Last updated May 24, 2018 at 2:27 pm
The second night of Stargazing Live had everything from world records (maybe), to gold, even the end of the universe. Here’s what we learnt.
It was night two of Stargazing Live, and we were back on the couch, martini in hand, for another night among the stars. Here’s what we learnt from the second episode.
Good work team, in less than 24 hours we found a supernova while it was happening!
The Type 1A supernova has been named SN2018bwq, and was located by 4 people using the site: supernovasighting.org.
Since the launch of the project during Episode 1 there has been over 1 million images classified as they streamed in from telescopes around the world.
With the discovery of the brand new SN2018bwq, astronomers swung their telescopes towards the event, and were able to watch the supernova happening live in real time. That information will be vital for a range of projects, including one to determine the exact age of the universe.
Brian even threw out an intriguing possibility – if Stargazing Live viewers can find enough supernovae over the next few days, they might be able to age the universe based solely on data from the show. It’ll be our very own research project.
NASA are recruiting Panda astronauts
The universe’s days are numbered
The big question for the night was how will the universe end?
To find out, we need to start at the very start of time itself – the Big Bang 13.75 billion years ago.
Since then, all the galaxies in the universe are moving away from us. Using an inflating balloon, Brian showed that that was possible – galaxies on the surface were expanding outwards and moving away as the balloon expanded. It’s exactly the same idea as the expansion of the universe itself.
However, mass attracts, so the very mass of the galaxies should be pulling them inwards. That means that something else more powerful than gravity itself if driving that expansion, and that gravitational attraction is at best slowing down the speed of inflation.
It was thought that the gravitational attraction would eventually lead to all the galaxies reversing and rushing back in towards each other, eventually crunching down into an area the size of an atom. However, a new idea has emerged.
Five billion years ago the rate of expansion of the universe suddenly increased, like something had given it more momentum. Scientists have no idea what it was that caused this acceleration, so named it “dark energy.” We can’t see it, but we can detect its effects.
One of those effects is the shape and arrangement of galaxies in the universe.
Tamara Davis is one of the world’s top experts when it comes to dark energy. She explained that the galaxies aren’t scattered randomly through the universe, but are instead arranged in giant donuts.
Those donuts are from sound waves that rippled through the universe at the very beginning of the universe. After the Big Bang the universe was an entire field of particles, which were actually close enough together to allow sound to travel through space.
Like ripples in a pond, the sound waves propagated outwards from their source. However, the universe was also expanding, meaning those particles were not only carrying sound waves through the universe, but also gradually moving further and further away from each other due to that expansion.
Eventually the field of particles expanded enough that sound waves could no longer be passed to each other, so the waves were essentially frozen in space 380,000 years after the Big Bang. The rings are those frozen sound waves.
After the sound waves could no longer travel, gravity took over, pulling matter together and forming the stars and planets. At the limits of the sound waves there was a higher concentration of particles, meaning more galaxies formed in those regions.
By looking at that ring distribution of galaxies over time, astronomers can measure how much the universe has expanded, potentially giving an idea about some of the properties of dark energy.
However, if that expansion keeps accelerating, and especially if there is another dramatic acceleration, it might reach a point where the universe ends up in a “Big Rip” where atoms themselves are literally ripped apart through expansion, and everything ceases to exist.
But it won’t happen for billions of years yet.
Space Gandalf watches his home planet
Greg Quicke was out in the cold once again with Kumi Taguchi, this time looking at the Moon, where I like to think he is really from.
You can get a really good view of the features of the Moon using only a pair of binoculars, however for full-on mindblowingness a telescope is the way to go.
He also suggested looking along the boundary between the light and dark, the terminator, where some of the features like craters and mountains can be more clearly seen thanks to the angle of the sun.
He then went out with actress Magda Szubanski, where it was revealed she was a moon-landing obsessive as a kid, knowing everything there was to know about it.
Magda was particularly interested in the craters on the surface of the moon, some of which are 100km across, and why there were so many more than on Earth. This, Greg said, is due to the lack of atmosphere on the Moon compared to Earth – here our atmosphere causes asteroids to burn up on descent, and we have wind and rain which erode away some of the craters that do form.
She’s anything but a gold digger
Lisa Harvey-Smith was finding the source of all the gold on Earth.
From your ring to your phone, it’s thought that none of the gold on Earth was created here, but was instead created far far away.
Last year the massive LIGO detector in the US sensed a disturbance in the universe – gravitational waves. Immediately, telescopes around the world swing into action, looking for the source of these waves.
What they saw was a gigantic explosion with the power of 100 billion billion billion billion lightning bolts. After investigating it closer, astronomers found it was the collision of two neutron stars which had pulled each other inwards with their gravitational pull, circling and circling faster and faster until they smashed into each other, releasing a monumental amount of energy.
They also noticed giant bubbles thousands of kilometres wide emerging from the cataclysmic impact. These bubbles were newly created elements, including gold. It was the first time that the creation of gold had ever been observed.
These elements were then scattered through the universe on the shockwaves of the explosion, and it’s now thought that all the gold in the universe was created in space by neutron star collisions, or similarly apocalyptic events.
Let’s cook with Julia
After 5 episodes of Stargazing Live, Julia has finally been let loose in the kitchen. Let’s see what delectable treats she has for us….
….it’s a comet. We were hoping for biscuits but it wasn’t to be.
Julia’s comet recipe
- Vinegar (standing in for amino acids)
- Alcohol (it is Julia after all, but it is common across the universe)
- Ammonia (nitrogen and hydrogen)
- Dirt (silicates)
- Cornflour (Julia’s secret ingredient – not actually in a comet)
- Mix the ingredients in a large bowl lined with a plastic bag until combined.
- Add dry ice to freeze the contents and stir well.
We’re not going to lie, we then completely missed everything Brian said while Julia struggled with her steaming bag of dry ice-comet mixture.
Serving suggestion: Put your frozen comet near a heat source. The heat (usually generated by the sun as the comet passes by) causes the volatile chemicals in the comet to start evaporating from the surface. The light from the sun illuminates this cloud of volatile chemicals, creating the visible tail characteristic of comets.
No word on the world record yet
Thousands of people around Australia joined star parties to take part in an attempt on the world record for the most people stargazing at once.
For the record to count, they needed to observe the same object (in this case the Moon) for 10 continuous minutes using some form of magnification device.
With cities and towns across Australia taking part (including Wudinna in western South Australia, with a total population of 580 and 400 of them attending the star party), the Guinness team will assess how many people could see the moon, and were actually observing the moon during that time, to come up with the actual number of observers and determine whether we broke the record.
Another night of cocktails on the couch, and still no recipes
Every night on Back to Earth the panel are given a space-themed cocktail. However, a constant frustration is that the ABC still haven’t released the recipes for them.
Help us out ABC, give us the proper recipes for the cocktails so we can make them at home. Even better, if you gave them to us in advance we could have one ready to go and drink with the panel during Back to Earth.
You know it makes sense.
— Aust Science Channel (@RiAus) May 23, 2018