The Grand Eclipse Expedition of 2023

by

Richard (Rick) Tonello

Chief Astronomer GDC Observatory

On the 20^th April 2023, along the sun drenched coastline of the Cape Range National Park, the Solar System will put on a spectacular show that will attract tens of thousands of people from across Australia and the world.

This celestial event will showcase the precision clockwork of the Solar System as the Sun, Moon and Earth perfectly align to create the spectacular phenomenon known as a Total Solar Eclipse.

Starting in the Great Southern Ocean, the shadow of the Moon will race across the surface of Earth at over 2700Km/h, skim over the Exmouth Peninsula and race northward from the Australian continent toward Timor-Leste and the Pacific Ocean.

For people along the narrow “Line of Totality” they will witness the Moon completely cover the blinding disc of the Sun revealing the complex structure of the Solar Corona. For a brief 62 seconds, observers will be plunged into an eerie twilight and the sky looking like a bullet has pierced its familiar continuum.

While there is a Total Solar Eclipse every 18 months somewhere around the world, this eclipse is special. The 2023 event is a rare Hybrid Eclipse that occurs once every decade. A Hybrid Eclipse is where the distance between the Earth and Moon is so finely balanced, that the curvature of Earth influences how much of the Moon covers the disc of the Sun. From the starting point in the Great Southern Ocean any observers will see an Annular Solar Eclipse, from Exmouth observers will see a Total Solar Eclipse.

Astronomers from the Gravity Discovery Centre Observatory will be on an expedition to Exmouth to observe, photograph and live stream the entire Total Solar Eclipse from the line of totality.

Live images will be provided from two, specialised Solar Telescopes and high-resolution cameras. One telescope will observe the Photosphere (Light Sphere), the surface of the Sun, while the other telescope will observe the Chromosphere (Colour Sphere), the dynamic layer located above the photosphere.

The broadcast provided by the GDC Total Solar Eclipse Expedition will be broadcasted to their FaceBook Page and YouTube Channel.

Local Media, social media and other organisations will pick up the GDC Observatory Total Solar Eclipse broadcast on the day of the Eclipse. Organisations such as Tourism WA, the Museum of Western Australia, the Singapore Science Centre, and to the Yagan Square Multimedia Screen are just a few of the organisations to utilise the live stream.

Those who are not observing from the Path of Totality will observe a Partial Solar Eclipse. Depending on the distance of the Observer from the path of Totality, the less of the Sun’s blinding disc will be obscured by the Moon.

Observers from Perth will witness a little over 70% of the Sun’s disc obscured by the Moon. Even though a majority of the Sun’s disc is covered, it is still dangerous to observe without the proper eye protection.  Never look directly at the Sun, even during the Partially Eclipsed phases. Even a 99% obscured Sun is enough to cause Solar Retinopathy (irreversible eye damage). Always use approved Solar Viewing Equipment (Eclipse Glasses) with the ISO 12312-2:2015 markings.

There are many ways to enjoy the Partial Eclipse through indirect viewing such as Pin-hole cameras, Camera Obscuras, kitchen colanders and Live streaming services.

There are many sources of information regarding Safe techniques to observe the Total and Partial Solar Eclipse such as the NASA, Gravity Discovery Centre & Observatory and Astronomical Society of Australia websites.

Through public education and correct information, let’s make this a date to remember for all the right reasons.

Ok so my suggestion to name this object LGM (Little Green Men) 2 was declined by my team Haha but we still aren’t 100% sure that these objects are Magnetars, and to avoid any potential conspiracy addicts (if you’re reading this) going into overdrive right now, it’s not aliens, my LGM 2 reference is a joke and ode to the original (half-jokingly name) LGM 1 which was given to the first Pulsar signal discovered before they knew it was a pulsar.

My Research team at CIRA (Curtin Institute of Radio Astronomy) has found a mysterious signal in Space, it is what we call a slow transient, transient meaning it turns off and on and slow meaning well… it does this slowly.

