Fermi bubbles defy explanation, Despite extensive analysis

This artist's representation shows the Fermi bubbles towering above and below the galaxy. 

Credit: NASA's Goddard Space Flight Center

Scientists from Stanford University and the Department of Energy's SLAC National Accelerator Laboratory have analyzed more than four years of data from NASA's Fermi Gamma-ray Space Telescope, along with data from other experiments, to create the most detailed portrait yet of two towering bubbles that stretch tens of thousands of light-years above and below our galaxy.

The bubbles, which shine most brightly in energetic gamma rays, were discovered almost four years ago by a team of Harvard astrophysicists led by Douglas Finkbeiner who combed through data from Fermi's main instrument, the Large Area Telescope (FGST).

The new portrait, described in a paper that has been accepted for publication in The Astrophysical Journal, reveals several puzzling features, said Dmitry Malyshev, a postdoctoral researcher at the Kavli Institute for Particle Astrophysics and Cosmology who co-led on the analysis.

For example, the outlines of the bubbles are quite sharp, and the bubbles themselves glow in nearly uniform gamma rays over their colossal surfaces, like two 30,000-light-year-tall incandescent bulbs screwed into the center of the galaxy.

Their size is another puzzle. The farthest reaches of the Fermi bubbles boast some of the highest energy gamma rays, but there's no discernible cause for them that far from the galaxy.

Finally, although the parts of the bubbles closest to the galactic plane shine in microwaves as well as gamma rays, about two-thirds of the way out the microwaves fade and only gamma rays are detectable.

Not only is this different from other galactic bubbles, but it makes the researchers' work that much more challenging, said Malyshev's co-lead, KIPAC postdoctoral researcher Anna Franckowiak.

"Since the Fermi bubbles have no known counterparts in other wavelengths in areas high above the galactic plane, all we have to go on for clues are the gamma rays themselves," she said.

What Made The Bubbles?
Soon after the initial discovery theorists jumped in, offering several explanations for the bubbles' origins.

For example, they could have been created by huge jets of accelerated matter blasting out from the supermassive black hole at the center of our galaxy.

Or they could have been formed by a population of giant stars, born from the plentiful gas surrounding the black hole, all exploding as supernovae at roughly the same time.

"There are several models that explain them, but none of the models is perfect," Malyshev said. "The bubbles are rather mysterious."

Creating the portrait wasn't easy.

"It's very tricky to model," said Franckowiak. "We had to remove all the foreground gamma-ray emissions from the data before we could clearly see the bubbles."

From the vantage point of most Earth-bound telescopes, all but the highest-energy gamma rays are completely screened out by our atmosphere.

It wasn't until the era of orbiting gamma-ray observatories like Fermi that scientists discovered how common extra-terrestrial gamma rays really are.

Pulsars, supermassive black holes in other galaxies and supernovae are all gamma rays point sources, like distant stars are point sources of visible light, and all those gamma rays had to be scrubbed from the Fermi data.

Hardest to remove were the galactic diffuse emissions, a gamma ray fog that fills the galaxy from cosmic rays interacting with interstellar particles.

"Subtracting all those contributions didn't subtract the bubbles," Franckowiak said. "The bubbles do exist and their properties are robust."

In other words, the bubbles don't disappear when other gamma-ray sources are pulled out of the Fermi data, in fact, they stand out quite clearly.

Franckowiak says more data is necessary before they can narrow down the origin of the bubbles any further.

"What would be very interesting would be to get a better view of them closer to the galactic center," she said, "but the galactic gamma ray emissions are so bright we'd need to get a lot better at being able to subtract them."

Fermi is continuing to gather the data Franckowiak wants, but for now, both researchers said, there are a lot of open questions.

NASA's TRMM satellite analyzes Mexico's soaking tropical rains

Rainfall totals were calculated using NASA's TRMM satellite data for the period May 29 to June 6, 2014 that included Tropical Storm Boris and System 90L. 

Over 535 mm (21.6 inches) where tropical storm Boris came ashore in southern Mexico. 

Credit: SSAI/NASA, Hal Pierce

The movement of tropical storm Boris into southern Mexico and a nearly stationary low pressure system in the southern Gulf of Mexico caused heavy rainfall in that area.

NASA and the Japan Aerospace Exploration Agency's Tropical Rainfall Measuring Mission (TRMM) satellite acts like a "rain gauge in space" and calculated that one area received almost 2 feet of rainfall.

