Searching the heavens -- GLAST

May 01, 2008

A new space mission, due to launch this month, is going to shed light on some of the most extreme astrophysical processes in nature - including pulsars, remnants of supernovae, and supermassive black holes. It could even help us comprehend the origin and distribution of dark matter, write three scientists currently preparing for the GLAST mission from NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, USA, in this month’s Physics World.

The Gamma-Ray Large Area Space Telescope (GLAST), to be launched on 16 May 2008, is a four-tonne observatory packed with state-of-the-art particle detectors that will study the gamma-ray sky in unprecedented detail.

Gamma rays are a form of electromagnetic radiation with much higher frequency and energy than visible light, UV light or even X-rays. Having such high energy, gamma rays are hard to collect and focus in the way that a conventional telescope does with visible light. Gamma rays are therefore the most difficult form of electromagnetic radiation to track in space.

Whereas visible light reveals thousands of stars and individual planets moving slowly across the sky, studying the skies at gamma-ray frequencies reveals a much weirder picture of space.

Gamma rays are not produced by hot, glowing objects, but from collisions between charged, very rapidly moving, particles and matter or light. The high frequency photons that are emitted from these collisions provide a glimpse of the most extreme astrophysical processes known.

Black holes, for example, accelerate matter to produce extreme energies in active galaxies. The gamma rays emitted in these scenarios have the equivalent energy to that of all the stars in an entire galaxy over all wavelengths.

Until now, however, existing ground-based gamma-ray detectors have not been sophisticated enough to measure these emissions in any detail over long periods. The astrophysicists cite looking for signatures of as-yet-unknown fundamental physical processes as a key reason for embarking on this project.

Julie McEnery, Steve Ritz and Neil Gehrels of NASA’s Goddard Space Centre, write, “We expect GLAST to have a large impact on many areas of astrophysics but what is most exciting are the surprises: with any luck, the greatest GLAST science has not even been thought of yet.”

Source: Institute of Physics

Explore further: NASA selects instruments to track climate impact on vegetation

add to favorites email to friend print save as pdf

Related Stories

Evidence of a local hot bubble carved by a supernova

20 hours ago

I spent this past weekend backpacking in Rocky Mountain National Park, where although the snow-swept peaks and the dangerously close wildlife were staggering, the night sky stood in triumph. Without a fire, ...

The source of the sky's X-ray glow

Jul 27, 2014

In findings that help astrophysicists understand our corner of the galaxy, an international research team has shown that the soft X-ray glow blanketing the sky comes from both inside and outside the solar system.

Discover the "X-factor" of NASA's Webb telescope

Jul 24, 2014

NASA's James Webb Space Telescope and Chandra X-ray observatory have something in common: a huge test chamber used to simulate the hazards of space and the distant glow of starlight. Viewers can learn about ...

Recommended for you

Lifetime of gravity measurements heralds new beginning

25 minutes ago

Although ESA's GOCE satellite is no more, all of the measurements it gathered during its life skirting the fringes our atmosphere, including the very last as it drifted slowly back to Earth, have been drawn ...

NASA's IceCube no longer on ice

4 hours ago

NASA's Science Mission Directorate (SMD) has chosen a team at NASA's Goddard Space Flight Center in Greenbelt, Maryland, to build its first Earth science-related CubeSat mission.

Tidal forces gave moon its shape, according to new analysis

18 hours ago

The shape of the moon deviates from a simple sphere in ways that scientists have struggled to explain. A new study by researchers at UC Santa Cruz shows that most of the moon's overall shape can be explained by taking into ...

User comments : 0