Skip to main content

Home/ Groups/ SciByte
Rss Feed
Sort By: Most Recent | Popular Filter: All | Bookmarks | Topics Simple Middle
Mars Base

ScienceShot: A New Class of Supernova - ScienceNOW - 0 views

news.sciencemag.org/...shot-a-new-class-of-super.html

scibyte88 Supernova

shared by Mars Base on 27 Mar 13 - No Cached
  • type Iax, release somewhere between 1% and 50% the energy of a type Ia supernova
  • spectra of type Iax stars don't include any signs of hydrogen
  • Type Iax supernovae most likely form in binary star systems when a superdense, carbon- and oxygen-rich white dwarf star (center of disk at left) robs material from its helium-rich partner, eventually accumulating enough mass on its surface to trigger an explosion
  • ...2 more annotations...
  • Astronomers likely have discovered so few type Iax supernovae only because they are faint, not because they are rare
  • estimates that for every 100 type Ia supernovae explosions that occur, there are about 31 type Iax supernovae
Mars Base

New Kind of "Runt" Supernovae Could be Lurking Unseen - 0 views

www.universetoday.com/...rnovae-could-be-lurking-unseen

scibyte88 Supernova

shared by Mars Base on 27 Mar 13 - No Cached
  • Until now, supernovae have come in two main versions
  • In one scenario, a huge star, 10 to 100 times more massive as our Sun, collapses causing a colossal stellar explosion
  • Type Ia supernovae, occurs when material from a parent star streams onto the surface of a white dwarf. Over time, so much material falls onto the white dwarf that it raises the core temperature igniting carbon and causing a runaway fusion reaction. This event completely disrupts the white dwarf and results in a colossal stellar explosion
  • ...14 more annotations...
  • Now astronomers have found a third type that is fainter and less energetic than a Type Ia. Called a Type Iax supernova
  • essentially a mini supernova
  • only about one-hundredth as bright as their supernova siblings
  • calculates that Type Iax supernovae are about as third as common as Type Ia supernovae
  • The researchers also did not find them in elliptical galaxies, filled with older stars, suggesting that Type Iax supernovae come from young star systems
  • team identified 25 examples of this new type of supernova
  • Based on observations, the team found that the new Type Iax supernovae come from binary star systems containing a white dwarf and a companion star that has burned all of its hydrogen, leaving an outer layer that is helium rich
  • not sure what triggers the Type Iax supernova
  • One explanation involves the ignition of the outer helium layer from the companion star. The resulting shockwave slams into the white dwarf and disrupts it, causing the explosion.
  • Alternately, the white dwarf might ignite first due to the overlying helium shell it has collected from the companion star.
  • it appears that in many cases the white dwarf survives the explosion unlike in a Type Ia supernova where the white dwarf is completely destroyed
  • Supernovae explosions release so much energy as heat and light that they outshine entire galaxies for brief periods of time
  • The extremely hot conditions naturally create new heavier elements, such as gold, lead, nickel, zinc and copper
  • Type Iax supernovas aren’t rare, they’re just faint
Mars Base

Mars Science Laboratory: Sun in the Way Will Affect Mars Missions in April - 0 views

mars.jpl.nasa.gov/...index.cfm

scibyte87 Curiosity

shared by Mars Base on 26 Mar 13 - No Cached
  • The positions of the planets next month will mean diminished communications between Earth and NASA's spacecraft at Mars
  • Mars will be passing almost directly behind the sun, from Earth's perspective. The sun can easily disrupt radio transmissions between the two planets during that near-alignment
  • To prevent an impaired command from reaching an orbiter or rover, mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., are preparing to suspend sending any commands to spacecraft at Mars for weeks in April
  • ...13 more annotations...
  • NASA's Mars Odyssey
  • sixth conjunction for
  • The travels of Earth and Mars around the sun set up this arrangement, called a Mars solar conjunction, about once every 26 months
  • The Mars solar conjunctions
  • are not identical to each other. They can differ in exactly how close to directly behind the sun Mars gets, and they can differ in how active the sun is
  • which has been orbiting Mars since 2001
  • Both orbiters will continue science observations on a reduced basis compared to usual operations. Both will receive and record data from the rovers.
  • Odyssey will continue transmissions Earthward throughout April, although engineers anticipate some data dropouts, and the recorded data will be retransmitted later
  • The Mars Reconnaissance Orbiter will go into a record-only mode on April 4.
  • anticipates that the orbiter could have about 40 gigabits of data from its own science instruments and about 12 gigabits of data from Curiosity accumulated for sending to Earth around May 1.
  • Mars Exploration Rover Opportunity is approaching its fifth solar conjunction. Its team will send no commands between April 9 and April 26. The rover will continue science activities using a long-term set of commands to be sent beforehand.
  • Curiosity
  • can also continue making science observations from the location where it will spend the conjunction period. Curiosity's controllers plan to suspend commanding from April 4 to May 1.
Mars Base

