“Should we ever discover that a second genesis had occurred in our solar system, independently outside the Earth,” said Carolyn Porco of the Space Science Institute in 2010 when she was director of flight operations and imaging team leader for the Cassini spacecraft during its flybys of Saturn's moon, Enceladus, “then I think at that point the spell is broken. The existence theorem has been proven, and we could safely infer from it that life was not a bug but a feature of the universe in which we live, that it’s commonplace and has occurred a staggering number of times.”
Continue reading "The Geysers of Enceladus -- Will Saturn's Moon Reveal a "Second Genesis"?" »
In their quest to understand life’s potential beyond Earth, astrobiologists study how organisms might survive in numerous environments, from the surface of Mars to the ice-covered oceans of Jupiter’s moon, Europa (above). For now, Earth is our only example of an inhabited planet, and studying the limits of habitability on Earth is a major component of astrobiology research. For this reason, scientists collect data from places on our planet where life is pushed to the absolute limits of adaptability, from the Antarctic to the Arctic, and from smoldering thermal vents to highly acidic rivers. But locations like the Antarctic Dry Valleys or deep-sea vents in the Pacific aren’t the only places in which astrobiologists study life as we know it. Low Earth orbit provides an opportunity to observe Earth-life in the harsh conditions of space.
Continue reading ""Beyond Astrobiology" --New Technologies in the Search for Extraterrestrial Life" »
The Milky Way is smaller than astronomers previously thought, according to new research. For the first time, scientists have been able to precisely measure the mass of the galaxy that contains our solar system. Researchers have found that the Milky Way is approximately half the weight of ou neighboring galaxy – Andromeda – which has a similar structure to our own. The Milky Way and Andromeda are the two largest in a region of galaxies which astronomers call the Local Group.
Continue reading ""Andromeda Galaxy Harbors Twice as Much Dark Matter as the Milky Way" --Royal Astronomical Society" »
Astronomers have long known that interstellar molecules containing carbon atoms exist and that by their nature they will absorb light shining on them from stars and other luminous bodies. Because of this, a number of scientists have previously proposed that some type of interstellar molecules are the source of diffuse interstellar bands -- the hundreds of dark absorption lines seen in color spectrograms taken from Earth.
Continue reading "Mystery Molecules of the Interstellar Medium --"Many of the Things Quite Abundant There are Unknown on Earth"" »
Earth and Mercury are both rocky planets with iron cores, but Mercury's interior differs from Earth's in a way that explains why the planet has such a bizarre magnetic field, UCLA planetary physicists and colleagues report. Measurements from NASA's Messenger spacecraft have revealed that Mercury's magnetic field is approximately three times stronger at its northern hemisphere than its southern one. In the current research, scientists have created a model to show how the dynamics of Mercury's core contribute to this unusual phenomenon. Mercury's peculiar magnetic field provides evidence that iron turns from a liquid to a solid at the core's outer boundary, say the scientists.
Continue reading "Mercury's Bizarre Magnetic Field --"Powered by Liquid Iron"" »
Unlike our solitary Sun, most stars form in binary pairs -- two stars that orbit a common center of mass. Though remarkably plentiful, binaries pose a number of questions, including how and where planets form in such complex environments. Stars and planets form out of vast clouds of dust and gas. As material in these clouds contracts under gravity, it begins to rotate until most of the dust and gas falls into a flattened protoplanetary disk swirling around a growing central protostar. Despite forming from a flat, regular disk, planets can end up in highly eccentric orbits, and may be misaligned with the star's equator. One theory for how planets can migrate to these unusual orbits is that a binary companion star can influence them — but only if its orbit is initially misaligned with the planets.
Continue reading "Image of the Day --Planetary Disks in Weird Orbits Around their Host Stars" »
The Universe is a big place, full of unknowns. Astronomers using NASA's Chandra X-ray Observatory have just catalogued a new one."I couldn't believe my eyes," says Esra Bulbul of the Harvard Center for Astrophysics. "What we found, at first glance, could not be explained by known physics." Together with a team of more than a half-dozen colleagues, Bulbul has been using Chandra to explore the Perseus Cluster, a swarm of galaxies approximately 250 million light years from Earth. Imagine a cloud of gas in which each atom is a whole galaxy—that's a bit what the Perseus cluster is like. It is one of the most massive known objects in the Universe. The cluster itself is immersed in an enormous 'atmosphere' of superheated plasma—and it is there that the mystery resides.
