Comets

It is an icy body that releases gas or dust. They are often compared to dirty snowballs, though recent research has led some scientists to call them snowy dirtballs and contain dust, ice, carbon dioxide, ammonia, methane and more. It orbit the sun, but most are believed to inhabit in an area known as the Oort Cloud, far beyond the orbit of Pluto. Occasionally a comet streaks through the inner solar system; some do so regularly, some only once every few centuries.

Halley's Comet

Halley’s Comet is named after English astronomer Edmond Halley who first determined its period of orbit. It was the first comet to be recognized as having a periodic orbit.

COINS LEFT ON TOMBSTONES

While visiting some cemeteries you may notice that headstones marking certain graves have coins on them, left by previous visitors to the grave.

These coins have distinct meanings when left on the headstones of those who gave their life while serving in America's military, and these meanings vary depending on the denomination of coin.

A coin left on a headstone or at the grave site is meant as a message to the deceased soldier's family that someone else has visited the grave to pay respect. Leaving a penny at the grave means simply that you visited.

A nickel indicates that you and the deceased trained at boot camp together, while a dime means you served with him in some capacity. By leaving a quarter at the grave, you are telling the family that you were with the solider when he was killed.

According to tradition, the money left at graves in national cemeteries and state veterans cemeteries is eventually collected, and the funds are put toward maintaining the cemetery or paying burial costs for indigent veterans.

In the US, this practice became common during the Vietnam war, due to the political divide in the country over the war; leaving a coin was seen as a more practical way to communicate that you had visited the grave than contacting the soldier's family, which could devolve into an uncomfortable argument over politics relating to the war.

Some Vietnam veterans would leave coins as a "down payment" to buy their fallen comrades a beer or play a hand of cards when they would finally be reunited.

The tradition of leaving coins on the headstones of military men and women can be traced to as far back as the Roman Empire.

Did you know?

Face Illusions are ambiguous images which exploit similarities between two or more distinct images. They are also known as reversal images, puzzle images and perceptual rivalry.

Optical Illusions

Do you see it?