Heart repair breakthroughs replace surgeon's knife - 0 views

medicalxpress.com/...eakthroughs-surgeon-knife.html

scibyte87 scibyte88 heart

shared by Mars Base on 25 Mar 13 - No Cached
  • Many problems that once required sawing through the breastbone and opening up the chest for open heart surgery now can be treated
  • through a tube
  • These minimal procedures used to be done just to unclog arteries and correct less common heart rhythm problems
  • ...42 more annotations...
  • Now some patients are getting such repairs for valves, irregular heartbeats, holes in the heart and other defects—without major surgery
  • Doctors even are testing ways to treat high blood pressure with some of these new approaches
  • Instead of opening the chest, we're able to put catheters in through the leg, sometimes through the arm
  • Many patients after having this kind of procedure in a day or two can go home
  • It may lead to cheaper treatment, although the initial cost of the novel devices often offsets the savings from shorter hospital stays
  • Not everyone can have catheter treatment, and some promising devices have hit snags in testing
  • Others on the market now are so new that it will take several years to see if their results last as long as the benefits from surgery do.
  • these procedures have allowed many people too old or frail for an operation to get help for problems that otherwise would likely kill them
  • You can do these on 90-year-old patients
  • also offer an option for people who cannot tolerate long-term use of blood thinners or other drugs to manage their conditions
  • Heart valves
  • Millions of people have leaky heart valves. Each year, more than 100,000 people in the United States alone have surgery for them
  • Without a valve replacement operation, half of these patients die within two years, yet many are too weak to have one.
  • just over a year ago,
  • Edwards Lifesciences Corp. won approval to sell an artificial aortic valve flexible and small enough to fit into a catheter and be wedged inside the bad one
  • At first it was just for inoperable patients. Last fall, use was expanded to include people able to have surgery but at high risk of complications.
  • Catheter-based treatments for other valves also are in testing. One for the mitral valve
  • mixed review by federal Food and Drug Administration advisers this week; whether it will win FDA approval is unclear. It is already sold in Europe
  • Heart rhythm problems
  • Catheters can contain tools to vaporize or "ablate" bits of heart tissue that cause abnormal signals that control the heartbeat
  • Now catheter ablation is being used for the most common rhythm problem—atrial fibrillation, which plagues about 3 million Americans and 15 million people worldwide.
  • Ablation addresses the underlying rhythm problem. To address the stroke risk from pooled blood, several novel devices aim to plug or seal off the pouch
  • The upper chambers of the heart quiver or beat too fast or too slow. That lets blood pool in a small pouch off one of these chambers
  • Clots can form in the pouch and travel to the brain, causing a stroke
  • a tiny lasso to cinch the pouch shut. It uses two catheters that act like chopsticks. One goes through a blood vessel and into the pouch to help guide placement of the device, which is contained in a second catheter poked under the ribs to the outside of the heart. A loop is released to circle the top of the pouch where it meets the heart, sealing off the pouch.
  • A different kind of device
  • sold in Europe and parts of Asia, but is pending before the FDA in the U.S
  • like a tiny umbrella pushed through a vein and then opened inside the heart to plug the troublesome pouch.
  • Early results from a pivotal study released by the company suggested it would miss a key goal, making its future in the U.S. uncertain.
  • Heart defects
  • St. Jude Medical Inc.'s Amplatzer is a fabric-mesh patch threaded through catheters to plug the hole
  • In two new studies, the device did not meet the main goal of lowering the risk of repeat strokes in people who had already suffered one, but some doctors were encouraged by other results
  • Сlogged arteries
  • The original catheter-based treatment—balloon angioplasty—is still used hundreds of thousands of times each year in the U.S. alone
  • A Japanese company, Terumo Corp., is one of the leaders of a new way to do it that is easier on patients—through a catheter in the arm rather than the groin
  • Newer stents that prop arteries open and then dissolve over time, aimed at reducing the risk of blood clots, also are in late-stage testing
  • High blood pressure
  • About
  • 1 billion people worldwide have high blood pressure, a major risk factor for heart attacks
  • Researchers are testing a possible long-term fix for dangerously high pressure that can't be controlled with multiple medications.
  • uses a catheter and radio waves to zap nerves, located near the kidneys, which fuel high blood pressure
  • At least one device is approved in Europe and several companies are testing devices in the United States
Mars Base

