Astronomía (Continuación)

Our galaxy, the Milky Way, is home to almost 300 billion stars, and over the last decade, astronomers have made a startling discovery — almost all those stars have planets. The fact that nearly every pinprick of light you see in the night sky hosts a family of worlds raises a powerful but simple question: “Where is everybody?” Hundreds of billions of planets translate into a lot of chances for evolving intelligent, technologically sophisticated species. So why don’t we see evidence for E.T.s everywhere?

The physicist Enrico Fermi first formulated this question, now called the Fermi paradox, in 1950. But in the intervening decades, humanity has recognized that our own climb up the ladder of technological sophistication comes with a heavy price.…  Seguir leyendo »

The march into space appears to be gathering speed. The not-for-profit Mars One says it plans to establish a human settlement on Mars by 2025, a goal that has attracted more than 200,000 applicants for the one-way trip (a number that has so far been winnowed down to 705 candidates). And before Virgin Galactic's SpaceShip2 crashed in October, nearly a thousand would-be space tourists spent as much as a quarter of a million dollars for the promise of a few minutes of suborbital weightlessness.

But, future astronauts, think very carefully: Space is a very dangerous and unpredictable place.

For decades, space scientists have used an array of sophisticated satellite experiments to study the environment of space from the Earth to the sun.…  Seguir leyendo »

The Southern Cross, Milky Way, Large Magellanic Cloud and Carina Nebula, viewed from Kenya. Credit Babak Tafreshi/National Geographic Society, via Corbis

Earlier this year, I visited Fernando de Noronha, an island off the northeastern coast of Brazil, only four degrees south of the Equator. When I was walking to a restaurant, I noticed something strange in the night sky: It was Ursa Major, the constellation that Americans call the Big Dipper and the British call the Plough.

The Big Dipper, commonplace in the north, is rarely seen in the Southern Hemisphere, though a friend of mine swears he saw it once from the top of a mountain in São Paulo. According to him, it was just above the horizon.

I’m jealous of those who have the Big Dipper.…  Seguir leyendo »

The amazing discoveries from NASA's Kepler planet-hunting space telescope keep rolling in. The latest, announced this week by astronomers, is the discovery of a planet just 10% larger than the Earth orbiting in the so-called "habitable zone" of the star Kepler-186.

In our solar system, Earth is the only planet in the habitable zone -- the distance from the sun where liquid water can exist on the surface without boiling away (like on Venus), or turning to ice (like on Mars).

The new planet, imaginatively dubbed Kepler-186f for now, appears to be in the same kind of Goldilocks place in its solar system.…  Seguir leyendo »

Durante la última semana y media, la gente se ha maravillado con el descubrimiento de las pruebas que respaldan la "inflación", teoría que describe los dolores de parto del Big Bang hace 13,700 millones de años. ¿Qué significan estos hallazgos y cómo se descubrieron?

En muchos artículos se dio a conocer la noticia, pero yo trataré de explicarla a fondo. No se vayan, porque este es uno de los descubrimientos astrofísicos más emocionantes en varias décadas.

Los humanos se han preguntado por el origen del universo desde hace milenios; la noticia de la semana pasada nos acercó un poco más a la respuesta.…  Seguir leyendo »

The other night, as I sat in the telescope operation room at the Keck Observatory in Waimea, Hawaii, preparing with colleagues to measure light from some of the most distant galaxies known, the phone rang with startling news.

An exploding star had been sighted in M82, one of the nearest big galaxies. The "supernova" (as such stellar explosions are called) was a special, rare "Type Ia" -- the kind that led to the Nobel-worthy discovery of dark energy.

Type Ia supernovae have happened in our galactic neighborhood only three times in the last 80 years. Like astronomers around the world, we were excited to be at a world-leading telescope, where we could collect new information about this rare event.…  Seguir leyendo »

The recent announcement by a team of astronomers that there could be as many as 40 billion habitable planets in our galaxy has further fueled the speculation, popular even among many distinguished scientists, that the universe is teeming with life.

The astronomer Geoffrey W. Marcy of the University of California, Berkeley, an experienced planet hunter and co-author of the study that generated the finding, said that it “represents one great leap toward the possibility of life, including intelligent life, in the universe.”

