Moon – Australian Science

Weekly Science Picks

Markus — Sun, 15 Dec 2013 00:12:55 +0000

It is with a heavy heart that I must say, this is my final set of Weekly Science Picks here on Australian Science. In fact, it’s to be the final set of Weekly Science Picks. Unfortunately, running a site like this one is a costly affair, and it’s been an honour to be a writer here over the past year and a half. Scientific progress will, of course, always carry on and I hope there will always be places to discuss new findings, implications, and effects of it on human culture and society.

So, proudly then, here are the final set of news stories which caught my eye this week. Make no mistake – there’s been some pretty cool news recently!

Firstly, and in my opinion most excitingly, is a medical breakthrough which could actually revolutionise surgery in the future. And anyone who knows me will know that I don’t use words like “revolutionise” lightly. Quite simply, the device is a small pen, developed by the Australian Research Council Centre of Excellence for Electromaterials Science (ACES), which will be able to deposit stem cells and growth factors directly into injuries. This means that this pen could help injured tissue – bones, muscle, and even nerves – to regrow. Oh, and did I mention it works using 3D printing technology?

BioPen to rewrite orthopaedic implants surgery

The BioPen prototype was designed and built using the 3D printing equipment in the labs at the University of Wollongong and was this week handed over to clinical partners at St Vincent’s Hospital Melbourne, led by Professor Peter Choong, who will work on optimising the cell material for use in clinical trials.

For a long time humans were considered unique in that we use tools where other animal species don’t. But since that old idea, more and more animals – from birds to octopodes – have been shown to use tools in their daily lives. The most recent addition to this collection of smart creatures is the crocodile which has been found to use lures while hunting. Perhaps this might help show that reptiles are smarter than we give them credit for!

Alligators and Crocodiles Use Tools to Hunt, in a First

Relatively less is known about crocodiles and alligators than many animals, because, as large predators, they are difficult to raise in the lab and study up close in the wild. Their cold-bloodedness also makes them slow. “They operate on a different time scale; they do things more slowly,” Burghardt said. “Sometimes we don’t have the patience to let them strut their stuff, as it were … so this kind of study is important.”

A huge plume of water has been spotted, gushing from the surface of Enceladus, Saturn’s tiny snowball moon. While the exact source of Enceladus’ warmth is still something of a mystery, this sighting means that its activity is quite clear – this water plume is reaching an altitude of around 201 km above the surface of the tiny world. That’s nearly ten times as high as Olympus Mons, the solar system’s largest mountain (which itself dwarfs Everest, the heighest mountain on Earth).

Hubble Space Telescope Sees Evidence of Water Vapor Venting off Jupiter Moon

“By far the simplest explanation for this water vapor is that it erupted from plumes on the surface of Europa,

Cite this article:
Hammonds M (2013-12-15 00:12:55). Weekly Science Picks. Australian Science. Retrieved: May 05, 2024, from http://australianscience.com.au/news/weekly-science-picks-58/
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Pluto’s new moons named: Spock still homeless

Kevin Orrman-Rossiter — Fri, 05 Jul 2013 00:09:08 +0000

This image, taken by the NASA/ESA Hubble Space Telescope, shows five moons orbiting Pluto, the distant, icy dwarf planet (ESA/Hubble/AFP/Showalter)

The dwarf planet, Pluto, can still generate plenty of public interest – if the naming of its two recently discovered moons is anything to go by. After their discovery, the leader of the research team, Mark Showalter, called for a public vote to suggest names for the two objects. The on-line contest, aptly named ‘Pluto Rocks!‘, concluded with Vulcan as the outright favorite, after a William Shatner led push by Star Trek fans. The names Cerberus and Styx ranking second and third respectively. The International Astronomical Union (IAU) has announced that the names Kerberos and Styx have officially been recognised for these fourth and fifth moons of Pluto. A decision that is probably correct, even if it proves not to be the most popular.

