Mysterious Objects at the Edge of the Electromagnetic Spectrum

March 16, 2012: The human eye is crucial to astronomy. Without the ability to see, the luminous universe of stars, planets and galaxies would be closed to us, unknown forever. Nevertheless, astronomers cannot shake their fascination with the invisible.

Outside the realm of human vision is an entire electromagnetic spectrum of wonders. Each type of light–­from radio waves to gamma-rays–reveals something unique about the universe. Some wavelengths are best for studying black holes; others reveal newborn stars and planets; while others illuminate the earliest years of cosmic history.

NASA has many telescopes “working the wavelengths” up and down the electromagnetic spectrum. One of them, the Fermi Gamma-Ray Telescope orbiting Earth, has just crossed a new electromagnetic frontier.

A new ScienceCast video takes viewers on a trip to the edge of the electromagnetic spectrum, where mysterious objects are puzzling astronomers.

“Fermi is picking up crazy-energetic photons,” says Dave Thompson, an astrophysicist at NASA’s Goddard Space Flight Center. “And it’s detecting so many of them we’ve been able to produce the first all-sky map of the very high energy universe.”

“This is what the sky looks like near the very edge of the electromagnetic spectrum, between 10 billion and 100 billion electron volts.”

The light we see with human eyes consists of photons with energies in the range 2 to 3 electron volts. The gamma-rays Fermi detects are billions of times more energetic, from 20 million to more than 300 billion electron volts. These gamma-ray photons are so energetic, they cannot be guided by the mirrors and lenses found in ordinary telescopes. Instead Fermi uses a sensor that is more like a Geiger counter than a telescope. If we could wear Fermi’s gamma ray “glasses,” we’d witness powerful bullets of energy – individual gamma rays – from cosmic phenomena such as supermassive black holes and hypernova explosions. The sky would be a frenzy of activity.

An artist’s concept of giant ‘Fermi bubbles’ emerging from the heart of the
Milky Way.

Before Fermi was launched in June 2008, there were only four known celestial sources of photons in this energy range. “In 3 years Fermi has found almost 500 more,” says Thompson.

What lies within this new realm?

“Mystery, for one thing,” says Thompson. “About a third of the new sources can’t be clearly linked to any of the known types of objects that produce gamma rays. We have no idea what they are.”

The rest have one thing in common: prodigious energy.

“Among them are super massive black holes called blazars; the seething remnants of supernova explosions; and rapidly rotating neutron stars called pulsars.”
And some of the gamma rays seem to come from the ‘Fermi bubbles’ – giant structures emanating from the Milky Way’s center and spanning some 20,000 light years above and below the galactic plane.

Exactly how these bubbles formed is another mystery.

Now that the first sky map is complete, Fermi is working on another, more sensitive and detailed survey.

“In the next few years, Fermi should reveal something new about all of these phenomena, what makes them tick, and why they generate such ‘unearthly’ levels of energy,” says David Paneque, a leader in this work from the Max Planck Institute in Germany.

For now, though, there are more unknowns than knowns about “Fermi’s world.”

Says Thompson: “It’s pretty exciting!”

Authors: Dauna Coulter, Dr. Tony Phillips | Credit: Science@NASA

Mysterious Objects at the Edge of the Electromagnetic Spectrum – NASA Science.

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STRANGE SOUNDS IN SKY EXPLAINED BY SCIENTIST

SATURDAY, 28 JANUARY 2012 09:17

Mr. Khalilov, what is the nature of the unusual very low-pitched sounds reported by a great number of people in different parts of the planet since the summer of 2011?

Many call them “The Sound of the Apocalypse”. Information about that comes from all over the world: US, UK, Costa Rica, Russia, Czech Republic, Australia, etc.

We have analyzed records of these sounds and found that most of their spectrum lies within the infrasound range, i.e. is not audible to humans. What people hear is only a small fraction of the actual power of these sounds. They are low-frequency acoustic emissions in the range between 20 and 100 Hz modulated by ultra-low infrasonic waves from 0.1 to 15 Hz. In geophysics, they are called acoustic-gravity waves; they are formed in the upper atmosphere, at the atmosphere-ionosphere boundary in particular. There can be quite a lot of causes why those waves are generated: earthquakes, volcanic eruptions, hurricanes, storms, tsunamis, etc. However, the scale of the observed humming sound in terms of both the area covered and its power far exceeds those that can be generated by the above-mentioned phenomena.

In that case, what could be causing this humming in the sky?

In our opinion, the source of such powerful and immense manifestation of acoustic-gravity waves must be very large-scale energy processes. These processes include powerful solar flares and huge energy flows generated by them, rushing towards Earth’s surface and destabilizing the magnetosphere, ionosphere and upper atmosphere. Thus, the effects of powerful solar flares: the impact of shock waves in the solar wind, streams of corpuscles and bursts of electromagnetic radiation are the main causes of generation of acoustic-gravitation waves following increased solar activity.

Given the surge in solar activity as manifested itself in the higher number and energy of solar flares since mid-2011, we can assume that there is a high probability of impact of the substantial increase in solar activity on the generation of the unusual humming coming from the sky. It should be pointed out that solar activity began to rise sharply since early 2011, with its amplitude significantly higher than all forecasts given by a number of influential scientific institutions in 2010 and 2011. Meanwhile, the observed increase in solar activity is fully consistent with the forecast of the International Committee GEOCHANGE published in the Committee’s Report in June 2010. If this growth rate of solar activity continues, its amplitude by the end of 2012 will be higher than the amplitude of 23rd solar cycle, and in 2013-2014 the solar activity will reach its peak the amplitude of which was predicted by us to be 1.5 – 1.7 times higher than the amplitude of the 23rd cycle.