This signal was actually recorded in 2018 by the MWA Telescope but not discovered until 2021 when an Honours student-led by Curtin Astrophysicist “Natashia Hurley-Walker” was combing through old Archive records and stumbled upon this mystery signal. It turns on for 1 minute and then off for just over 18 minutes which would indicate it rotates once every 18 minutes and that’s odd, Reasons for which I’ll explain further in the article. The team has spent over a year since following up with further observations with the MWA, Parks Telescope in NSW, and NASA’s Chandra X-ray Observatory but here’s the kicker, the signal was only active for 3 months between February – March 2018 and has since turned off and hasn’t been detected since.

The team has also tirelessly looked through the last 10 years of observations from the MWA looking for this signal but to no avail, so it randomly turned on for what seems to be the first time in February 2018 and turned off a few months after and hasn’t been seen since. Weird!

This is an image of our Galaxy in radio light with the position of the discovered object highlighted. Credit: ICRAR.

So, then what’s a Magnetar? A Magnetar is a Neutron star! These objects are the leftover collapsed dense cores of giant stars after the star explodes in a supernova! The core itself is mainly all Neutrons packed tightly into a ball with some Protons and Electrons in there that survived the collapse. Stars are already spinning, but when the star explodes and its core collapses, this causes it to spin faster and faster as it gets smaller, this is due to the conservation of angular momentum (think of a figure skater spinning on ice, they speed up as they draw in their arms).
This also makes the magnetic field skyrocket up in strength to a billion times stronger than our own Sun’s magnetic field! That’s strong enough to erase your credit card from a 100,000Km away! Magnetars are the most magnetic objects in our universe.
These Neutron stars are Dense, which means they have terrifyingly strong gravity! A single cubic Cementer of Neutronium (which is what Neutron stars are made up of) would outweigh Mount Everest!

Now only around 10% of all neutron stars turn into Magnetars, there is also another type of Neutron star that spins fast and as they spin, they produce beams of energy (Light) out of their North and South Magnetic poles, these objects are called Pulsars! These dead stars spin and as they spin, these beams of light turn with it (think of a lighthouse) when the beam of light turns and flashes at the earth, we see this pulse of light and can detect them via Radio Telescopes, but although rarer, Magnetars can also produce these Beams!
So, recap, all Pulsars and Magnetars are simply Neutron stars but with added more unusual properties!

What’s most important now is that we are not 100% sure what causes these Neutron stars to produce these emission beams. We do know that it’s to do with their strong magnetic field coupled with their fast spin that accelerates electrons on their surface & above its surface up the open magnetic field lines and well that’s what makes this discovery weird! At a spin of 18 Minutes per hour, that’s insanely slow for these objects and as far as our understanding goes, this just isn’t fast enough to produce the beams that we are detecting!

Comet C/2022 E3 (ZTF) is a newly discovered comet that was first observed in 2022 by the Zwicky Transient Facility (ZTF), a survey aimed at capturing transient astronomical events. It is named after the facility and its discovery year, 2022. Astronomers believe the Comet last visited us some 50,000 years ago. It has been nicknamed “The Green Comet” because of the out-gassing and ionisation of diatomic-Carbon along with cyanogens. Comets are small, icy bodies that originate in the outer solar system and can become visible when they approach the sun and release gas and dust, creating a glowing tail. The exact characteristics and behavior of C/2022 E3 (ZTF) are not known, but it is being monitored by astronomers to gather more information.

The Gravity Discovery Centre & Observatory will be closed on Sunday the 5th February 2023 die to fires in the area.

The centre is not under any immediate threat but there is a lot of smole in the area, road closures and emergency services buzzing around. Our first priority is to keep staff and visitors safe.

We will reopen on Tuesday the 7th February at 10.00 am. Apologies for any inconvenience and a huge thank you to all those fighting the fire.

Ever heard of, or even seen a “Blood Moon?’

Chances are, you have! It is more commonly known as a Total Lunar Eclipse and you will have a chance to see one on the 8th November between 6:30pm and 9:00pm AWST.

A Total Eclipse of the Moon (which is completely different to a Total Eclipse of the Heart) occurs when the Sun, Earth and Moon line up, this is called Syzygy (three “Y’s” – impressive!). But, I can hear you ask, doesn’t the Sun/Earth/Moon line up every month? Well, yeah, they do…..sort of.