Continue reading "Perseus Cluster Mystery Persists --"What We Found Could Not be Explained by Known Physics"" »
The difference between earth and the space station is buoyancy. When droplets of fuel burn on earth, buoyancy limits the amount of time gases can hang around in the high temperature zone around the droplets. So there isn’t enough time for the droplets’ chemistry to support the cool flames. But in micro-gravity, there is no buoyancy, so there is enough time for the gases to stay around the droplets and for that chemistry to develop.
Continue reading "ISS Destiny Module Leads to New Discovery --"Things can Happen Out There that Can’t Happen Here”" »
In findings that help astrophysicists understand our corner of the galaxy, an international research team has shown that the soft X-ray glow blanketing the sky comes from both inside and outside the solar system. “We now know that the emission comes from both sources, but is dominated by the local hot bubble,” said Massimiliano Galeazzi, professor and associate chair in the Department of Physics at the University of Miami and principal investigator of the study. “This is a significant discovery. Specifically, the existence or nonexistence of the local bubble affects our understanding of the galaxy in the proximity to the Sun and can be used as foundation for future models of the Galaxy structure.”
Continue reading ""Glow in Space" --Evidence of A Hot Bubble Left by a Supernova in Our Galactic Neighborhood 10 Million Years Ago" »
The Bubble Nebula or NGC 7635 is 10 light-year diameter object a mere 11,000 light-years away toward the constellation Cassiopeia near a giant molecular cloud which contains the expansion of the bubble. Above and right of the Bubble's center is a hot, O-type star, several 100,000 times more luminous and approximately 45 times more massive than our Sun. Fierce stellar winds and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud.
Continue reading "Image of the Day: Nearby Cosmic Bubble Harbors a Star 100,000 Times More Luminous than the Sun" »
According to MIT's Alan Guth , originator of the inflationary universe theory, our Universe is a product of eternal inflation --eternal into the future, but not into the past. An eternally inflating Universe produces an infinite number of pocket universes , which in turn are producing more new universes. The old, mature universes are vastly outnumbered by universes that have just barely begun to evolve. Guth called it the "Youngness Paradox."
Continue reading ""The Youngness Paradox" (Weekend's Most Popular)" »
The surface of Mars is incredibly violent, hostile and destructive to any kind of biosignature, whereas things get preserved much better when they are buried. Astrobiologits are thinking that if there’s life on Mars or if there’s evidence of past life, we have a much better chance of finding it in the subsurface.
Continue reading "Earth's Alien Habitats--Harbingers of Subsurface Life on Mars?" »
A team of astronomers using NASA's Hubble Space Telescope have gone looking for water vapour in the atmospheres of three planets orbiting stars similar to the Sun – and have come up nearly dry. The three planets, HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away, and are all gas giants known as 'hot Jupiters.' These worlds are so hot, with temperatures between 900 to 2200 degrees Celsius, that they are ideal candidates for detecting water vapor in their atmospheres. The new discovery highlights some major challenges in the search for the exoplanet 'holy grail' – an exoplanet with a climate similar to Earth, a key characteristic of which is the presence of liquid water.
Continue reading "NASA's Quest for Water on Alien Worlds --"The Holy Grail?"" »
Large clumps of mass in the Universe warp and distort the space-time around them. Acting like lenses, they appear to magnify and bend light that travels through them from more distant objects. This warping of space-time by large objects in the Universe was one of the predictions of Albert Einstein’s theory of general relativity.
Continue reading "Image of the Day --A Massive Galaxy Cluster 160 Trillion Times Mass of the Sun" »
In 2012, the Voyager mission team announced that the Voyager 1 spacecraft had passed into interstellar space, traveling further from Earth than any other manmade object. But, in the nearly two years since that historic announcement, and despite subsequent observations backing it up, uncertainty about whether Voyager 1 really crossed the threshold continues. There are some scientists who say that the spacecraft is still within the heliosphere – the region of space dominated by the Sun and its wind of energetic particles – and has not yet reached the space between the stars.
