In the science news this week, Rosetta wakes up, jet lag disrupts hundreds of genes, JAXA to launch magnetic space net, and finally… a new river dolphin species is discovered.
Rosetta! Wake up!
A spacecraft that is chasing a comet 800 million km away “woke up” on Monday, after 31 months of hibernation as it travelled to intercept it, reported the BBC .
It was a nail-biting wait for the scientists at the European Space Agency’s (ESA) control room in Darmstadt, Germany, but three quarters of the way through the hour-long window of opportunity, Rosetta’s signal to say it was powering up returned to Earth.
Now that Rosetta is awake, engineers will finesse its final trajectory towards Comet 67P/Churyumov-Gerasimenko. The spacecraft will intercept the comet in August, where it will travel side-by-side, eventually sending a probe to land on the surface to take direct measurements of the composition of the comet.
"We will sample the physical and chemical composition of the comet," said Matt Taylor, ESA's Rosetta project scientist.
"This will give us knowledge on how and where the comet was formed, and about its subsequent journey through the evolution of the Solar System.
"We can connect that as well to the formation of the planets themselves. And, in addition, the elemental make-up of the comet can be considered 'star stuff' - it will provide us knowledge of the formation processes within the Sun itself."
Over the next few months, ESA scientists will run a series of tests to make sure the spacecraft is performing normally. But it will be a slow process – at the moment it takes 45 minutes for the messages to be sent from the probe to Earth (or vice versa).
Rosetta is now arcing back towards the Sun, so it will start collecting energy from its solar panels to fuel its activities.
"From now until mid-March, we have planned virtually no activities on the spacecraft. We can afford to run only some basic check-outs," explained Andrea Accomazzo, the spacecraft operations manager.
"But from mid-March to the end of April, we will be switching on the instruments one by one. We'll check them out and in a few cases even update their software."
From May, Rosetta will start to approach the comet as their orbits get closer together – at the moment, Rosetta is nine million km away from Comet 67P, by mid-September it will be just 10km.
Jet lag and night shifts disrupt hundreds of genes
Researchers from University of Surrey have found evidence to suggest that abnormal sleep patterns cause “profound disruption” to more than 1,000 genes, reported the Guardian .
The researchers believe that this disruption could be the reason why some people with jet lag can feel so unwell. Tests showed that hundreds of genes with activity that would normally rise and fall on a daily basis lost their rhythm when someone had jet lag.
The study involved 22 men and women aged between 22 and 29 who stayed at a centre where the lighting was controlled to transform a normal 24-hour day into a 28-hour day.
All of the participants’ sleep-wake cycles were shifted by 12 hours by the third day of the study, meaning they were completely out of sync with their body’s typical 24-hour clock.
"None of these people are sleep deprived. They get enough sleep. Our aim was to tease apart the effects of the body clock and the effects of sleep," said Simon Archer, a reader in chronobiology and first author of the study.
Blood samples taken from the participants on the first day showed that there were 1,396 genes that had activity which rose and fell based on a 24-hour cycle. However, by the third day, just 40 or so of those genes had kept their rhythms, and another 180 genes that normally kept a constant level of activity, began to rise and fall instead.
"If you desynchronise sleep from your body clock with jet lag or shift work, so many processes are affected, in terms of the timing of when things happen," said Archer. "It explains why you feel so bad when you're jetlagged or doing shift work.
"Sleeping at the wrong time is bad for you. We know it has a massive effect on the temporal organisation of gene expression and that must link up with negative outcomes."
Japan to launch space debris net
Space debris is a big problem but finding a solution to remove all the junk left orbiting our planet – or at least some of it – has not been easy.
However, the Japanese space agency, JAXA, are planning to trial one idea next month – launching a large electromagnetic net into space, reported New Scientist .
They have teamed up with Nitto Seimo, a company that specialises in fishing equipment, to build a 700-metre-long mesh of aluminium and steel wires to collect drifting debris.
The net is attached to an uncrewed spacecraft and is fitted with sensors that look for light reflecting from small pieces of debris. Once detected, the spacecraft automatically aligns itself so it can attract the material towards the net.
The electrical current flowing through the wires creates an electromagnetic field that attracts the debris and pushes the net away from the Earth’s geomagnetic field.
Once the net has caught enough debris, the spacecraft will be ordered to slow down and de-orbit, destroying the debris, craft and net as they burn up in the Earth’s atmosphere.
New species of river dolphin is discovered
A new species of river dolphin has been discovered in the Araguaia river in Brazil – the first river dolphin species to be discovered since 1918, reported the BBC .
It is only the fifth known species of its kind in the world – and the researchers believe there are about 1000 of the dolphins living in the Araguaia river basin.