The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) at the NASA Goddard Space Flight Center in Greenbelt, Maryland monitors rainfall over the global tropics using data from the TRMM satellite.

TMPA rainfall totals were calculated for the period May 29 to June 6, 2014 that covered the time that Tropical Storm Boris made landfall in southwestern Mexico and System 90L soaked eastern Mexico.

TRMM data showed the highest rainfall totals of over 535 mm where tropical storm Boris came ashore in southern Mexico. System 90L, located in the Bay Of Campeche for most of that time brought more heavy rain in southeastern Mexico before it dissipated on June 7.

On June 7, there was good and bad news about System 90L. The good news was that it moved further inland and was dissipating so it no longer had a chance to develop into a tropical cyclone.

The bad news was that it moved further inland and continued to produce gusty winds and heavy rains along with life-threatening flash flooding over eastern and southeastern Mexico.



TRMM satellite data showed that some areas in southwestern Mexico received over 12 inches of rainfall (red) from Boris, while System 90L on the eastern side of Mexico brought similar totals to parts of the Yucatan. 

Credit: SSAI/NASA, Hal Pierce

At NASA's Goddard Space Flight Center in Greenbelt, Maryland, the NASA/NOAA GOES Project created an animation of satellite imagery from NOAA's GOES-East satellite imagery.

The movie shows the movement of System 90L over land and dissipating between June 6 and June 7 at 2000 UTC (4 p.m. EDT).

The Mexican Weather Service reported the city of Veracruz recorded 7.1 inches (180 mm) of rain! Huixtepec in Oaxaca reported 2.9 inches (73.4 mm) of rain.

On June 7, the National Hurricane Center noted that the low was centered near 18.0 north and 96.5 west. By June 9, System 90L had dissipated.

Solar Ultraviolet Imager (SUVI): New satellite sensor will analyze and predict severe space weather

Lockheed Martin engineers in Denver install the Solar Ultraviolet Imager (SUVI) on the GOES-R Sun Pointing Platform. 

SUVI was built at the Lockheed Martin Advanced Technology Center in Palo Alto, Calif.

Credit: Lockheed Martin

Lockheed Martin has delivered a new solar analysis payload that will help scientists measure and forecast space weather, which can damage satellites, electrical grids and communications systems on Earth.

The Solar Ultraviolet Imager (SUVI) instrument was integrated with the first flight vehicle of the National Oceanic and Atmospheric Administration's (NOAA) next-generation Geostationary Operational Environmental Satellite, known as GOES-R.

The GOES-R Series spacecraft are designed and built by Lockheed Martin in Denver, Colo.

"It is enormously satisfying to see the first GOES-R satellite and its instruments coming together, and it is great to see SUVI in flight configuration on the satellite's Sun-Pointing Platform," said Jeff Vanden Beukel, Lockheed Martin SUVI program director at the Advanced Technology Center in Palo Alto, where the instrument was built.

"We look forward to continuing our collaboration with NASA and NOAA to produce state-of-the-art scientific instruments that increase safety and improve quality of life."

SUVI will provide the required solar observational capabilities that enable NOAA's Space Weather Prediction Center in Boulder, Colo.,;

• to monitor solar activity and to issue accurate, real-time alerts; when space weather could affect the performance and reliability of technological systems in space and on the ground, 
• through the enhanced detection of coronal holes, solar flares and coronal mass ejections, 
• as well as improved geomagnetic storm and power blackout forecasts.

Extreme Space weather is known to disrupt satellite operations, communications, navigation, and the distribution of electricity through power grids.

Timely forecasts of severe space weather events would help satellite operators and electrical grid technicians mitigate potential damage to such systems.

Lockheed Martin is under contract to build the first four next-generation GOES satellites (R, S, T, and U).

Four of the six instruments for the GOES-R satellite have been delivered to the Denver facility and are being integrated with the spacecraft.

Once the instrument complement is completely integrated, a full suite of environmental tests will be conducted. Launch of the GOES-R satellite is scheduled for the first quarter of 2016.

NASA MARS Curiosity: Starts Drilling

The percussion drill in the turret of tools at the end of the robotic arm of NASA's Mars rover Curiosity has been positioned in contact with the rock surface in this image from the rover's front Hazard-Avoidance Camera (Hazcam).