Planck's Cosmic Map Reveals Universe Older, Expanding More Slowly - 0 views

www.universetoday.com/...se-older-expanding-more-slowly

scibyte87 PlanckConstant

shared by Mars Base on 22 Mar 13 - No Cached
  • show the same 10-square-degree patch of sky as seen by NASA’s Cosmic Background Explorer, or COBE, NASA’s Wilkinson Microwave Anisotropy Probe, or WMAP, and Planck.
  • Planck has a resolution about 2.5 times greater than WMAP
  • This graphic
Mars Base

Universe is a teeny bit older than thought | Matter & Energy | Science News - 0 views

www.sciencenews.org/...a_teeny_bit_older_than_thought

scibyte87 PlanckConstant

shared by Mars Base on 22 Mar 13 - No Cached
  • Launched by the European Space Agency in 2009, the Planck satellite scans the sky for the cosmic microwave background, radiation that dates back to about 380,000 years after the Big Bang
  • Planck is essentially a supersensitive thermometer that can probe the temperature of this radiation to millionths of a degree
  • The red spots in the map are about 1 part in 100,000 hotter than the average temperature, while the blue spots are slightly colder
  • ...4 more annotations...
  • the theory of inflation, which posits that, around 10-30 seconds after the Big Bang, the universe briefly expanded faster than the speed of light.
  • Researchers who analyzed the telescope’s data announced that the universe is about 13.81 billion years old, or 80 million years older than previously thought
  • The telescope is still making observations, and in about a year researchers will add
  • data t
Mars Base

Planck's most detailed map ever reveals an almost perfect Universe - 0 views

phys.org/...3-planck-reveals-universe.html

scibyte87 PlanckConstant

shared by Mars Base on 22 Mar 13 - No Cached
  • the most detailed map ever created of the cosmic microwave background
  • the relic radiation from the Big Bang
  • was released
  • ...31 more annotations...
  • revealing the existence of features that challenge the foundations of our current understanding of the Universe
  • The image is based on the initial 15.5 months of data from Planck and is the mission's first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380 000 years old.
  • At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2700ºC
  • protons and electrons joined to form hydrogen atoms, the light was set free
  • As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero.
  • that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today
  • According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
  • Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before
  • By analysing the nature and distribution of the seeds in Planck's CMB image, we can determine the composition and evolution of the Universe from its birth to the present day
  • because precision of Planck's map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood
  • Since the release of Planck's first all-sky image in 2010, we have been carefully extracting and analysing all of the foreground emissions that lie between us and the Universe's first light
  • revealing the cosmic microwave background in the greatest detail yet
  • One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model
  • their signals are not as strong as expected from the smaller scale structure
  • Another is an asymmetry in the average temperatures on opposite hemispheres of the sky
  • This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look
  • a cold spot extends over a patch of sky that is much larger than expected.
  • The asymmetry and the cold spot had already been hinted at with Planck's predecessor
  • NASA's WMAP mission, but were largely ignored because of lingering doubts about their cosmic origin
  • One way to explain the anomalies is to propose that the Universe is in fact not the same in all directions on a larger scale than we can observe
  • In this scenario, the light rays from the CMB may have taken a more complicated route through the Universe than previously understood, resulting in some of the unusual patterns observed today.
  • ultimate goal would be to construct a new model that predicts the anomalies and links them together
  • we don't know whether this is possible and what type of new physics might be needed
  • the Planck data conform spectacularly well to the expectations of a rather simple model of the Universe, allowing scientists to extract the most refined values yet for its ingredients
  • dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for less than previously thought.
  • Normal matter that makes up stars and galaxies contributes just 4.9% of the mass/energy density of the Universe
  • Dark matter, which has thus far only been detected indirectly by its gravitational influence, makes up 26.8%, nearly a fifth more than the previous estimate.
  • Planck data also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant
  • At 67.15 kilometres per second per megaparsec, this is significantly less than the current standard value in astronomy
  • The data imply that the age of the Universe is 13.82 billion years.
  • We see an almost perfect fit to the standard model of cosmology, but with intriguing features that force us to rethink some of our basic assumptions
Mars Base

