Last updated May 26, 2017 at 5:14 pm
Recent advances and events from the world of science and technology with Miles Gough.
Journey to Jupiter
In July, after nearly five years of space travel, the Juno spacecraft finally arrived at its far-flung destination of Jupiter – 588 million km from Earth. After a tense approach, Juno successfully entered the planet’s orbit and has since executed the first of 36 planned flybys, returning some astonishing images of the gas giant.
“First glimpse of Jupiter’s north pole, and it looks like nothing we have seen or imagined before,” said Scott Bolton, principal investigator for the mission.
The spacecraft will spend another two years around Jupiter, trying to learn more about how our solar system’s largest planet formed.
Image credits: NASA, ESA, and J. Nichols (University of Leicester)
…and a near-Earth asteroid
Another remarkable mission is underway: this time by the OSIRIS-Rex spacecraft, which is charged with recovering space rocks from the surface of a near-Earth asteroid called Bennu.
Asteroids are 4.5 billion-year-old remnants from the early solar system and thought to have played a key role in planet formation. They may have delivered to Earth, for example, the key ingredients necessary for life, including water and other organic molecules.
The OSIRIS-REx spacecraft, launched last September, will spend a year circling the Sun before chasing down Bennu. It will use an array of rocket thrusters to match the asteroid’s velocity – a blisteringly fast 28 km/s. In July 2020, the spacecraft will perform a daring contact maneuver during which a 3m-long robotic arm will reach out and slap the asteroid’s surface. It will shoot out three bursts of nitrogen gas, stirring up small space rocks and dust, which will then be quickly captured.
If all goes to plan, the spacecraft will be able to return about 60 grams of asteroid dust to Earth for analysis in late 2023.
Scientists have found evidence of an ancient flood that kick-started Chinese civilisation
According to legend, the dawn of the Xia dynasty and Chinese civilisation coincided with a great flood, about 4000 years ago. Now, a Chineseled research team has found proof of a massive flood that occurred around 1900 BC, close to the timeline of the mythical disaster.
Writing in the journal Science, the team described a devastating flood caused by a landslide in the Jishi Gorge, which created a colossal dam by blocking the great Yellow River for up to nine months. The researchers say that when the dam eventually burst, more than 300,000 cubic metres of water per second would have been released.
“It’s among the largest known floods to have happened on Earth during the past 10,000 years,” said co-author Dr Darryl Granger, from Purdue University in the United States.
The team found sediment from the dammed lake high on the walls of the gorge, and 25km downstream at a prehistoric settlement called Laija. They were able to date the sediment at each site to determine the time of the flood.
Good news…for planet Earth
While the climate change debate continues to heat up, there’s been a fantastic new development for another major atmospheric pollution problem. Scientists have found evidence suggesting that the thinning ‘hole’ in the ozone layer above Antarctica is healing.
A team of researchers from the Massachusetts Institute of Technology have used observational data from weather balloons and satellites, and computer modelling, to measure the size of the area where the ozone layer has thinned dramatically.
The team, led by atmospheric scientist Susan Solomon, found that between 2000 and 2015 the ‘ozone hole’ decreased in size by about 4 million square kilometres – an area equivalent to about half of Australia.
The ozone layer is a protective shield in the stratosphere that absorbs most of the harmful ultraviolet radiation from the Sun. Scientists, including Solomon, first noticed a dramatic thinning in the ozone layer above Antarctica in the 1980s. She helped determine that this was caused by human-made substances known as chlorofluorocarbons (CFCs). These release chlorine and bromine molecules, which deplete the ozone layer. In 1987, an international treaty known as the Montreal Protocol phased out the production of CFCs by the year 2000.
But harmful chlorine, which has a lifetime of about 50-to-100 years, remains in the atmosphere: “It will be many years before the hole closes completely,” Solomon told ABC Science online.
- Further reading: more Memorable Moments in STEM
Originally published in Ultimate Careers magazine. Read the magazine and find your Ultimate Careers here.
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