Massive stars end their life with a bang, exploding as supernovas and releasing massive amounts of energy and matter. What remains of the star is a small and extremely dense remnant: a neutron star or a black hole. Neutron stars come in several flavours, depending on properties such as their ages, the strength of the magnetic field concealed beneath their surface, or the presence of other stars nearby. Some of the energetic processes taking place around neutron stars can be explored with X-ray telescopes, like ESA's XMM-Newton.
Continue reading "Image of the Day: "The Blue Monster" --Rare Million-Year-Old Neutron Star Discovered Near a Recent Supernova" »
During an August 20 event at NASA headquarters, called Ancient Earth, Alien Earths, a panel of scientists from NASA and other organizations discussed how vastly different and inhospitable we all would find ancient Earth, if we could go back in time. Despite the conditions, though, it was an environment in which life began and evolved – and understanding how that was possible could help us recognize habitable planets around other stars.
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Scientists continue to investigate the development of self-replicating, intricate sets of chemistry — in other words, life — from the chemical compounds thought available on early Earth. Out of this mixture of prebiotic chemicals, two nucleic acids — RNA and DNA — emerged as champions. Astrobiologists want to understand the origin of DNA and its genetic cousin, RNA, because figuring out how life got started here on Earth is key for gauging if it might ever develop on alien planets. New research intriguingly suggests that DNA, the genetic information carrier for humans and other complex life, might have had a rather humbler origin. In some microbes, a study shows, DNA pulls double duty as a storage site for phosphate. This all-important biomolecule contains phosphorus, a sometimes hard-to-get nutrient.
Continue reading "Origins of DNA --Shows How Life Could Have Evolved on Early Earth or Alien Planets" »
Only one species of the billions of species that have existed on Earth has shown an aptitude for radios and even we failed to build one during the first 99% of our 7 million year history. Charley Lineweaver, a provocative cosmologist with The Australian National University, believes the "Planet of the Apes Hypothesis" -a theory subscribed to by Carl Sagan and the astronomers involved with the Search for Extraterrestrial Intelligence (SETI), that human-like intelligence is a convergent feature of evolution -that there is an intelligence niche, into which other species will evolve if the human species goes extinct is based on a flawed notion of evolution, a notion that could have serious implications for our search for intelligent life elsewhere in the Milky Way Galaxy.
Continue reading ""The 'Intelligence Niche' is a Flawed Notion of Evolution" (Holiday Weekend Feature)" »
"Fundamentally, the solar system and everything in it was ultimately derived from a cloud of interstellar gas and dust," says Andrew Westphal, physicist at the University of California, Berkeley's Space Sciences Laboratory and lead author on the paper published this week in Science titled "Evidence for interstellar origin of seven dust particles collected by the Stardust spacecraft". "We're looking at material that's very similar to what made our solar system."
Continue reading "Stardust Mission Captures Origins of Our Solar System --"Clues to the Origin of Life Itself"" »
It may sound like science fiction, but astronomers have worked out a scheme that will allow them to detect and measure particles ten times smaller than the width of a human hair, even at many light-years distance. They can do this by observing a blue tint in the light from far-off objects caused by the way in which small particles, no more than a micron in size (one-thousandth of a millimeter) scatter light.
Continue reading ""Detecting Alien Planet Particles Smaller than a Human Hair" --New SETI Breakthrough" »
Astrophysicists obtained for the first time spectra of radiating cobalt registered at the supernova SN2014J, shown above, located 11 million light-years from Earth. Isotope 56Co has a half-life of just 77 days, and does not exist in normal conditions. However, during a giant thermonuclear explosion of a supernova, this short-lived radioactive isotope is produced in large quantities. The reason was the rarity of explosions at such a distance – 11 million light-years is a large value on the galactic scale (the diameter of a galaxy is about 100,000 light-years, the distance between stars is a few light-years), but on an intergalactic scale it is a relatively short distance. There are several hundreds of galaxies within a radius of ten million light-years; supernovae produce explosions like this (type Ia explosions) once every few centuries in a galaxy, including a type Ia supernova that exploded in the Milky Way in 1606.
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Astronomers using the National Science Foundation’s (NSF) Green Bank Telescope (GBT) have discovered that filaments of star-forming gas near the Orion Nebula may be brimming with pebble-size particles -- planetary building blocks 100 to 1,000 times larger than the dust grains typically found around protostars. If confirmed, these dense ribbons of rocky material may well represent a new, mid-size class of interstellar particles that could help jump-start planet formation.
Continue reading "Vast Streams of Gravel Detected in Orion Molecular Cloud -- "A Long and Winding Road in Space Essential for Planet Formation"" »
A fully developed elliptical galaxy is a gas-deficient gathering of ancient stars theorized to develop from the inside out, with a compact core marking its beginnings. Astronomers have for the first time caught a glimpse of the earliest stages of massive galaxy construction. The building site is a dense galactic core blazing with the light of millions of newborn stars that are forming at a ferocious rate.
Continue reading "First Ever Observation of an Emerging Ancient Elliptical Galaxy --"Twice as Many Stars as Milky Way in a Region Only 6,000 Light Years Across"" »
Quasars are the brightest objects in the Universe; their intense light is generated by gas as it falls towards a black hole. These mysterious objects emitting radio waves were first identified in 1963 by radio astronomers who called them quasi-stellar radio sources, or quasars. Galaxies can contain millions or billions of stars, but are still dim by comparison. Understanding whether the numerous small galaxies outshine the rare, bright quasars will provide insight into the way the universe built up today’s populations of stars and planets. It will also help scientists properly calibrate their measurements of dark energy, the agent thought to be accelerating the universe’s expansion and determining its far future.
Continue reading "Quasars --"Are They the Origin of Light in Our Universe?"" »