Continue reading ""Where None Have Gone Before" --Uncertainty Surrounds Voyager 1 Team Claims of Entering Interstellar Space " »
In late June 2013, an exceptional binary containing a rapidly spinning neutron star underwent a dramatic change in behavior never before observed. The pulsar's radio beacon vanished, while at the same time the system brightened fivefold in gamma rays, the most powerful form of light, according to measurements by NASA's Fermi Gamma-ray Space Telescope.
Continue reading ""The Vanishing Pulsar" -- Tracked by NASA's Fermi Gamma-ray Space Telescope" »
A new home-grown instrument based on bundles of optical fibres is giving Australian astronomers the first 'Google street view' of the cosmos — incredibly detailed views of huge numbers of galaxies. Developed by researchers at the University of Sydney and the Australian Astronomical Observatory, the optical-fibre bundles can sample the light from up to 60 parts of a galaxy, for a dozen galaxies at a time. The technological leap is the 'hexabundle', sixty or more optical fibres close-packed and fused together, developed by the University of Sydney's astrophotonics group.
Continue reading ""Google Street View" of the Cosmos Unveiled" »
By using Chandra, astronomers can peer into the Whirlpool Galaxy to uncover things that can only be detected in X-rays. In this new composite image, Chandra data are shown in purple. Optical data from the Hubble Space Telescope are red, green, and blue. The galaxy is officially named Messier 51 (M51) or NGC 5194, but often goes by its nickname of the "Whirlpool Galaxy." Like the Milky Way, the Whirlpool is a spiral galaxy with spectacular arms of stars and dust. M51 is located 30 million light-years from Earth, and its face-on orientation to Earth gives us a perspective that we can never get of our own spiral galactic home.
Continue reading "Image of the Day: Black Hole "Mine Field" Lights Up a Spectacular Galaxy" »
The stars of the first generation were formed out of a primordial gas which consisted only of hydrogen and helium. Their mass ranged from ten to five hundred times the mass of our Sun. Nuclear processes in the interior of these stars created heavy elements like iron, silicon, carbon, and oxygen. When the stars died during the first supernova explosions, the heavy elements were ejected and formed the stars of the second generation. There's no iron in this 13.6 billion-year-old fireball.
Continue reading "Milky Way's "Methuselah" --The Oldest Known Star of Our Galaxy" »
By utilising the unique space-based location of the NASA/ESA Hubble Space Telescope and its sensitive Advanced Camera for Surveys and Wide Field Camera 3/, a team of astronomers has probed the halo surrounding the prominent giant elliptical galaxy Centaurus A, also known as NGC 5128, to unprecedented distances. They have found that its halo spreads far further into space than expected and does so in an unexpected form. This is the most remote portion of an elliptical galaxy ever to have been explored.
Continue reading ""Extreme Space" --The Most Remote Portion of an Elliptical Galaxy Ever Explored" »
Astronomers have discovered a transiting exoplanet with the longest known year. Kepler-421b circles its star once every 704 days. In comparison, Mars orbits our Sun once every 780 days. Most of the 1,800-plus exoplanets discovered to date are much closer to their stars and have much shorter orbital periods. The planet's orbit places it beyond the "snow line" - the dividing line between rocky and gas planets. Outside of the snow line, water condenses into ice grains that stick together to build gas giant planets.
Continue reading "New Alien Planet Detected Beyond the 'Snow Line' --The Boundary Between Rocky and Gas Planets " »
An extraterrestrial spacecraft lurking in a satellite’s orbit near Earth would be able to see city lights and pollution in our atmosphere. But what if it searched for signs of life on Earth from afar? This question has great pertinence to those searching for other Earths outside of our solar system. NASA’s Kepler space telescope is among a fleet of telescopes and spacecraft searching for rocky planets similar to our own. Once the size and location of these worlds are plotted, the next step is examining the chemical composition of their atmospheres.