The Moon’s orbit around Earth is tilted at ~5 degrees with respect to the ecliptic (the flat, race-track like plane of the Solar System where all the planets speed around the Sun).  Most of the time, the Earth’s shadow misses the Moon because it either falls above or below the Moon. However, when the Moon’s inclined orbit intersects the Ecliptic (called Nodes) this is when you have the Moon entering the shadow of Earth and, voila! A Total Lunar Eclipse!

Now, why does the Moon turn Red (hence the overly-dramatic Blood Moon name). We’ll, it’s the same reason why we have beautiful sunsets here on the West Coast.

It’s called Rayleigh Scattering. 

How this works is like this:

Light travels in waves, and different colours of light have different physical properties. Blue light has a shorter wavelength and is scattered more easily by particles in Earth’s atmosphere than red light, which has a longer wavelength. Red light, on the other hand, travels more directly through the atmosphere. When the Sun is overhead, we see blue light throughout the sky because of this scattering. But when the Sun is setting, sunlight must pass through more atmosphere and travel farther before reaching our eyes. The blue light from the Sun scatters away, and longer-wavelength red, orange, and yellow light pass through.

Ok, stick with me….. So the Red/ Orange/ Yellow wavelengths of light pass through Earth’s atmosphere and are scattered deep into Earth’s shadow, so when the Moon passes through Earth’s shadow, it doesn’t go completely dark because there is Red/ Orange/ Yellow light within the shadow area….. hence a Red/ Orange Moon (or a Blood Moon if you insist).

Total Lunar Eclipses are a fun reminder of the beautiful mechanics of our Solar System. The Total Lunar Eclipse on the 8th November will be a bit tricky to see initially. Firstly, the Moon will be in Totality (totally eclipsed) as it rises. The Sun will be setting as the Eclipsed Moon is rising, so observing the Eclipsed Moon may be difficult. However as dusk turns to night, our view will improve. The Moon won’t leave Totality until 7:42pm AWST, so you’ll have a chance to observe it.

The Gravity Discovery Centre Observatory Chief Astronomer, Rick Tonello, will be hosting a LIVE-SKY Astronomy broadcast from Mill Point in South Perth for the occasion. You can pop by and say “Hi!” and see the eclipsed Moon rising above the spectacular Perth City skyline!

You might even want to take a picture!

Mars, named after the Roman God of War is the next destination in our Solar System for humanity to put “boots-on-the-ground” and explore its dry and dusty surface.

Mars is so attractive to human exploration because it exhibits a geological similarity to our home planet, its has a thin atmosphere and may have once been a harbour for life in the early days of the Solar System. We have see via hi-resolution images and surface rover images that, at some stage in Mars’ ancient past, it was covered in a shallow, liquid water ocean. Perfect conditions for life to begin its first evolutionary steps.

To give you an idea about the challenges that future explorers face, lets look at a couple of features about the famous “Red Planet.”

Mars is about half the size of Earth. Its diameter is 6778Km as compared to Earths diameter of 12756Km which makes it quite a bit smaller than our home planet. It orbits our Sun every 687 days, about twice as long as Earth’s 365.25 days. This difference is due to Mars’ orbit being further out from the Sun. The average distance from Earth to Mars is 166.78 million Km. Like all the other planets in our Solar System, Mars’ orbit has a small amount of Eccentricity – meaning its orbit is elliptical (oval) rather than a circular orbit. This eccentricity can vary from 128 million Km to 154 million Km away from the Sun. Every 26 Earth months, we have an alignment of the Sun, Earth and Mars – this is called “Opposition.” The Opposition of Mars would be an ideal time to launch a mission to the Red Planet due to its proximity to Earth. The journey to Mars, with current rocket technology, is estimated to take between six to nine months. Once on the surface, explorers will have two opportunities to return to Earth. The first opportunity is approximately 30 days from landing on the surface, this will enable the spacecraft to return while Mars is still near Opposition, thereby making the journey while both planets are close in their orbits. The second opportunity is twenty six months later when Earth and Mars are at opposition again. This model is the most favourable, and the most difficult.

See, you would want to spend a good amount of time exploring this planet and thirty days just ain’t enough. Its akin to traveling from Perth to New York, spending 20 minutes at the airport gift shop then hopping back on a plane back to Perth – that’s no way to explore the “Big Apple” and certainly no way to explore Mars (even if they had a gift shop!)

