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Not long a go astronomers discovered something strange happening to a star called kic-8462852: Its light was dimming and returning as if something huge - possibly much huge-er than a planet - was passing in front of it. The size and timing of the dips don't match anything known, and all the natural explanations anyone has been able to think of involve coincidences - and scientists really don't like invoking coincidence. There is one other explanation: That the dips are caused by some kind of massive artificial structure, built by an unknown intelligence. So, to investigate this possibility, SETI (Search for Extra Terrestrial Intelligence - guess what they do) turned the Allen radio telescope array on the star, looking for signals that might be due to an alien intelligence... and they haven't found any.
Sorry to burst any hopes - although it might be a bit too soon for saying that: Firstly this star is 1500 light years away, so a signal would need to be huge to get detected. Secondly SETI has only looked for two types of signals: Those expected from deliberate attempts to talk to use (which assumes a lot) and those that might be by products of beamed energy propulsion (which also assumes a lot).
Even though aliens has never been a very likely explanation, and now looks less likely still, we still have a very odd astrophysical phenomena happening here - something that will hopefully teach us new things about this universe. Personally I'm in agreement with SETI astronomer Seth Shostak. who has said:
“The history of astronomy tells us that every time we thought we had found a phenomenon due to the activities of extraterrestrials, we were wrong. But although it’s quite likely that this star’s strange behaviour is due to nature, not aliens, it’s only prudent to check such things out.”
|Above:: The Allen array. Courtesy of SETI.|
Mars' atmosphere is being removed at a hundred grams per second
The MAVEN team have revealed results that pin down just how fast the atmosphere of Mars is being eroded by the solar wind ( I was right - you can tell a lot from who's going to be on the panel at these things). Without a strong magnetic field the solar wind (a gale of charged particles put out by the Sun) has been gradually destroying the Martian atmosphere for billions of years. This has turned a world that once supported lakes and rivers into one where liquid water can barely exist at all. Today's rate of loss is only around a hundred grams a second, which doesn't account for all the lost air, but the MAVEN team aren't surprised by this:
“We’ve seen that the atmospheric erosion increases significantly during solar storms, so we think the loss rate was much higher billions of years ago when the sun was young and more active,”said Bruce Jakosky, MAVEN principal investigator.
Above: A graphic from the press conference, showing hoew the Martian atmosphere is being stripped away. Courtesy of NASA.
Above: The press conference itself. Courtesy of NASA.
ESA study Mars' fleeting UV aurora
Staying at Mars: For a long time it was thought that only planets with a global magnetic field could experience aurora. On Earth the magnetic field funnels storms in the solar wind away from most of the planet and into the polar atmosphere, where they cause the air to glow - producing the aurora. But now it seems a global magnetic field is not needed: The remnant fields locked in the Martian rocks can be enough to cause strange aurora that shine in UV light over some parts of Mars.
“It seems that the emissions are controlled by a special shape of the local magnetic field: as it starts to become open, it makes an umbrella shape, allowing access to the energised electrons,” said Jean-Claude Gérard of the University of Liège, lead author of the paper.
|Above: An infographic showing whwere the Martian aurora have been detected. courtesy of ESA|
Beautiful shot of Mars' marathon valley
This comes from the imaging wizards over at unmannedspaceflight.com: It's the southern wall of Marathon valley, where the Opportunity rover isgetting eready for its winter science campaign.
|Above: The sourthern face of Marathon Valley, based on images courtesy of NASA, processing courtesy of James Canvin.|
ESA to build a warning network for space storms
Following on from a US announcement that it intends to build a better warning and protection strategy against space storms - their strategy is here and an action plan is here - ESA has announced that it intends to build a space weather monitoring network. Europe’s economy, like any technology dependant economy, could be damaged by severe space weather - some of the fields that might be vulnerable include telecoms, broadcasting, drilling, exploration, navigation and power distribution. The most famous such storm was the Carrington event of 1859, and a similarly powerful storm today could cause billions of dollars of damage.
|Above: The aurora over Britain - the result of a solar/space storm hitting our planet. Courtesy of Pete Collins.|
UK Space Agency’s first national spacecraft has completed its mission
Most people don't realise the UK has a space agency - that's because it's tiny, and also pretty new. So it's nicely fitting to have a story about the UK space agency completing its first space mission - a tiny technology demonstration mission called UKube. The satellite was an off the shelf cubesat craft that tested a number of new technologies in orbit. Mission Manager Dr Helen Walker said: "It has been a very exciting time, made possible only with the great support from all the teams involved."
|Above: An artists impression of UKube-1, courtesy of Clydespace.|
Antimatter mystery deepens
Antimatter, the mirror image of normal matter that explodes on contact with it*, has always posed a bit of a problem for physics. Not just because of the explosion part - most theories predict the universe should have come into being with equal amounts of matter and antimatter, but this is clearly not the case as everything we look at is made of matter. One idea to explain the imbalance is that antimatter behaves slightly differently to matter, making it more likely to be destroyed. That idea has taken a blow this week, as results from the most recent experiments to measure the forces between anti particles shows them to be identical in strength to those between matter particles, making the absence of antimatter even more mysterious....
Above: Fraser Cain of Universe today, explains why the missing antimatter is a mystery...Courtesy of Universe Today.* Science is more fun when stff explodes.