be visible throughout the night.
At present the comet is visible with a powerful pair of binoculars or amateur telescope as long as the night is clear and away from the lights of big cities. The comet can be better observed one hour before sunrise.
His relationship with the Big Comet of 1680
ISON may be the long-lost sibling of the Great Comet of 1680, NASA scientists speculate. The similarities of two bodies are many and astronomers speculate that these are two parts of a large comet that broke up millions of years ago. Due to gravitational interactions and the passage of time, one comet visited our inner solar system 333 years ago and now follows the second with a slightly different trajectory.
The Big Comet was estimated to have passed 0,42 astronomical units away from the Sun (one astronomical unit is the Earth-Sun distance), and at just the same distance ISON will pass.
In some calculations, if ISON survives, it may explode forever away from our solar system and never return.
It weighs over 3 trillions of kilos
The size of a small mountain seems to be what the comet has as its diameter according to the latest calculations by NASA's JPL laboratory does not exceed 4,8 kilometers. Its weight is estimated to range from 3,2 billion kilograms to 3,2 trillion kilograms. Like all comets it is a "dirty snowball" consisting of frozen dust and gases, water, ammonia, methane, carbon dioxide. In other words, these are fundamental components data which 4,5 billion years ago coalesced to also create the planets of our solar system. Scientists speculate that it originates from the Oort Cloud, which extends up to a light-year from the sun and is a belt dotted with comets and comet-like objects.
