Smoke from several large fires burning on Portugal's Madeira Island were seen blowing over the Atlantic Ocean on Aug. 10 when NASA's Terra satellite passed overhead.
Madeira is an archipelago of four islands located off the northwest coast of Africa. They are an autonomous region of Portugal.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this natural-color image at 8:25 a.m. EDT (12:05 UTC). Places where MODIS detected active fire are located in red.
Image Credit: NASA Goddard's Rapid Response Team, Jeff Schmaltz
NASA Goddard Space Flight Center enables NASA's mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA's accomplishments by contributing compelling scientific knowledge to advance the Agency's mission.
%feed http://feedproxy.google.com/~r/TheDailyGalaxyNewsFromPlanetEarthBeyond/~3/--mZttLd_wI/unknown-forces-at-work-alien-megastructure-star-decreasing-in-brightness-at-unprecedented-rate.html NASA/Kepler-Mission Mystery: "Unknown Forces at Work" -- 'Alien-Megastructure' Star Decreasing in Brightness At Unprecedented Rate
Space Researchers have added more evidence about the ongoing mystery of KIC 8462852, aka Tabby's Star. Benjamin Montet with the California Institute of Technology and Joshua Simon with Observatories of the Carnegie Institution have enhanced their study of the star by analyzing data from the Kepler space observatory over the past four years. They found that the star has been decreasing in brightness at an unprecedented rate.
The tale of Tabby's Star began in September of last year when Louisiana State University astronomer Tabetha Boyajian reported anomalies in the unusual light curve of star KIC 8462852—over the years 2009 to 2013, its light appeared to dip in ways that did not conform to what would be expected if it were due to a planet passing in front of it, temporarily blocking some of its light. Her paper led to observations, commentaries and theories from others in the space community, though no one was able to come up with a reasonable explanation for what she had found.
One researcher actually proposed that it might be due to alien activity. Then, earlier this year, Bradley Schaefer with Louisiana State University published results of his efforts studying photographic plates that had captured the star going back to the 19th century—he reported that the light from the star had dimmed 19 percent over just the past century. His report was not received warmly by all, as many suggested his data or approach was likely flawed.
But now, another team has found something similar. Montet and Simon studied images from the space-based Kepler observatory and found that light from Tabby's Star had decreased in brightness by approximately .34 percent a year for 1000 days starting in 2009, which was actually twice the rate that Schaefer had found. Even stranger, they found that over the next 200 days, the brightness of the star dimmed by another 2.5 percent before it finally leveled out.
Various scientists have offered possible explanations for the strange behavior of Tabby's star—from comet swarms to planetary remnants to the construction of a Dyson Sphere-like structure around the star to capture its energy by aliens—but so far, none of the theories has been able to take into account all of the odd observations.
That may change soon, however, as Boyajian, the astronomer who first noticed the star's strange behavior, ran a successful crowdsourcing campaign to pay for time at the Las Cumbres Observatory Global Telescope Network over the course of a year—this will give her a chance to catch the star in the act of blinking, allowing her to alert the rest of the astronomy community, which will presumably its sights on the star at once, and in so doing, perhaps solve the mystery.
Using data from NASA's Kepler and Spitzer Space Telescopes, the artist's concept at the top of the page shows a star behind a shattered comet. Observations of the star KIC 8462852 by NASA's Kepler and Spitzer space telescopes suggest that its unusual light signals are likely from dusty comet fragments, which blocked the light of the star as they passed in front of it in 2011 and 2013. The comets are thought to be traveling around the star in a very long, eccentric orbit.
The life of an astronaut in space consists of following many step-by-step procedures. We've all wished we had an extra arm when following the instructions to self-assembly furniture and for astronauts it is no different except their procedures, instructions and hardware are more complex as well as their lives often depending on following the instructions correctly.
ESA has developed a system that improves on the basic step-by-step procedures used on the International Space Station that are displayed on a computer. The current system requires constant floating back and forth from the computer to the workplace to check the next step, and mission control cannot easily follow progress.
The mobile procedure viewer or ‘mobiPV' is a wearable system that displays each step in a task, synchronises between the astronaut, ground control and third parties, automatically logs steps and communication and allows for video conferencing, note-taking and text chat.
