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NASA Develops Interstellar Network
By Kevin Parrish, November 21, 2008

• Constellation Program: First Flight Delayed To 2014


Although having an Interplanetary Internet in space seems like something that should already be in place, apparently NASA is just now getting around to it after ten years of development. However, the first "deep space internet" isn’t a way for astronauts to stream videos from YouTube despite its Internet-based roots... at least, not yet. In fact, according to NASA, the TCP/IP protocol would break down because of long distances in space.

For this reason, NASA has created a new protocol: Disruption-Tolerant Networking (DTN) in order for spaceships to communicate with each other even when they’re too far away to keep a constant connection alive. Instead of discarding packets of information if the destination cannot be reached, the nodes using the DTN protocol actually stores information until the recipient computer comes back online, or the node might find another computer to hold the information until the recipient returns in order to keep the information moving.


• Interplanetary Internet links (more)


NASA compares this protocol to basketball players passing the ball to the closest player until the data is "slam dunked" into its final destination. "It’s like the Internet, only the Internet assumes basically everything’s connected and there aren’t a lot of delays," said Jay Wyatt, manager of the Space Networking and Mission Automation Program office at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "The Internet model kind of breaks down in deep space." Recently NASA completed a month-long experiment of the new protocol using the just-launched Epoxi spacecraft located around 20 million miles from Earth, posing as a Mars data-relay orbiter. The test also included nine computers planted firmly at JPL that emulated simulate Mars landers, orbiters and ground mission-operations centers; the DTN network ultimately consisted of ten nodes total.

NASA hopes to alleviate the manual labor associated with current communications to and from earth, creating a more automated environment that should make life much easier for both mission control and astronauts. "In space today, an operations team must manually schedule each link and generate all the commands to specify which data to send, when to send it, and where to send it," said Leigh Torgerson, manager of the DTN Experiment Operations Center at JPL. "With standardized DTN, this can all be done automatically." The project began ten years ago as a joint development partnership between NASA and the now-vice president of Google, Vint Cerf, who coincidentally actually co-designed the original TCP/IP protocol. The goal was to create an Interplanetary Internet that must endure disruptions, long delays and disruptions due to the nature of space.

The Interplanetary Internet is expected to ease the management of multiple vehicles - landed, mobile and orbiting - during complex missions. There’s no doubt that NASA plans to have the network loaded and primed by the time NASA heads out to Mars. However, for now, the month-long experiment, which just concluded, is but one of many NASA plans to conduct over the next few years. The next step is to load the protocol software into International Space Station computers next summer. If successful, perhaps astronauts can finally stream ALIEN or 2001: A Space Odyssey into the ISS lounge.
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Related Articles:

• Stratford.edu: Origin of the Internet. As Viewed by its Creators

BBC News: The Internet reaches out to final frontier » Audio: Vint Cerf on how to take the Web into space
- A programme to kick-start the use of internet communications in space has been announced by the US government. The Department of Defense's Iris project will put an internet router in space by the start of 2009. It will allow voice, video and data communications for US troops using standards developed for the internet. Eventually Iris could extend the net into space, allowing data to flow directly between satellites, rather than sending it via ground stations. "Iris is to the future of satellite-based communications what Arpanet was to the creation of the internet in the 1960s," said Don Brown, of Intelsat General, one of the companies who will build the platform. Arpanet (Advanced Research Projects Agency Network), the predecessor of the internet, was developed by the United States Department of Defense. MORE » Related Blog


• Space: Intelsat To Test Internet Routing In Space For The US Military

• Space.qinetiq.com: Integration of Russian Satellite Data Information Resources with the global network of Earth Observation information Systems (IRIS)

IT News: How The Internet Could Go From Cyberspace To Outer Space
- The US military is to trial putting internet routers into orbit in an experiment that could have important implications for civilian applications. The internet routing in space (IRIS) project will be run over three years in conjunction with Cisco and Intelsat. The system will carry network services for voice, video and data communications, enabling military units or allied forces to communicate with one another using internet protocol and existing ground equipment. MORE »

• Astronomy Picture of the Day: http://apod.nasa.gov / 2 / 3 / 4 / 5 / 6 /7 • Photos by Rancho Del Sol Observatory • Audio Astro Slideshow


On the Net:

(more)


• Photos: Travelblog.org - http://world-information.org
• Astrophysics Archive links: http://heasarc.gsfc.nasa.gov
• Astrophysics Research links: http://lambda.gsfc.nasa.gov
• Library, Physics and Astronomy links: www.adsabs.harvard.edu • fas.org more...

