The announcement was short. It lasted only a fraction of second — a blink of an eye. But a spacecraft in Earth’s orbit, keeping an eye on such events, captured it on June 3 this year. The announcement may have been brief, but it told us that two exotic dead stars, called neutron stars, have collided with each other. This is a relatively rare event, but it bears good news for the merchants in the Sona bazaar. This collision has created gold — lots of it.
But before you head over to Sona bazaar, you should know that this particular collision happened in a galaxy so far away that it has taken light — traveling at a stupendous speed of 186,000 miles every second — four billion years to reach us! In astronomical terms, this collision happened in a galaxy four billion light-years away. In comparison, light from our Sun gets to us in 8 minutes, and is therefore only 8 light-minutes away. The distance of billions of light-years doesn’t intimidate astronomers, as they routinely study events and objects that are even farther away than this particular galaxy. The significance of this event, however, resides in the fact that for the first time, astronomers have been able to study light from collisions that may help us understand the way elements like gold are created in the universe.
Before we get too caught up in the cosmic glamour, we should remember that almost all of the elements that make our bodies were cooked up inside the stars: the carbon in our DNA, oxygen in our lungs, and iron in our blood. Hydrogen in the water molecule, on the other hand, is a leftover from processes in the early history of the universe. The classic quote from the late astronomer Carl Sagan is indeed true: “We are made up of star stuff”.
Excerpt from an article written by Salman Hameed at the IHT. Continue THERE
Explaining and Ordering the Heavens is an online exhibition from The Library of Congress, examining evolving views of the universe over 8 centuries.
“Why do we pay this obsessive attention to backing up a document, which we can reproduce, when we pay no attention to backing up our civilization?” — Andreas Tziolas.
Ross Andersen: Project Icarus, which will focus on the mission’s technological challenges, is a theoretical engineering study that was launched in 2009 by the British Interplanetary Society with the purpose of designing an interstellar spacecraft. It brings together an international group of volunteer aerospace engineers from government space agencies, universities and the private sector with the purpose of generating technical reports on the engineering layout, functionality, physics, operation, and mission profile of an interstellar probe. You can think of it as a kind of repository for bleeding-edge thinking about interstellar travel.
Project Icarus takes its inspiration from Project Daedalus, a five-year study launched by the British Interplanetary Society in 1973 to determine whether interstellar travel was feasible at all. Project Daedalus ultimately concluded that interstellar was possible, but acknowledged that the technical challenges were significant. Icarus aims to pick up where Daedalus left off, by trying to chip away at some of those technical challenges. Andreas Tziolas, a former research fellow at NASA who holds a Ph.D. in Gravitation and Cosmology, is the Project Leader for Project Icarus. Yesterday I spoke to Tziolas about how and, more interestingly, why we might someday send a mission to the stars.
Click HERE to read the full article and for an interview with Andreas Tziolas who is drafting a blueprint for a mission to a nearby star. Via The Atlantic
Most astronomers gaze at the heavens and see stars. William Chaplin hears an orchestra — a celestial symphony in which the smallest stars are flutes, the medium-sized ones are trombones and the giants are reverberating tubas.
The sounds are internal vibrations that reveal themselves as a subtle, rhythmic brightening and dimming of a star, explains Chaplin, an astrophysicist at the University of Birmingham, UK, and a specialist in asteroseismology. These waves provide information that astronomers can’t get in any other way: triggered by the turbulent rise and fall of hot gases on the star’s surface, the vibrations penetrate deep into the stellar interior and become resonating tones that reveal the star’s size, composition and mass (see ‘Celestial music’). So by watching for the characteristic fluctuations in brightness, says Chaplin, “we can literally build up a picture of what the inside of a star looks like”.
Better still, he adds, asteroseismologists are now hauling in the data wholesale. After years of being hampered by Earth’s turbulent atmosphere, which obscures the view of the Universe and has limited asteroseismology to about 20 of the brightest nearby stars, researchers have been astonished by the trove of information coming from a new generation of space observatories. Thanks to the French-led Convection, Rotation and Planetary Transits (COROT) space telescope, launched in 2006, and NASA’s Kepler space telescope, launched in 2009, they can now listen in on hundreds of stars at a time.
“We are in a golden age for the study of stellar structure and evolution,” says Hans Kjeldsen, an astronomer at Aarhus University in Denmark.
“Nature seems to have been kind to us,” agrees Ronald Gilliland, an astronomer at Pennsylvania State University in University Park. “The stars seem not to be shy about showing us lots of oscillations that will allow us to reveal their innermost secrets.” The flood of data has shed light on the interior of red-giant stars, and forced astronomers to question their understanding of how stars and galaxies form.
Text by Ron Cowen of NATURE. Continue HERE