Catch a falling star – meteor search

There is a little bit of magic in the air when a shooting star is spotted streaking across our skies. But how many shooting stars are there falling to Earth? The Global Meteor Network wants us to start shooting the shooting stars.  

Global Meteor Network (GMN) is a network of over 450 cameras pointing to our night skies across 23 countries hosted by both amateur and professional astronomers. They aim to capture the hundreds of tonnes of small objects, mostly meteors, as they fall to the Earth viewed as shooting stars. If two cameras are aiming at the same part of the sky, meteor orbits can be calculated to establish where in the Solar System the meteor came from.  

Led by Canadian Western University’s Denis Vida, the GMN project aims to establish a network of cameras to observe meteor activity across as much of the night sky, across the world.

“The main operational goal of the project is to establish a decentralized, science-grade instrument which observes the night sky every night of the year from as many locations around the world as possible,” said Vida, a postdoctoral associate in Western’s department of physics and astronomy.

“A few friends and I realized that we can use low-cost Raspberry Pi single-board computers and reduce the cost of a single meteor observing system by 10 times, allowing us to install many more cameras than was previously possible,” said Vida.

The massive array of cameras that form the GMN are increasing as more people around the world join in on the hunt for the meteors.  

So, what’s the difference between a meteoroid, a meteor, and a meteorite? It’s the same object just at a different place. 

A meteoroid can be as tiny as a grain of sand or as large as a small asteroid. When it's an object in space, it's a meteoroid.

When a meteoroid enters Earth’s atmosphere at high speed, it ignites and becomes a meteor or a shooting star. Larger meteors are also called fireballs. A meteor shower is when a larger number of meteoroid activity happens at regular intervals and are usually named for the star or constellation that is close to where the meteors appear in the sky. The most well-known meteor shower is Perseids, which occur in August each year. The Perseid meteors are fragments of the comet Swift-Tuttle.

If a meteor survives to hit the ground, it is called a meteorite. Very few meteorites are able to be found and recovered.

Meteor astronomers, like Western University’s Denis, have a unique challenge to get their data. Unlike other fields of astronomy, where the objects of interest such as planets or distant galaxies are usually so far away that they can be observed from virtually any point on the globe, meteors occur much closer to Earth and most burn up in the atmosphere at heights of around 100 km. 

“Other astronomers can pool their resources to build a big telescope on top of a mountain where the skies are dark and clear year-round, but meteor astronomers need spatial coverage most of all,” said Vida.

GMN started when Vida was an undergraduate student. The first system was installed at Western University in 2017. Since then, it has continued to grow with cameras now in Alberta, Ontario and Quebec, as well as the UK, Spain, Belgium, Croatia and Brazil. 

To date, there are only two cameras located in Australia - Melbourne and Western Australia - while there are also two in New Zealand’s South Island with Jeremy Taylor’s Tasmanskies blog detailing his passion for the meteor hunt. 

“Having discovered meteor monitoring and seen how easy it is to get involved, I have been trying to raise visibility for the GMN project in the Southern Hemisphere,” said Jeremy. 

“It’s the sort of project anyone with an interest in space and astronomy can get involved with, even if they cannot afford visual telescope or astrograph equipment. The camera and lens used in a GMN RMS come to less than NZ$100; everything else is either control-and-communication electronics or weather sealing.” 

So how did the GMN project end up on the South Island of New Zealand?

“Hamish Barker, the convenor of the local astronomy club (Nelson Science Society’s Astronomy Section) asked if I was interested in building a GMN RMS and covering the same volume of sky as the station he had already established,"  said Jeremy.

“I like the idea of astronomy having a low barrier to entry or activity. The GMN RMS station I set up at his prompting is constantly working every night now, without my active effort. I also like the fact that I am contributing in some small way to real astronomy research. 

“For instance, longer-term, I would like to get equipment together for routine sky surveying for asteroid and comet hunting, and collecting data for AAVSO. Hamish collects spectra for the ASAS-SN project, which is pretty cool. The GMN project offered me what I think is an easy way to contribute in a real way to the field of astronomy, without a daunting cost threshold and without the gatekeeping that can close off other opportunities for contribution.

“In addition to knowing that my data could, maybe, be useful to Dr Denis Vida and other researchers, it is also simply cool each morning to check my dashboard and see a timelapse of the sky to the south from the previous night, a stack of all the detected meteors, and a plot associating them with radiants. I can look up a plot that shows the paths through the sky of meteors detected by both my camera and the ones I overlap with.

“Can I do anything practical with this myself? Not really, but I get a kick out of it. I can share it on social media, and that is arguably better than a selfie. Certainly a selfie of me.”

While other projects also capture meteors such as Desert Fireball Network(DFN), the data captured by GMN is shared using CCBY-4.0 making it available for anyone to access and use.  

“Overall, it is important that we increase the amount of sky being monitored because we have a blind spot when it comes to meteoroid monitoring. I have every confidence that the researchers behind different projects, be they global projects like CAMS or GMN or regional ones like DFN, will contribute to each other’s work when possible,” said Jeremy 

Through the network, meteorite locations have even been determined with the recovery of rare meteorites in the UK earlier this year.

Several GMN cameras in the UK tracked the fireball together with other meteor networks, leading to important data retrieval and its discovery in Winchcombe, the UK, in March this year. Scientists recovered almost 300 grams of an extremely rare type of meteorite called carbonaceous chondrite, which has been known to contain organics and amino acids – ingredients for life.  

“So far, this is only the fifth meteorite of this type with a known orbit, and the most pristine one because it was recovered immediately after the fall,” said Vida.

“Imagine you take some eggs, flour, and sugar. You follow a recipe, mix them together and bake them in the oven. Voila, you have nice cake,” said Vida. “The cake is our Solar System. Baked, mixed, changed. In this analogy, carbonaceous chondrites are a chunky mix of eggs, flour and sugar that somehow ended up in the freezer, and we’re using them now to figure out how the cake, in this case, the Solar System, was made.”

Vida says carbonaceous chondrites are also very important because they contain presolar grains, which are small dust particles even older than the Sun.

“They are rare, direct evidence for liquid water outside the Earth,” said Vida. “Some contain up to 20 per cent water, and are full of organic compounds, including amino acids.”

Inspired by the Winchcombe meteorite find, more than 150 meteor enthusiasts in the UK are eager to install GMN cameras. 

“There are already more than 100 existing ones in the UK, so that’s really exciting,” said Vida. “Its role in the recovery and analysis of the Winchcombe meteorite fall is proof positive that GMN works.” 

If you’re after a citizen science project during the lockdown, this could be the one for you. The initial setup costs will come to around \$400 - \$500 with support and information on what equipment is needed and how to set up cameras available on the GMN site.

Once operational, dashboards are available to view image stacks of the previous night’s captures as well as radiant charts to show the part of the sky the meteors come from. If there is more than one camera in your vicinity, you may even be able to contribute to greater data sets.  

If you want to find out more about setting up your own meteor camera, as well as more information on how your own meteor observations as a citizen scientist can contribute to understanding our solar system, take a look at the wiki on www.globalmeteornetwork.org.

For the locations of all the GMN cameras, the latest data is available for anyone to explore, via the website: https://tammojan.github.io/meteormap/