The moons of Pluto

The new moons were discovered in 2011 and 2012, during observations of the Pluto system made with the NASA/ESA Hubble Space Telescope. Their discovery increasing the number of known Pluto moons to five. Kerberos lies between the orbits of Nix and Hydra, two bigger moons discovered by Hubble in 2005, and Styx lies between Charon, the innermost and biggest moon, and Nix. Both have circular orbits assumed to be in the plane of the other satellites in the system. Kerberos has an estimated diameter of 13 to 34 kilometres, and Styx is thought to be irregular in shape and is 10 to 25 kilometres across.

Artist illustration of Pluto (centre) from one of its small moons. The largest moon Charon is on the right. Credit: NASA, ESA and G. Bacon (STScI)

The recent discoveries of the two small moons orbiting Pluto raise interesting new questions about how the dwarf planet formed. We now know that a total of four outer moons circle around a central “double-planet” comprising Pluto and its large, nearby moon Charon.

No home for Spock

The International Astronomical Union (IAU) is the arbiter of the naming process of celestial bodies, and is advised and supported by astronomers active in different fields. On discovery, astronomical objects receive unambiguous and official catalogue designations. When common names are assigned, the IAU rules ensure that the names work across different languages and cultures in order to support collaborative worldwide research and avoid confusion.

To be consistent with the names of the other Pluto satellites, the names had to be picked from classical European mythology, in particular with reference to the underworld — the realm where the souls of the deceased go in the afterlife. Showalter submitted Vulcan and Cerberus to the IAU where the Working Group for Planetary System Nomenclature (WGPSN) and the Committee on Small Body Nomenclature (WGSBN) discussed the names for approval.

After a final deliberation, the IAU Working Group and Committee agreed to change Cerberus to Kerberos — the Greek spelling of the word, to avoid confusion with an asteroid called 1865 Cerberus. According to mythology, Cerberus was a many-headed dog that guarded the entrance to the underworld. In keeping with the underworld theme the third most popular name was chosen — Styx, the name of the goddess who ruled over the underworld river, also called the Styx.

The IAU decided against the name Vulcan for a number of reasons: Vulcan had already been used for a hypothetical planet between Mercury and the Sun (although this planet was found not to exist), the term “vulcanoid

Cite this article:
Orrman-Rossiter K (2013-07-05 00:09:08). Pluto's new moons named: Spock still homeless. Australian Science. Retrieved: May 05, 2024, from http://australianscience.com.au/space/plutos-new-moons-named-spock-still-homeless/
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Giant Impact: making the moon

Charles Ebikeme — Fri, 19 Oct 2012 07:28:44 +0000

It began… where it always begins — out there — in the vastness of space. What would it look like, that void of empty nothingness? So early on in the sound of creation, indescribable things all around. Not yet planets, not yet moons. Not yet defined. A titanic mass of rock. Different. Ugly and melancholic. Mischievous and cumbersome. As immediately as it’s gone, another smaller rock — about a tenth the size of its predecessor — in the other direction. We will come to realise that they are almost on the same path. A perilous planetary orbit around our sun.

One is a destroyer. The other is to be destroyed. The larger mass continues to grow as it gobbles up remnants from a cloud of dust. A hot, violent place with molten rock mantles wrapped around a dense hot core. On the other side of our sun swings the smaller mass. Both will have the same fate. On the far side, they collide. A cataclysm of apocalyptic proportions. In the vacuum/vacuous of space not a sound is heard. The smaller rock ploughs into its destroyer, like the little man in a fight with a lot to prove. It sinks deep into its molten core. Spiralling vast amounts of debris in long arcs into orbit. Debris, drawn together by nothing more simple than gravity, clump together, forging something close to a primitive moon. And with primitive moons come primitive planets. Finally, one defines the other.

This has always been the theory… at least, more eloquently put in the form of maths, calculations, numbers and analysis. The origin of our Moon by giant impact has always been the leading theory. Leading because it is able to explain so many features of the Earth-Moon system. From it’s current spin and angular momentum to its composition. Both Earth and Moon are very similar in their oxygen, tungsten, chromium, and titanium isotopes — leading to the logical conclusion that one was formed from the other, since these isotopes vary differently in different planetary bodies and meteorites.

