"These signals are the first direct evidence that thunderstorms make antimatter particle beams," said Michael Briggs, a university researcher whose team, located at UAHuntsville, includes scientists from NASA Marshall Space Flight Center, the University of Alabama in Huntsville, Max-Planck Institute in Garching, Germany, and from around the world. He presented the findings during a news briefing at the American Astronomical Society meeting in Seattle.
Scientists think the antimatter particles are formed in a terrestrial gamma-ray flash (TGF), a brief burst produced inside thunderstorms that has a relationship to lighting that is not fully understood. As many as 500 TGFs may occur daily worldwide, but most go undetected.
The spacecraft, known as Fermi, is designed to observe gamma-ray sources in space, emitters of the highest energy form of light. Fermi’s GBM constantly monitors the entire celestial sky, with sensors observing in all directions, including some toward the Earth, thereby providing valuable insight into this strange phenomenon.
When the antimatter produced in a terrestrial thunderstorm collides with normal matter, such as the spacecraft itself, both the matter and antimatter particles immediately are annihilated and transformed into gamma-rays observed by the GBM sensors. The detection of gamma-rays with energies of a particular energy -- 511,000 electron volts -- is the smoking-gun, indicating that the source of the observed gamma-rays in these events is the annihilation of an electron with its antimatter counterpart, a positron, produced in the TGF.
Since the spacecraft’s launch in 2008, the GBM team has identified 130 TGFs, which are usually accompanied by thunderstorms located directly below the spacecraft at the time of detection. However, in four cases, storms were a far distance from Fermi. Lightning-generated radio signals, detected by a global monitoring network, indicated the only lightning at the time of these events was hundreds or more miles away.
During one TGF, which occurred on December 14, 2009, Fermi was located over Egypt. However, the active storm was in Zambia, some 2,800 miles to the south. The distant storm was below Fermi’s horizon, so any gamma-rays it produced could not have been detected directly. Although Fermi could not see the storm from its position in orbit, it was still connected to it through sharing of a common magnetic field line of the Earth, which could be followed by the high-speed electrons and positrons produced by the TGF. These particles travelled up along the Earth’s magnetic field lines and struck the spacecraft. The beam continued past Fermi along the magnetic field, to a location known as a mirror point, where its motion was reversed, and then 23 milliseconds later, hit the spacecraft again. Each time, positrons in the beam collided with electrons in the spacecraft, annihilating each other, and emitting gamma-rays detected by Fermi’s GBM.
NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership. The spacecraft is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The GBM instrument is a collaboration between scientists at NASA's Marshall Space Flight Center, the University of Alabama in Huntsville, and the Max-Planck Institute in Garching, Germany. The Fermi mission was developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.
Ray Garner | Newswise Science News
Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute
Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Physics and Astronomy
09.12.2016 | Physics and Astronomy
09.12.2016 | Life Sciences