But “possibility” is not the same as likelihood. If a planet is to be inhabited rather than merely habitable, two basic requirements must be met: the planet must first be suitable and then life must emerge on it at some stage.…  Seguir leyendo »

The phrase “scientific revolution” tends to get overused. But there is one happening right now that could arguably alter the entire trajectory of human existence by profoundly realigning what we know of the complex, undulating road that has taken us from atoms adrift in the void to living, thinking beings in merely four billion years.

Using techniques of exquisite sensitivity and technological finesse, astronomers have spent the past two decades on an astonishing voyage of cosmic discovery. They have found that the universe is full of planets: Cold, small, and dark next to their large and glaring suns, these worlds have previously been hidden from us.…  Seguir leyendo »

El 27 de abril, los satélites Fermi y Swift de la NASA detectaron una fuerte señal proveniente del brote de rayos gamma más brillante en décadas.

Debido a que se encontraba relativamente cerca, fue miles de veces más deslumbrante que otros que el Swift observa frecuentemente. Los científicos ahora tratan de saber más.

Sabemos que cuando a las estrellas más grandes se les agota el combustible, no se desvanecen en silencio. En cambio, su explosión es grandiosa y se convierten en lo que conocemos como supernova. Con frecuencia, estas transformaciones estelares son lo suficientemente brillantes como para poder verlas, incluso, si se encuentran en galaxias a miles de millones de años luz de nuestro hogar, en la Vía Láctea.…  Seguir leyendo »

Is anybody out there?

For millennia, humans have gazed at the night sky, asking this question. That's why scientists and NASA are eagerly searching for "exoplanets" -- that is, planets that orbit around stars other than our sun.

Last week NASA's Kepler satellite reported the discovery of three Earth-sized exoplanets within the so-called "habitable zone," defined as the neighborhood of a star where liquid water -- essential for life as we know it -- can exist.

In our solar system, only three planets lie in the sun's habitable zone -- Venus, Earth and Mars.

Planets too close to the star they orbit, like Mercury, are too hot for liquid water.…  Seguir leyendo »

Friday was an extremely unusual day, astronomically speaking. Just as scientists were gearing up to witness an asteroid's closest ever approach to Earth in recorded history, a sizeable meteor exploded over Russia, causing thousands of injuries and major damage to buildings.

The asteroid, named DA14, came within 17,000 miles or so, as close as a telecommunication satellite in geosynchronous orbit. DA14 is quite a bit smaller than YU55, the asteroid that passed Earth in November 2011, but DA14 came more than 10 times closer.

These two rare events occurred the same day. Your inner mathematician and your inner prophet of the end times think they should be connected.…  Seguir leyendo »

A meteor broke apart over rural Russia on Friday morning, injuring at least 1,200 people. Hours later, an asteroid known as 2012 DA14 passed about 17,000 miles above Earth’s surface — a close shave in astronomical terms, passing nearer than many of our communications satellites. One was predicted; the other was not.

These events were unrelated, but they underscore how crucial it is that nations know, quickly, what is falling from the sky and what, if any, dangers are posed.

Every day about 40 tons of space debris hit the atmosphere, burn and settle to Earth, NASA has found. The vast majority of the detritus consists of meteoroids no larger than a grain of sand, but even tiny specks pack a wallop: A typical meteor hits Earth traveling at least seven miles per second, at least 30 times faster than a bullet shot from a handgun.…  Seguir leyendo »

On Feb. 15, an asteroid designated 2012 DA14 will pass safely within about 17,200 miles of Earth’s surface — closer than the communication satellites that will be broadcasting the news of its arrival. The asteroid is about 150 feet in diameter and has a mass estimated at about 143,000 tons.

Should an object of that size hit Earth, it would cause a blast with the energy equivalent of about 2.4 million tons — or 2.4 megatons — of TNT explosives, more than 180 times the power of the atomic blast that leveled Hiroshima.

