b'Geophysics in the surveysNewsFigure 5.Selected radiometric window from the 2021 Tasmanian Tiers airborne magnetic and radiometric survey. Shown as ternary images with Kred, Ublue and Thgreen, the original processed data (left hand side) is missing the sharpness of the 3D processed image (right hand side). Additionally, several areas with high counts and steep topography generate corrections in concentrations of over 50%. The full report with processed gridded data will be released through GA and MRT portals.International Atomic Energy Agency,spectrometric data. Extended Abstract,Mike Barlow Vienna. ASEG 24th International GeophysicalGeoscience Australia Minty, B and Brodie, R., 2015. The 3DConference and Exhibition, Perth, 15 -Mike.Barlow@ga.gov.auinversion of airborne gamma-ray18 February 2015.Henderson byte: How old is magnetism?An astronomer at CSIRO in Perth, Dr Tessa Vernstrom, is aiming to find out just how old is magnetism. Prior to coming to Australia in 2015, Vernstrom conducted her postdoctoral research at the Dunlap Institute at the University of Toronto, where a Sydney-born astronomer Dr Bryan Gaensler has been the Director since 2014. Dr Gaensler is a leader in the field of cosmic magnetism and is well known in Australia.As described in New Scientist (26 June, 2021), earlier this year astronomers led by Vernstrom detected magnetic field lines between two galaxies 50 million light years apart. The sheer extent of their existence suggests the fields could be relics from the birth of the universe. However, these fields are weaker the further the search goes back in time. This is where another Australian asset, the powerful Australian Square Kilometre Array (ASKA) telescope becomes vital. Gaensler says the field strength that we can now measure using ASKA is 100 times weaker than before.There is not sufficient space here to explain in detail the fascinating methods used to detect magnetic fields in the cosmos. Acommon way is to observe the alteration of certain characteristics caused by the presence of the fields. In one case recently discovered Fast Radio Bursts (FRBs) are polarised and twisted by the magnetic field as they pass through, causing what is known as Faraday rotation. More of these FRBs are being detected by ASKA and other arrays to provide the vast amounts of data needed to allow for the detection of magnetism earlier in time. Gaensler suggests that ultimately, with enough measurements, a map of the magnetism of the universe may be produced.The latest paper on the above discovery by Tessa Vernstrom and co-authors, to be published in August, is: Vernstrom, T, etal., 2021. Discovery of magnetic fields along stacked cosmic filaments as revealed by radio and X-ray emission. Monthly Notices of the Royal Astronomical Society, 505 (3).While colleagues of Vernstrom and Gaensler, in North America and Italy, are collaborating in this study, it is pleasing to note the strong Australian presence in this quest to find the age of magnetism.Roger Henderson rogah@tpg.com.auAUGUST 2021 PREVIEW 12'