Top 10 science stories of 2013
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Voyager 1 became the first man-made object to leave the solar system.
Image: elenart/Shutterstock

From the first vat-grown hamburger to the discovery of the world’s largest volcano, scientists pushed back the limits of human knowledge in 2013 and developed technologies that could radically change how we live our lives. 

1. Space sounds revealed Voyager 1 had boldly gone: In September, NASA’s Voyager 1 spacecraft became the first man-made object to leave our solar system and venture into interstellar space. The probe, launched in 1977 with the aim of reaching Jupiter and Saturn, is now over 19 billion kilometres from the sun. Scientists listened in to vibrations in the plasma surrounding Voyager – the sound of interstellar space – after it was hit by a massive solar wave in April. The vibrations allowed them to calculate the plasma’s density, which differs between our solar system and interstellar space, confirming Voyager was no longer in our solar system.

2. Carbon dioxide hit a new peak and human influence on the climate was clearer than ever: In May, levels of carbon dioxide in the Earth’s atmosphere reached a symbolic milestone, passing 400ppm (parts per million) for the first time in human history. Just a few months later in September, the leading international body for the assessment of climate change, the Intergovernmental Panel on Climate Change (IPCC), found that human influence on the climate system is clearer than ever -we are now 95 percent certain that humans are the cause of global warming. Climate scientists from New Zealand were among the more than 600 scientists and researchers who worked on the IPCC report.

3. Scientists created human stem cells using cloning techniques: In May, researchers used therapeutic cloning to create human embryonic stem cells for the first time. The process involved taking the nucleus – which contains the genetic material – from a normal cell and transferring it into an unfertilised egg with its own genetic material removed. While this approach had previously been used in monkeys and mice, it had never succeeded using human cells. This discovery, described by Australian scientists as “a major breakthrough in regenerative medicine”, could help develop personalised therapies for a range of currently untreatable diseases. However, the process requires human donor eggs, which are not easy to obtain, and raises a number of ethical issues.

4. Do you want fries with that? The world’s most expensive burger was grown in the lab: The world’s first lab-grown burger was cooked and eaten at a news conference in London in August this year – generating headlines around the world. The burger patty – which one food critic described as ‘close to meat’ – was developed by scientists from Maastricht University in the Netherlands through research funded by Google co-founder Sergey Brin. Starting with stem cells from a biopsy of two cows (a Belgian Blue and a Blonde d’Aquitaine), the scientists grew muscle fibres in the lab. The fibres were pressed together with breadcrumbs and binding ingredients, then coloured with beetroot juice and saffron, resulting in the most expensive hamburger in history at a cost of around NZ$400,000.

5. Doctors stopped HIV in its tracks in the “Mississippi baby”: A child born with HIV and treated with a series of antiviral drugs for the first 18 months of its life was found to be free of the virus more than 12 months after treatment ended. When the infant was 30 months of age, HIV-1 antibodies remained completely undetectable. However, the big question of whether this child, known as the “Mississippi baby”, has truly been cured of HIV remains unanswered. “The best answer at the moment is a definitive maybe”, HIV expert Scott Hammer, wrote in a New England Journal of Medicine editorial which accompanied the research.

6. Redefining mental illness: In May, the new version of the diagnostic reference manual used by clinicians in the U.S. and around the world to diagnose mental disorders was released. The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is the first update in nearly 20 years and followed a decade of review and consultation. It’s publication met with widespread controversy. One of its major changes is to introduce a graded scale known as Autism Spectrum Disorder combining the former four autism-related disorders: autistic, Asperger’s, childhood disintegrative, and pervasive developmental disorder. Elsewhere, several new disorders were added, new suicide risk assessment scales were introduced and the threshold for diagnosing Post Traumatic Stress Disorder (PTSD) was lowered. Critics of DSM-5, including New Zealand experts,  argue that it will lead to the over-diagnosis of mental disorders, stigmatising millions of people who are essentially normal.

7. Human liver grown in mouse: Scientists successfully transplanted tiny ‘liver buds’ derived from human stem cells into mice with disable immune systems, staving off the deaths of the animals. The preliminary results, published in Nature, will need years of follow-up research and trials, but hint at a potential solution to the worldwide scarcity of human livers available for transplant. Major technical hurdles have to be overcome before the treatment is useful for humans, including mass-producing the trillions of human iPS-derived precursor cells to even replace even part of a human liver.

8. A king turned up in a car park: In February the bones of Richard III were discovered in the inauspicious surroundings of a car park in Leicester, England – more than 500 years after he died. Radiocarbon dating, radiological evidence, DNA and bone analysis all helped confirm the identity of last Plantagenet king. As if the indignity of being dug up in a car park wasn’t bad enough, further research revealed Richard was infected with roundworms in his intestines.

9. The croaking dead: An Aussie frog was resurrected: Australian scientists announced in March that they had succeeded in growing early stage embryos containing the DNA of an extinct frog. The research is the first step of Project Lazarus, which aims to bring the Australian gastric-brooding frog back to life. The scientists took nuclei – which contain the extinct frog’s DNA – from frozen tissue samples collected in the 1970s. The nuclei were injected into donor eggs from a distantly-related frog, and some of the eggs went on to divide and grow into embryos, reviving hopes for an animal that has been extinct since 1983. The research was listed as one of Time magazine’s top 25 inventions of this year

10. The world’s largest volcano was discovered: In September, scientists discovered the largest single volcano on Earth under the Pacific Ocean. The megavolcano spans 650 km – similar to the distance between Melbourne and Canberra – but don’t worry, it’s been slumbering for the last 145m years. Scientists had thought the volcano, known as Tamu Massif, was a series of volcanoes, but the Integrated Ocean Drilling Program – of which Australia is a partner – showed that it is in fact a single, immense volcano, constructed from massive lava flows that emanated from the volcanic centre to form a broad, shield-like shape.

Editor's note: The original press release can be found here. This list was compiled by the Australian Science Media Centre in conjunction with RiAus and CSIRO