However, simulations have shown this not to be the case. It is the Moon that should have a similar isotopic composition to the smaller impactor in this scenario, but instead it is made up mostly of material from Earth. Researchers had been tinkering around with the permutations and combinations to find such a scenario of impact that could satisfy all conditions. But to date, none had come close.

In papers published in Science by researchers from Harvard and the Southwest Research Institute, a new model is proposed. One that adequately accounts for a similarity in composition while also coming out with an appropriate mass for Earth and Moon. One paper describes two bodies of similar mass colliding slowly, while the other describes a giant erosive impact (with a small impactor) happening really fast. Both have the same solution to the problem. That is to have the Earth-Moon system losing angular momentum over time, reaching its present state through the Sun’s gravitational influence. Thereby, in the end, both coming to a compromise in explaining the physics and the overall geo-chemistry of the Earth-Moon system.

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Neil Armstrong’s speech in Sydney 24 August 2011

Alan Kerlin — Sun, 26 Aug 2012 15:21:44 +0000

UPDATE: Regrettably, the CPA engaged lawyers to threaten me with everything they could think of if I didn’t pull the recording (below). So pull it I have. Please feel free to pass on any feelings about this to them. At least for the time it was available, about 500 people got to hear the great man’s words. All is not lost though. I have a contact in the US who is friends with one of the family. When the time is right, I hope she will be able to raise the issue with him. Too soon right now of course.

On 20 July 1969, my entire school in the very young city of Canberra packed into the hall to watch Neil Armstrong step onto the Moon. The school’s only television set was tiny, and my only real memories of that historic day were black and white blobs on the television screen, and teachers constantly shushing all the children.

But I did witness the event, and it is one of the earliest endures memories I have from my childhood – certainly the earliest world event I can recall. As an inspiration, the Moon landings – this first one, and all the others that followed – laid the foundation for an education in science.

On 24 August 2011, Neil Armstrong delivered a very rare and unique speech in Sydney. And it was to rekindle in me an interest in science and space exploration that had laid essentially dormant for many years.

Neil Armstrong delivering his speech in Sydney, 20 August 2011

Somewhat curiously, the event was the 125th Anniversary of the Certified Practising Accountants Australia. The CPA’s CEO Alex Malley pulled off a real coup, based on the knowledge that Armstrong’s father Steven had been an auditor.

Courtesy of my wife being a CPA, I was privileged to attend that incredible event with her. I recorded the entire speech, plus about one hour of questions and answers after that, but I was only using a cheap point-and-shoot camera, picking up the sound through the PA system. I haven’t published it beforehand though, not wanted to circumvent any speaking tours he might undertake.

However, one year and one day following that event, the man who inspired so many of us has passed away, following complications stemming from heart surgery he had a couple of weeks ago. So I feel there’s now a responsibility to get his words out there for everyone.

The speech is about 42 minutes. It doesn’t include the questions and answers – I’ll post that as soon as can get get the editing done.

CPA Australia also published an extended interview with Armstrong. The introduction to that interview contained these prophetic words:

“Rarely, if ever again, will Neil Armstrong conduct an interview such as this.”

Nor a speech like this one…

A sad sad day.

Cite this article:
Kerlin A (2012-08-26 15:21:44). Neil Armstrong's speech in Sydney 24 August 2011. Australian Science. Retrieved: May 05, 2024, from http://australianscience.com.au/history/neil-armstrongs-speech-in-sydney-24-august-2011/
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The whole Earth-side of the Moon should be protected forever

Alan Kerlin — Thu, 09 Aug 2012 06:57:56 +0000

Apollo 12 landing site, taken from NASA's Lunar Reconnaissance Orbiter in 2011

Earlier this year, the New York Times had an interesting piece about museums seeking to protect small areas of the Moon around the Apollo landing sites. And a good thing too: “…the next generation of people visiting the moon might carelessly obliterate the site of one of humanity’s greatest accomplishments.”