Curiosity Demonstrates New Capability to Scan 360 Degrees for Life Giving Water - and i... - 0 views

www.universetoday.com/...giving-water-and-is-widespread

scibyte87 Curiosity

shared by Mars Base on 19 Mar 13 - No Cached
  • The science team guiding NASA’s Curiosity Mars Science Lab (MSL) rover have demonstrated a new capability that significantly enhances the robots capability to scan her surroundings for signs of life giving water
  • from a distance
  • the rover appears to have found that evidence for water at the Gale Crater landing site is also more widespread than prior indications.
  • ...14 more annotations...
  • Mastcam cameras
  • can now also be used as a mineral-detecting and hydration-detecting tool to search 360 degrees around every spot she explores for the ingredients required for habitability and precursors to life
  • Some iron-bearing rocks and minerals can be detected and mapped using the Mastcam’s near-infrared filters
  • scientists used the filter wheels on the Mastcam cameras to run an experiment by taking measurements in different wavelength’s
  • a rock target called ‘Knorr’ in the Yellowknife Bay area were Curiosity is now exploring
  • Researchers found that near-infrared wavelengths on Mastcam can be used as a new analytical technique to detect the presence of some but not all types of hydrated minerals
  • The first use of the Mastcam 34 mm camera to find water was at the rock target called “Knorr.”
  • see elevated hydration signals in the narrow veins that cut many of the rocks in this area
  • These bright veins contain hydrated minerals that are different from the clay minerals in the surrounding rock matrix
  • Mastcam thus serves as an early detective for water without having to drive up to every spot of interest, saving precious time and effort
  • But Mastcam has some limits
  • It is not sensitive to the hydrated phyllosilicates found in the drilling sample at John Klein
  • Mastcam can use the hydration mapping technique to look for targets related to water that correspond to hydrated minerals
  • Yellowknife Bay basin possesses a significant amount of phyllosilicate clay minerals; indicating an environment where Martian microbes could once have thrived in the distant past.
Mars Base

Mars Science Laboratory: Images - 0 views

mars.jpl.nasa.gov/...images

scibyte87 Curiosity

shared by Mars Base on 25 Mar 13 - No Cached
  • left image is the raw, unprocessed color, as it is received directly from Mars
  • center rendering was produced after calibration of the image to show an estimate of "natural" color, or approximately what the colors would look like if we were to view the scene ourselves on Mars
  • right image shows the result of then applying a processing method called white-balancing, which shows an estimate of the colors of the terrain as if illuminated under Earth-like, rather than Martian, lighting
Mars Base

Crow-Size Pterosaur Named After 9-Year-Old Fossil Hunter -- National Geographic - 0 views

