Thursday, 19 December 2013

The End of Night

The bright lights of Europe spilling into the night as seen from the Space Station.

Night is no longer as dark as it used to be. Street lamps, neon signs, ‘security' lights and the rest all contribute to an ever-present glow that has transformed the natural world and turned modern life into a wash of artificial light.

It is a theme the Lighthouse Keeper has looked at in several blog essays this autumn, partly inspired by one of this summer's best-selling books ‘The End of Night', written by US-based journalist Paul Bogard.

Light pollution around the world has expanded exponentially in recent decades and now it is reckoned that the vast majority people across Western Europe and the United States no longer experience a truly dark night.

Night's natural darkness is invaluable for our spiritual health and the health of the natural world and as a consequence every living creature, including ourselves, suffers from its loss.

Like the advancement of technology it is one of those things that changes subtly against the backdrop of busy lives – and almost without noticing we become accustomed to a new ‘normal'.

The Bortle scale, which classifies the darkness of skies from point of view of an astronomer, 
was originally published in Sky & Telescope magazine in 2001 and is an apt illustration for Bogard’s theme.

In his book, Bogard investigates the meaning of darkness and travels to some of the world's intensely lit cities - from Paris, the ‘city of light' to glittering Las Vegas and to still gas-lit streets of London's Westminster district, meeting an inimitable range of characters along the way.

Bogard contrasts the skies above our cities and urban populations to some of the most remote and darkest places on the globe, like the great national parks in America and the Island of Sark off the British coast.

He discusses how light is negatively affecting the natural world, how our well-being is significantly influenced by darkness or its lack, and how it's not a matter of using light at night or not, but rather when and where, how and how much.

Travelling the world looking for dark skies, Bogard considers our affinity for artificial light, the false sense of security it provides, and its implications.

He covers such broadly diverse issues as the health impacts of working the night-shift to the persecution of bats, and urges the reader to weigh the ramifications of light pollution and our failure to address them.  

The growth of light piollution across the United States, including
a projection for the year 2025.

"We think that because of television, the internet, or jet travel we see a lot of the planet," says Bogard.

"But the only chance we really have to retain our sense of the scale in the real universe is by looking at the night sky."

As we approach the winter solstice when the dark nights of the northern hemisphere reach their longest, what better time to delve into such a book?

Bogard's evocation of the night blends environmental and cultural history to make reading about light pollution a surprising pleasure.

By reclaiming the night we stand only to gain. Not least in decreased energy costs and redressing the balance of life but also in that other fast-disappearing phenomenon - wonder.

Bogard draws attention to the naturally dark night as a landscape in its own right - a separate, incredibly valuable environment that we overlook and destroy at our own peril.

‘The End of Night’ by Paul Bogard
is published by Fourth Estate and
is available at your local bookshop
or from Amazon.

Monday, 16 December 2013

Polar ice melt

Three major glaciers in West Antarctica (Pine Island, Thwaites and Smith) are melting into the Amundsen Sea faster than previously thought.

ESA’s Cryosat polar orbiting spacecraft possesses the capability to observe features in more detail than previous missions and has revealed that the region is now losing more than 150 cubic km of ice into the sea every year.

Cryosat was launched in 2010 with a radar specifically designed to measure the shape of ice surfaces - and its latest results indicate the loss appears to be accelerating

The data, presented at the recent American Geophysical Union (AGU) in San Francisco, show that the loss of ice equates to a 15 percent increase in West Antarctica's contribution to global sea level rise.

Prior to Cryosat, scientists concluded that ice losses from West Antarctica had pushed up global sea levels by some 0.28 mm a year between 2005 and 2010. The new Cryosat data starts from the end of that period.

Scientists say that ice at the Pine Island, Thwaites and Smith glacier ‘grounding lines’ - the places where the ice blocks split from the land and begin to float out over the ocean - is now thinning by between four and eight metres per year.

Three years of CryoSat measurements show that
the West Antarctic Ice Sheet is losing over
150 cubic kilometres of ice each year.
Launched in 2010, CryoSat carries a radar altimeter that can ‘see’ through clouds and in the dark, providing continuous measurements over areas like Antarctica that are prone to bad weather and long periods of darkness.

The radar can measure the surface height variation of ice in high resolution, allowing scientists to calculate its volume accurately.

