Astrophiz 89: Dr Andy Tomkins

 

Astrophiz 89: Dr Andy Tomkins – Meteorites, Life on Mars & Fireballs in the Sky.

Listen: https://soundcloud.com/astrophiz/astrophiz-89-dr-andy-tomkins-meteorites
Dr Andy Tomkins conducts analyses of meteorites and applies his research looking for evidence of life on Mars. Andy is an associate Professor in the School of Atmosphere and Environment at Monash University in Melbourne Australia, and he and his team of PhDs and Honours students have collected over a third of Australia’s extensive meteorite haul, often from the vast and inhospitable Nullarbor Plain and they are one of the local driving forces of the Citizen Science project, ‘Fireballs in the Sky’.

Then, in ‘What’s Up Doc’ our regular host Dr Ian Musgrave tells us what observers and astrophotographers can look for in the skies for the next two weeks and in ’Ian’s Tangent’ he tells us about the re-discovery of ‘Snoopy’ the command module from Apollo 10  which was presumably lost in space.

In the News:
Our first story is from the NASA website:

“Mystery of Purple Lights in Sky Solved With Help From Citizen Scientists”

From 2015 to 2016, citizen scientists — people who are excited about a science field but don’t necessarily have a formal educational background — shared over 30 reports of  mysterious lights associated with Auroras,  in online forums and with a team of scientists that run a project called Aurorasaurus. The citizen science project, funded by NASA and the National Science Foundation, tracks the aurora borealis through user-submitted reports and tweets.

 

The Aurorasaurus team, led by Liz MacDonald, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, conferred to determine the identity of this mysterious phenomenon. 

MacDonald and her colleague Eric Donovan at the University of Calgary in Canada talked with the main contributors of these images, amateur photographers in a Facebook group called Alberta Aurora Chasers, which included Notanee Bourassa and lead administrator Chris Ratzlaff. Ratzlaff gave the phenomenon a fun, new name, Steve, and it stuck.

But people still didn’t know what it was.

Scientists’ understanding of Steve changed on a night that Bourassa snapped his pictures, because Bourassa wasn’t the only one observing Steve. Ground-based all-sky cameras, run by the University of Calgary and University of California, Berkeley, took pictures of large areas of the sky and captured Steve and the auroral display far to the north and up in space, ESA’s (the European Space Agency) Swarm satellite just happened to be passing over the exact area at the same time and documented Steve as well.

For the first time, scientists had ground and satellite views of Steve, and have now learned, despite its ordinary name, that Steve may be an extraordinary puzzle piece in painting a better picture of how Earth’s magnetic fields function and interact with charged particles in space. Their fantastic findings are published in a study just released in Science Advances. You can read it in full at tinyurlDOTcom/aurorasteve because it is not behind a predatory journal paywall.


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And here’s another interesting story. We have been reporting on the SKA regularly since we started this podcast back in 2016 and The construction of the Square Kilometre Array (SKA) in South Africa and Australia has become the feather in the cap of both country’s scientific communities. 

When completed in the mid-2020s the South African SKA will have 197 dishes searching for faint radio signals from distant stars and galaxies.

Now South Africa’s sparsely populated Northern Cape province, near the town of Carnarvon, is the perfect location for this international scientific endeavour: sprawling farms separate towns that are small and far-flung, keeping radio interference to a minimum.

Except, ironically, nobody thought to look up. Above Carnarvon at 35,000 feet is the flight path connecting Capetown and Jo’burg, with over 50 scheduled flights a day.

Now back in 2007, South Africa’s government passed the Astronomy Geographic Advantage Act protecting the “Karoo Central Astronomy Advantage Areas,” where the SKA is located. According to the act, the use of the radio frequency spectrum from100 megahertz to 25.5 gigahertz – is prohibited in that region, and that includes all of the frequencies that are allocated for the use of aviation.

It’s worth noting that the act specifically excludes aviation for now, but the door is open for the ministers of Transport and Science and Technology to agree on “measures necessary for the protection of the Karoo Core and Central Astronomy Advantage Areas.”

To find a solution a technical working group has been formed, with representatives from the SKA, Department of Transport, Department of Science and Technology, Civil Aviation Authority, the aviation industry and Air Traffic Navigation Services (ATNS), the agency responsible for the country’s airspace management.

So there you have it, the aviation industry versus science, this will be a good one to watch play out.

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Finally, Another continuing story we are following here at Astrophiz is the ongoing quest to find the cause of FRBs, fast radio Bursts.

In a new paper, accepted into The Astrophysical Journal, and currently available on the pre-print resource arXiv, the research team behind this work has analysed the magnetar XTE J1810-197’s low-frequency radio output.

According to their analysis of XTE J1810-197, the millisecond bursts of low-frequency radio waves sputtered out by the magnetar show an unusual similarity to FRB signals. It’s far from conclusive proof that the two phenomena are linked, but it’s one of the most tantalising hints yet.

A reminder that Magnetars are neutron stars with extremely strong magnetic fields (over a quadrillion times stronger than Earth’s magnetic field). Scientists first spotted the magnetar XTE J1810−197 after an X-ray outburst in 2003, and in 2004, researchers detected a radio emission from the source. The magnetar produced the first transient radio emission ever detected by scientists. But after a few years of emitting variable radio emissions, the magnetar went quiet in 2008. 

Then it reactivated last year in December 2018. Scientists detected a bright, pulsed radio signal at 1.52 gigahertz (GHz) coming from the magnetar, the second radio outburst observed from this source. A strange and exciting observation, scientists led by Yogesh Maan of the Netherlands Institute for Radio Astronomy, launched an investigation of the object, studying it at low radio frequencies using the Giant Metrewave Radio Telescope (GMRT). 

The team, found that radio bursts from this magnetar are relatively narrow, it is also relatively strong, the researchers found. 

“The bursts exhibit spectral structures which cannot be explained by interstellar propagation effects,” the team of astronomers wrote in the paper describing their findings, which was published Aug. 12 in the preprint journal arXiv, stating that the bursts from XTE J1810−197 don’t disseminate in space as expected.

Now if anyone would like a Nobel Prize, join the race to identify the cause of FRBs. Or just do it because your curious and you like a challenge. Now go!

 

 

 

https://soundcloud.com/astrophiz/astrophiz-89-dr-andy-tomkins-meteorites