From NASA’s Scientific Visualization Studio. This video takes images from the Solar Dynamics Observatory and applies additional processing to enhance the structures that are visible. The result is a beautiful, new way of looking at the sun. The original frames are in the 171 Angstrom wavelength of extreme ultraviolet. This wavelength shows plasma in the solar atmosphere, called the corona, that is around 600,000 Kelvin. The loops represent plasma held in place by magnetic fields. They are concentrated in “active regions” where the magnetic fields are the strongest. These active regions usually appear in visible light as sunspots. The events in this video represent 24 hours of activity on September 25, 2011.
Exo-Planet Hot Flareup
From HubbleCast. An international team of astronomers using data from NASA’s Hubble Space Telescope has made an unparalleled observation, detecting significant changes in the atmosphere of a planet located beyond our solar system. The scientists conclude the atmospheric variations occurred in response to a powerful eruption on the planet’s host star, an event observed by NASA’s Swift satellite.
The exoplanet is HD 189733b, a gas giant similar to Jupiter, but about 14 percent larger and more massive. The planet circles its star at a distance of only 3 million miles, or about 30 times closer than Earth’s distance from the Sun, and completes an orbit every 2.2 days. Its star, named HD 189733A, is about 80 percent the size and mass of our Sun. Astronomers classify the planet as a “hot Jupiter.” Previous Hubble observations show that the planet’s deep atmosphere reaches a temperature of about 1,900 degrees Fahrenheit (1,030 degrees Celsius).
HD 189733b periodically passes across, or transits, its parent star, and these events give astronomers an opportunity to probe its atmosphere and environment. In a previous study, a group led by Lecavelier des Etangs used Hubble to show that hydrogen gas was escaping from the planet’s upper atmosphere. The finding Continue reading Exo-Planet Hot Flareup
Finding Another Earth Within Reach
From EsoCast. Planet hunters unveil the tricks of the trade for finding planets around nearby stars and scanning them for signs of life.
Are we alone? It’s the biggest question ever. And the answer is almost within reach. With so many galaxies, and each with so many stars, how could the Earth be unique?
In 1995, Swiss astronomers Michel Mayor and Didier Queloz were the first to discover an exoplanet orbiting a normal star. Since then, planet hunters have found many hundreds of alien worlds. Large and small, hot and cold, and in a wide variety of orbits. Now, we’re on the brink of discovering Earth’s twin sisters. And in the future: a planet with life — the Holy Grail of astrobiologists.
Michel Mayor’s team found hundreds of them from Cerro La Silla, ESO’s first Chilean foothold. Here’s the CORALIE spectrograph, mounted on the Swiss Leonhard Euler Telescope. It measures the tiny wobbles of stars, caused by the gravity of orbiting planets.
ESO’s venerable 3.6-metre telescope is also hunting for exoplanets. The HARPS spectrograph is the most accurate in the world. So far, it has discovered more than 150 planets. Its biggest trophy: a rich system containing at least five and Continue reading Finding Another Earth Within Reach
How Large is the Universe?
The universe has long captivated us with its immense scales of distance and time. How far does it stretch? Where does it end, and what lies beyond its star fields and streams of galaxies extending as far as telescopes can see?
These questions are beginning to yield to a series of extraordinary new lines of investigation and technologies that are letting us to peer into the most distant realms of the cosmos. But also at the behavior of matter and energy on the smallest of scales. Remarkably, our growing understanding of this kingdom of the ultra-tiny, inside the nuclei of atoms, permits us to glimpse the largest vistas of space and time. In ancient times, most observers saw the stars as a sphere surrounding the earth, often the home of deities. The Greeks were the first to see celestial events as phenomena, subject to human investigation rather than the fickle whims of the Gods.
One sky-watcher, for example, suggested that meteors are made of materials found on Earth… and might have even come from the Earth. Those early astronomers built the foundations of modern science. But they would be shocked to see the discoveries made by their counterparts today. The Continue reading How Large is the Universe?
Solar Storms Rising
Solar forecasters predict the Sun will reach the peak of its eleven year cycle sometime in 2013. Meanwhile, after one of the least active solar minimums on record, the Sun is rising again. Here are some of the highlights captured so far by NASA satellites: powerful X-class flares, flamboyant CMEs, and swirling turbulence on its surface. Our favorite is the “magnificent CME” from August 2012. You can be sure there’s more of this to come.
When Will Time End?
