The Hellenic Navy (HN) (Greek: Πολεμικό Ναυτικό, Polemikó Naftikó, abbreviated ΠΝ) is the naval force of Greece, part of the Greek Armed Forces. The modern Greek navy has its roots in the naval forces of various Aegean Islands, which fought in the Greek War of Independence. During the periods of monarchy (1833–1924 and 1936–1973) it was known as the Royal Navy (Βασιλικόν Ναυτικόν, Vasilikón Naftikón, abbreviated ΒΝ).The total displacement of all the navy's vessels is approximately 150,000 tons.The motto of the Hellenic Navy is "Μέγα το της Θαλάσσης Κράτος" from Thucydides' account of Pericles' oration on the eve of the Peloponnesian War. This has been roughly translated as "Great is the country that controls the sea". The Hellenic Navy's emblem consists of an anchor in front of a crossed Christian cross and trident, with the cross symbolizing Greek Orthodoxy, and the trident symbolizing Poseidon, the god of the sea in Greek mythology. Pericles' words are written across the top of the emblem. "The navy, as it represents a necessary weapon for Greece, should only be created for war and aim to victory."...............The Hellenic Merchant Marine refers to the Merchant Marine of Greece, engaged in commerce and transportation of goods and services universally. It consists of the merchant vessels owned by Greek civilians, flying either the Greek flag or a flag of convenience. Greece is a maritime nation by tradition, as shipping is arguably the oldest form of occupation of the Greeks and a key element of Greek economic activity since the ancient times. Nowadays, Greece has the largest merchant fleet in the world, which is the second largest contributor to the national economy after tourism and forms the backbone of world shipping. The Greek fleet flies a variety of flags, however some Greek shipowners gradually return to Greece following the changes to the legislative framework governing their operations and the improvement of infrastructure.Blogger Tips and Tricks
This is a bilingual blog in English and / or Greek and you can translate any post to any language by pressing on the appropriate flag....Note that there is provided below a scrolling text with the 30 recent posts...Αυτό είναι ένα δίγλωσσο blog στα Αγγλικά η/και στα Ελληνικά και μπορείτε να μεταφράσετε οποιοδήποτε ποστ σε οποιαδήποτε γλώσσα κάνοντας κλικ στη σχετική σημαία. Σημειωτέον ότι παρακάτω παρέχεται και ένα κινούμενο κείμενο με τα 30 πρόσφατα ποστς....This is a bilingual blog in English and / or Greek and you can translate any post to any language by pressing on the appropriate flag....Note that there is provided below a scrolling text with the 30 recent posts...Αυτό είναι ένα δίγλωσσο blog στα Αγγλικά η/και στα Ελληνικά και μπορείτε να μεταφράσετε οποιοδήποτε ποστ σε οποιαδήποτε γλώσσα κάνοντας κλικ στη σχετική σημαία. Σημειωτέον ότι παρακάτω παρέχεται και ένα κινούμενο κείμενο με τα 30 πρόσφατα ποστς.........

Thursday, October 14, 2010

Astronomers probe 'peculiar' object..[ 1876 ]

High-speed asteroid pile-up prompts X-File


By Lester Haines
Posted in Space, 14th October 2010 10:30 GMT

The Hubble Space Telescope has captured the aftermath of just what happens when two asteroids collide at 11,000 mph (17,702 km/h), prompting an explosion "as powerful as the detonation of a small atomic bomb".
The result is a "peculiar" object - dubbed P/2010 A2 - which boasts a comet-like debris trail behind a mysterious X-shaped formation.
Hubble image of P/2010 A2, as seen by Hubble. Pic: NASA
The asteroid belt pile-up happened in early 2009, according to NASA, but it wasn't until January this year that the Lincoln Near-Earth Research (LINEAR) Program Sky Survey spotted the tail.

Hubble's Wide Field Camera 3 observations indicate a surviving 400-foot-wide (122m-wide) object, which was hit by a smaller body, "perhaps 10 to 15 feet wide" (3 to 4m). The latter was vapourised in the blast, and its remains and material thrown off from the former were swept into a tail by solar radiation.
Astronomers are keen to find out just how much dust such high-speed encounters eject into interplanetary space, and while they reckon that "modest-sized asteroids smash into each other about once a year", they're difficult to spot.
But P/2010 A2 doesn't conform to the scientists' predictions. David Jewitt, of the University of California in Los Angeles, said: "We expected the debris field to expand dramatically, like shrapnel flying from a hand grenade. But what happened was quite the opposite. We found that the object is expanding very, very slowly."
The X shape, meanwhile, has the boffins stumped. NASA says: "The crisscrossed filaments at the head of the tail suggest that the colliding asteroids were not perfectly symmetrical. Material ejected from the impact, therefore, did not make a symmetrical pattern, a bit like the ragged splash made by throwing a rock into a lake. Larger particles in the X disperse very slowly and give this structure its longevity."
Jewitt and colleagues plan to turn Hubble's attention back to P/2010 A2 next year, in order to "see how far the dust has been swept back by the sun's radiation and how the mysterious X-shaped structure has evolved".
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