Halley’s Comet Dust Caused Droughts and Famine Centuries Ago – Study

Halley's Comet Dust Caused Droughts and Famine Centuries Ago – Study

Climate change in AD 535-536 was caused by dust spilled into the atmosphere by Halley’s Comet, according to a new study.

The dust is thought to have cooled the atmosphere to an extent causing unseasonal weather and crop failures, leading to droughts and famine.

The climate change and accompanying famines triggered by the dust veil are also believed to have rendered humans more susceptible to “Justinian’s plague” of AD 541-542, Europe’s first recorded emergence of Black Death.

The years are recorded in history for unusual and extreme weather events in much of the northern hemisphere. The event was believed to have been caused by an extensive dust veil, while the observed episode was explained using several hypotheses including a large volcanic eruption in the tropics and debris from comet impact.

Dallas Abbott, a research scientist at Columbia University’s Lamont-Doherty Earth Observatory, told Livescience that smoke from volcanic eruption alone cannot explain the spread of dust across continents.

Researchers have found evidence of cometary residue on Greenland ice laid down between AD 533 and 540.

“I have all this extraterrestrial stuff in my ice core”, Abott said at a meeting organised by the American Geological Union.

The ice cores from the seven-year period have deposits of tin, nickel and iron oxide spherules from an extraterrestrial source.

High levels of tin are associated with alien dust especially that of a comet, Abbott explained. Studies suggest that the alien particulate matter was deposited during spring time, coinciding with the Eta Aquarid meteor shower from Halley’s Comet.

Scientists say that in the next four to five years of the impact, the earth cooled by as much as 5.4° Fahrenheit (3° Celsius).

A 2004 study estimated that a comet fragment about 2,000 feet (600 metres) wide is enough to have caused AD 536-537 cooling event.

However, this is not the only comet impact to have affected human beings in the last 20,000 years after the end of the Stone Age.

About 13,000 years ago, a probable impact event over North America is suspected to have caused widespread forest fires in the continent, leading to the extinction of several animal species and the subsequent collapse of the North American Clovis culture.

Explosion in Atmosphere

A major airburst caused by an asteroid or comet can be traced not too far back in recent history. In 1908, a large explosion in the atmosphere was caused by burning extraterrestrial rocky fragments near the Tunguska River in Russia.

Different Russian studies on the event reported that the native settlers heard sounds of explosion accompanied by a shock wave that knocked people off their feet and broke windows hundreds of kilometres away and levelled forests spread over an area of about 2,150 km2 (830 mi2).



Buzz Aldrin calls for humans to colonise the Red Planet

Buzz Aldrin calls for humans to colonise the Red Planet

On 21 July 1969, when Neil Armstrong and Buzz Aldrin first set foot on the surface of the Moon, it appeared as though mankind was on the verge of a new age of space exploration. After all, if the moon could be conquered, what could prevent us travelling to other planets, even to other solar systems?

The Mars Curiosity Rover has been taking images of the planet since August 2012

The Mars Curiosity Rover has been taking images of the planet since August 2012

“It’s in human nature to explore, to find a location to begin a settlement. And it is in reach”

Buzz Aldrin
Nearly half a century later, the dreams that once seemed so tangible now look more remote than ever. The last man to walk on the Moon was Eugene Cernan, who made the long trip home in December 1972. Since then, humans have been content to orbit the earth, in the realms occupied by satellites and the International Space Station. But we have never again broken free.

Now, one of the original lunar pioneers believes the time has come to make another great leap for mankind. Buzz Aldrin thinks that manned missions to Mars should take place sooner rather than later – within the next quarter of a century. And we shouldn’t stop there. He thinks we should begin planning a permanent colony on the Red Planet.

I caught up with him on a visit to the Paris Air Show, where he has been publicizing his new book, “Mission to Mars: My Vision for Space Exploration”. A relatively sprightly 83-year-old, he has a reputation for tetchiness – and he certainly dealt rather brusquely with onlookers’ requests for autographs. But when I asked him about Mars, he became engaging and animated, showing a boyish enthusiasm for the subject.

So why does he think we should be sending astronauts to the red planet?

“Why did the the pilgrims on the Mayflower set out to open up the New World?” he asks.

Colleagues at Nasa’s Jet Propulsion Lab celebrate the Mars Curiosity Rover’s successful landing in 2012
“Because it’s in human nature to explore, to find a location to begin a settlement. And it is in reach.”

The simple answer then, appears to be “because it’s there”. But there is also a more pragmatic reason. He believes that efforts to explore the surface of Mars to date have taken far too long, because the current generation of Mars rovers have to be controlled remotely from Earth – and it takes about 20 minutes for radio signals to be passed each way.

“One programme manager, who was in charge of doing that with two robots for five years has said we could have accomplished just as much in a single week, if we had had human intelligence controlling them from nearby – from an orbit around Mars itself”, he says.

But a mission to Mars would have to overcome huge technological challenges, and would certainly be phenomenally expensive. So who would pay for it all?

“The nation that decides that it is worth doing,” he says, “and I believe that is the United States. The United States will commit to doing that.”

Yet, at the moment governments around the world are attempting to cut back their spending, and Washington is no exception. In the current climate, it seems almost inconceivable that a government could commit untold billions to fund interplanetary exploration.

On the other hand, private firms are showing an interest – companies such as Mars One, a not-for-profit Dutch foundation, which says it plans to establish a colony on Mars by 2023. It wants to use technology developed by the American firm Space X, a business fronted by the maverick entrepreneur Elon Musk.

Mr Aldrin points to these firms as evidence that there is enthusiasm for exploring Mars – yet he still believes that governments will have to lead the way.

“Private enterprise usually enters into activities seeking a return on investment,” he says.

“That’s why we didn’t go to the moon in the ’60s and ’70s just relying on private investment. It was a national investment is science, in development and to assist in the commercialization of space.”

In other words, the commercial benefits may be there – but the rewards are too uncertain to attract enough private backing.

Buzz Aldrin believes we should colonize Mars over the next 25 years
Mr Aldrin’s vision involves astronauts being trained on the Moon for a life on Mars, and ultimately for new colonists to be brought to the new settlement on a routine basis. He thinks this could be done using “interplanetary cyclers”, spacecraft that are permanently moving between Mars and Earth.

But such a plan needs willing volunteers, who must be prepared to travel across space with little prospect of ever returning home. A return journey may in fact become physically impossible after much time spent in the weaker gravity of Mars.

Yet he thinks there will be no shortage of volunteers, and the response to the Mars One initiative suggests he is right. Since announcing its plans in April, it has received tens of thousands of applications from would-be Martian explorers.

“I think that the people who go there will be remembered in history as pioneers,” he says, “and the world leader who makes a commitment to establishing a permanent presence on another planet will also be remembered in history as a pioneer.”

In fact, as befits one of the very few men ever to have set foot on another world, “pioneer” seems to be Buzz Aldrin’s favorite word. It’s a term that has rather fallen out of fashion on our well-mapped planet.

But he believes the time has come time to broaden our horizons – and rediscover once again the spirit of exploration.