The answer to this question may depend on whether Stephen Hawking was right in his theory that describes how black holes shed mass and eventually decay. Time is flying by on this busy, crowded planet as life changes and evolves from second to second. At the same time, the arc of the human lifespan is getting longer: 67 years is the global average, up from just 20 years in the Stone Age.
Modern science provides a humbling perspective. Our lives, indeed even that of the human species, are just a blip compared to the Earth, at 4.5 billion years and counting, and the universe, at 13.7 billion years.
It now appears the entire cosmos is living on borrowed time. It may be a blip within a much grander sweep of time. When, we now ask, will time end?
Our lives are governed by cycles of waking and sleeping, the seasons, birth and death. Understanding time in cyclical terms connects us to the natural world, but it does not answer the questions of science.
What explains Earth’s past, its geological eras and its ancient creatures? And where did our world come from? How and when will it end? In the revolutions spawned by Copernicus Continue reading When Will Time End?
The Most Powerful Objects in the Universe
All across the immense reaches of time and space, energy is being exchanged, transferred, released, in a great cosmic pinball game we call our universe.
How does energy stitch the cosmos together, and how do we fit within it? We now climb the power scales of the universe, from atoms, nearly frozen to stillness, to Earth’s largest explosions. From stars, colliding, exploding, to distant realms so strange and violent they challenge our imaginations. Where will we find the most powerful objects in the universe?
Today, energy is very much on our minds as we search for ways to power our civilization and serve the needs of our citizens. But what is energy? Where does it come from? And where do we stand within the great power streams that shape time and space?
Energy comes from a Greek word for activity or working. In physics, it’s simply the property or the state of anything in our universe that allows it to do work. Whether it’s thermal, kinetic, electro-magnetic, chemical, or gravitational.
The 19th century German scientist Hermann von Helmholtz found that all forms of energy are equivalent, that one form can be transformed into any other. The laws of physics say that in a Continue reading The Most Powerful Objects in the Universe
The Largest Black Holes in the Universe
Our Milky Way may harbor millions of black holes… the ultra dense remnants of dead stars. But now, in the universe far beyond our galaxy, there’s evidence of something far more ominous. A breed of black holes that has reached incomprehensible size and destructive power. Just how large, and violent, and strange can they get?
A new era in astronomy has revealed a universe long hidden to us. High-tech instruments sent into space have been tuned to sense high-energy forms of light — x-rays and gamma rays — that are invisible to our eyes and do not penetrate our atmosphere. On the ground, precision telescopes are equipped with technologies that allow them to cancel out the blurring effects of the atmosphere. They are peering into the far reaches of the universe, and into distant caldrons of light and energy. In some distant galaxies, astronomers are now finding evidence that space and time are being shattered by eruptions so vast they boggle the mind.
We are just beginning to understand the impact these outbursts have had on the universe: On the shapes of galaxies, the spread of elements that make up stars and planets, and ultimately the very existence of Earth. The discovery Continue reading The Largest Black Holes in the Universe
Black Hole Merger Simulation
From NASA’s Scientific Visualization Studio. Supercomputer models of merging black holes reveal properties that are crucial to understanding future detections of gravitational waves. This movie follows two orbiting black holes and their accretion disk during their final three orbits and ultimate merger. Redder colors correspond to higher gas densities.
The initial magnetic field of the gas is amplified by 100 times. Magnetic fields evacuate the region above the black hole and produce a thinner, hotter, denser disk in the immediate vicinity of the black hole than in simulations without them. The merged black hole resides within a hot, dense disk of ionized gas. The base of the low-density funnel is visible near the center. Such a structure could support a jet of particles moving near the speed of light, although one was not yet produced before the simulation ended. This model, which includes the effects of general relativity, magnetic fields and gas dynamics, produced an electromagnetic signal 10,000 brighter than in simulations that ignored the gas effects.
The sequence ends with a simulation of the merger of two black holes and the resulting emission of gravitational radiation. The colored fields represent a component of the curvature of space-time. The outer red sheets Continue reading Black Hole Merger Simulation
Curiosity Finds River Rocks and River Beds on Mars
NASA’s Curiosity rover mission has found evidence a stream once flowed across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence — images of rocks containing ancient streambed gravels — is the first of its kind. Scientists are studying the images of stones cemented into a layer of conglomerate rock. The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow.
The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow. “From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep,” said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. “Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”
The finding site lies between the north rim of Gale Continue reading Curiosity Finds River Rocks and River Beds on Mars