Celebrating 50 years of astronomy

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Celebrating 50 years of astronomy

A celebration of half a century of optical astronomy at New Zealands premier astronomical research facility is the focus of a new book published by Canterbury University Press (CUP) this month.

Mt John The First 50 Years: A celebration of half a century of optical astronomy at the University of Canterbury looks at the history of one of the most beautiful astronomical observatories in the world, Mt John University Observatory at Tekapo.

In this richly illustrated book authors Professor John Hearnshaw and Alan Gilmore explore the turbulent history of the observatory which was founded at Lake Tekapo in the Mackenzie Basin and opened in 1965. The work carried out at Mt John, especially in stellar astronomy, is known and respected around the world.

I hope the book provides an engrossing and enthralling account of the development of an iconic New Zealand scientific institution, says Hearnshaw, Professor Emeritus of Astronomy at the University of Canterbury.

There were personality battles, funding shortfalls, a student demonstration and even a destructive fire to contend with as the observatory grew in size and importance.

Astronomical research has thrived at Mt John over the past 50 years. In the past decade it has been complemented by the rise of astronomical tourism. Now Mt John is now both a research observatory and a mecca for stargazing astro-tourists, who come to see the pristine landscape and the amazing dark night skies.

In the past decade, Mt John and the Mackenzie region have become prominent in astro-tourism. They are both recognised as places to visit to see the natural night sky, says Gilmore.

There is an interest in the observatorys origins and development. It is also a tourist route and receives several hundred visitors a day.

The book is richly illustrated with almost 200 images, many of them outstanding landscape and nightscape photographs taken by the acclaimed Tekapo photographer Fraser Gunn.

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Celebrating 50 years of astronomy

Airframe Parachutes Might Have Prevented The Germanwings Crash

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The founder of an aerospace company dedicated to manufacturing airframe parachutes for general aviation and legacy aircraft says that eventually such technology could even guard against sabotage virtually preventing catastrophes like this weeks Germanwings A320 crash.

Even though IATA, the global trade association for the airline industry, reassured a jittery flying public that air remains the safest way to travel, perhaps its time to take a hard look at airframe parachutes for commercial aircraft. That is, not for passengers buckled into the fuselage, but the aircraft itself.

The sky is going to get more and more crowded and there are going to be even more and more accidents, Boris Popov, Founder and CEO of Minneapolis-based BRS Aerospace, told Forbes. At some point, he says, major airframe manufacturers will be forced to include them as standard operating equipment to mitigate situations including: pilot incapacitation; mid-air collisions; mechanical failure; bird strikes; structural failure; pilot error; and even sabotage. Since 1993, Popovs company has been providing general aviation and a few aircraft legacy manufacturers with options for airframe parachutes. BRS notes that FAA-certified tests have shown that full parachute inflation could occur at altitudes as low as 260 feet and, thus far, notes that aircraft using his system have saved well over three hundred lives.

A recent BRS airframe parachute deployment during an airshow in Argentina. The pilot walked away unhurt. Credit: BRS Aerospace

The secret to our system, says Popov, is that it opens almost instantaneously. BRS rocket-propelled parachutes deploy from the back of the aircraft and accelerate to 100 mph. In less than a second, they provide a canopy that stretches tightly over the airframe. Once the aircraft is stable descends at a rate of some 21 feet-per-second which enables it to touchdown with an impact force akin to leaping to the ground from a height of roughly seven feet.

Cirrus and Flight Design already have BRS products as standard equipment and Popov says Cessna has made it an option on two of its models. He says his company has also tested systems capable of deploying parachute systems that can safely bring down 12 passenger commuter aircraft.

As for costs?

If our parachute tech exceeds 15 percent of the airplanes value, then buyers start to back off very quickly, said Popov.

But is the tech available to equip large Airbus- or Boeing Boeing-built turbofan jet aircraft flying at high altitude with cruise speeds pushing that of sound?

It basically requires a square foot of material to bring down one pound of aircraft, said Popov. For a 500,000-pound Boeing 757, youll need half a million square feet of parachute cloth.

