Can Moons have Moons?

Astronomers can say with near certainty that there are no moons with moons in our solar system. But that doesn't mean it's physically impossible. After all, NASA has successfully put spacecraft into orbit around our moon.

Although astronomers have spotted some asteroids with moons, a parent planet's strong gravitational tug would make it difficult for a moon to retain control of its own natural satellite, says Seth Shostak, a senior astronomer at the nonprofit SETI Institute. "You would need to have a wide space between the moon and planet," he says. Orbiting far away from its parent planet, a relatively massive moon might be able to hold onto a moon of its own.

Conditions like these might exist in far-off solar systems, but while some 250 exoplanets have been detected, there's almost no chance we'll be able to spot exomoons, much less moons of exomoons, for decades to come. This is because our current methods for planet-hunting—such as spotting one as it passes a large star—lend themselves to detecting mostly huge, Jupiter-like planets, not their moons.

Even if astronomers spot a moon with a moon, it probably won't last long. "Tidal forces from the parent planet will tend, over time, to destabilize the orbit of the moon's moon, eventually pulling it out of orbit," says Webster Cash, a professor at the University of Colorado's Center for Astrophysics and Space Astronomy. "A moon's moon will tend to be a short-lived phenomenon."

Caracteristics of the moon: A moon is a large body or mass or material that orbits around a planet. It is usually much smaller than the planet. The Earth has only one moon, while Mars has two moons and Jupiter has 9 moons.

Our Moon is only about 1/4 the diameter of the Earth. Its gravity affects the Earth's tides. The Moon looks bright at night because of sunlight that is reflected off its surface. It has some distinct surface features that can be seen with the naked eye. Astronauts examined the surface more closely during Moon landings.

Moon Phases:

DOES SMOKING CONTRIBUTE TO WLOBAL WARMING?

Yes,smoking is not only bad for your health, but also helps to kill the climate. According the World Health Organisation, about 1.1 billion people worldwide smoke, and this number is expected to triple over the next 25 years.

All that smoke and tobacco farming will surely have an impact on the climate. Smoking alone spews 2.6 million tons of CO2 and 5.2 million tons of methane into the atmosphere every year.

But that’s not the worst part, tobbacco farming and disposing of waste has impacts on the environment too. The widespread monoculture inherent in growing tobacco extracts six times more potassium from the soil than growing other plants does.

But now comes the big hammer: 150 kg of wood are needed for drying one kilogram of tobacco, which converts to 1.2 million hectares of forest. About 600 million trees are chopped down annually to make room for tobacco plants. These trees could remove 22 million tons of the climate-killing gas yearly.

Not only that, all those cigarette filters end up on the ground and contaminate the groundwater with nicotine, dioxin, formaldehyde and cadmium.

Do dogs sweat from their tongues?

Dog's Armpits Dog's "sweat" through their exhale/breathing and through the pads on the bottom of their paws. It is not considered "sweating" anyway. Sweating in humans is to dampen the skin so that when the fluid evaporates it causes a cooling effect. 

Their main way to cool down is through panting or breathing very rapidly which cool them internally. They do not have armpits, because they do not have arms. Those aren't pits; they're called flanks. They have 4 legs. 

Dogs do have "sweat glands" on their paws. They do sweat heavily through their feet. That's why it is recommended that if you have a long-haired dog or a dog that requires frequent grooming to make sure you take it to a groomer on schedule to have its feet cleaned up.

IS THE INTERNATIONAL SPACE STATION NOISY?

LET'S FIND OUT

You'dthinkthatsoaringaroundEarthonthe International SpaceStationwould be prettyquiet, butitturnsoutlifeaboardhumanity's orbital outpostissurprisinglynoisy — albeit in thatcomforting, white-noisesort of way. This, straightfromcommander Chris Hadfield'stwitter, is a recordingtakenfrominsidethe U.S. lab of the ISS:

https://soundcloud.com/colchrishadfield/space-station-noise

Hadfield describes theambientnoise as being "somewhatnoisy," butthat "thesounds are of theenvironmentthatkeepsusalive. Perhapslike in thewomb.

The ISS is a noisy place. Tobettercharacterizetheacousticenvironment as itchangeswithassembly, the International SpaceStationAcousticMeasurementProgram (ISS Acoustics) has collected data frombefore a permanentcrewoccupiedthe ISS. Theexperiment uses one B&K Type 2260 SoundLevel Meter (SLM) and threeAmetek Mark I audio (acoustic) dosimetersto monitor the ISS acousticnoiseenvironment. 

Forpeacefulsilence, saysHadfield, astronautsneedonlytakethemselvesoutside the ISS:"Spacewalks are whisper-quiet, just radio comm and yourownbreath."

 Snowstorms are mute

snowstorms are not frecuent,                  To produce lightning

they dont produce lightning                    and thunthers you

and thunthers.                                          need that the difference

                                                                 between the positive

                                                                 top charge and the low

This is just because of the                       denial is sufficiently

wind in winter is not                               significant a lightning

the same as wind in summer.                  takes place.

During the summer, the

troposfera is full of humid

and warm air. Above, the air                   So in winter the wind

is cold and is full of crystals                    is dry and the cauds

of ice. When the warm air                       doesn´t produce

ascends, going I obtain steam                  friction between them

of water, the molecules rub                      so thunthers and

the crystals of ice and the                        lightning aren´t

friction believe an electrical                    produced.

field in the cloud, as when

you brush the doormat with

the feet. The crystals of ice

acquire a light positive charge,

and the ascending current

takes them to the top part of

the cloud, so that in the low

part there stays a network of

negative charge.

