Feel free to use these quotes in your stories.  Any further comments will be posted here. If you would like to speak to an expert, please don’t hesitate to contact us on (08) 7120 8666 or by email.

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Jonathan Nally is a science writer and editor of the Australian space news web site, SpaceInfo.com.au (Sydney-based)

“The solar cycle and accompanying solar storm activity, rises and falls over a period of 11 years and has been doing so for billions of years.

NASA reports that the spectacular storm unleashed by the Sun this week is the second-largest (so far) of the current solar cycle. The cycle is on the rise at the moment and is forecast to peak in the next 12 months, so we can expect to see more of these storms.

Not all solar storms are ejected in a direction that aims at Earth, although this week’s one was and it has been predicted to reach us today.

These storms can induce effects in technological systems and have the potential to disrupt power grids, long pipelines, and terrestrial and satellite radio communications. But the effects are well understood and the operators of such systems are vigilant and well-prepared to take precautions that minimise or eliminate service interruptions.

Such “space weather” can also produce stunning aurorae – the Northern and Southern Lights – a harmless and beautiful side-effect of the phenomenon.

They can be seen from far northern and southern latitudes, but unfortunately most of Australia is too far north to see the Southern Lights.”

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Dr Alina Donea is an astrophysicist in the Monash Centre for Astrophysics, Monash University, Victoria

“With the solar cycle entering a more active phase, today’s solar flare is a sign of things to come. Our dependence on high tech communications systems has made us more vulnerable to such events but we should not panic. Previous flares have taught researchers lessons: we learned more about how to operate the instruments during extreme solar activity.

Solar flares are categorised by their size (according to the peak flux recorded in watts per square meter, W/m²), as an A, B, C, M or X class flare. A B-class solar flare releases 10 times more energy than an A-class flare, while a C-class eruption releases 10 times more than a class B flare (and 100 times more than class A) and so on. Within each letter class there is a finer scale from 1 to 9.

The most powerful flare measured with modern methods was in 2003, during the last solar maximum, and it was so powerful that it overloaded the sensors measuring it. The sensors cut out at X28.

This current flare is expected to be of a similar size as the Bastille Day Flare, which occurred on the 14^th February 2000. That flare was one of the largest geomagnetic storms of the previous solar cycle, accompanied by a massive coronal mass ejection and shock which was initially traveling at a speed of ~1800 km/s.

It was big enough to cause the earth’s magnetosphere to become extremely compressed and eroded (on the day-side), causing 3 geosynchronous satellites to enter the magnetosheath for an extended time period (3h). The Extreme ultraviolet Imaging Telescope (EIT) on NASA’s SOHO satellite found itself so bombarded by high flux from the sun that it became saturated and couldn’t record any useful readings.

The Sun also sent Solar energetic particles (SEPs) towards Earth. Through a series of chemical reactions in our atmosphere, these SEP protons drastically diminished the upper-most areas of the ozone layer, a protective blanket mostly in the stratosphere that blocks life-threatening ultraviolet radiation from reaching the Earth. This did not, however, result in a significant impact on human health, especially considering that most of the ozone loss documented in this study occurs over the northern polar region, they are important scientifically.

So, a general comment is that we should expect more or less a similar impact to the Earth.

A very important question for us in relation to these flares of March 2012 is:  has this March 2012 X5 flare produced a solar quake in the Sun? The Bastille Day flare did not generate a seismic event, but this one might have ignited a very big one. We will find the answer soon (the Monash University team works on this). If the flare generated a sunquake then our puzzle about why some flares produce quakes and other do not is even bigger.”

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A map of the satellite’s orbit around the Earth during the above window can be found here.

Below an expert in the area of space archaeology and space ‘junk’ provides a response below.

Feel free to use these quotes in your stories.  If you would like to speak to an expert, please don’t hesitate to contact us on (08) 7120 8666 or by email.

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Dr Alice Gorman is a lecturer in the Department of Archaeology, specialising in space archaeology, at Flinders University in SA. She is also an Adjunct Fellow of the Research School of Astronomy and Astrophysics at The Australian National University’s Mount Stromlo Observatory.