• The Morwenstow Station Facility, with its antennas directed toward Intelsat satellites over the Atlantic and Indian Ocean.
INTELSAT is in business since 1964 and owns and operates, as the worlds’ most extensive and secure satellite communications network, a global communications satellite system of 50 geostationary satellites, providing capacity for voice, video, corporate/private networks and Internet in more than 200 countries and territories.
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On the Net:
Wikipedia: Intelsat
Intelsat: www.intelsat.com/network/satellite

World Wide Links Related to Satellite Missions:


• Satelitte: Misions Info • Satelitte List • Space Images


• Ajisai (JAXA • ALOS (JAXA, Earth Observing Research Center) • ANDE (USNO) • Advanced Tether Experiment
• CHAMP (GFZ) • CryoSat (ESA) • Envisat (AVISIO, ESA, CNES) • ERS-1, -2 (ESA, maneuver history, JPL) • Etalon (FAS)
• Engineering Test Satellite ETS-VIII (JAXA) • Galileo (ESA, EU, Galileo Joint Undertaking) • GFO-1 (NOAA, maneuvers history)
• GFZ-1 (GFZ Home Page, JPL Mission and Spacecraft Library) • GIOVE-A • GLONASS (Russia, FAS, IGS/IGLOS) • CEOS IDN, NL.
• GPS (NAVSTAR GPS JPO, USCG, IGS, USNO) • Gravity Probe B (Standford University) • ICESat (NASA, CSR, Ball Aerospace)
• Indian Remote Sensing Satellites (IRS) • International Space Industry Report (ISIR) Newsline) • Jason-1 (JPL, CNES, AVISO)
• Jason-2 (JPL, CNES, Eumetsat, NOAA, AVISIO) • LAGEOS (NASA Destination Earth) • LAGEOS-III (ESA) • Link Budget Calculations


• Satelitte view images


• Meteor-3M • Meteosat P2 • Mission and Spacecraft Library (JPL) • Mission Parameters (Sat. nr's, orbit parameters, bin sizes)
• MSTI-II • Predictions (CDDIS, at EDC, at NSGF; NORAD 2-line elements from Celestrak or Orbits Information Group) • RESURS
• Small Satellite Home Page • Solar System Dynamics ephemeris information (JPL) • SPACEWARN Bulletin, satellite information
• STARSHINE-3 (US Navy, AZINET) • Stella and Starlette (Observatoire de la Cote d'Asur) • SUNSAT (Home) • T2L2 (OCA) • TiPS
• Time Bias Functions Data Files produced by RGO (CDDIS or EDC) • TOPEX/Poseidon (CNES, JPL, AVISO, CCAR, NOAA)
• WESTPAC • Future Greenhouse Gases Observing Satellite "IBUKI"

• Links to all space agencies: Ilrs.gsfc.nasa.gov/agencylinks
• European Space Agency Blog News, Videos

On the Net:

Earth Observing System: http://eospso.gsfc.nasa.gov
Satellite laser ranging service: http://ilrs.gsfc.nasa.gov

• APOD: Yuri's Planet (more)

• Earthtoday.net • Science.qj.net

Jwst.nasa.gov

The Birth of Stars and Protoplanetary Systems

Stars, like our Sun, can be thought of as “basic particles” of the Universe, just as atoms are “basic particles” of matter. Groups of stars make up galaxies, while planets and ultimately life arise around stars. Although stars have been the main topic of astronomy for thousands of years, we have begun to understand them in detail only in recent times through the advent of powerful telescopes and computers.


Stages of solar system formation


A hundred years ago, scientists did not know that stars are powered by nuclear fusion, and 50 years ago they did not know that stars are continually forming in the Universe. Researchers still do not know the details of how clouds of gas and dust collapse to form stars, or why most stars form in groups, or exactly how planetary systems form. Young stars within a star-forming region interact with each other in complex ways. The details of how they evolve and release the heavy elements they produce back into space for recycling into new generations of stars and planets remains to be determined through a combination of observation and theory.

Astronomers know that a large number of stars that are like our Sun have gas-giant planets. They have discovered nearly 100 planetary systems containing over 200 planets outside our Solar System. Many of these planets are very large (like Jupiter), but unlike similar planets in our Solar System, they are in very close orbits around their own sun. Some only take 3 days to orbit their sun, which is closer than Mercury is to our Sun.