More recently, NASA has released draft guidelines around protecting the landing sites from damage.

But isn’t that a bit like how Cairo almost swallows the Pyramids?

Surely we need to go further? Much further?

For thousands of years, all of Earth-bound humanity will gaze up on the Earth side of the Moon. And it’s exactly the same view looked upon by all of humanity throughout history.

Surely that whole view is worthy of protection? After all, any changes made that are visible from Earth will be visible forever. There’s no atmosphere or weather to sweep away our transgressions over time. What is done on the Moon stays done…

I raised these concerns with a NASA engineer a couple of years ago after his presentation at the Questacon national science museum about the (now ill-fated) Constellation project to return to the Moon.

It seemed to me that the American disposable society mantra was writ large in their plans, with leftover bits free to crashland wherever once done with. It’s that sort of mentality that’s got us into a spacejunk problem in Earth orbit.

I have no doubt that there will come a day – possibly while I’m still alive – that we are strip-mining parts of the Moon for minerals to build spaceships and Moonbase buildings and to fuel them.

But surely there should be a commitment from all nations for this sort of permanent scarring to be limited to the far side (the incorrectly named dark side!) of the Moon only. And for communications facilities and potentially colonies to be positioned around the Earthside perimeter for minimal visual impact, while maintaining direct communications.

There should also be strict controls on escape of artificial light. Surely the sort of light pollution that we spew pointlessly upwards from our Earth should not be shining back at us one day from the Moon?

We owe our future generations that much, I believe.

And while looking back – enjoy this handheld footage of the Earthrise, from Apollo 10, right out at the Moon, to very fitting music:

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Who found the water on the Moon?

Kevin Orrman-Rossiter — Mon, 26 Mar 2012 07:06:39 +0000

At just over two tonnes, the second stage of an Atlas V rocket, makes for an unusual ‘kinetic probe’. Nonetheless on October 9, 2009 NASA deliberately impacted a spent Centaur rocket into the lunar south polar crater Cabeus. The target area was a permanently shadowed region within this crater. The impact, not surprisingly, ejected a spectacular plume of debris, dust and vapour.

Science experiment, observe the system, perturb it, and measure what happens

The US scientists had thrown a heavy object at the Moon. They then threw all the instruments possible to monitor the impact. The prize was a decades-long search to directly find water on the Moon.

The impact would have been majestic to watch. Picture those slow motion images of Apollo astronauts on the Moon. Hold that thought and then imagine the impact. An observer could marvel at the slow motion, low gravity, return of the dust and debris cloud to the Moon’s surface. If you could see in the infra-red, the impact flash lasts for 10 seconds. There is a cloud of debris, dust, and vapour rising. At eight seconds the the ejecta cloud is 4.5km in diameter, in the ultra-violet spectrum, the plume is 10km in diameter. At 20 seconds after impact the ejecta cloud was is at its maximum diameter of 8.5km and the plume has reduced to little less than 10km.

The observer would be watching a science experiment on a grand scale.

The observer in this experiment was neither you nor I, it was a trailing “shepherding spacecraft”. The Centaur had propelled NASA’s Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite to the Moon. Shortly after launch the Lunar Reconnaissance Orbiter had separated to go on its own mission. Once in lunar orbit the Centaur had vented its remaining fuel. Control was then assumed, for the next four months, by the Lunar Crater Observation and Sensing Satellite as the shepherding satellite. During this next period the shepherding satellite maneuvered the Centaur to allow the Sun to bake-out residual water and volatiles. This was to ensure that no contaminant chemicals were passengers to the lunar impact site. The Centaur’s fuel was a volatile combination of liquid hydrogen and liquid oxygen, both chemicals that were to be scanned for in the impact cloud. The Lunar Crater Observation and Sensing Satellite also calibrated its instruments, then targeted the Centaur to impact with the Moon. Four months of meticulous preparation.