But you said that the cause of the “sky hum” can lie within Earth’s core as well, what does it mean?

There is one more possible cause of these sounds and it may lie at the Earth’s core. The fact is that the acceleration of the drift of the Earth’s north magnetic pole which increased more than fivefold between 1998 and 2003 and is at the same level today points to intensification of energy processes in the Earth’s core, since it is processes in the inner and outer core that form the Earth’s geomagnetic field. Meanwhile, as we have already reported, on November 15, 2011 all ATROPATENA geophysical stations which record three-dimensional variations of the Earth’s gravitational field almost simultaneously registered a powerful gravitational impulse. The stations are deployed in Istanbul, Kiev, Baku, Islamabad and Yogyakarta, with the first and last one being separated by a distance of about 10,000 km. Such a phenomenon is only possible if the source of this emanation is at the Earth’s core level. That huge energy release from the Earth’s core at the end of the last year was some kind of a start signal indicating the transition of the Earth’s internal energy into a new active phase.

Intensification of the energy processes in the Earth’s core can modulate the geomagnetic field which, through a chain of physical processes at the ionosphere – atmosphere boundary level, generates acoustic-gravity waves the audible range of which has been heard by people in the form of a frightening low-frequency sound in different parts of our planet.

In both cases, even though the causes of acoustic-gravity waves are of a quite understandable geophysical nature, they are indicative of the expected significant increase in solar activity and the geodynamic activity of our planet. There is no doubt that processes in the core rule the internal energy of our planet, therefore, we should expect by the end of 2012 a sharp rise in strong earthquakes, volcanic eruptions, tsunamis and extreme weather events with peak levels in 2013 – 2014.

via STRANGE SOUNDS IN SKY EXPLAINED BY SCIENTISTS.

NASA’s NPP Satellite Acquires First VIIRS Image

11.22.11

An image taken by the NPP Visible Infrared Imager Radiometer Suite (VIIRS) on Nov. 21, 2011. This high-resolution image is wrapped on a globe and shows a broad swath of Eastern North America from Canada’s Hudson Bay past Florida to the northern coast of Venezuela. The NASA NPP Team at the Space Science and Engineering Center, UW-Madison created the image using 3 channels (red, green and blue) of VIIRS data. Credit: NASA/NPP Team

GREENBELT, Md. — The Visible Infrared Imager Radiometer Suite (VIIRS) onboard NASA’s newest Earth-observing satellite, NPP, acquired its first measurements on Nov. 21, 2011. This high-resolution image is of a broad swath of Eastern North America from Canada’s Hudson Bay past Florida to the northern coast of Venezuela. The VIIRS data were processed at the NOAA Satellite Operations Facility (NSOF) in Suitland, Md.

VIIRS is one of five instruments onboard the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) satellite that launched from Vandenberg Air Force Base, Calif., on Oct. 28. Since then, NPP reached its final orbit at an altitude of 512 miles (824 kilometers), powered on all instruments and is traveling around the Earth at 16,640 miles an hour (eight kilometers per second).

“This image is a next step forward in the success of VIIRS and the NPP mission,” said James Gleason, NPP project scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md.

VIIRS will collect radiometric imagery in visible and infrared wavelengths of the Earth’s land, atmosphere, and oceans. By far the largest instrument onboard NPP, VIIRS weighs about 556 pounds (252 kilograms). Its data, collected from 22 channels across the electromagnetic spectrum, will be used to observe the Earth’s surface including fires, ice, ocean color, vegetation, clouds, and land and sea surface temperatures.

“VIIRS heralds a brightening future for continuing these essential measurements of our environment and climate,” said Diane Wickland, NPP program scientist at NASA headquarters in Washington. She adds that all of NPP’s five instruments will be up and running by mid-December and NPP will begin 2012 by sending down complete data.

“NPP is right on track to ring in the New Year,” said Ken Schwer, NPP project manager at NASA Goddard. “Along with VIIRS, NPP carries four more instruments that monitor the environment on Earth and the planet’s climate, providing crucial information on long-term patterns to assess climate change and data used by meteorologists to improve short-term weather forecasting.”

NPP serves as a bridge mission from NASA’s Earth Observing System (EOS) of satellites to the next-generation Joint Polar Satellite System (JPSS), a National Oceanic and Atmospheric Administration (NOAA) program that will also collect weather and climate data. NASA Goddard manages the NPP mission for the Earth Science Division of the Science Mission Directorate at NASA Headquarters in Washington. The JPSS program provides the NPP ground system and NOAA provides operational support.

During NPP’s five-year life, the mission will extend more than 30 key long-term datasets that include measurements of the atmosphere, land and oceans. NASA has been tracking many of these properties for decades. NPP will continue measurements of land surface vegetation, sea surface temperature, and atmospheric ozone that began more than 25 years ago.

“The task now for the science community is to evaluate VIIRS performance and determine the accuracy of its data products,” said Chris Justice a professor of geography at the University of Maryland, College Park, who will be using VIIRS data in his research.

“These long-term data records are critical in monitoring how the Earth’s surface is changing – either from human activity or through climate change.”

NASA’s NPP mission will continue collecting critical climate data to help scientist unravel the mysteries of climate change. NPP is carrying five instruments on board. The biggest and most important instrument is The Visible/Infrared Imager Radiometer Suite or VIIRS. This video focuses on VIIRS and why it is so important to Earth’s science.

Goddard Release No. 11-083

Rani Gran
Goddard Space Flight Center, Greenbelt, Md.
301-286-2483
Rani.C.Gran@nasa.gov

John Leslie
National Oceanic and Atmospheric Administration, Silver Spring, Md.
301-713-0214
john.leslie@noaa.gov

via NASA – NASA’s NPP Satellite Acquires First VIIRS Image.