                                                        

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IF EVOLUTION HAD TAKEN A DIFFERENT  TURN COULD DRAGONS EXISTED? 

It would have taken quite a few turns for natural selection to have produced dragons, but if you're willing to stretch a bit, most classic dragon characteristics do exist in other species. They just don't come packaged in one animal.

First up on the dragon checklist: flying. Dragon wings are usually depicted in one of two ways—a third pair of limbs connected to the backbone, or webbed forearms. Jack Conrad, a paleontologist and reptile expert at the American Museum of Natural History in New York, thinks the latter is more plausible.

"It seems that six appendages are very unlikely in vertebrates," he says. "The only thing close to having six limbs are these frogs in the western part of the U.S. that get this bad parasite and end up generating extra limbs. Even then, the new limbs are identical to the hind limbs, and the frogs don't do well. It seems that anytime nature tries to generate a vertebrate hexapod, it dies. That seems to be the main limitation."

In Conrad's opinion, the leathery wings of a pterosaur are the best possible flight mechanism for a giant lizard. "Quetzalcoatlus had a 30-foot wingspan," he says. "That would do the trick." Big, strong wings are necessary to compensate for the weight of a dragon's skin, which, of course, would need to withstand bow-and-arrow attacks. "Let's throw a little alligator in there for armor," Conrad says. An alligator's skin, he explains, is made partly of bony plates. When European settlers first encountered the reptiles, the skin proved to be tough enough to turn away a musket ball, plenty strong for a dragon.

OK, so we've got a very large alligator with the wings of a pterosaur that can repel musket fire. Now it just needs to breathe flames. This is where no parallel exists—there are no known animals that can spit fire or even a flammable liquid. But there are some beetles that can shoot caustic chemicals from their abdomen that can burn people's skin, so it's not totally out of the question that some animal at some point in time could make a flammable liquid. Cobras can spit venom with great accuracy at objects six feet away; the dragon could borrow that ability to propel the flammable liquid. As for lighting it? "Well, maybe, if you had some specialized organ like an electric eel's tail dangling in the mouth, that could spark that liquid and allow the creature to breathe fire," Conrad says. "Of course, this is all very theoretical.

By Andrea González 2°C

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Which Is The World´s Smallest Vertebrate?

It is a fly-size frog

The record was broken about 2 years ago by Paedophryne amauensis, which has an average length of only 7.7 mm. Actually, it's a double record, as Paedophryne amauensis became both the world's

smallest known frog and the smallest known vertebrate.

The existence of a frog that is just a bit bigger than the common fly is really mind-blowing!

Why so small? 

Austin believes that P.amauensis and other tiny frog species have evolved this way in an effort to fill a niche that nothing else is filling. Their tiny size allows them to consume very small invertebrates, like mites, that no other predator eats.

Description
P. amauensis has an average body length of only 7.7 millimetres (~0.30 in) and comes with dark-brown, earth-like colors that allow it to blend in with the leaves of the forest floor. Individuals are essentially invisible to the naked eye.

Their skeleton is reduced and there are only seven presacral vertebrae present.

Discovery
The species was discovered in August 2009, by Louisiana State University herpetologist Christopher Austin and his PhD student Eric Rittmeyer, during an expedition to explore the biodiversity of Papua New Guinea. It was formally described in January 2012, and was discovered near Amau village in the Central Province.

In their paper, the researchers note that discovering the species was not easy. Male frogs use calls that resemble sounds made by insects and both sexes camouflage themselves in the leaves of the forest floor. These two traits, combined with their tiny stature is most probably why the species has gone unnoticed for such a long time.

To catch them, the researchers resorted to sound triangulation, as the high pitch of the calls made them especially hard to locate using human hearing.

Finding the frogs was not an easy assignment. They are well camouflaged among leaves on the forest floor, and have evolved calls resembling those of insects, making them hard to spot. -"The New Guinea forests are incredibly loud at night; and we were trying to record frog calls in the forest, and we were curious as to what these other sounds were," said research leader Chris Austin from Louisiana State University in Baton Rouge, US. -"So we triangulated to where these calls were coming from, and looked through the leaf litter. -"It was night, these things are incredibly small; so what we did after several frustrating attempts was to grab a whole handful of leaf litter and throw it inside a clear plastic bag. -"When we did so, we saw these incredibly tiny frogs hopping around," he told BBC News. The Paedophryne amauensis was identified only recently, and consists of a number of tiny species found at various points in the eastern forests of Papua New Guinea.The tiny limbs of amauensis (top) and swiftorum are rendered translucent

They're occupying the relatively thick leaf litter of tropical forest in low-lying parts of the island, eating incredibly small insects that typically are much smaller than insects that frogs eat," said Professor Austin.

“And they're probably prey for a large number of relatively small invertebrates that don't usually prey on frogs."

Predators may well include scorpions.

Before the Paedophrynes were found, the title of "world's smallest frog" was bestowed on the Brazilian gold frog (Brachycephalus didactylus) and its slightly larger Cuban relative, the Monte Iberia Eleuth (Eleutherodactylus iberia). They both measure less than 1cm long.

The smallest vertebrates have until now been fish.
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