LCROSS spacecraft with Centaur stage, image credit NASA

The Lunar Crater Observation and Sensing Satellite carried nine instruments, including cameras, spectrometers and a radiometer. The spectrometers measured the reflected light at different wavelengths. These enabled the identification of the chemicals present in the ejected cloud.

Near-infrared absorbance attributeble to water vapour and ice, and ultraviolet emissions attributable to hydroxyl radicals (OH-) support the presence of water in the debris. The researchers determined from these observations that there was over 5%, by mass, of water ice in the lunar regolith of the impact site. Certainly this is small by terrestrial soil standards, but more substantial than most earlier estimates.

Over a year after the impact, in the October 22, 2010 issue of the journal Science, the results of this experiment were delivered to the world’s attention. This certainly marked a defining moment for lunar scientists, directly confirming the availability of water on the moon. It was however neither the first nor last word on this.

Cabeus crater LCROSS impact site, photo credit NASA

Early attempts

Since the first lunar sample were carried back to earth by Apollo astronauts in the late 1960s, scientists have operated under the presumption that the moon was entirely dry. In total 382kg of lunar material was bought to Earth by the Apollo missions astronauts and a further 0.32kg by the unmanned USSR Lunar missions. New analyses of these rocks with improved analytical techniques have made it possible to perform highly sensitive isotopic measurements on very small lunar grains. These analyses are revealing water in Apollo samples that were once thought to be dry.

Well before these new studies, scientists had been puzzling about why more water was not seen on the moon. It was thought that volatile materials, such as water, could be accumulating at the moon’s permanently shaded polar regions. Here they could be trapped for geological periods of time without significant loss. The in 1998, the orbiting Lunar Prospector spacecraft measured the the abundance of elements on the moon’s surface using neutron spectroscopy. This provided compelling evidence for enhanced hydrogen concentrations, and by inference water, at both of the lunar poles.

In 1999 the Cassini spacecraft flew by the moon on its way to Saturn. It turned its Visual and Infrared Mapping Spectrometer to the moon. By measuring the surface reflectance of light from the moon scientists found absorption attributed to hydroxyl and water on the sunlit surface of the moon. These results were not published until 10 years later, in October 2009. The reason was renewed interest in water on the moon.

On October 22, 2008 Chandrayaan-1 was launched on a lunar mission by the Indian Space Research Organisation. One of its major scientific missions was to look for water on the moon. It had three different instruments ready to make 2008-10 an interesting period for lunar water exploration.

Chandrayaan-1, India’s lunar water finder

The Chandrayaan-1 story is told in detail elsewhere. Here I intend to showcase the marvelous outcome of Chandrayaan-1’s water finding experiments. Perhaps the most exciting of all these was one of the simplest. This was the CHandra’s Altitudinal Composition Explorer (CHACE) on board the Moon Impact Probe.

On November 14 2008 (the birthday of the late Pandit Jawaharlal Nehru, India’s 1st Prime Minister) the Moon Impact Probe became the first Indian built object to reach the surface of the Moon. The probe was a 34kg box-shaped object containing a video image system, radar altimeter, and The CHACE mass spectrometer.

Symbolically the Indian tricolour was painted on three sides of the Moon Impact Probe. This enables India to also lay claim to having the “Indian tricolour placed on the Moon”. Needless to say that “placing” in this case was a hard landing in the Moon’s south polar region near the Shackleton crater, flying over the Malapert mountain en route.

The CHACE mass spectrometer took 650 spectra of the tenuous lunar atmosphere during its 1487 second, 98km, plunge to the lunar surface. Tenuous is right the atmosphere even on the sunlit side is only 7/10,000,000,000th of the Earth’s atmosphere.

The mass spectrometer was tuned to look find water and direct evidence of water it did find. The team leader of the experiment, Dr S M Ahmed, remembers, “We all were jumping when we saw water was literally pouring out of our instrument

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