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Airframe Parachutes Might Have Prevented The Germanwings Crash

Photodesorption of H2O, HDO, and D2O ice and its impact on fractionation

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Carina Arasa (1,2), Jesper Koning (1), Geert-Jan Kroes (1), Catherine Walsh (2), Ewine F. van Dishoeck (2,3) ((1) Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P. O. Box 9502, 2300 RA Leiden, The Netherlands, (2) Leiden Observatory, Leiden University, P. O. Box 9513, 2300 RA Leiden, The Netherlands, (3) Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748 Garching, Germany)

(Submitted on 2 Mar 2015)

The HDO/H2O ratio in interstellar gas is often used to draw conclusions on the origin of water in star-forming regions and on Earth. In cold cores and in the outer regions of protoplanetary disks, gas-phase water comes from photodesorption of water ice. We present fitting formulae for implementation in astrochemical models using photodesorption efficiencies for all water ice isotopologues obtained using classical molecular dynamics simulations. We investigate if the gas-phase HDO/H2O ratio reflects that present in the ice or whether fractionation can occur during photodesorption. Probabilities for the top four monolayers are presented for photodesorption of X (X=H,D) atoms, OX radicals, and X2O and HDO molecules following photodissociation of H2O, D2O, and HDO in H2O amorphous ice at temperatures from 10-100 K. Isotope effects are found for all products: (1) H atom photodesorption probabilities from H2O ice are larger than those for D atom photodesorption from D2O ice by a factor of 1.1; the ratio of H and D photodesorbed upon HDO photodissociation is a factor of 2. This process will enrich the ice in deuterium atoms over time; (2) the OD/OH photodesorption ratio upon D2O and H2O photodissociation is on average a factor of 2, but the ratio upon HDO photodissociation is almost constant at unity for all temperatures; (3) D atoms are more effective in kicking out neighbouring water molecules than H atoms. However, the ratio of the photodesorbed HDO and H2O molecules is equal to the HDO/H2O ratio in the ice, therefore, there is no isotope fractionation upon HDO and H2O photodesorption. Nevertheless, the enrichment of the ice in D atoms due to photodesorption can over time lead to an enhanced HDO/H2O ratio in the ice, and, when photodesorbed, also in the gas. The extent to which the ortho/para ratio of H2O can be modified by the photodesorption process is also discussed. (Abridged)

Comments: 12 pages, 3 figures, accepted for publication in Astronomy & Astrophysics

Subjects: Astrophysics of Galaxies (astro-ph.GA); Earth and Planetary Astrophysics (astro-ph.EP)

Cite as: arXiv:1503.00394 [astro-ph.GA](or arXiv:1503.00394v1 [astro-ph.GA] for this version)

Submission history

From: Catherine Walsh

[v1] Mon, 2 Mar 2015 02:19:34 GMT (202kb,D)

http://arxiv.org/abs/1503.00394

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Photodesorption of H2O, HDO, and D2O ice and its impact on fractionation

Higher Computing Artificial Intelligence Spider Diagram Revision – Video

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Higher Computing Artificial Intelligence Spider Diagram Revision
Intentionally missed out the Turing Test .... Revision video covering #39;all #39; of the elements in the AI unit of the course. This is an optional unit, so don #39;t worry if you are studying another!

By: Colin McAlpine

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Higher Computing Artificial Intelligence Spider Diagram Revision - Video

Ferram Aerospace Research Tutorial E02 Engines, Intakes, and Landing Gear – Video

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Ferram Aerospace Research Tutorial E02 Engines, Intakes, and Landing Gear
In this episode, we cover intakes: How many you need and the different types. Engines: How the thrust changes with speed, ect. Landing Gear: Pro #39;s and Con #39;s of the different configurations....

By: silentdeth

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Ferram Aerospace Research Tutorial E02 Engines, Intakes, and Landing Gear - Video

Ferram Aerospace Research Tutorial E03 Swept Wings and Control Surfaces – Video

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Ferram Aerospace Research Tutorial E03 Swept Wings and Control Surfaces
In this episode, we cover control surfaces and various forms of swept wings. A comprehensive tutorial series for the kerbal space program mod Ferram Aerospace Research aka FAR. Playlist:...

By: silentdeth

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Ferram Aerospace Research Tutorial E03 Swept Wings and Control Surfaces - Video