The discovery of such planetary systems came as a surprise to astronomers. Their discovery made scientists re-think their ideas and theories about how planets are formed. Scientists realize that to get a better understanding of how planets form, they need to have more observations of planets around young stars, and more observations of leftover debris around stars, which can come together and form planets. To unravel the birth and early evolution of stars and planets, we need to be able to peer into the hearts of dense and dusty cloud cores where star formation begins. These regions cannot be observed at visible light wavelengths as the dust would make such regions opaque and must be observed at infrared wavelengths. MORE »
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On the Net:
New Worlds Atlas: http://planetquest1.jpl.nasa.gov

Jwst.nasa.gov

Planets & Origins of Life

The first planet outside our solar system was discovered in 1995. Since then, we have discovered a multitude of planets around other stars. We have come to the realization that planets may in fact be quite common. Most of the planets discovered so far are large gas giants like Jupiter, although modern detection techniques are now helping scientists detect smaller planets. The ultimate objective of the search is to find another Earth and perhaps even signs of life elsewhere in the Universe. At right is an image of a likely planet (red) orbiting a brown dwarf.


• ESO: Brown Dwarf 2M1207 and its Planetary Companion (more)


To trace the origins of the Earth and life in the Universe, scientists need to study planet formation and evolution, including the material around stars where planets form. A key issue is to understand how the building blocks of planets are assembled. Scientists do not know if all planets in a planetary system form in place or travel inwards after forming in the outer reaches of the system. It is also not known how planets reach their ultimate orbits, or how large planets affect the smaller ones in solar systems like our own.

The icy bodies and dust in the outer reaches of our Solar System are evidence of conditions when our Solar System was very young. Scientists can directly compare those conditions to the objects and dust observed around other stars. In addition to studying planets outside our solar system, scientists want to learn more about our own home. Studying the chemical and physical history of the small and large bodies that came together to form the Earth may help us discover how life developed on Earth. MORE »


• List of curently known extrasolar planets

Jwst.nasa.gov

The Assembly of Galaxies

How did the very first galaxies form? How did we end up with the large variety of galaxies we see today? We now know that extremely large black holes live at the centers of most galaxies – what is the nature of the relationship between the black holes and the galaxy that hosts them? These are some of the fundamental questions about galaxies that the future JWST will tackle.


» Spitzer Photos

- Spitzer Space Telescope image of the dusty, starry arms of the spiral galaxy M81


Computer models that scientists have made to understand galaxy formation indicate that galaxies are created when dark matter merges and clumps together. Dark matter is an invisible form of matter whose total mass in the universe is roughly five times that of “normal” matter (i.e., atoms). It can be thought of as the scaffolding of the universe. The visible matter we see collects inside this scaffolding in the form of stars and galaxies. The way dark matter "clumps" together is that small objects form first, and are drawn together to form larger ones.

This build-up of large systems is accompanied by the formation of luminous stars from gas and dust. As stars evolve, and eventually die, they give way to new generations of stars. Scientists believe that the interaction of stars and galaxies with the invisible dark matter produced the present-day galaxies, organized into what is known as the "Hubble Sequence of galaxies" This process of galaxy assembly is still occurring today – we see many examples of galaxies colliding and merging to form new galaxies. In our own local neighborhood of space, the Andromeda galaxy is headed toward the Milky Way for a possible future collision - many billions of years from now!

Scientists today know that galaxies existed about one billion years after the 'Big Bang'. While most of these early galaxies were smaller and more irregular than present-day galaxies, some are very similar to those seen nearby today. Despite all the work done to date, there are still many questions. Scientists do not really know how galaxies are formed and what gives them their shapes. Scientists do not know how the chemical elements are distributed through the galaxies, and the details of how the central black holes in galaxies influence their host galaxies. Scientists are also still searching for answers on what happens when small and large galaxies collide or join together. MORE »




- Our Milky Way galaxy looks very much like the spiral galaxy NGC 7331 photographed by NASA's Spitzer Space Telescope.