“Phobos-Grunt is a bit different to other recent spacecraft re-entries such as UARS and Rosat, as it was never intended to remain in its current form. Its original mission to Phobos would have seen the spacecraft separate into components – the main propulsion unit, the landing and return vehicles, and let’s not forget the Chinese satellite Yinghuo 1 – with only the sample return capsule having to make it back through Earth’s atmosphere.  Because it was stuck in low Earth orbit rather than heading towards Mars, this has meant that it’s full of fuel too. The fuel tanks, according to the Russian space agency, are made of aluminium.  More than 50 per cent of all re-entered spacecraft material is titanium, beryllium or steel, which has a melting point twice that of aluminium, so the likelihood of the fuel tanks surviving is very low. The fuel is reported to be hydrazine and nitrogen tetroxide, which boil at 113°C and 21°C respectively, so it will evaporate at high altitude once the tanks go.

If anything is likely to survive the fall to Earth, it’s the 11kg return capsule which has a heat shield and was of course designed for re-entry. But now it’s still attached to the entire spacecraft, so how it will fare is hard to say. I’d guess not very well.”

NASA’s Upper Atmosphere Research Satellite (UARS) returned to Earth on Saturday, (24 September) Australian time.   According to NASA, the satellite fell back to Earth between 1:23pm AEST and 3:09pm AEST. The precise re-entry time is still not known but NASA believes the satellite penetrated the atmosphere over the Pacific Ocean.

UARS was launched on 12 September 1991 and decommissioned on 15 December 2005. Its total dry mass is about 5.5 tonnes, compared to SkyLab which was about 77 tonnes. Debris from SkyLab landed in Western Australia in 1979. UARS is one of the largest NASA satellites to plunge back to Earth uncontrolled in the last 30 years.

RESOURCES:

Unofficial data provided by the Centre for Orbital and Re-entry Debris Studies (CORDS), had the expected re-entry time for the UARS satellite as 3.10pm Australian EST (05:10 UTC) ± 2 hours on Saturday 24 September.

A map showing the satellites’ ground track during the window of re-entry is at: http://reentrynews.aero.org/1991063b.html.

NASA have been providing semi-regular updates at: www.nasa.gov/mission_pages/uars/index.html

An authoritative source of tracking information including the current position of the UARS satellite (keep refreshing the page) can be found at: www.heavens-above.com/

A conceptual image of the satellite can be found at:  www.nasa.gov/mission_pages/uars/uars-concept.html (credit: NASA)

A video animation has also been prepared by AGI and is available at: http://blogs.agi.com/agi/?p=3756#comment-8339

Some useful background information on spacecraft reentry can be found at:  www.aero.org/capabilities/cords/reentry-overview.html

Feel free to use the quotes below in your stories.  Any further comments will be posted here. There are very few space debris experts in Australia but if you wish to speak to an expert, contact us on (08) 7120 8666 or by email.

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Jonathan Nally is a former editor of two space magazines and currently editor of the Australian Space News web site, SpaceInfo.com.au. He also appears regularly on Channel 9 and the ABC to discuss astronomical and spaceflight matters.

“Space junk comes in different shapes and sizes, and can poses two main kinds of threats — a threat to other spacecraft (unmanned and manned) through collisions, and threats to us down here on Earth.

The satellite making news at the moment — the former Upper Atmospheric Research Satellite, and better characterised as a decommissioned or defunct satellite rather than space junk — falls into the second category.

In 2005, NASA decommissioned UARS and intentionally placed it into an orbit a couple of hundred kilometres lower than its operational orbit.  This was done to accelerate is eventual demise, and means it is re-entering the atmosphere 20 years earlier than it otherwise would have done.

This was a very responsible thing to do. The longer a spacecraft stays in orbit, the more chance it has of being hit by other orbital debris, leading to a destructive breakup and therefore more bits of debris.

UARS poses a negligible threat to life and property on Earth. Most of the satellite will burn up during re-entry, with perhaps as many as 26 stronger or harder small pieces surviving to reach the surface.

But with the majority of Earth comprising oceans or uninhabited (or very sparsely inhabited) remote regions, the chances are overwhelming that any pieces of UARS that survive re-entry will fall harmlessly and never be seen again.

Because the spacecraft is no longer powered, NASA has no control over where it comes down. It is thought to be tumbling gently as it makes its final orbits. Friction with the thin upper atmosphere is slowly lowering its orbit, bit by bit, until sometime in the next 24 hours it reaches a low enough point and sufficient air friction so that it can no longer maintain orbital velocity. At this point it will begin to burn up and streak across the sky like a huge fireball. It would be quite something to see, but chances are that no one will witness it.

The other kind of space junk — bits of orbital debris that range from less than a millimetre wide up to entire spacecraft — is more of a worry. Space junk can damage or destroy an operational spacecraft, leading to loss of the asset and the service it provides.”