The drill was positioned for pre-load testing, and the Hazcam recorded this image during the 170th Martian day, or sol, of Curiosity's work on Mars (Jan. 27, 2013).>br />
CREDIT: NASA/JPL-Caltech
NASA's Mars rover Curiosity is sizing up a target rock and flexing its robotic arm ahead of its first-ever drilling activity on the Red Planet, which should take place in the coming days.

The 1-ton Curiosity rover pressed down on the rock in four different places with its arm-mounted drill Monday (Jan. 27). These "pre-load" tests should allow mission engineers to see if the amount of force applied matches predictions, researchers said.

The six-wheeled robot won't be ready to start boring into the rock until it completes several additional hardware tests and other checks, which should keep the rover busy through at least the end of this week, they added.

NASA Mars Rover Curiosity Image: Rock named 'Jake Matijevic' Holds Surprises

This image shows where NASA's Curiosity rover aimed two different instruments to study a rock known as "Jake Matijevic" in late September 2012. 

The red dots indicate where Curiosity fired its laser at the rock. 

The circular black and white images are ChemCam images to examine the laser burns. 

Purple circles show spots where Curiosity used its Alpha Particle X-ray Spectrometer (APXS) to study the rock.

CREDIT: NASA/JPL-Caltech/MSSS

NASA Mars Curiosity Rover: Martian Soil Samples taken and Shaken - Video

NASA’s Curiosity rover is seen in the video above clutching and then vigorously shaking a tiny bit of Mars in its scoop.

Curiosity is currently in an area known as the Rocknest, where it has been picking up fine Martian sand and vibrating it at a tooth-rattling speed to remove any overfill and help engineers identify and discard large pebbles.

Soon, the rover will also be vibrating the material through its interior chemical testing systems to sand blast them and remove a residual oily film from Earth.

The equipment is so sensitive it could easily detect even a tiny smidgen of Earth dust, which would skew any results looking at Mars’ chemical makeup.

Engineers are planning to have Curiosity spit out its current sandy haul, then scoop and respit two more times to completely clean everything out.

After that, the rover will be ready to deliver a half-baby-aspirin-sized sample to its laboratory equipment, housed inside its body, for detailed chemical analysis.

Scientists think that this sample will be fairly boring, showing nothing they don’t expect, but will help them calibrate their instruments for future exploration.

Curiosity’s MastCams captured this film at about eight frames per second, though the full 256-frame video includes interpolated frames to bring it up to a 32-frame-per-second video.

Video: JPLnews/Youtube

Christopher Stringer: Rethinking "Out Of Africa"

CHRISTOPHER STRINGER: is one of the world's foremost paleoanthropologists.

He is a founder and most powerful advocate of the leading theory concerning our evolution: Recent African Origin or "Out of Africa".

He has worked at The Natural History Museum, London since 1973, collaborating with scientists across all the disciplines of paleoanthropology, and is a Fellow of the Royal Society, with over 200 papers and books to his name.

"At the moment, I'm looking again at the whole question of a recent African origin for modern humans—the leading idea over the last 20 years.

This argues that we had a recent African origin, that we came out of Africa, and that we replaced all of the other human forms that were outside of Africa.

But we're having to re-evaluate that now because genetic data suggest that the modern humans who came out of Africa about 60,000 years ago probably interbred with Neanderthals, first of all, and then some of them later on interbred with another group of people called the Denisovans, over in south eastern Asia.

If this is so, then we are not purely of recent African origin. We're mostly of recent African origin, but there was contact with these other so-called species.

We're having to re-evaluate the Out-of-Africa theory, and we're having to re-evaluate the species concepts we apply, because in one view of thinking, species should be self-contained units.

They don't interbreed with other species. However, for me, the whole idea of Neanderthals as a different species is really a recognition of their separate evolutionary history—the fact that we can show that they evolved through time in a particular direction, distinct from modern humans, and they separated maybe 400,000 years ago from our lineage

Morphologically we can distinguish a relatively complete Neanderthal fossil from any recent human.

You could argue that they're an extreme variant of Homo sapiens, but a very different 'race' from anyone alive today, or, as I prefer to argue, they're a separate species, with a separate evolutionary history.

I've never actually said that that meant they were completely reproductively isolated from us. We know that many closely related species in primates, for example, can interbreed.

Various species of monkey can interbreed and have fertile offspring, and so can our closest living relatives, Bonobos and common chimpanzees.