Continue reading ""Signs of Alien Life" --Viewing Earth from an Extraterrestrial Spacecraft" »
"Early in 2013 we announced our startling discovery that half of the dwarf galaxies surrounding the Andromeda Galaxy are orbiting it in an immense plane," said Geraint Lewis, of the University of Sydney's School of Physics. "This plane is more than a million light years in diameter, but is very thin, with a width of only 300 000 light years. Everywhere we looked we saw this strangely coherent coordinated motion of dwarf galaxies. From this we can extrapolate that these circular planes of dancing dwarfs are universal, seen in about 50 percent of galaxies," Lewis added. "This is a big problem that contradicts our standard cosmological models. It challenges our understanding of how the universe works including the nature of dark matter."
Continue reading "Dwarf Galaxies "Challenge Our Understanding of How the Universe Works"" »
Researchers have made an important step in the race to discover whether other planets could develop and sustain life. New findings published today in the journal Astrobiology shows the vital role of oceans in moderating climate on Earth-like planets. Until now, computer simulations of habitable climates on Earth-like planets have focused on their atmospheres. But the presence of oceans is vital for optimal climate stability and habitability.
Continue reading ""Oceans Capacity to Control Climate Critical for Extraterrestrial Life"" »
"Do we believe there is life beyond Earth?"asked former astronaut and NASA Administrator Charles Bolden at a recent panel discussion at NASA headquarters with with the nation's leading space scientists. "I would venture to say that most of my colleagues here today say it is improbable that in the limitless vastness of the Universe we humans stand alone." "Just imagine the moment, when we find potential signatures of life," added Matt Mountain, director of the Space Telescope Science Institute. "Imagine the moment when the world wakes up and the human race realizes that its long loneliness in time and space may be over—the possibility that we're no longer alone in the Universe."
Continue reading ""The Search for Earth 2.0" --NASA's New Quests for Extraterrestrial Life " »
A collision of one universe with another would leave what Perimeter Institute's Matthew Johnson, calls “a disk on the sky” – a circular bruise in the cosmic microwave background. That the search for such a disk has so far come up empty makes certain collision-filled models less likely. The Perimeter team is at work figuring out what other kinds of evidence a collision might leave behind. It’s the first time that anyone has produced a direct quantitative set of predictions for the observable signatures of bubble universe collisions. And though none of those signatures has so far been found, some of them are possible to look for.
Continue reading "'Disk on the Sky' --The Search for an Alien Universe: "A Circular Bruise in the Cosmic Microwave Background" " »
Newly discovered soils by NASA's Curiosity rover provide more benign and habitable soil conditions than known before on Mars. Their dating to 3.7 billion years ago, he noted, puts them into a time of transition from "an early benign water cycle on Mars to the acidic and arid Mars of today." Life on Earth is believed to have emerged and began diversifying about 3.5 billion years ago, but some scientists have theorized that potential evidence that might take life on Earth farther back was destroyed by plate tectonics, which did not occur on Mars.
Continue reading "New NASA 'Curiosity' Evidence --"Mars was Once Much Warmer and Wetter"" »
Lawrence Livermore scientists for the first time have experimentally re-created the conditions that exist deep inside giant planets, such as Jupiter, Uranus and many of the planets recently discovered outside our solar system. The data described in this work are among the first tests for predictions made in the early days of quantum mechanics, more than 80 years ago, which are routinely used to describe matter at the center of planets and stars. While agreement between these new data and theory are good, there are important differences discovered, suggesting potential hidden treasures in the properties of diamond compressed to such extremes.
Continue reading "Journey to the Center of Jupiter" »
Curiosity's ChemCam's laser has zapped more than 600 rock and soil targets on Mars since Curiosity landed in the planet's Gale Crater in August 2012 to assess ancient habitable environments and major changes in Martian environmental conditions. On Saturday, July 12 by the Mars Hand Lens Imager (MAHLI) camera on the arm of NASA's Curiosity Mars Rover's Chemistry and Camera (ChemCam) instrument fired multiple laser shots to investigate a target rock's composition created the first observed plasma plume flashes. Preliminary analysis of the ChemCam spectra from this target rock, appropriately named "Nova," indicates a composition rich in silicon, aluminum and sodium, beneath a dust layer poor in those elements. This is typical of rocks that Curiosity is encountering on its way toward Mount Sharp (above).
Continue reading " Zap! NASA's Curiosity Lasers Mars' Rock to Assess Ancient Habitable Potential" »