It’s almost as if nature is firing a shot across our bow to direct our attention to the vast number of nearby rocky asteroids and a few icy comets that make up what we call the near-Earth object population.…  Seguir leyendo »

Al tiempo que el rover del Curiosity inició su emocionante viaje a través de la superficie de Marte hasta el pico del Monte Sharp, es importante saber que este logro fue planeado hace más de 10 años. Una exploración de esta importancia no es para los débiles de corazón, toma tiempo y persistencia.

¿Entonces qué sigue? ¿Qué hay en la línea de espera? ¿Qué revolucionará nuestro entendimiento de la vida en el sistema solar en unos 10 o 20 años? La respuesta es simple, nada. El Curiosity lo es todo. Después del Curiosity no hay hasta el momento otra misión en puerta que explore mundos potencialmente habitables más allá de la Tierra.…  Seguir leyendo »

Sometime this year Voyager 1, a probe sent from Earth 35 years ago, will cross a threshold no human-fashioned object has reached before. Passing through a sun-driven shock wave at the edge of the solar system, it will reach the icy dominions of interstellar space. Voyager is one of the fastest vessels we’ve ever blown out of Earth’s gravity well. Still, after three and a half decades of hyper-velocity spaceflight, it will take another 700 centuries for the craft to cross the distance to the nearest star.

Short of a scientific miracle of the kind that has never occurred, our future history for millenniums will be played out on Earth and in the “near space” environment of the other seven planets, their moons and the asteroids in between.…  Seguir leyendo »

Venus slides between us and the Sun today, an exceedingly rare spectacle that scientists hope will expand their understanding of our solar system and refine their inquiries about distant planets.

A transit of Venus has been recorded just six times before; one will not recur until 2117. Each time, astronomers understand it far better than we did the last time; when it is over, our curiosity only grows. Each time, too, it stirs our imaginations. The 1882 transit inspired Edmond-Louis Dupain to paint, on a ceiling at the Paris Observatory, a near-nude Venus, goddess of love, floating across the path of the sun god Helios in his chariot in the sky.…  Seguir leyendo »

The illusion of purpose and design is perhaps the most pervasive illusion about nature that science has to confront on a daily basis. Everywhere we look, it appears that the world was designed so that we could flourish.

The position of the Earth around the sun, the presence of organic materials and water and a warm climate — all make life on our planet possible. Yet, with perhaps 100 billion solar systems in our galaxy alone, with ubiquitous water, carbon and hydrogen, it isn't surprising that these conditions would arise somewhere. And as to the diversity of life on Earth — as Darwin described more than 150 years ago and experiments ever since have validated — natural selection in evolving life forms can establish both diversity and order without any governing plan.…  Seguir leyendo »

Almost every scientific talk or seminar in astronomy today starts from the idea that we live in a universe in which a mysterious force known as dark energy makes up about 70 percent of the total cosmic amount of everything. A mysterious substance known as dark matter makes up about 25 percent. And ordinary matter — the stuff of the periodic table, including interesting assemblies of matter like galaxies, stars, planets and people — is a paltry 5 percent.

If this is right, the things we observe in the universe are not the important things. Think of it this way: when you look at a snow-covered mountain, what you see is the snow, but the snow is not the mountain.…  Seguir leyendo »

Walk through the halls of UC Irvine's astronomy wing after dinner on a weeknight and you will find roomfuls of young graduate students, crammed into small desks, solving equations, writing computer code and developing innovative ways to analyze data. They do not have to be here. These are people with career options. They are scary-smart, creative and hardworking. Yet they have come here from all over the country and the world to sit in windowless offices and make a fifth of the money they could make back home or up the street. Why? They want to unlock the universe.

The United States is still the scientific light of the world.…  Seguir leyendo »

Astronomers announced last month that, contrary to previous assumptions, the orbiting body Eris might be smaller than Pluto after all. Since it was the discovery in 2005 of Eris, an object seemingly larger than what had been considered our smallest planet, that precipitated the downgrading of Pluto from full planet to “dwarf”, some think it may be time to revisit Pluto’s status.

Most of us can’t help rooting for Pluto. We liked the idea of a ninth planet, hanging out there like a period at the end of the gorgeous sentence of the solar system. It gave us a sense of completeness.…  Seguir leyendo »