news.nationalgeographic.com/...aurs-dinosaurs-science-animals

scibyte87 dinosaur

shared by Mars Base on 22 Mar 13 - No Cached
  • A new species of crow-size pterosaur has been named in honor of the nine-year-old fossil hunter who discovered it
  • While exploring the U.K.'s Isle of Wight (map) in 2008, the then-five-year-old Morris came across blackened "bones sticking out of the sand
  • The Morris family brought the fossil to paleontologist Martin Simpson at the University of Southampton, who, with the help of colleagues, identified it as a new species
  • ...9 more annotations...
  • In pterosaurs, certain parts of the skeleton, especially the skull and the pelvis, are really distinct between different [species
  • The newfound creature also belonged to a group of pterosaurs called the azhdarchoids
  • All are from the Cretaceous, all are toothless, and many—perhaps all—were especially well adapted for life in terrestrial environments like woodlands, tropical forests, and floodplains
  • From the size of the pelvis
  • estimate
  • had a wingspan of about 2.5 feet (75 centimeters) and was just over a foot (35 centimeters) from snout to tail, making it about the size of a gull or large crow.
  • also inspired study co-author Simpson to write a children's book entitled Daisy and the Isle of Wight Dragon.
  • V. daisymorrisae lived in 145 to 65 million years ago
  • it probably had a head crest, was a reasonably good walker and runner on the ground, and could expertly fly through dense forests.
Mars Base

Robot snake automatically wraps around an object when thrown (w/ Video) - 0 views

phys.org/...utomatically-thrown-video.html

scibyte87 robot

shared by Mars Base on 23 Mar 13 - No Cached
  • Robot snakes have been developed in recent years to mimic the actions of their real life counterparts
  • researchers have developed such snakes that are able to travel over terrain in ways very similar to a real snake, and even to climb up objects such as a person's arm.
  • researchers have extended the capability of a robot snake to include wrapping and holding on to an object when thrown at it
  • ...6 more annotations...
  • researchers were able to give the snake such an ability by making use of accelerometers embedded in its body
  • It's able to detect the sudden stop that occurs when it strikes an object
  • taking advantage of programming that had already been done by the team to get it to wrap itself around the object that it had struck
  • there is a difference between wrapping and constricting
  • this robot snake does the former, but not the latter
  • it doesn't squeeze the target, it simply wraps itself around it to allow it to hold on
Mars Base

NASA Moon Probes' Impact Craters Spotted from Space | Grail Mission | Space.com - 0 views

www.space.com/-grail-moon-probes-graves.html

scibyte87 Grail

shared by Mars Base on 20 Mar 13 - No Cached
  • NASA's Lunar Reconnaissance Orbiter (LRO) snapped a series of photographs of the two 16.5-foot-wide (5 meters) craters, which mark where the space agency's twin Grail probes ended their gravity-mapping mission, and their operational lives, on Dec. 17.
  • It's a bit of a surprise that the LROC team was able to find the craters at all
  • the craters are small, nondescript features on a body riddled with impact scars
  • ...13 more annotations...
  • The two Grail spacecraft — known as Ebb and Flow — slammed into a mountain near the lunar north pole at 3,771 mph (6,070 km/h), striking the surface about 20 seconds apart.
  • The Grail craters first showed up in LROC photos from January, but images taken on Feb. 28 show them in much greater detail
  • used these later photos to produce a topographic map of the impact zone
  • This map revealed that the two craters are separated by about 7,250 feet (2,210 m) in straight-line distance and 985 feet (300 m) in altitude
  • the crashes ejected material that appears darker than the surrounding lunar dirt.
  • these may be dark due to spacecraft material being mixed with the ejecta
  • may be residual fuel left in the probes' lines, or bits of their carbon-fiber bodies
  • LRO didn't get any images of the actual crashes, which occurred in the dark.
  • ultraviolet imaging spectrograph did see emissions from mercury and atomic hydrogen in the ejected plumes when they rose high enough to reach sunlight
  • The analysis of the Grail impact plumes is ongoing
  • The probes' measurements have allowed scientists to create the best-ever gravity map of any celestial body
  • And that map is getting better all the time, as researchers continue to analyze the data
  • The twin probes, which were each about the size of a washing machine, zipped around the moon at an average altitude of just 7 miles (11 km) in their final days
Mars Base

Google Maps climbs Everest - Telegraph - 0 views

www.telegraph.co.uk/...oogle-Maps-climbs-Everest.html

scibyte87 GoogleMap

shared by Mars Base on 22 Mar 13 - No Cached
  • Google did not get to Everest's peak, which is at an altitude of 29,035 feet, or 8,850 meters, but the maps now include 360-degree views of four of the seven summits
  • highest peaks on all seven continents
  • lightweight camera and tripod with a fish-eye lens and in 2011, the spent 12 days
« First ‹ Previous 861 - 880 of 2613 Next › Last »
Showing 20▼ items per page