Yale Univ. astronomers have identified the first “changing look” quasar, a gleaming object in deep space that appears to have its own dimmer switch. The discovery may offer a glimpse into the life story of the universe’s great beacons. Quasars are massive, luminous objects that draw their energy from black holes. Until now, scientists have been unable to study both the bright and dim phases of a quasar in a single source.
Pioneering new research has debunked the theory that the asteroid thought to have led to the extinction of dinosaurs also caused vast global firestorms that ravaged planet Earth. A team of researchers from the Univ. of Exeter, Univ. of Edinburgh and Imperial College London recreated the immense energy released from an extraterrestrial collision with Earth that occurred around the time that dinosaurs became extinct.
The generation of cosmic magnetic fields has long intrigued astrophysicists. Since it was first described in 1959, a phenomenon known as Weibel filamentation instability has generated tremendous theoretical interest from astrophysicists and plasma physicists as a potential mechanism for seed magnetic field generation in the universe. However, direct observation of Weibel-generated magnetic fields remained challenging for decades.
Scientists plumbing the depths of the ocean have made a surprise finding that could change the way we understand supernovae, exploding stars way beyond our solar system. They have analyzed extraterrestrial dust thought to be from supernovae that has settled on ocean floors to determine the amount of heavy elements created by the massive explosions.
Two teams of astronomers led by researchers at the Univ. of Cambridge have looked back nearly 13 billion years, when the universe was less than 10% its present age, to determine how quasars regulate the formation of stars and the build-up of the most massive galaxies. The team used a combination of data gathered from powerful radio telescopes and supercomputer simulations in their study.
A study by astrophysicists at the Univ. of Toronto suggests that exoplanets are more likely to have liquid water and be more habitable than we thought. Scientists have thought that exoplanets behave in a manner contrary to that of Earth. If so, exoplanets would rotate in sync with their star so that there is always one hemisphere facing it while the other hemisphere is in perpetual cold darkness.
Though scientists don’t completely understand what triggers solar flares, Stanford Univ. solar physicists Monica Bobra and Sebastien Couvidat have automated the analysis of those gigantic explosions. The method could someday provide advance warning to protect power grids and communication satellites.
Meteors that have crashed to Earth have long been regarded as relics of the early solar system. These craggy chunks of metal and rock are studded with chondrules, tiny, glassy, spherical grains that were once molten droplets. Scientists have thought that chondrules represent early kernels of terrestrial planets.
If you sweep a laser pointer across the moon fast enough, you can create spots that actually move faster than light. Anyone can do it. At a meeting of the American Astronomical Society in Seattle, Wash., Robert Nemiroff, a physics professor at Michigan Technological Univ., reported that this theoretical curiosity may turn out to be practically useful out in the cosmos.
By analyzing the light of hundreds of thousands of celestial objects, Johns Hopkins Univ. astronomers from the Sloan Digital Sky Survey (SDSS) have created a unique map of enigmatic molecules in our galaxy that are responsible for puzzling features in the light from stars. The map was unveiled Jan. 8 at the 225th meeting of the American Astronomical Society in Seattle.
The central regions of many glittering galaxies, our own Milky Way included, harbor cores of impenetrable darkness—black holes with masses equivalent to millions, or even billions, of suns. What is more, these supermassive black holes and their host galaxies appear to develop together, or "co-evolve." Theory predicts that as galaxies collide and merge, growing ever more massive, so too do their dark hearts.
Astronomers announced they have found eight new planets in the "Goldilocks" zone of their stars, orbiting at a distance where liquid water can exist on the planet's surface. This doubles the number of small planets (less than twice the diameter of Earth) believed to be in the habitable zone of their parent stars. Among these eight, the team identified two that are the most similar to Earth of any known exoplanets to date.
If you want to see just how far Brigham Young Univ. (BYU)’s latest research extends, step outside of your house tonight, look up towards the sky, focus your view between the constellations of Cygnus and Lyra, and then zoom in about 100 million light years. That’s the home of a galaxy known as KA 1858, which contains a black hole that BYU scientists observed with the help of NASA and astrophysicists throughout the Univ. of California system.
Working at temperatures matching the interior of the sun, researchers have been able to determine experimentally, for the first time, iron’s role in inhibiting energy transmission from the center of the sun to near the edge of its radiative band. Because that role is much greater than formerly surmised, the experimentally derived amount of iron’s opacity helps close a theoretical gap in the Standard Solar Model.
How do you make an Earth-like planet? The "test kitchen" of Earth has given us a detailed recipe, but it wasn't clear whether other planetary systems would follow the same formula. Now, astronomers have found evidence that the recipe for Earth also applies to terrestrial exoplanets orbiting distant stars.
NASA's Mars rover, Curiosity, has detected spikes of methane in the planet's atmosphere. That suggests something is producing or venting the scientifically tantalizing gas, but no one knows what. Most of Earth's atmospheric methane comes from animal and plant life, and the environment itself. So the Martian methane raises the question of past or present microbial life.
Nearly 2,000 planets beyond our solar system have been identified to date. Whether any of these exoplanets are hospitable to life depends on a number of criteria. Among these, scientists have thought, is a planet’s obliquity—the angle of its axis relative to its orbit around a star.
Several experiments, including the BaBar experiment at the SLAC National Accelerator Laboratory, have helped explain some, but not all, of the imbalance between matter and antimatter in the universe. Now a SLAC theorist and his colleagues have laid out a possible method for determining if the Higgs boson is involved.
Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent version of our own sun. By making detailed observations of the protoplanetary disk surrounding the star known as HD 107146, the astronomers detected an unexpected increase in the concentration of millimeter-size dust grains in the disk's outer reaches.
Did Mars ever have life? Does it still? A meteorite from Mars has reignited the old debate. An international team that includes scientists from EPFL has published a paper in Meteoritics and Planetary Sciences, showing that Martian life is more probable than previously thought.
Planets orbiting close to low-mass stars are prime targets in the search for extraterrestrial life. But new research led by an astronomy graduate student at the Univ. of Washington indicates some such planets may have long since lost their chance at hosting life because of intense heat during their formative years.
Today’s atmosphere likely bears little trace of its primordial self: Geochemical evidence suggests that Earth’s atmosphere may have been completely obliterated at least twice since its formation more than 4 billion years ago. However, it’s unclear what interplanetary forces could have driven such a dramatic loss.
High above Earth’s atmosphere, electrons whiz past at close to the speed of light. Such ultra-relativistic electrons, which make up the outer band of the Van Allen radiation belt, can streak around the planet in a mere five minutes, bombarding anything in their path. Exposure to such high-energy radiation can wreak havoc on satellite electronics, and pose serious health risks to astronauts.
A team of scientists hope to trace the origins of gamma-ray bursts with the aid of giant space microphones. Researchers at Cardiff Univ. are trying to work out the possible sounds scientists might expect to hear when the ultra-sensitive LIGO and Virgo detectors are switched on in 2015.
In a showdown of black hole versus G2—a cloud of gas and dust—it looks like G2 won. Recent research shows that G2 came within 30 billion km of the super-massive black hole at the center of our galaxy, yet managed to escape from the gravitational pull of the black hole.