Tabla de contenidos para Jan-13 en Science Illustrated

The Challenger Deep, located in the Mariana Trench in the western Pacific near Guam, lies at a depth of 35,840 feet and could easily hold the 29,029-foot Mount Everest. The Deep was discovered in 1875, and people have been attempting to precisely measure its depth ever since. The first manned mission was made in 1960 by Swiss oceanographer Jacques Piccard and U.S. Navy Lieutenant Don Walsh in the customized bathyscaph Trieste. After a descent lasting nearly five hours, they reached the bottom of the Deep, staying for 20 minutes. The next two vessels to reach the bottom of the world were unmanned, remotely operated underwater vehicles (ROVs): the Japanese submersible Kaiko, in 1995, and the U.S. vessel Nereus, which in 2009 collected samples of water and rocks from the bottom…

The Milky Way is headed on a collision course with the larger Andromeda Galaxy — but they won't collide anytime soon. Andromeda, which is 2.5 million light-years away, is approaching us at a speed of 250,000 mph. Based in part on studies of our galactic neighbor using the Hubble space telescope, U.S. astronomers say that the spiral galaxies will crash together in about 4 billion years. After the big bang-up, the Milky Way and Andromeda will combine to form one gigantic galaxy. And although the billions of individual stars in the two galaxies will not collide, they will be completely rearranged, and the solar system will likely end up very far from the center of the newly formed galaxy. The gravitational pull between the Milky Way and Andromeda will cause…

At first, it would appear as merely a speck in the sky, but an approaching comet heading directly toward Earth would soon roar into the inner solar system at a speed faster than 124,000 mph. Its impact would generate a tsunami several hundred feet tall and would kick up a massive cloud of water vapor, sulfur and dust into the stratosphere that would block sunlight and send temperatures plummeting across the globe. Scientists from Australia's University of New South Wales think that this may have happened some 2 1/2 million years ago, when a comet a little more than a mile wide plunged into the Pacific between Chile and Antarctica. A comet — essentially a large, dirty snowball — builds great momentum in its oblong orbit around the sun, giving…

A brand-new space race has begun — not, as in the past, between nations, but between private companies with lofty visions and the finances to realize them. Critics charge that the space industry has become a sport for the wealthy, but if so, it's one that will someday greatly influence space travel, as well as working and even living in space. The price of sending satellites and humans into space will plummet, as innovative companies develop new technologies. In the course of a few decades, space will become a destination for wealthy tourists and perhaps even colonists. Rocket launches will become routine, and the next round of adventures in space might even breathe new life into the global economy, if raw materials can one day be obtained from asteroids. The…

Planetary Resources was founded with the goal of extracting the many valuable resources that asteroids contain. These massive space rocks, some of which closely approach Earth now and then, are thought to have significant stores of the lucrative metals that belong to the platinum group of elements. But first the company will attempt to find water, which is very costly to transport into space. In the course of the next few years, Planetary Resources intends to develop the tools that will make asteroid mining a reality: a space telescope to locate asteroids orbiting near Earth; probes to collect data about their shape, density and contents; and, once an asteroid is found to have a sufficient quantity of water or other resources, a craft manned by mining robots to do the…

An egg that is fertilized by a sperm cell begins to develop into an early embryo. For reasons that are still unknown, the embryo sometimes starts to divide in two within the first 15 days; both of these halves will try to develop into a baby. If the division starts before 12 days have passed, it often continues until the two embryos have separated into identical twins. If the division begins after 12 days have passed, it may be incomplete: The two embryos never fully separate, but still continue to develop, resulting in conjoined twins. Presented in 2000, this theory holds that conjoined twins occur when two identical twins who were initially completely separated are somehow joined back together.…

A scientist's description of the supercontinent Rodinia would probably go something like this: a vast, desertlike landmass where barren plains stretching endlessly toward the horizon are drenched in a never-ending tropical rain that slowly eats away at the rocky landscape. It might sound like an alien world, but Rodinia was the catalyst for a number of events that caused life as we know it to develop. It was the first supercontinent in which all of Earth's present landmasses were united, and, more importantly, it was located along the equator. Continents reflect more sunlight than oceans do, so Rodinia caused Earth to absorb less heat from the sun than it does in the present era, in which oceans cover large swaths of the equator. And as the relentless tropical rain eroded…

