Last updated April 21, 2017 at 3:18 pm
For the last time this year our newest best friends Julia Zemiro and Brian Cox were on our screens for Stargazing Live. It was the first time this BBC production has aired in Australia and viewers loved it. For the final episode they were talking aliens. Here are our highlights.
“The Dish” at Parkes is searching for aliens
In 2007 the radiotelescope at Parkes picked up a mysterious signal. It was loud and far away, and was only received once. Dubbed a Fast Radio Burst, or FRB, it perplexed astronomers around the world. Six years later they received 10 more, but their cause remains a mystery.
With no explanation of the origin of these FRB’s, ideas abound. The power required to generate signals this strong from so far away would be huge, and one out-there idea is that they could be pulses from alien spaceships. If an advanced civilisation used some form of super powerful engine to propel themselves at high speeds, these bursts of radiation could be the result of them firing those engines. Of course, that is entirely speculation, but all options are on the table.
Stephen Hawking is one big name behind a $100 million worldwide search for extra-terrestrial life, and one facility involved is Parkes. It’ll be upgraded to investigate FRB’s further and search for other signals which may originate from unearthly life forms.
Brian Cox doesn’t think there is intelligent life out there
“Doubt it” was Brian Cox’s short reply to the question of extra-terrestrial intelligent life.
He pointed out there are two schools of thought which broadly group into astronomers and biologists. Astronomers will point out there could be more than 20 billion Earth-like planets in the universe where life could have formed.
On the other hand, biologists say that there has been 4 billion years since life arose on Earth, and it’s really only been relatively recently that we’ve had human-like intelligent life. It took evolution that long to produce a species capable of advanced civilisation, and it was really through quite a specific pathway with twists and turns to lead us here. So, while there might be 20 billion planets capable of supporting life, it doesn’t mean that there has been a similar evolutionary path that lead to an intelligent, advanced lifeform. The origins of life (single-celled organisms like bacteria) might exist elsewhere, but where else has evolution taken a similar course?
Space Gandalf loves the moon
Greg Quicke showed ABC journalist Kumi Taguchi the features of his home planet.
He started by pointing out the seas on the moon. They’re not water covered, but large dark areas on the face. The biggest is the Sea of Tranquility, which was made famous as the landing site of Apollo 11 and where Neil Armstrong and Buzz Aldrin became the first humans to ever set foot on another planetary body.
They then moved on to look at the Copernicus crater. It’s a massive crater nearly 100km cross and has walls 4km high. Curiously it also has a mountain in the centre slightly higher than the mountain on which Siding Spring Observatory sits.
Europa could support life
Lisa Harvey-Smith was investigating the moons of Jupiter to find out whether they could support any life, and homed in on Europa.
She looked at spectroscopy data taken from observing Europa, which detects what kinds of chemicals are on the surface and atmosphere. Examining the data, Lisa found that the spectra showed that Europa does have water on its surface. And that, she reminded us, is a critical thing to support life.
Underneath Europa’s icy surface are salty oceans which are so large they contain more water than what is found on Earth. Plus, the floor of these oceans are thought to have volcanic vents similar to volcanic vents found on the floor of Earth’s oceans. We know from studying Earth’s vents that these conditions give rise to and support all sorts of life, many of which are completely different to what we see anywhere else on Earth. This increases the chances that there might be similar life on the bottom of Europa’s oceans.
Europa has Jupiter to thank for not being a cold dead planet
The volcanic vents on the floor of Europa’s oceans are due to Europa’s high core temperature. Many moons cool down over time and become cold dead rocks, however Europa has Jupiter to thank for not suffering the same fate.
Europa follows an elliptical orbit of Jupiter meaning sometimes it is close to Jupiter, and other times a bit further away. This orbit means that Jupiter’s gravitational pull on it changes slightly depending on how far Europa is away from it, and this change in gravitational effect results in Europa being squashed and flexed at different points in its travels. These forces result in friction within Europa’s structure, causing heat and stopping Europa’s core from cooling.
Canberra is one of the most important places in the world
Just outside Canberra is the Canberra Deep Space Communication Complex which plays a vital role in communicating with spacecraft throughout the solar system (and in the case of Voyager, beyond). The complex of satellite dishes transmits and receives signals from spacecraft, including messages, control instructions, experiment results and photographs. It’s just one of three Deep Space Network facilities dotted around the world (Goldstone in California and Madrid, Spain being the others).
The Canberra facility has to precisely lock onto the location of spacecraft. The signals spacecraft send back to Earth are incredibly low powered, generally weaker than a 40-watt lightbulb. As a result, there is very little margin for error, just a little bit off and the dishes struggle to establish connection.