In this image, ESA's Matthias Maurer is testing the system during a simulated space mission 20 m underwater off the coast of Florida, USA, during NASA's Extreme Environment Mission Operations (NEEMO).
The main part of the equipment is the smartphone and camera on a 3D-printed wrist-band. mobiPV can display the procedure on a separate tablet to see more information. Here Matthias has connected a third device for testing all three screens are synchronised.
Versions of mobiPV have been tested during NEEMO before and even in space during ESA astronaut Andreas Mogensen's ‘iriss' mission last year. This version, branded mobiPV++, uses a redesigned system and tests the device without a head-mounted display.
The NEEMO crew used mobiPV to run a new way of sampling water that shows promise for use on the International Space Station, called Aquapad. The procedure was displayed on the tablet with ground control following from the coast and the mobiPV team watching from ESTEC, ESA's technical heart in the Netherlands. The astronauts and NEEMO crew were very positive with the results.
The mobiPV team is continuing to refine the system and hope to have a second test on the International Space Station with ESA astronaut Thomas Pesquet during his six-month Proxima mission starting later this year.
Credit: NASA
astronomy
1470904830000
astronomy
%feed http://feedproxy.google.com/~r/TheDailyGalaxyNewsFromPlanetEarthBeyond/~3/LBZbGyLa5tU/massive-black-holes-lurking-in-the-milky-ways-halo-the-primary-source-of-dark-matter.html Black Holes Hiding in the Milky Way's Halo? --"Survivors from the Beginning of the Universe"
Are massive black holes hiding in the halos of galaxies, making up the majority of the universe's mysterious dark matter?Roughly 27% of the mass and energy in the observable universe is made up of “dark matter” — matter invisible to us, which is neither accounted for by observable baryonic matter nor dark energy. What makes up this dark matter? Among the many proposed candidates, one is massive compact halo objects, or MACHOs. MACHOs are hypothesized to be black holes that formed in the early universe and now hide in galactic halos. We can't detect light from these objects — but their mass adds to the gravitational pull of galaxies.
So far, MACHOs' prospects aren't looking great. They have not been detected in gravitational lensing surveys, ruling out MACHOs between 10-7 and 30 solar masses as the dominant component of dark matter in our galaxy. MACHOs over 100 solar masses have also been ruled out, due to the existence of fragile wide halo binaries that would have been disrupted by the presence of such large black holes.
But what about MACHOs between 30 and 100 solar masses? In a new study, Timothy Brandt (NASA Sagan Postdoctoral Fellow at the Institute for Advanced Study, in Princeton, NJ) uses a recently discovered faint galaxy, Eridanus II, to place constraints on MACHOs in this mass range.
MACHO constraints from the survival of a star cluster in Eri II, assuming a cluster age of 3 Gyr (a lower bound; constraints increase when assuming an age of 12 Gyr). Eridanus II is an ultra-faint dwarf galaxy that lies roughly 1.2 million light-years away from us. This dim object is a satellite galaxy of the Milky Way, discovered as part of the Dark Energy Survey. One feature of Eri II is especially intriguing: a single bright star cluster nearly coincident with the galaxy's center.
What makes this cluster so interesting? Ultra-faint dwarf galaxies are dominated by their dark matter content — so if MACHOs make up most of the universe's dark matter content, Eri II should be full of them! But, Brandt points out, interactions between such MACHOs and Eri II's star cluster would result in dynamical heating of the cluster. This would cause the cluster to puff up in size.
Brandt calculates that the compact star cluster observed in Eri II couldn't exist if the galaxy's dark matter is made up of MACHOs of mass >15 solar masses.
This same argument can be extended to the entire stellar populations of dwarf galaxies. Due to dynamical heating, compact ultra-faint dwarfs would have much larger radii than we observe if their dark matter were in the form of MACHOs.
Brandt shows that the existence of these compact dwarfs rules out dark matter consisting entirely of MACHOs of mass >10 solar masses, closing the gap in our tests of the MACHO model for dark matter. Though black holes hiding in halos could still make up part of the universe's dark matter, an additional culprit will need to be identified to explain the bulk of it.
