Astronomy expert Gary Sparks talks about the meteor shower caused by Comet Wirtanen. Video / Warren Buckland
A “very rare” meteor shower is set to light up Northland’s sky tonight, with those in the east predicted to have the best view of the phenomenon.
Hundreds of shooting stars are expected to appear as part of the one-off event caused by dust ejected from Comet 46P/Wirtanen.
The dust trail, which has formed into a “clump”, is headed towards Earth and will result in a meteor shower between 9pm and midnight.
According to MetService meteorologist John Law, conditions were looking favourable for Northland this evening, with only moderate cloud cover throughout the region.
The evening would be relatively clear, though he expected some clouds over the western parts of Northland, particularly in Dargaville and surrounds.
Wind would also play a factor in tonight’s viewing.
“There will be a southwesterly wind tonight so it will be pretty blustery, which means it’s likely the more western parts of the region will catch the clouds,” Law said.
“As you head to the east, you’ll be able to see the sky quite well due to better conditions, so hopefully it will mean a good chance to see the stars.
“While it will be pretty windy, it won’t be too cold, with temperature lows in Whangārei expected to sit at around 12-13 degrees.”
To mark the occasion, Planetarium North in Whangārei will be holding a public event tonight for those interested in viewing the meteor shower with others.
Director Peter Felhofer said there was every chance of a “rather dense” cometary dust trail, with a likelihood of hundreds of shooting stars per hour.
“Meteor showers are always an unknown and this is the first time Earth will go through this cometary dust trail, unlike Geminids or Orionids which we pass through on a yearly basis.
A one-off meteor shower will appear across the Northland night sky between 9pm-midnight tonight. Photo / 123RF
“We also don’t know how much solar wind has pushed and dispersed it since the trail started, but the opportunity to be surprised is there.
“I’m looking forward to the chance to look up and see some shooting stars which should be burning quite bright.”
Watching from a dark location wouldn’t be necessary, Felhofer said, thanks to the shooting stars still burning brightly when hitting the atmosphere.
Unless there were many cumulus clouds, it would be possible to see the stars even above high cirrus clouds.
“When we talk about 100 shooting stars, that’s about 1-2 per minute, so it won’t be raining with stars, but it would be awesome if it was.
“If you wanted to take a time-lapse of the event, that would look amazing.”
According to University of Otago geology professor James Scott, Wirtanen orbited the Earth every 5.4 years.
Professor James Scott, of the University of Otago.
This cometary dust trail was estimated to be just over a kilometre wide and was part of the Jupiter Family comet.
“Code 46P” stands for the 46th periodic comet to be identified, with the “P” meaning it had an orbital period of less than 200 years.
In 1972, Wirtanen passed extremely close to Jupiter, where a load of material was ejected.
This material, Scott said, had made several close passes to Earth but tonight’s event was believed to be the first time it would intersect Earth’s orbit.
“Therefore, we are viewing the birth of a meteor shower.
“The debris is travelling relatively slowly – about 10km a second – and the size of the particles is not well constrained, but is predicted to be quite small, on the centimetre to millimetre scale.
“That means it won’t drop meteorites but the debris will burn up in the atmosphere – hence giving rise to a meteor shower.
“The radiant – the area of the night sky the material is expected to come from – is near the southern constellation of Sculptor.”
An added complication (or bonus), he explained, was the Geminid meteor shower.
This event, which could reach hundreds of particles over the course of the night, would be coinciding with tonight’s Wirtanen meteor shower.
Because of the interception time, paired with uncertainty around the particles’ size, Scott said it was hard to predict just what tonight would look like.