This precision will be critically important in September 2017 when the Saturn-orbiting Cassini spacecraft is sent its final task. Cassini will be told to crash itself into the surface of Saturn, and Canberra will be the only dish complex in the world capable of establishing connection. In those last moments of life Cassini will be sending back huge amounts of information about Saturn’s atmosphere, and it will be up to Canberra to receive that information before Cassini is lost forever. They have one chance to get it right.
Parkes telescope saved Apollo 13
Back in the 1960s and 70s Canberra wasn’t the only Australian facility tasked with communicating with spacecraft, there was also a dish at the nearby Honeysuckle Creek. On April 14 1970, everything went wrong for the astronauts aboard Apollo 13. The story has been told before – an explosion onboard damaged the survival equipment – but what is less known was the effort on the ground to re-establish communications with the stricken craft.
The explosion damaged the communications antenna, making contact with Earth difficult. The dish at Honeysuckle Creek was unable to make contact, so NASA turned to the largest dish in Australia, located in the New South Wales town of Parkes. Technicians flew into Parkes to retask the dish to establish contact with Apollo 13, but found it configured for radiotelescope research and not communications.
The technicians needed to reconfigure the Parkes facility to enable it to communicate with the spacecraft, managing to complete the 1-week task in a single day. Now it was online, the large dish was better able to contact the astronauts onboard, but a new problem arose. The signal between Parkes and Apollo 13 had severe interference so the technicians on the ground took a risk, and told the astronauts to turn off their radios.
With no signals coming in from Apollo, the techs worked to isolate and eliminate the interfering signal, and then attempted to re-establish communications with the spacecraft. With a new clean signal NASA were once again able to communicate with the astronauts. Parkes played this critical role in allowing mission control to talk to the astronauts and guide them home.
Without the communications established through Parkes, the outcome of Apollo 13 could have been very different.
Stargazing Live viewers legit discovered a new solar system
The biggest thing we learnt was also only being learnt by scientists at the same time.
90 new exoplanets (Earth-like planets orbiting other stars) were discovered through the citizen science project, Exoplanet Explorers, which had been running during Stargazing Live. This project relied on the public classifying data from the Kepler space observatory to identify potential planets passing in front of stars, and was resulting in the discovery of planets which had never been seen before.
But the big news was that out of those 90 planets, four all belonged to the same star – in other words, the viewers of Stargazing Live had discovered a brand new solar system! And it was located only 600 light years away, which in galactic terms is quite close!
The four planets are all around twice the size of Earth and are probably rocky Earth-like bodies. They are quite close together and are also likely to be quite hot, the one furthest from its star is still only one-third the distance that Mercury is from our Sun.
Their orbits are also quite interesting, displaying resonance, or in other words timed with each other. For every 3 orbits of the closest planet around the star, the second does 2 orbits. And for every 3 orbits of the second planet, the third does two. This 3-for-2 pattern applies to all the planets in this system, but surprisingly means that all the planets in the system won’t line up in a single line until July 9, 4288.
It’s worth repeating, this discovery wasn’t made by professional astronomers, but by everyday viewers of Stargazing Live who jumped online to sift through data. Like this dead set legend who was the first to discover one of the planets. After revealing he’d gone through about a thousand images on the first night, he said “Yeah I punched through a few.”
The citizen scientists who discovered the planets will all be listed as authors on a scientific paper describing the new system, to be published soon.
There’s a reason Julia Zemiro looked cold
Because it was.
Not only was the temperature outside cold (Kumi Taguchi showed viewers the hot water bottle she was using to stay warm), but even inside the telescope dome the temperatures are kept cool, but for a good reason.
If the temperatures inside the dome were warm, when the astronomers opened the doors to allow the telescope to see out all the hot air would rush out through the hole. This isn’t only bad for electricity bills, but this rising hot air in front of the telescope will affect the image quality.
Just like if you look at a road and see the rising heat haze, the hot air will distort images through the telescope the same way. So to avoid that heat haze, the air inside the domes is kept cool as well.
By the way, can we please get Julia Zemiro hosting more science programs? She was as brilliant as she ever is.
So that was Stargazing Live. After seven seasons in the UK it made its way down under for the first time. And judging by the reactions on social media, viewers absolutely loved it. We know we did. Can’t wait for next time.
#StargazingABC #StargazingQuestions Wow well that was the best tele in ages @RiAus
— Shayne Calliss (@SCalliss) April 6, 2017
Over and out from the #StargazingABC crew. Thanks for watching ? pic.twitter.com/ie7oSPn8ju
— ABC TV Australia (@ABCTV) April 6, 2017
Catch up on previous episodes of Stargazing Live:
Images from the ABC
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