Related Information:
• Latest Space Online Articles
• The Mysteries of deep space
• Telescopes for Deep Space Astronomy

On the Net:
Space Images: www.spaceimages.com - Photojournal.jpl.nasa.gov

Jpl.nasa.gov

Hubble Telescope Finds Carbon Dioxide on an Extrasolar Planet
By NASA's Jet Propulsion Laboratory, Dec. 09, 2008




- Exoplanet orbiting the star HD 189733.


Pasadena, Calif. -- NASA's Hubble Space Telescope has discovered carbon dioxide in the atmosphere of a planet orbiting another star. This breakthrough is an important step toward finding chemical biotracers of extraterrestrial life. The Jupiter-sized planet, called HD 189733b, is too hot for life. But the Hubble observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars. Organic compounds also can be a by-product of life processes, and their detection on an Earthlike planet someday may provide the first evidence of life beyond our planet.

Previous observations of HD 189733b by Hubble and NASA's Spitzer Space Telescope found water vapor. Earlier this year, Hubble found methane in the planet's atmosphere. "Hubble was conceived primarily for observations of the distant universe, yet it is opening a new era of astrophysics and comparative planetary science," said Eric Smith, Hubble Space Telescope program scientist at NASA Headquarters in Washington. "These atmospheric studies will begin to determine the compositions and chemical processes operating on distant worlds orbiting other stars. The future for this newly opened frontier of science is extremely promising as we expect to discover many more molecules in exoplanet atmospheres."


• Space.gs


Mark Swain, a research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., used Hubble's near-infrared camera and multi-object spectrometer to study infrared light emitted from the planet, which lies 63 light-years away. Gases in the planet's atmosphere absorb certain wavelengths of light from the planet's hot glowing interior. Swain identified carbon dioxide and carbon monoxide. The molecules leave a unique spectral fingerprint on the radiation from the planet that reaches Earth. This is the first time a near-infrared emission spectrum has been obtained for an exoplanet. "The carbon dioxide is the main reason for the excitement because, under the right circumstances, it could have a connection to biological activity as it does on Earth," Swain said. "The very fact we are able to detect it and estimate its abundance is significant for the long-term effort of characterizing planets to find out what they are made of and if they could be a possible host for life."

This type of observation is best done on planets with orbits tilted edge-on to Earth. They routinely pass in front of and then behind their parent stars, phenomena known as eclipses. The planet HD 189733b passes behind its companion star once every 2.2 days. The eclipses allow an opportunity to subtract the light of the star alone, when the planet is blocked, from that of the star and planet together prior to eclipse. That isolates the emission of the planet and makes possible a chemical analysis of its atmosphere. "In this way, we are using the eclipse of the planet behind the star to probe the planet's day side, which contains the hottest portions of its atmosphere," said team member Guatam Vasisht of JPL. "We are starting to find the molecules and to figure out how many there are to see the changes between the day side and the night side."

This successful demonstration of looking at near-infrared light emitted from a planet is very encouraging for astronomers planning to use NASA's James Webb Space Telescope after it is launched in 2013. These biomarkers are best seen at near-infrared wavelengths. Astronomers look forward to using the Webb telescope to look spectroscopically for biomarkers on a terrestrial planet the size of Earth or a "super-Earth" several times our planet's mass. "The Webb telescope should be able to make much more sensitive measurements of these primary and secondary eclipse events," Swain said.

Latest Space News:
Jpl.nasa.gov/news - Photojournal.jpl.nasa.gov

Ulysses.jpl.nasa.gov

DSN Antennas, the Largest and Most Sensitive Global Spacecraft Communications Network


» Esa.int - Canberra DSD - 1 / 2 / 3

"Communicating with a growing number of spacecraft over long distances is a great challenge. To effectively manage this
task a worldwide communications system was constructed. Read about this Deep Space Network and how it works." (more)


The DSN is the largest and most sensitive spacecraft communications network in the world consisting of three deep space communications complexes located approximately 120 degrees of longitude apart around the globe: at Goldstone, California; near Madrid, Spain; and near Canberra, Australia. To illustrate the sensitivity, the DSN is capable of receiving signals from a spacecraft billions of kilometers away, which, upon arrival on Earth, can be as weak as a billionth of a billionth of a watt -- that is 20 billion times less than the power required for a digital wristwatch. Each deep space communications complex provides capabilities required to perform telemetry data processing, including signal reception and amplification, signal demodulation and decoding, and data extraction. It also provides a capability to send commands to satellites, spacecrafts and manned missions in space. All DSN complexes are linked to NASA's JPL via a world-wide communications network.


