Archive for October, 2013


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!


A quick and easy one for today. Have you watched Man of Steel? I’d rather (better) not comment on the movie itself, but we can probably agree than Zach Snyder was going for visually striking all through the film. Hence, there’re flying scenes everywhere where he shows how Superman breaks the sonic barrier and … kaboom, here’s a trail of white smoke on his tail like in jet planes!

Whether it is cool or not, is it scientifically sound that a flying man (go figure) can generate that trail?

In fact, jets do generate that white smoke because their engine exhaust mixes with the much cooler atmosphere, like when we exhale white poofs under very cold weather. In order to condense into clouds, the water vapor released by the jet needs the chemicals in the exhaust, including carbon dioxide, oxides of sulfur and nitrogen, unburned fuel, soot and metal particles, although other particles present in the air (if any, at those heights) can also help. All the mix in the contrail rotates with respect to the surrounding air and, voila, here comes the trail!


In brief: it Superman leaves a contrail during his flight he needs to: i) throw heat into the atmosphere; and ii) release a mix of chemicals and a large amount of water vapor. I, for one, do not wanna go there 😀


On a side note, it is interesting to note that the shape and duration of contrails may be used as weather indicator, since they feed on air humidity: a thick, lasting one might well predict a coming storm.

Leaving the chemicals sky spread aside, it’s been suggested that contrails might contribute to global warming because they behave like an insulating layer of moisture and gases in the atmosphere. More information in PhysOrg and Wired.

We’ve seen them in a bunch of movies: massive storms in barren planets that may last for days, weeks or even months. Maybe the storm in Riddick (2013) does not qualify, but planetary storms in Soldier (1998) that forced people underground definitely do.

The question, this time, would be … are these storms even possible in planets with different atmospheres and weather conditions? And, yep, the answer is affirmative.

The Centre de Serveis Científics i Acadèmics de Catalunya (CESCA), and the computer services at the Institut de Ciències de l’Espai (ICE) have been working specifically on Saturn storms. For example, its North Pole hurricane is lasting for years and its eye alone is about half the length of Australia! When Cassini arrived at Saturn in 2004, the north of the planet was hidden in winter darkness, but when spring arrived in 2009, the hurricane revealed in all its glory. It is about 20 times larger than hurricanes on Earth and its winds are four times stronger than ours: around 530 Km/h.


And this is not all! Each year in Saturn (around 30 years on Earth), a gigantic storm known as the Great White Spot roams the planet. The first one was observed in 1876 (when the telephone was invented), and the last one in 2010, when Cassini was already there observing the planet. The thing started as a small brilliant white cloud on the northern hemisphere and expanded rapidly to cover thousands of millions of km2 during more than seven months. Cassini provided high resolution images of this Great White Spot.


Scientists at CESCA and ICE used this information to study and explain the storm origins this time. Apparently, its focus is high: around 300 km above the visible clouds. The storm brings moist gas all the way up to form visible clouds. The process releases large quantities of energy, that interacts violently with the usual Saturn wind, pumping it up to 500 km/h. Just like in Soldier, too.