Archive for the ‘Look at the stars’ Category

250px-Warren_Elliis_Ocean_1_cover

Hi, comicbook friends. Any fan of Warren Ellis out there? Me, I like Chris Sprouse as well, so it is only natural I enjoyed Ocean. Set 100 years from now, the story focuses on a UN special weapon inspector sent to Cold Harbor, a UN research station in orbit around Europa. Deep, under the ice surface of that moon, there is an ocean and a set of nonhuman artifacts have been discovered. I’m not going further into the plot, in case anyone wants to read it spoiler-free and also because I don’t need to. It was only natural at the time that Ellis thought of Europa as a background for his plot: the smoothness of the surface has led people to think there might be a water ocean beneath its icy crust, kept liquid by tidal acceleration. Nasa also reported detection of water vapor plumes in 2013.

Europa-moon

However, it turns out it’s its bigger sister Ganimede who might be proven to yield an ocean first. NASA’s Hubble Space Telescope has the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter’s largest moon. The subterranean ocean is thought to have more water than all the water on Earth’s surface.

Noaa_ganymede

And, because science is cool like that, they figured it out by observing Ganymede’s aurorae borealis. The idea behind this statement is pretty simple. Aurorae appear when plasma from a solar storm reaches Earth. Our electromagnetic field basically works like a shield that deflects particles from the storm.

magnetic_field_2

The shape of the magnetic field lets some particles reach our magnetic poles, both when it moves past us and backwards,sort of like a wave in the sea that hits you when the water retreats. An excellent explanation of the full process can be watched in the following 4 minutes video.

So far, so good, but what does this have to do with Ganymede? Easy. Ganymede is the only moon in our system that has its own magnetic field and, hence, aurorae in regions circling the north and south poles of the moon. However, since it is so close to Jupiter, its own magnetic field interacts with Jupiter’s. As a result, its aurorae “rock” back and forth. The plot below, for example, shows how our geomagnetic field changes depending on Earth orbital motion due to interaction with the interplanetary magnetic field brought to you by courtesy of the solar wind (see full explanation on A Hitchhiker’s Guide to Space and Plasma Physics).

tumblr_n0s97wH6kI1rnq3cto1_r2_500

According to calculations, given the proximity of Jupiter and Ganymede, aurorae should rock up to 6 degrees. However, if a saltwater ocean were present, Jupiter’s magnetic field would create a secondary magnetic field in the ocean1 that would counter Jupiter’s field. That second field would actually suppress the rocking of the aurorae. And, ta-daaa, indeed they rock only 2 degrees according to estimations!

hs-2015-09-a-web

Scientists estimate the ocean is 60 miles (100 kilometers) thick — 10 times deeper than Earth’s oceans — and is buried under a 95-mile (150-kilometer) crust of mostly ice.

Fuente: Hubblesite.org

1. Dissolved salts in seawater conduct electricity, and as ocean currents move within the planet main magnetic field, they generate their own secondary magnetic field (see here).

Advertisements

futurama_s02e10_11

Anyone recalls that Futurama episode where Professor Farnsworth builds a Smell-O-Scope to search the galaxy and Jupiter smells like strawberries? Turns out it’s not such a crazy idea. In fact, scientists from the Max Plank Institute used the IRAM radio telescope in Spain to study a dust cloud near the center of the galaxy and, guess what? it smells like raspberries … and rum. Yummy! I knew I liked astronomy for a reason.

 NASA JPL/Caltech/Univ. of Wisconsin

Apparently, the chemicals they found in those clouds include ethyl formate, the dominant flavor in raspberries and a key one in rum, although there are other molecules that might mess up with the smell.

Of course, scientists do not actually smell those clouds: they identify the chemicals and map them into familiar earth compounds just to explain what they’ve found. One would think — booo-riiing. But we could actually very well build a smell-o-scope under these premises.

In 1932 Huxley’s book Brave New World, he proposed full sensory movies called “feelies”. The key idea is that smells are due to volatile molecules called odorants that constantly evaporate and reach our olfactory receptors. In the early 1950s, Hans Laube actually created the Smell-O-Vision, by pumping into tiny tubes spread around a theater a combination of 30 different smells including flowers, garlic, smoke, oranges, etc.  The process had to be steadily controlled to avoid residual smells and the concept did not catch.

Nevertheless, half a century later, there is still people working on smell interfaces, like Meta Cookie or the Smelling screen. The idea is the same (odorant containers released in a sequence) but systems are more portable. So, in theory, if we identify some molecules in a far away galaxy, we can release LOCALLY the smell that they are supposed to yield straight to the observer’s nose.

Now, on a smaller scale, believe it or not, Denver cops have been using what they call Nasal Ranger Field Olfactometer since they legalized marijuana to enforce the so called “odor-ordinance”. In this case, the device indeed enhances smells so they can be detected at 500:1 ratio. This works as long as one is within the smell source range, so no raspberries for us – duh

Anyway, all in all, if one combines whatever the telescope finds with a smell interface … duh, Smell-O-Scope, everyone. If it’s in Futurama, it’s technically sound 🙂

More on the raspberry-er Center of the Galaxy (The Guardian)
More on Smell Interfaces (Sensoree)
More on Olfactometer (St Croix Sensory)


wanderer

Any Leiber fan out there? While I’m particularly fond of Fafhrd and the Gray Mouser and Conjure Wife, I’ve read other Leiber’s novels, like the Wanderer. That novel in particular, focuses on the arrival of a wandering planet to Earth orbit. On its arrival, it consumes the moon and, hence, releases all kinds of natural disasters on the planet, just like in the beginning of Oblivion, too. Not among my fav novels, but I read recently about the effects of changes in lunar orbit and I kind of recalled the book.

The simulation focus on a different situation: instead of losing the moon, it actually gets way closer to Earth, approximately where the International Space Station is floating. It’s a bit difficult to figure out space scale, but if  Earth was an orange in the middle of your everyday round table, the moon would be a pearl earring just on the table border. The ISS would be almost in contact with the orange, instead. While the video pictures a pretty, giant moon in the sky, it does not address the obvious problem: gravity. Joe Hanson actually explains it well in his blog It’s ok to be smart. The basic idea is that when two large astronomical bodies come together, the pull of gravity and tidal forces eventually warps the less massive one into disintegration. Not to mention that those forces would also ravage the larger planet’s crust into a volcanic nightmare. Back we go to the Wanderer scenario!

Actually, the full effects of not having a moon have already been evaluated and filmed by BBC in the documentary “Do We Really Need the Moon?” that is fully available on Youtube:

Spoilers here: looks like we really do!