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Friday 11 December 2015

A new planet? Whoa there.....

ALMA array finds new member of our solar system?

This is the big news hitting the web today: The ALMA array may have detected something big - an Earth sized planet big or bigger sort of big - on the edge of our solar system....but I really need to put the emphasis on 'may' and 'something': 
  • Firstly, a lot of people are pointing out that it's a huge coincidence for ALMA, which has a tiny field of view, to have detected this object by pure either ALMA has been very lucky,or there are a lot of these things, or it's not real - some kind of illusion caused by a problem with the array.
  • Second, as the authors of the paper make clear themselves, it's not at all clear what this thing is, or even how big it is. It's literally just a point on a couple of their scans.
  • Lastly, the paper is a preprint - that means it's a rough draft and hasn't been peer reviewed or accepted for publication by anyone. In other words no-one has independently fact checked it, and that's a HUGE part of good science. Scientific American has good write up on this aspect of it.
So watch this space... but don't send your new planet name suggestions off just yet....

Above: The ALMA array.

Mists and fogs on Ceres?

For years now astronomers have been puzzled by the mysterious bright areas on the surface of Ceres. At first they were just some slightly brighter patches visible to Hubble. The the dawn mission arrived, and revealed some irregularly shaped patches of the surface that seemed to have incredibly bright white surfaces.... and that's where our knowledge stopped: These patches were unlike anything we'd ever seen. They mystified us. To be frank they still do.

Just recently Dawn has been able to send back some new clues: We now know these patches are probably not ice, but a paper published this week seems to show evidence that at certain times of the Cerean day these bright patches are emitting vapours and fogs of some kind. That's deepened the mystery still further as the most likely material to evaporate and cause fogs - probably clouds of vapour crystals rather than clouds of water droplets - is ice, which has been ruled out as a cause of the bright patches. All we can do is keep gathering data, and wait for the right clues to solve the puzzle....

Above: Images and caption from the paper, showing the purported mists: Occator contains the brightest spot on Ceres. This is a pit covered by bright material, and the surrounding area shows a specific diurnal brightness rhythm, which becomes detectable at oblique views. a, Oblique view at noon reveals a diffuse near-surface haze (white) that fills the floor of its host crater. This haze disappears completely at dusk (b). The low column density of the haze is indicated by the very oblique limb views at noon (c and d), and the haze does not extend above the elevated southwestern part of the crater floor (left in c). There is a lapse of 450 s between the taking of the images shown in c and d

Vapour farming experiment approved for testing on Mars

Salt has a lot to answer for on Mars: Especially a particular group of salts that suck moisture out of the thin Martian air until they self-dissolve into tiny water droplets. This phenomena, called deliquescence, is suspect number 1 for how the seeps that are thought to cause recurring slope linea form, and earlier this year Javier Martin-Torres and his colleagues reported results from NASA’s Curiosity rover suggesting that liquid water pools just beneath the surface of Mars at night before evaporating during the day. 

To test the idea in a more controlled way, the ESA ExoMars rover will carry an experiment called HABIT, which will use salts to absorb 5 millilitres of water from the atmosphere a day, and it can hold up to 25  millilitres in total. The motivation isn't pure curiosity: If the process works, it can easily be scaled up to provide water for future crewed missions to Mars. "HABIT can be easily adapted to ‘water-farms’ for in-situ resource production,” Torres told New Scientist Magazine. “We will produce Martian liquid water on Mars, that could be used in the future exploration of Mars for astronauts and greenhouses.”

Above: The 'recurring slope linea' that form on some Martian slopes and are thought to be due to liquid water. Courtesy of NASA.

Deal struck to build Jupiter Icy Moons Explorer mission

Airbus and the European Space Agency have signed the contract that will lead to the construction of a space probe known as JUICE (JUpiter ICy moon Explrer - the things people will do for a good acronym)  to study Jupiter and its icy moons.
The probe will launch in 2022 and arrive at the giant planet 7.5 years later. The 5.5-tonne probe is being built in Toulouse in France, however components will be sourced from across Europe, America, and Japan. The full price for the JUICE is expected to exceed one billion euros, one of ESA's biggest missions to date, and as well as other goals it will help us understand the potential habitability of Jupiter's icy moons..

Above: Ganymede, one of Jupiter's potentially ocean bearing moons.

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