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Dr Alice Gorman is a lecturer in the Department of Archaeology, specialising in space archaeology, at Flinders University in SA.

“The UARS satellite re-entry is very reminiscent of Skylab in 1979 – there is the same exaggeration of the hazard through the media, public anxiety as the advance warning allows for speculation, and a lack of understanding of what the risks actually are. Should it land in Australia, we might expect the same rush for souvenirs as we saw with Skylab, as anything that has been in space has a special meaning on Earth.”

Last year the Hayabusa capsule landed in Woomera, South Australia, with a sample of asteroid dust. The dust has now been analysed and the results of the preliminary investigation are being published in Science on Friday 26 August.  Below two co-authors, including the only Australiant  involved in the research respond.

*Four papers published in Science on 26 August, 2011, including Irradiation History of Itokawa Regolith Material Deduced from Noble Gases in the Hayabusa Samples, Nagao et al., Science, 26 Aug 2011

Feel free to use these quotes in your stories.  Any further comments will be posted here. If you would like to speak to an expert, please don’t hesitate to contact us on (08) 7120 8666 or by email.

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Professor Trevor Ireland, Professor of Earth Chemistry, The Australian National University, and author on two of the papers.

“The Hayabusa mission has provided us with samples of a pristine asteroid – and what a message it contains. 

We can now unequivocally link the asteroids we see in space with meteorites that we collect on land.  There have been problems relating the nature of asteroids with meteorites because meteorites are ablated as they come in through the atmosphere.  The samples from Itokawa are the previously unknown ‘skin’ of an asteroid.  

It should be noted that the original intent was for a gun to fire into the surface of Itokawa when Hayabusa touched down, with the ejected sample collected into the sample chamber.  This would have provided us with a bulk sample of the asteroid to analyze.  However, a software interlock prevented the gun from firing.  This was seen as disappointing in that we did not get as much material returned as was intended.  

In hindsight though, a bulk sample would not necessarily have provided the same information as we have obtained from these small dust grains that sat on the very surface of the asteroid.  These were the samples we really wanted and these have been delivered back to us.

These samples illustrate the dynamic nature of the solar system.  The samples from the skin of the asteroid show that they have been exposed to cosmic rays and solar wind for less than 10 million years.  This is very young in solar system terms.  The ages of the parent bodies are over 4.5 billion years old, and when the parent body of Itokawa had a collision, material was broken off and reassembled into Itokawa and sent on an orbit through the inner solar system.

This demonstrates how the inner solar system asteroids are only with us for a short time (geologically speaking!).  They are ejected from the asteroid belt and their orbits will decay until they fall into the Sun, collide with the planets, or otherwise get accelerated away when they come in close proximity to the planets.”   

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Dr Michael Zolensky is the curatof of stratospheric dust at NASA’s Johnson Space Centre in Houston.  He was in Woomera in June 2010 assisting JAXA with their retrieval of the capsule. Dr Zolensky was a co-author of the papers.

“We have been analysing the samples with mounting excitement as we have realised how wonderful they are. Participation in this mission has been one of the highlights of my life. I am especially grateful to have been on the capsule recovery team in Woomera, an experience I can highly recommend.”

Australia and New Zealand are in the final stages of their bid to host a hugely ambitious new project to create a radio telescope 10,000 times more effective than the world’s current best. The radio telescope, known as the Square Kilometre Array (SKA), will help many projects including the search for Earth-like planets and intelligent life, exploring the first black holes and stars and looking at what happened just after the big bang. The SKA will be located in either Africa or Australia-New Zealand.

The speakers will be in Canada giving their presentations at a meeting in Banff and the embargo will lift after this (5.30 am AEST Thu 7 July).

Join the briefing to ask questions such as:

• What new things will this telescope actually enable us to do?
• Why do Australian scientists want the SKA?
• Why should the Australian public care?
• Why spend money on this particular project?

Watch the full briefing here (Webex)

See a bio notes for the speakers here (pdf)

SPEAKERS:

• Senator the Hon Kim Carr, Minister for Innovation, Industry, Science and Research, Australian Government | Listen (mp3)
• Dr Brian Boyle, anzSKA Project Director | Listen (mp3)
• Professor Peter Quinn, Director of The International Centre for Radio Astronomy Research | Listen (mp3)
• Listen to the Q and A session here (mp3)

BRIEFING DETAILS:

DATE:  Today, Wed 06 July

START TIME: 10am AEST

DURATION: 30 min

VENUE:  Online

For further information, please contact the AusSMC on 08 7120 8666 or email.