The major set-back for the human exploration of mars is this….. Humans. Human physiology is negatively affected by spending so long in a less than 1G (one Earth gravity) environment. Lack of that 1G is detrimental to the physical health of the explorers going to Mars. Also, you must keep them alive. Water, food, power, radiation shielding, breathable air is a big one….

We’ve been to Mars before, a quite few times before, but with highly successful robot explorers. They seem to do a better job than us squishy humans, I mean, they don’t need air or water or food, they don’t complain, they don’t get home-sick or miss loved-ones, they do what you program them to and they handle cosmic radiation a lot better than this fat-based neuro-processor that controls a meat robot which runs a million year old program called “Survival1.exe”

However, despite the large obstacles before us on the road to Mars, these are not insurmountable. Through Science and Technology, these bumps-in-the-road to Mars can be smoothed out that will allow future explorers to pave the way to a new world full of opportunity, adventure and knowledge.

Curved Space and Warped Time – Australia Tests Einstein 1922
The Wallal Exhibition
A group of scientists, historians and students in Western Australia created an exhibition on the Great Wallal Eclipse Expedition that took place in Western Australia less than four years after the First World War. This expedition was a heroic national and international effort that was supported and feted across the country. They measured the warping of space by observing stars during the eclipse of the sun. The expedition confirmed the accuracy of Einstein’s General Theory of Relativity, the theory that revolutionised our understanding of the universe, and the one which we use today every time we use a GPS satellite navigation system. The testing was needed because earlier tests of Einstein’s theory had given inconclusive results despite public claims to the contrary.
This year marks the centenary of the Great Wallal Expidition. Locally, as a discovery made in Western Australia, it is one for which all West Australian’s should be proud. Foundation Professor of Physics at UWA, Professor Alexander Ross played a major role along with scientists from USA, Canada, Britain and India. Today the Wallal Expedition has largely been forgotten, in spite of its immense world significance in proving the theory that underpins our understanding of gravity and the universe. The Wallal Exbibition on show at the GDC and Observatory has been created by a group of scientists, historians and students from UWA and members of the Gravity Discovery Centre and Observstory. The exhibition was funded from National Science Week 2015, Lotterywest and Healthway.
Curved Space and Warped Time – Australia tests Einstein 1922 is located in the cosmology Gallery at the Gravity Discovery Cnetre and Observatory.  A video on a large screen brings the Wallal expedition to life, based on old footage from the Australian Film Archive as well as modern eclipse material and material on the implications of the discovery using modern imagery of the universe of curved space and warped time revealed by the Hubble Space Telescope.
The Australian International Gravitational Observatory, now known as OzGrav, The Zadko Optical Telescope and the Geoscience Australia Magnetic
Observatory are located on the same site as the Gravity Discovery Centre. Curved Space and Warped Time – Australia tests Einstein 1922 brings people on a journey of discovery from the first clear sight of curved space near the sun, to our modern understanding of the universe. through time, from the pre-eclipse excitement across Australia in 1922, to the wooden telescopes and donkey trains towing wagons out of the surf on 80 Mile Beach, to the world of today with GPS navigators and the internet.
The exhibition was designed by a team consisting of Sue Graham-Taylor, curator for the National Anzac Centre, Dr Ron Burman: Historical Research, David Blair: Co-ordinator, Damon Annison: Photographer and Graphics Designer, Patrick Obiri-Boateng: Video production
Here are a few interesting facts about the Wallal expedition:
• The location for the Wallal Expedition camp was selected for the presence of a Government well constructed in the late 1870s by Alexander Forrest. Forrest saw it as an important water source for when cattle were later driven south on the way to market. The Wallal eclipse expedition camp – established just north of the well – found the water ‘excellent’ and commented that the well was 16 feet deep and ‘it never fails’. Wallal means ‘abundant water’.
• The Indigenous people made a big contribution to the expedition. Fifty indigenous people met the boats when they landed on Eighty Mile Beach.
• The Royal Australian Navy played a major role in organising and running the expedition.
• The Australian Government arranged for the trans-Australia railway to carry equipment free of charge from Sydney to Perth for on-shipment to Broome and then to Wallal.
• Thirty five tonnes of telescopes and other equipment was brought to Wallal from all over the world, including Toronto and Lick Observatory (California).
• The expedition provided data that confirmed that Einstein was right, and was not improved upon for 50 years.
• The scientists were feted and newspapers across Australia were full of stories about the expedition.
• Aviation pioneers Kingsford Smith and Norman Brearley were involved in the expedition.