Scarred victims for life CASUALTIES: 300-500 million When a worldwide vaccination effort eradicated smallpox in nature, it was hailed as one of the most significant medical achievements of the 20th century. For at least 500 years, the disease had ravaged the world; in South America alone, it almost wiped out the entire Inca population. Characterized by distinctive large pustules, the ordinary form of the virus attacked the major organs and, on average, killed more than 30 percent of those infected; more extreme forms were invariably fatal. Most survivors were scarred with pockmarks. Killed a third of Europe's population CASUALTIES: 200 million Vomiting blood, painful growths the size of apples, gangrene of the extremities — these were the gruesome effects of the plague, which repeatedly wiped out large swaths of the…

1 Which of these figures is not like the others? 2 Which sheet does not belong? 3 What numbers replace X, Y and Z? 4 The figure at right can be folded to make which of the squares below? 5 What number replaces the question mark? Problem 1: Figure A is different. In each of the other figures, the points where all of the circles touch are aligned on the same axis. Problem 2: Sheet B does not belong. In the other sheets, the product of the number of diagonal lines in each corner of the sheet equals the number of lines in its center. For example, in sheet C: 2 x 3 x 1 x 3 = 18 5 + 5 + 5 + 3 = 18 Problem 3:…

1 RIGHT, 2 WRONG Only one of the three statements on each card is correct; the others contain one or more errors. See page 70 for the answers. A The 1908 Ford Model A was the first mass-produced car. After 30 years, 15 million of them had been sold. B Since 1911, the Spirit of Ecstasy, which depicts the archangel Gabriel, has adorned Rolls-Royce hoods. C Cadillacs are named for the French explorer Antoine Laumet de la Mothe, Sieur de Cadillac. A The comet that visits Earth most frequently is Halley's Comet. It passes by us once every 75 to 76 years. B The word comet comes from the ancient Greek words aster and kometes, meaning hairy star. C Comets move in highly elliptical orbits around Earth and are often…

Venus is the only planet in the solar system where a day lasts longer than a year: It takes 225 days to complete its orbit around the sun, but 243 days — 18 days longer — to rotate around its own axis. And unlike the other planets, Venus rotates clockwise, even though its orbit follows the same counterclockwise path that all of the solar system's planets make around the sun. The explanation for this most likely lies in the planet's very early history. When the solar system was young, it had many protoplanets, which often collided violently with each other. It's possible that Venus rotated more quickly and in a counterclockwise direction when it formed, but that the tremendous impact from a crash with another planet both slowed and reversed…

We humans have been predicting our own demise as far back as the Roman Empire, when the Romans feared their city would fall into ruin in 634 BCE. Christopher Columbus determined that the apocalypse would occur in 1658, while the self-appointed prophet/poet Nostradamus predicted that it would take place in the seventh month of 1999. Even acclaimed scientist Isaac Newton put some thought into the matter, studying the Bible and concluding that our time would not run out until sometime after the year 2060. One of the most recent predictions about the end of Earth is due to culminate on Dec. 21, 2012, when the 13th B'ak'tun of the ancient Maya calendar concludes. Despite the theory's persistence, it's unlikely that the Maya believed that the world would end on that…

Not only has the processing power of computers increased exponentially since their invention, but we're now creating robots that can learn independently — it's just a matter of time before they gain full artificial intelligence. And these smart robots could quickly outcompete humans. In his book The Singularity Is Near, futurologist Ray Kurzweil predicts that we'll be outdistanced sometime around 2045. If he's right, our future is indeed uncertain. The majority of the world's 19,000 nuclear weapons are located in the United States and Russia. If the two countries ever use them, three quarters of a billion people would die immediately. The rest of the world would be hard-pressed to survive the aftermath, as the massive explosions and subsequent fires would send hundreds of millions of tons of soot into…

The space industry is awash in private firms, big and small, that are aiming to capitalize on the final frontier by carrying satellites, cargo and humans into space. The majority are focusing on traditional rockets, but a miniature space shuttle and a giant aircraft are also among the proposed projects for the next generation of spacecraft. In May, the Dragon space capsule docked with the International Space Station, and the SpaceX company, which developed both the capsule and the Falcon 9 rocket that launched it, will mark the greatest achievement to date in the private aerospace industry. The Falcon 9 is powerful enough to ferry 6 1/2 tons of supplies or seven astronauts to the ISS and, at 180 feet in height when combined with the Dragon, is as tall…