The Daily Galaxy via American Astronomical Society
Image credits: ESO and Caltech
astronomy
1470904828000
astronomy
%feed https://www.theguardian.com/science/across-the-universe/2016/aug/10/this-weeks-perseid-meteor-shower-could-be-best-in-years-for-northern-hemisphere-viewers This week's Perseid meteor shower could be best in years for northern hemisphere viewers
Up to 200 Perseid meteors per hour could blaze across the northern hemisphere sky in the early hours of Friday morning. Here's what they are and how to see them
Night owls in the northern hemisphere could be in for a treat this Thursday night/Friday morning. The annual Perseid meteor shower reaches its peak on the night of 1112 August, and this year it is predicted to give double its usual rate of meteors.
Up to 200 shooting stars per hour could be seen under perfect conditions, according to Bill Cooke of Nasa's Meteoroid Environments Office in Huntsville, Alabama. The International Meteor Organization goes as far as wondering whether this week's spectacle is going to be “the best in years”. The optimism is being driven by two reasons.
%feed https://www.sciencedaily.com/releases/2016/08/160810104412.htm Discovery of a time-resolved supernova signal in Earth's microfossils Physicists have succeeded in detecting a time-resolved supernova signal in the Earth's microfossil record. As the group shows, the supernova signal was first detectable at a time starting about 2.7 million years ago. According to the researcher's analyses, our solar system spent one million years to transit trough the remnants of a supernova. astronomy
1470902391000
astronomy
%feed https://www.sciencedaily.com/releases/2016/08/160810084622.htm Stellar lab in Sagittarius The small smattering of bright blue stars in a new ESO image is the perfect cosmic laboratory in which to study the life and death of stars. Known as Messier 18 this star cluster contains stars that formed together from the same massive cloud of gas and dust. astronomy
!["Portugal's]("http://chimpfeedr.com/img/?url=http%3A%2F%2Ffarm9.staticflickr.com%2F8827%2F28819877271_46058ee21d_m.jpg&width=540&mix=d4e49-astronomy")
!["PIA20053-PossibleCometSwarmAroundKIC8462852-ArtistConcept-20151124"]("http://chimpfeedr.com/img/?url=http%3A%2F%2Fwww.dailygalaxy.com%2F.a%2F6a00d8341bf7f753ef01b7c8858b3a970b-800wi&width=540&mix=d4e49-astronomy" "\"PIA20053-PossibleCometSwarmAroundKIC8462852-ArtistConcept-20151124\"")
!["KeplerOverview"]("http://chimpfeedr.com/img/?url=http%3A%2F%2Fwww.dailygalaxy.com%2F.a%2F6a00d8341bf7f753ef01b7c8858bee970b-800wi&width=540&mix=d4e49-astronomy" "\"KeplerOverview\"")
![]("http://chimpfeedr.com/img/?url=http%3A%2F%2Ffeeds.feedburner.com%2F%7Eff%2FTheDailyGalaxyNewsFromPlanetEarthBeyond%3Fd%3DyIl2AUoC8zA&width=540&mix=d4e49-astronomy")
![]("http://chimpfeedr.com/img/?url=http%3A%2F%2Ffeeds.feedburner.com%2F%7Er%2FTheDailyGalaxyNewsFromPlanetEarthBeyond%2F%7E4%2F--mZttLd_wI&width=540&mix=d4e49-astronomy")
!["Follow]("http://chimpfeedr.com/img/?url=http%3A%2F%2Ffarm9.staticflickr.com%2F8379%2F28606638320_75f5153cfc_m.jpg&width=540&mix=d4e49-astronomy")
!["Black-holes-merger-1-banner"]("http://chimpfeedr.com/img/?url=http%3A%2F%2Fwww.dailygalaxy.com%2F.a%2F6a00d8341bf7f753ef01bb0928cf3b970d-800wi&width=540&mix=d4e49-astronomy" "\"Black-holes-merger-1-banner\"")
!["Howastarclus"]("http://chimpfeedr.com/img/?url=http%3A%2F%2Fwww.dailygalaxy.com%2F.a%2F6a00d8341bf7f753ef01b7c885826f970b-800wi&width=540&mix=d4e49-astronomy" "\"Howastarclus\"")
![]("http://chimpfeedr.com/img/?url=http%3A%2F%2Ffeeds.feedburner.com%2F%7Er%2FTheDailyGalaxyNewsFromPlanetEarthBeyond%2F%7E4%2FLBZbGyLa5tU&width=540&mix=d4e49-astronomy")