In my view the Neanderthals were closely related and probably potentially able to interbreed with modern humans, but until recently I considered that while there could have been interbreeding forty or fifty thousand years ago, it was on such a small scale that all trace of it vanished in the intervening years.

It now seems from Neanderthal genome studies that that was not so. We do have a bit of Neanderthal in us, you and I, it's a small amount, but certainly not negligible.

Does that mean Neanderthals are a different species or does it mean we should include them in Homo sapiens?

Well, they are still only a small part of our makeup now, reflecting something like a 2.5% input of their DNA. Physically, however, they went extinct about 30,000 years ago.

They had distinct behaviour and they evolved under different conditions from us, so I still think it's useful to keep them as a separate species, even if we remember that that doesn't necessarily preclude interbreeding."

Read more of this fascinating article here at EDGE: Rethinking 'Out of Africa' - Includes a Video and audio transcript.

NASA Mars Science Lab Mission: SAM

The SAM instrument is the largest of the 10 science instruments for NASA's Mars Science Laboratory mission. 

It will examine samples of Martian rocks, soil and atmosphere for information about chemicals that are important to life and other chemical indicators about past and present environments. Credit: NASA

The Mars Science Laboratory is on its way to the red planet, and its rover Curiosity should touch down next summer. If the mission hits paydirt and comes across organic material, then one instrument in particular has the chemical tools for studying these building blocks of life.

The instrument is called Sample Analysis at Mars, or SAM (or "Samantha" to those who built her). As the name makes clear, SAM is there to analyze samples taken from the surface and from the atmosphere. It uses sophisticated chemical lab equipment packed into the size of a microwave oven.

SAM sits in the belly of the rover and will be fed solid samples by the robotic arm. It is one of 10 science instruments on Curiosity that all work together to study the past and present habitability of Mars.

"Life on Earth means water, energy and the complexity of carbon chemistry," says Paul Mahaffy from NASA Goddard Space Flight Center and the PI of the SAM instrument. "We'll be looking for all of the above, but with a special emphasis on the complexity."

Curiosity's predecessors, the Mars Exploration Rovers Spirit and Opportunity, had a mantra of "follow the water." Now, the paradigm is shifting towards "follow the carbon," Mahaffy says.

SAM will have the sensitivity for measuring organic molecules at a level of a few parts per billion, but there's no guarantee that any organics will be found.

A more sure-fire bet is that the mission will better characterize whether Mars was ever friendly to organic compounds and the life that depends on them.

NASA Analysis: Road Transportation is Key Driver of Climate Warming

The on-road transportation sector releases significant amounts of carbon dioxide, black carbon, and ozone—all substances that cause warming.

In contrast, the industrial sector releases many of the same gases, but it also tends to emit sulfates and other aerosols that cause cooling by reflecting light and altering clouds. Credit: NASA GISS/Unger

For decades, climatologists have studied the gases and particles that have potential to alter Earth's climate. They have discovered and described certain airborne chemicals that can trap incoming sunlight and warm the climate, while others cool the planet by blocking the Sun's rays.

Now a new study led by Nadine Unger of NASA's Goddard Institute for Space Studies (GISS) in New York City offers a more intuitive way to understand what's changing the Earth's climate. Rather than analyzing impacts by chemical species, scientists have analyzed the climate impacts by different economic sectors.

Each part of the economy, such as ground transportation or agriculture, emits a unique portfolio of gases and aerosols that affect the climate in different ways and on different timescales.

"We wanted to provide the information in a way that would be more helpful for policy makers," Unger said. "This approach will make it easier to identify sectors for which emission reductions will be most beneficial for climate and those which may produce unintended consequences."

Unger's model finds that in 2020 (left), transportation, household biofuels and animal husbandry will have the greatest warming impact on the climate, while the shipping, biomass burning, and industrial sectors will have a cooling impact.

By 2100 (right), the model finds that the power and industrial sector will become strongly warming as carbon dioxide accumulates. Credit: NASA GISS/Unger

In a paper published online on Feb. 3 by the Proceedings of the National Academy of Sciences, Unger and colleagues described how they used a climate model to estimate the impact of 13 sectors of the economy from 2000 to 2100. They based their calculations on real-world inventories of emissions collected by scientists around the world, and they assumed that those emissions would stay relatively constant in the future.

Unger's analysis is one of the first of its kind to incorporate the multiple effects that aerosol particles can have on clouds, which affect the climate indirectly. Credit: NASA's Johnson Space Center

You can read the full article on the NASA website - Click here...