• Photos: Canberra DSN complex


A joint NASA-ESA project, Ulysses is the only mission that has been exploring the heliosphere in three dimensions (in addition to the dimension of time). The heliosphere is a bubble in space caused by the solar wind emanating from the Sun blowing into the interstellar medium, which consists predominantly of hydrogen and helium that permeates our galaxy. The goal of the Ulysses mission is to explore the Sun's environment as a function of the complete range of solar latitudes. Ulysses has transformed our view of the integrated Sun-heliosphere system. It has overcome the limitations of measurements restricted to the vicinity of the ecliptic plane as the only spacecraft surveying the environment above and below the poles of the Sun. MORE »


» Cdscc.nasa.gov

- The Canberra Deep Space Communication Complex features a number of antennas that are required daily to receive
from, and transmit information to a wide variety of satellites and other spacecraft flying in space.


The large dish-shaped antennas of the Deep Space Network (DSN) are radio telescopes measuring up to 70 meters in diameter. These huge structures must be pointed to within a small fraction of a degree of a spacecraft's location in the sky in order to be able to receive its downlink. The area of the sky to which the antenna points is no larger than the area seen through a soda straw, so the spacecraft's navigators must publish predictions of where the spacecraft will appear to be in the sky. Then, based on previously developed commands stored on the spacraft, the spacecraft turns to point its 4-meter dish-shaped high-gain antenna toward Earth. The spacecraft's downlink can then be received by the Deep Space Network, and the stored data can be played back.

Once the downlink has been received, the DSN can begin transmitting the uplink at X-band frequency (about 8.5 Ghz) to send commands to provide a reference frequency for the spacecraft to set its downlink for coherent Doppler and carrying out ranging measurements. In carrying out radio science experiments, some DSN stations can uplink at Ka-band frequency (about 32 GHz). The Ka-band uplink forms such a narrow beam that it must be pointed slightly ahead of where the spacecraft is in the sky. Then, by the time the signal has traveled the distance, the spacecraft will have moved into the Ka-band beam, and can receive it. This "leading" the Ka-band uplink pointing is accomplished automatically when needed. MORE »

On the Net:
Articles: A Meeting with the Universe
All Space Shuttle Missions: www.nasa.gov/shuttlemissions

Weatherspace.org

European Space Agency ESA Announces European Mars500 Crew.
By Space News, December 14th, 2008


• ESA: The Exploration of Mars. • Mars Photos


The final four Europeans who are set to take part in a 105-day simulated Mars mission were presented to the media in Paris today (December 11). From March next year, two of the group will join four Russian participants inside an isolation facility in Moscow. After completing a two-month period of training for their mission, two of the group will be chosen as prime crew to join four Russian-selected crewmembers inside the specially designed isolation facility in Moscow. The other two will act as backup crew, stepping in to replace a prime crewmember right up until the last moment if necessary.

During this time they will experience elements of a simulated Mars mission. Their stay is in preparation for the full Mars500 study due to start later in 2009, which will see another six-member crew sealed in the chamber to experience a complete 520-day Mars mission. The purpose of the Mars500 study is to gather data, knowledge and experience to help prepare one day for a real mission to Mars. MORE » • JPL: Next Mars Mission Rescheduled for 2011




- The Shuttle Carrier Aircraft carries Endeavour back to its home base at NASA’s Kennedy Space Center in Florida. MORE
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On the Net:
• JPL: Space Gallery • Space News: www.space.gs
• Space Shuttle and ISS related news: http://weatherspace.org/space-shuttle
• Latest Space and Astronautix News: http://post.space.gs • astrophysics.gsfc.nasa.gov

Space.org

Chandra Observes Effects of Dark Energy on Galaxy Cluster Growth
By Space News, December 16th, 2008

- For the first time, astronomers have clearly seen the effects of ‘dark energy’ on the most massive collapsed objects in the Universe, using the Chandra X-ray Observatory. Putting all of this data together gives us the strongest evidence yet that dark energy is the Cosmological Constant, or in other words, that ‘nothing weighs something’,’ said Vikhlinin. ‘A lot more testing is needed, but so far Einstein’s theory is looking as good as ever.’ These results have consequences for predicting the ultimate fate of the Universe. MORE »


• Solar System Exploration • Web Links


The discovery that the universe is accelerating, not slowing down from the mass it contains, is the surprise that sets the initial research program of 21st Century cosmology. Our quarry is the dark energy, the reasons the universe is accelerating. (more)


• Beyond Einstein

- Newton's theory of gravitation represented a giant leap in the understanding of physics. Similarly, Einstein's General Relativity revolutionized physics two centuries later. By truly understanding what happens at the very edge of a black hole, we may be poised at the threshold of another revolution in physics that will take us Beyond Einstein. » What happens at the edge of a black hole?