Prof Andrew Shepherd of Leeds University, who led the West Antarctica study, said that part of the increase of ice loss could be due to faster thinning and part may also be down to CryoSat’s capacity to observe previously unseen terrain.

The mission has also provided three consecutive years of accurate Arctic sea ice thickness measurements, which show that ice covering Earth’s north polar region continues to thin.

Prof Shepherd added: "CryoSat continues to provide clear evidence of diminishing Arctic sea ice.

"From the satellite’s measurements we can see that some parts of the ice pack ice have thinned more rapidly than others, but there has been a decrease in the volume of winter and summer ice over the past three years.

"The volume of the sea ice at the end of last winter was less than 15 000 cubic km, which is lower than any other year going into summer and indicates less winter growth than usual."

Thursday, 5 December 2013

Sleeping satellite

If all goes to plan China’s Chang'e 3 probe will land on the Moon at the end of next week and open up a new era of lunar exploration.

The mission is a symbol of China's power and prowess. But look behind the political smokescreen and there is a sharp commercial edge to the country’s space ambitions.

Forty plus years ago it was the United States that inspired a generation growing up in the 1960s by making the ‘giant leap’ from Earth to the Moon.

Capitalism proved it could be first but it was more of a means to an end and became politically unsustainable even before the last men left the Moon in 1972.

How fortunes have changed. Communist China is now the world’s leading and most buoyant economy and has its sights set firmly on the opportunities presented by our nearest planetary neighbour.

Chang'e 3 is scheduled to land on 14 December in a region known as Bay of Rainbows, or Sinus Iridum, located on the upper-left part of the full Moon as viewed from Earth.

The mission blasted off from Xichang in the south of the country at 17.30 GMT on Sunday (1 December) and the spacecraft’s landing module includes a six-wheeled robotic rover called Yutu (translated as Jade Rabbit).

It will be China's first lunar rover as well as becoming the first spacecraft since the Soviet Luna 24 mission in 1976 to make a soft landing on the Moon,

According to information released by its design company the Shanghai Aerospace Systems Engineering Research Institute, the 120 kg Jade Rabbit rover can climb slopes of up to 30 degrees and travel at 200 m per hour.

Its name - chosen in an online poll of 3.4 million voters - derives from an ancient Chinese myth about a rabbit living on the Moon as the pet of the lunar goddess Chang'e.

Both the rover and lander are powered by solar panels but some sources suggest they also carry radioisotope heating units (RHUs) containing plutonium-238 to keep them ‘warm’ during the cold lunar night.

The mission - which will explore the Moon's surface and search for evidence of natural resources such as rare metals - carries a sophisticated payload, including ground-penetrating radar which will gather measurements of the lunar soil and crust.

It marks a milestone in China's ambitious long-term space exploration programme, which includes establishing a permanent space station in Earth orbit.

Future planned launches include a flight to bring back samples of lunar soil to Earth and ultimately sending Chinese nationals to the Moon, in what would likely be the first manned lunar missions since the US Apollo programme in the late 1960s and 1970s.

China knows the Moon is full of plunder that is there for the taking - mainly rare earth elements like titanium and uranium that Earth is really short of. And one day these valuable resources can be mined without limitation.

With NASA currently lacking even its own rocket and relying on the Russians to transport its astronauts to the International Space Station (ISS) it seems, in the words of the chart-topping song ‘Sleeping Satellite’, that the West may have ‘peaked too soon’.

It was the debut single by the British singer-songwriter Tasmin Archer and, in the light of China’s Moon mission and ambitious plans, the lyrics are more poignant than when it was released in 1992.

I blame you for the moonlit sky and the dream that died with the eagles' flight; I blame you for the moonlit nights when I wonder why are the seas still dry? Don't blame this sleeping satellite.
Did we fly to the moon too soon; did we squander the chance in the rush of the race; the reason we chase is lost in romance; and still we try to justify the waste for a taste of man's greatest adventure.

"It's not intended as anti-space travel," says Archer. "It's just the opposite and bemoans the fact that at the time of the anniversary the initiative had not been progressed from the original achievement."

The US may never quite catch up again and will probably one day rue the decision made by its politicians not to re-visit our ‘Sleeping Satellite’ sooner. Perhaps Archer is right and they did peak too soon - and lost a collective sense of adventure in the process.

Tasmin Archer performing 'Sleeping Satellite' at the
SECC in Glasgow in 2008.