Found: Ancient Warrior's Helmet, Owner Unknown

A Greek bronze helmet was found in the waters of Haifa Bay in Israel. The helmet is about 2,600 years old and likely belonged to a wealthy Greek mercenary.

A Greek bronze helmet, covered with gold leaf and decorated with snakes, lions and a peacock's tail (or palmette), has been discovered in the waters of Haifa Bay in Israel. But how this helmet ended up at the bottom of the bay is a mystery.

The helmet dates back around 2,600 years and likely belonged to a wealthy Greek mercenary who took part in a series of wars, immortalized in the Bible, which ravaged the region at that time. Archaeologists believe that he likely fought for an Egyptian pharaoh named Necho II.

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Dredging discovery

The helmet was discovered accidentally in 2007 during commercial dredging operations in the harbor. After it was discovered, conservators with the Israel Antiquities Authority went to work cleaning it and archaeologists began to analyze it.

They discovered that it is very similar to another helmet found in the 1950s near the Italian island of Giglio, about 1,500 miles (2,300 kilometers) away. That helmet has been dated to around 2,600 years ago, something which helped the researchers arrive at a date for the Haifa Bay helmet.

"The gilding and figural ornaments make this one of the most ornate pieces of early Greek armor discovered," writes Jacob Sharvit, director of the Marine Archaeology Unit with the Israel Antiquities Authority, and John Hale, a professor at the University of Louisville, in a summary of their research being presented at the meeting.

This Greek warrior likely would have been a very wealthy individual, as few soldiers could afford such an ornate helmet. The researchers aren't sure where the helmet was made, though they suspect the warrior could be from one of the Greek colonies in Ionia, on the west coast of modern-day Turkey. (The History of Human Aggression)

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Greek warrior loses helmet

At the time the helmet was made, circa 600 B.C., Greek colonies dotted the Mediterranean coast, stretching from the Black Sea to southern France. Even so, there is no evidence of Greek colonies in Israel, indicating the warrior who ventured into Haifa Bay was likely the leader of a group of Greek mercenaries.

This warrior was likely one of Egyptian pharaoh Necho II's troops, which he sent through Israel accompanied by a fleet of ancient ships. The pharaoh was heavily involved in military campaigns in the region for nearly a decade, operations in which this warrior and his group likely were involved. [Photos: Amazing Egyptian Discoveries]

"They were not fighting for the Greeks, they were fighting for Egypt," Sharvit told LiveScience in an interview.

The series of wars engulfed Egypt, Judah (a Jewish kingdom), Assyria and Babylon, with Necho II of Egypt intervening on the side of Assyria. 

The end result of these conflicts was the conquest of Judah and the rise of a resurgent Babylon led by King Nebuchadnezzar II. These events would be immortalized in the Torah (the Christian Old Testament).

At some point, amidst all this history, the elite Greek warrior's helmet ended up at the bottom of Haifa Bay.

Bottom of the harbor

The simplest (albeit most embarrassing) explanation is as to how the helmet ended up at the bottom of Haifa Bay is that somebody dropped it while the warrior's ship was sailing into the harbor.

Another possibility is that the ship carrying the warrior sank, suggesting an ancient shipwreck awaits discovery. "We are planning to go back to the same site and to try to locate other (archaeological) material there," Sharvit said.

Yet another possibility (again, an embarrassing one for the warrior) is that the helmet was lost during a retreat after Necho II's armies were defeated by the Babylonians.

The results of the researchers' work were presented in January at the annual meeting of the Archaeological Institute of America. The helmet itself is now on display at the National Maritime Museum in Haifa.

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Detecting Light Echoes from Ancient Star Eruption

Between 1838 and 1858, the star Eta Carinae underwent its "Great Eruption," making it the second brightest star in the sky. Astronomers at the time didn't have the technology to study the event in detail. Today, with the help of 170-year old light echoing off Eta Carinae's nebula, astronomers have been able to study the eruption.

During the mid 1800's, the well known star Eta Carinae underwent an enormous eruption becoming, for a time, the second brightest star in the sky.

Although 19th Century astronomers did not yet have the technology to study one of the largest eruptions in recent history in depth, astronomers from the Space Telescope Science Institute recently discovered that light echoes are just now reaching us.

This discovery allows astronomers to use modern instruments to study Eta Carinae as it was between 1838 and 1858 when it underwent its Great Eruption.

Light echoes have been made famous in recent years by the dramatic example of V838 Monocerotis. While V838 Mon looks like an expanding shell of gas, what is actually depicted is light reflecting off shells of gas and dust that was thrown off earlier in the star's life.

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The extra distance the light had to travel to strike the shell, before being reflected towards observers on Earth, means that the light arrives later. In the case of Eta Carinae, nearly 170 years later!