“Want to know more about other Wallal eclipse centenary celebrations?

The University of Western Australia & Scitech has a range of events and activities over a two-week period celebrating the centenary of the Wallal eclipse expedition. Click here to find out more for UWA activities and click here for Scitech activities.

So, you want to buy a telescope?
Getting into amateur astronomy can be one of the most rewarding hobbies out there. Wanting to
get a closer look at what’s up there in the night sky is a dream for many; but taking the leap into
buying a telescope can be quite a daunting task.
How much should I spend?
What are all the different types of telescopes?
Which is the best telescope for beginners?
These are all questions I have been asked countless times and there is no short answer to any of
these.
My personal response is do not buy a telescope…
What? Really?
Yes!
There is nothing that breaks my heart more than to see people with telescopes that sit in the corner
covered in dust and cobwebs. The reason for them being there is people not wanting to put in the
time and effort to learn how to use their telescope properly. This is usually the result of some good
old fashion retail therapy and putting your covid relief payment to good use.
If you are keen on getting into astronomy, I would recommend starting with a good pair of 10×50
binoculars (a decent pair will set you back around $300-$400).
Binos? Really?
YES! REALLY!
Granted you won’t be able to make out the rings of Saturn or the great red spot on Jupiter, but there
is so much that binoculars have to offer! You will be able to see plenty of open clusters, globular
clusters, the Moon, some bright nebulae and even the moons of Jupiter!
I would avoid going for “Astro binoculars” if this is your first time using them, these are usually
15X70 or larger. Dedicated astronomy binoculars can be quite heavy and rather unwieldy to use by
hand. Pretty much all astronomy binoculars come with an adaptor that allows you to mount them on
a camera tripod for much more stable use.
If you can stick with a pair of binoculars for 6 months and spend that time thoroughly learning the
sky, then it’s time to move onto a telescope. If you fall out of love with it at least you will have a pair
of nice binos to take to the footy.
“But Mitch I want a telescope” I hear you say.
Well if you’ve got some money burning a hole in your pocket the short answer is get yourself an 8
inch dobsonian. There are a number of benefits that dobs have over other telescopes that make
them perfect for beginners. The first is price, in terms of dollars spent per inch of aperture you can’t
beat a Newtonian. The second is the mount, this is what dobsonians are famous for. A ground-based
alt/az mount slapped on top of a lazy Susan makes this the most user-friendly option for telescope
mounting, it’s quite literally point and shoot. Finally, the diversity of objects you will be able to see
through this telescope is what sells it for me. Whether it’s the rings around Saturn, the coloured

belts on Jupiter, clusters, nebulae, or bright galaxies; there is such a diverse range of things you will
be able to see.

An 8 inch dob will set you back around $800 brand new, but there are number on the second-hand
market at around the $600 mark.
A word of warning: There are two things that you should never do to your telescope as a beginner.
1. Clean the mirror, even if its dusty. That dust is going to have a marginal impact on the optical
performance of the mirror. If you take to it with Windex you will be doing more harm than
you know.
2. Adjust the collimation screws on the bottom of the telescope. Unless you know what your
are doing just don’t, you risk throwing you collimation completely out and rendering your
telescope useless until corrected properly.

In closing there is no best beginner telescope and the recommendations I have made here are purely
my opinion. Get out there and start exploring the night sky!
P.S. if you are really struggling check out our tame your telescope course for some hands on help.

The Gravity Discovery Centre & Observatory has introduced a new stargazing session aimed at Astronomy enthusiasts. The Life Cycle Of Stars: From Dust To Destruction covers the life of some the largest bodies in the universe from birth until their fiery fate. The Life Cycle of Stars is presented in two parts. The first, a 1 hour lecture which will take you on a journey from the birth of a stars inside of molecular clouds all the way through to its spectacular death. The second part of the evening will be spent in the observatory observing stars in their different stages of life.

The Life Cycle of Stars sessions are scheduled to run on Thursday’s once or twice a month. For a list of scheduled dates click here.