A rocky landing somewhere
EARTH isn’t the beall and endall of everything and occasionally it is good to be reminded of that.
As we go about our busy, sometimes selfimportant, intermittently futile, lives on the surface of this planet, it is all too easy to forget there are a lot of things, and a lot of things happening, “out there”, beyond our world and our influence.
It does us no harm to feel minuscule and unimportant in the grand scheme of matters, and to be awestruck by the scale and majesty of something far greater.
This is not some kind of advertisement for religion, or an attempt to promote any particular god. Instead, it is about the need for humankind, with its sometimes greedy, violent and ugly side, to feel small and insignificant and ephemeral. Its really good for our collective ego.
Just sporadically, something from that realm beyond our atmosphere reaches out — to use the awful parlance of the day — to us, and offers earthlings a tangible connection to the bigger picture.
And that is why a group of enthusiasts with an eye on the skies have been marching and stamping their way across Otago paddocks, farmland and hillsides in the past week, on the lookout for a piece of something wonderful from another space and time.
Late on Sunday August 28, a meteor arced across the South Island skies, seen from Dunedin to Queenstown and Oamaru to Invercargill.
It was a fireball of extraordinary brilliance, whose dazzling trail was caught on a network of five nightsky cameras deployed at locations including the Beverly Begg Observatory in Dunedin and Dunstan High School in Alexandra to record just such a moment.
The experts at the evocatively named group Fireballs Aotearoa then calculated that a meteorite landed somewhere in the middle of the group’s network, somewhere west of Outram and southeast of Middlemarch.
Within a few days, the search was under way, with locals and University of Otago geology students beginning the hunt and scouring the hills for what was believed would be a black metallic rock about 1kg in weight, lying within or close to a crater of about 1m in diameter.
Master’s student Thomas Stevenson homed in on the space rock’s location by looking at close to 1000 drone images of a 4-square-kilometre area on a Lee Stream farm.
Observers and scientists now think the meteorite may be a lot larger than originally believed, and could be as heavy as 30kg, lying in a severalmetrewide crater. It is also possible its impact site could be beyond the initial search area, with physicists and others using weather models and the like to establish a more precise location.
So why go to all this bother about a rock? And what can we learn from meteorites, which are relatively rare arrivals into New Zealand?
In the past 150 years, only nine meteorites have been confirmed as falling here. One of the most wellknown was the last of those, a 1.3kg, four billionold rock which blasted through a roof in Ellerslie, Auckland, bounced off a sofa and finished up on the floor of the lounge.
As well as their intrinsic scientific interest, because of their mysterious origins and their rarity, detailed analysis of meteorites helps scientists better understand the Solar System, where all meteors come from.
Most are shards of ironnickel asteroids which fractured many million of years ago. We see these meteor showers when the Earth moves through the debris trail of either asteroids or comets.
It is in our interest to know as much about asteroids as we can. Scientists recognise that the scenario of an asteroid hitting Earth poses one of the biggest threats to our continuing existence.
Sixtysix million years ago, just such a collision led to the extinction of the dinosaurs. If we learn more about the asteroids, it may be possible to take steps to avoid or minimise such a devastating impact in future.