The reflected light has its properties changed by the motion of the material off which it reflects. In particular, the light shows a notable blueshift, telling astronomers that the material itself is traveling 210 km/sec.

This observation fits with theoretical predictions of eruptions similar to the type Eta Carinae is thought to have undergone. However, the light echo has also highlighted some discrepancies between expectation and observation.

Typically, Eta Carinae's eruption is classified as a "supernova impostor." This title is fitting since the eruptions create a large change in the overall brightness.

However, although these events may release 10 percent of the total energy of a typical supernova or more, the star remains intact.

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The main model to explain such eruptions is that a sudden increase in the star's energy output causes some of the outer layers to be blown off in an opaque wind. This shell of material is so thick, that it gives a large increase in the effective surface area from which light is emitted, thereby increasing the overall brightness.

For this to happen, models predict that the temperature of the star prior to the eruption needs to be at least 7,000 K. Analyzing the reflected light from the eruption places the temperature of Eta Carinae at the time of the eruption at a much lower 5,000 K.

This would suggest that the favored model for such events is incorrect and that another model, involving an energetic blast was (a mini-supernova), may be the true culprit, at least in Eta Carinae's case.

Yet this observation is somewhat at odds with observations made in the years following the eruption.

As spectrography came into use, astronomers in 1870 visually noticed emission lines in the star's spectrum which is more typical in hotter stars.

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In 1890, Eta Carinae had a smaller eruption and a photographic spectrum put the temperature around 6,000 K. While this may not accurately reflect the case of the Great Eruption, it is still puzzling how the star's temperature could change so quickly and may also indicate that the favored model of the opaque-wind model is a better fit for later times or the smaller eruption. This suggests two different mechanisms causing similar results in the same object on short timescales.

Either way, Eta Carinae is a marvelous object. The team has also identified several other areas in the shell surrounding the star which appear to be brightening and undergoing their own echoes which the team promises to continue to observe which would allow them to verify their findings.

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Could Ancient Pottery Improve Spacecraft Tiles?

You might not think that a collaboration to study the chemical and physical properties of ancient Attic pottery would have anything to do with space missions, but, well, you'd be mistaken.

Earlier this year, the National Science Foundation (NSF) awarded nearly $500,000 to scientists from the Getty Conservation Institute, Stanford's National Accelerator Laboratory (SLAC) and the Aerospace Corporation to do just that.

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Among other objectives, it is hoped that the project will improve our understanding of iron-spinel chemistry, which is critical to the advanced ceramics used for thermal protection in aerospace applications, such as protective tiles on the Mars Rover Sojourner, or the fleet of space shuttles, for example.

"Ceramic components are used all through space technology and space vehicles," materials scientist Mark Zurbuchen told Physorg.com. "We need to continue to learn about interactions of components within these materials to help us better understand any real-world issues that may arise in actual space components."

Attic pottery features red and black figures (see image, right) and was a fixture in ancient Greece from the sixth to fourth centuries B.C. The precision required to produce the impressive detail seen in such pieces is very high, and our understanding of the methods and techniques used by various artists -- and how those evolved over time -- is incomplete.

Attic pottery was created by artisans working with their hands with clay and pigment. Space mission ceramic tiles, in contrast, are made with high-tech laser beams controlled by a computerized machine tooling system.

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However, "Something doesn't need to be complex to be sophisticated. If we can understand the technology with which these works of art were made, we can use the knowledge for a surprisingly wide variety of applications," Karen Trentalman, a Getty conservation scientist who is leading the collaboration, explained.

The tiles used in space missions must be able to withstand a wide range of extreme temperatures, from as low as -250 degrees F (the chill of deep space) to as high as 3000 degrees F (during re-entry).

The iron-spinel ceramic pigments found in Attic pottery are able to remain chemically stable at very high temperatures. It's the degree of iron oxidation that provides the red and black coloring associating with Attic pottery. (Modern versions of such pigments are typically synthesized from mixtures of iron oxide and chromium oxide.)

The researchers involved in the Getty project are using a technique called x-ray absorption near edge structure (XANES) -- a type of spectroscopy -- to determine the states of iron oxidation in pottery fragments, combined with x-ray absorption fine structure (EXAFS) to glean more information about the molecular structure of the iron minerals used.

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From this, it is hoped they can identify telltale material "signatures" of the specific artists who created certain pottery fragments. This can shed light on how the techniques used might have changed and evolved over time, and help with classifying unsigned works. It could, in turn, also lead to improved conservation methods and better ceramic tiles for the aerospace industry -- including NASA.

Image (top): The underside of space shuttle Discovery before docking with the space station (NASA)

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