Processing plants separate valuable metals from asteroid ore and split water into oxygen and hydrogen for rocket fuel. Drilling robots extract metals from the asteroid's interior, while other robots collect ore on the surface. Ice on the surface is scraped off and collected by robots. Metals can also be mined from dust and lumps of rock. Robotic spacecraft transport water and precious metals back to low Earth orbit, where the vessels can be refueled and their cargo can be offloaded to Earth-bound shuttles. Human miners are tethered to the asteroid with safety lines to compensate for the low gravitational pull. It's neither easy nor cheap to travel to an asteroid and bring material back to Earth, but the potential profits are too great to ignore. NASA has earmarked more than…

A group of children in Huanchaquito, a small fishing village in northern Peru, found something unusual last year as they were playing in the sand outside the local pizzeria: a large collection of old bones. The owner of the pizzeria contacted archaeologist Oscar Gabriel Prieto, who was working at another excavation site nearby at the time, and he and his team decided to look into the discovery. What they found was the site of a mass sacrifice of children; after just one day of work, 20 well-preserved skeletons had been unearthed. And within a few weeks, the archaeologists had found 43 skeletons in total, all of which appeared to have been victims of execution. Each child had received a clean cut through the breastbone, and the chest had been cut…

Some 345 million years ago, three large continents began to assemble into one: Pangaea. This supercontinent stretched from pole to pole and was dotted with many shallow lakes and crisscrossed by rivers. Mosses and ferns grew in abundance as life thrived in the muddy swamps. Biologists think that it was in those pools where fish began to evolve lungs in response to the water level dipping too low. Using their strong fins, they threw themselves onto the shore, developing into amphibians that could live both in water and on land. The long “snowball” period and subsequent thaw had filled the atmosphere with such a high oxygen content that insects grew huge. But although Pangaea provided a breeding ground for life, the continent was warm and dry — not until it…

Offspring: Usually one Childhood: Eight years Parenting strategy: Patience Chimps live in groups with complex social structures, so they depend on their mothers to teach them the skills they'll need to survive. Mother chimps curtail violent behavior in their offspring with sounds and gestures and also teach them how to procure food. With a relatively long childhood as compared to other animals, there's plenty of time to learn everything. And true to the social nature of the species, chimp grandparents, siblings and alpha males may also assist the mother in raising the young. Offspring: One Childhood: One year Parenting strategy: Extreme attention A humpback whale calf rarely strays far from its mother — she's a full-time milk dispensary for the hungry infant, which feeds almost constantly for the first 11…

Which of the items described below is shown in the picture (right)? 1 RADIO TELESCOPE DISK Radiation from the universe outside the visible spectrum can be observed by radio telescopes. The largest of these has a 1,000-foot disk. 2 STETHOSCOPE The stethoscope was inven-ted in 1816 by French doctor René Laënnec, who discovered that it was easier to hear a patient's heartbeat when listening through a rolled-up sheet of paper. 3 BOTTOM OF AN APOLLO ROCKET The objective of the Apollo program, named for the Greek god of the sun, was fulfilled when the first man landed on the moon, in 1969. Guess What: 2. Stethoscope…

Hanging beneath the throat of a moose is a flap of skin covered with hair, which is called a bell. It has its own blood supply and is often equipped with a tail, which can be up to 12 inches long in young animals. Among older moose, the tail is much shorter or even nonexistent, while the rest of the bell is larger and shaggier. Since the appearance of the bell varies with gender and age, scientists think that moose identify each other by the shape of the bell. Among young moose, males and females are about the same size, so the bell can be used to estimate the animal's gender and maturity. The bell may also be used among moose for mating purposes. Researchers have observed male moose spraying…

During excavations in spring 2012 in the Maya city of La Corona in Guatemala, American archaeologists came across a battered stairway block that had been left behind by grave robbers. When scientists at Tulane University in New Orleans took a closer look at the barely perceptible inscriptions, they found a date: Dec. 21, 2012. Doomsday prophets had already marked this date — the end of the longest cycle of the Maya calendar — as the one on which life as we know it would come to an end. The discovery of the 1,300-year-old Guatemalan block seemed to bolster their claims, as it contains the second known reference to Dec. 21. (The first was identified in Mexico in 2004.) But even though the date of our supposed day of reckoning is…

