Scientists at Sandia National Laboratories in New Mexico believe that the glass was made from a natural airburst.

A colossal instance of such a burst happened when Comet Shoemaker-Levy 9 collided with Jupiter and exploded into its atmosphere, creating the largest incandescent fireball ever witnessed.

The New Mexico researchers created a simulation much like the 1994 Jupiter collision to learn more about what happens during such an event.

The results showed an impact that could have created a fireball hot enough to generate ground temperatures of 1,800 Celsius, and possibly leave behind a field of glass.

According to the researchers, airborne explosions happen roughly once every 100 years.

They say another such event is likely to happen in the near future.

Let me set the record straight. The Mona Lisa is indeed part of one of the biggest cover ups in history. But, hear me out before you bite my head off. That cover up consists simply of this: there is absolutely no mystery surronding the Mona Lisa.

That's right folks. None. We know exactly who she was, and why she was painted. We also know what that little smile is all about. None of this DaVinci in drag nonsense, or hidden cryptic clues pertaining to some masonic cult...

The truth is simply this: the title Mona Lisa stemmed from the artist's biographer Giorgio Vasari, who wrote 31 years after the death of Leonardo. The painting is a portrait of Lisa, the wife of wealthy Florentine businessman Francesco del Giocondo. Mona is a contraction of the word 'madonna' meaning 'my lady' or the English equivalent of 'Madam' thus meaning literally 'Madam Lisa.' The Italians call her La Gioconda, which is the feminine form of Giocondo, the man to whom the lady in question was married. The word 'Giocondo' can also mean light hearted (a word which was adapted to be 'jocund' in English), thus the feminine form 'Gioconda' means literally 'light hearted woman.' This gives the title it's double meaning, due to her so-called mysterious smile.

In his same biography Vasari states that the reason for the smile was that during the sitting a small band was playing, and caused the lady to smile in reality, which DaVinci consequently put into his painting. Wow, amazing mystery!

The mystery about why The Mona Lisa's background isn't level can also be answered quite easily. Take a print of the Mona Lisa and roll it so the sides of the painting match up as if you're making a paper telescope. When you see the new edge that is created, you'll also notice it matches up perfectly. The painting was originally enclosed by painted pillars, but DaVinci asked that they be removed for this very reason. A similar technique is used today to prevent monetary fraud, match up the edges of a $5 note and you'll see what I mean.

So there you have it guys. The truth. That's the big cover up. There is nothing slightly mysterious about her. She is simply an astounding piece of art and should simply be admired as such.

The team, led by Dr RV Karanth, a former professor of geology at the Maharaja Sayajirao University in Vadodara, Gujarat, has been involved in a palaeoseismological study of the Kutch region for the past 11 years.

Palaeoseismology involves the study of sediments, landforms and other geological evidence of past earthquakes to unravel their history and determine the nature and occurrence of present-day earthquakes.

This feature was discovered at a hillock 3km from the sleepy oasis township of Khavda, which is also known as the gateway to the Rann of Kutch, an extensive salt marsh of western India and southeast Pakistan between the Gulf of Kutch and the Indus river delta.

Man-made feature?

The Kutch region is host to several archaeological findings belonging to the Harappan civilisation (3000-1500 BC).

This has led to the speculation that this feature could be related to the Harappan civilisation.

Dr Karanth clarifies that it is too early to arrive at any conclusion.

"It could be a manmade feature or may have been formed naturally due to erosion of the hill slope along a fracture formed by the movement of earth's crust," he says.

"However structures formed naturally due to erosion generally tend to be parallel to each other. But here, all three arms are in different directions. Besides, all the ditches are almost uniformly wide and deep."

Dr Karanth says such trenches have not been noticed elsewhere in the region. Archaeologists, he says, can now pursue further research.

Geometric lines and animal shapes etched into the desert plain by people of the Nazca civilisation (AD 1-700) of Peru are well known.

"But such signs on hill-slopes have not been reported from Peru," says Dr Karanth.

Astronomy

He says that one of the prominent explanations given for the Peruvian features is that they may have been constructed to make astronomical observations and calculations.

"The Tropic of Cancer passes through Kutch. So if this structure is man-made, it is likely that the slope of the hillock was utilised for making certain astronomical calculations in the past," explains the geologist.

Interestingly, there are numerous indications to suggest that Harappans were well-versed in astronomy.

The straight streets of that time were oriented in the cardinal directions - east, west, north and south.

Linkages between ancient Harappan scripts and latter Vedic texts also suggest that Harappan priest-astronomers tracked the progress of various planets and mapped the sky.

Dr Karanth has also discovered ruins of a fort-wall, houses, storage tank and a temple on the hilltop.

They may, he says, belong to the period of the Kathi Darbar, a warrior class from the Kathiawad region.