A red-hot desert planet lies in ruins. Craters and grooves in its crust indicate that, many years ago, it was dominated by vast oceans, but they evaporated long ago, due to the heat from the nearby sun. The vapor from these dry oceans and lakes has generated an accelerating greenhouse effect, and now the only remaining signs of the globe's once-abundant life are the die-hard bacteria clinging to life on the barren surface. Welcome to Earth in 1.6 billion years. Even if we manage to avoid all the other threats to our existence, we will not escape the global warming caused by the sun's expansion as it dies. And it will be much more extreme than most people can imagine. The planet's ecosystems can only take so much heat. A…

Space stations made of metal are large and heavy, and even the most powerful rockets have a limit to how much they can lift. Consequently, the International Space Station (ISS) consists of multiple modules that have been transported into orbit over the course of several years by rockets and space shuttles. It would be easier and cheaper to launch modules that are larger but also lighter and more flexible, so Bigelow Aerospace has developed a new module, made of material that can be packed tightly for launch and transport and then unfolded and inflated once in orbit. The company has two prototypes orbiting Earth, Genesis I and II. Each is 47 1/2 feet long and some 8 feet in diameter, and they are powered by eight solar panels. The Genesis…

Canadian twins Tatiana and Krista Hogan are unique. Not only are their heads conjoined down to the neck, but they also, quite exceptionally, share major parts of their brains. The sisters' sight centers are conjoined, allowing nerve signals to pass between their brains, apparently enabling one twin to perceive what the other one is seeing, even though their eyes are looking in different directions. The twins' parents recount how a cartoon will sometimes make Tatiana laugh even when it is on the television behind her and only Krista can actually see it. Tatiana and Krista are extremely rare. The majority of twins who are conjoined by the head share only the skull and some of the blood-circulation system. This type accounts for 6 percent of all conjoined twins, occurring in…

Kenorland, one of Earth's earliest supercontinents, formed 2.7 billion years ago and was responsible for one of the planet's greatest climate disasters — one that essentially allowed life as we know it to exist: the Great Oxidation Event (GOE). Up until Kenorland's formation, the young planet's oceans and atmosphere were rich in methane, creating a favorable environment for anaerobic bacteria. Oxygen-loving bacteria were relegated to life on the ocean floor, where, deep in the abyss, they accumulated in microscopic rock-layer cracks, generating a biosphere. When the new landmass emerged from the collision of the continental plates, parts of the seafloor were thrust toward the surface, forming shallow lakes and inland oceans. With a boost from the faint light of a weak sun, the exposed aerobic bacteria began to pump oxygen…

North America Moved to the northeast. The continent was left with only one active zone in the west, where the Pacific plate grinds against the North American plate. South America Separated from Africa 110 million years ago, moving to the northwest. The collision with the Pacific plate created the Andes. Africa Disintegration left the continent in peace, with earthquakes and volcanic eruptions occurring only near the Mediterranean zone. Australia Hasn't changed in almost 500 million years. Antarctica Was the only continent to head south. The ice cap limits our ability to study its history. Europe Moved to the northeast, rotating along its axis. The pressure created the Alps. Asia Eurasia collided with the Indian plate, creating the Himalayas and the massive mountain ranges near Pakistan. Large lakes, such as Lake…

Better virus tests A new biosensor provides a fast diagnosis. Cheaper solar energy Metal-based solar cells save expensive silicon. Faster electronics Smaller computer chips contain more information. Safer cancer therapy Diseased cells are destroyed without side effects. Thomas Ebbesen held a thin sheet of gold foil up against the light and watched, surprised, as the light filtered through the foil. It must be an error, he thought, because according to everything we know about classical optics, that should not have been possible. A Norwegian-born physical chemist working for the U.S.-based NEC Research Institute, Ebbesen knew that the 100 million tiny holes in the foil were 200 times smaller than the diameter of a human hair, and thus much smaller than the wavelength of visible light. In other words, the light…

Which of the people described below is shown in the picture (left)? 1 JANE GOODALL The 78-year-old British primatologist revolutionized our view of chim-panzees through her research, particularly with her landmark discovery that chimps use tools. 2 RITA LEVI-MONTALCINI Italian neurologist Levi-Montalcini was awarded the Nobel Prize for discovering the neural growth factor (NGF) protein. At 103, she is the oldest living Nobel Prize recipient. 3 JILL TARTER Tarter, an American astronomer, has long been an important player in the search for extraterrestrial intelligence, helping to establish the SETI Institute in 1984. Guess Who: 1. Jane Goodall…