- A dramatic new Chandra image of the nearby galaxy Centaurus A provides one of the best views to date of the effects of
an active supermassive black hole. (more) • Origin & Evolution of the Universe • Chandra X-ray Observatory: Images

Astrodev.uchicago.edu/astro

Pierre Auger Cosmic Ray Observatory (AUGER)




Pierre Auger Observatory: Photos - Satellite view


On the vast plain known as the Pampa Amarilla (yellow prairie) in western Argentina, a new window on the universe is taking shape. There, the Pierre Auger Cosmic Ray Observatory is studying the universe's highest energy particles, which shower down on Earth in the form of cosmic rays. While cosmic rays with low to moderate energies are well understood, those with extremely high energies remain mysterious. By detecting and studying these rare particles, the Auger Observatory is tackling the enigmas of their origin and existence.

Cosmic rays are charged particles (usually a proton or a heavy nucleus) that constantly rain down on us from space. When a cosmic ray particle reaches Earth, it collides with a nucleus high in the atmosphere, producing many secondary particles, which share the original primary particle's energy. The secondary particles subsequently collide with other nuclei in the atmosphere, creating a new generation of energetic particles that continue the process, multiplying the total number of particles. The resulting particle cascade, called ''an extensive air shower,'' arrives at ground level with billions of energetic particles extending over an area as large as 10 square miles.





For a detailed exploration of the Southern Observatory using the Google Earth program, visit collaborator Stephane Coutu's website at Penn State University.

The Southern Pierre Auger Observatory covers an area over 3000 km2 in Mendoza province, Argentina, and aims to resolve the mystery of the origin of the highest energy particles in the Universe. Another such array is planned for deployment in the Northern hemisphere, in Colorado, USA. The project utilizes two techniques to detect these extremely rare particles. When they reach the Earth's atmosphere, they generate a cascade of billions of particles which can be detected when they strike the ground with an array of surface detectors. (more)




One of the 1600 cosmic particle detectors of the Observatory: Photos


The Pierre Auger Observatory is exploring the mysteries of the highest-energy cosmic rays — charged particles showering the Earth at energies 10 million times higher than the world’s highest-energy particle accelerator. Until now, there has been no consensus on the origin of these highest-energy cosmic rays. To witness these extremely rare events, the Pierre Auger Collaboration began the construction of its Southern Observatory in the year 2000. The project consists of an array of 1600 detectors spread over 3000 square kilometers in Argentina’s Mendoza Province, just east of the Andes Mountains. Surrounding the array is a set of 24 fluorescence telescopes that view the faint ultraviolet light emitted by the cosmic-ray shower particles as they cascade through the atmosphere. The collaboration includes more than 350 physicists from 70 institutions in 17 countries, which have shared the construction cost of approximately $53 million.

The Pierre Auger collaboration published its first physics results in the fall of 2007, revealing new insights into the properties of the highest-energy particles in the universe. The collaboration found that the arrival directions of the highest-energy cosmic rays are anisotropic. The arrival directions correlate with nearby galaxies that contain actively radiating black holes. Several science organizations selected this remarkable result as one of the most important scientific breakthroughs in 2007.

The collaboration used its growing detector array to measure the cosmic-ray energy spectrum at the highest energies, achieving higher precision than any previous experiment. The Auger scientists found a fall-off of the flux at the highest energies. This is consistent with an idea, proposed about 40 years ago, that cosmic rays interact with photons of the ubiquitous microwave background radiation on their way through the universe. New limits on the photon and neutrino content in cosmic rays have put stringent limits on theories of cosmic-ray origins. The Pierre Auger collaboration includes more than 370 scientists and engineers from 60 institutions in 17 countries. More than 40 funding agencies are contributing to the Pierre Auger Observatory. MORE »
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On the Net:
High Energy Astrophysics
Pierre Auger Observatory (AUGER): http://astrodev.uchicago.edu
Southern P. A. Observatory: www.auger.org - www.auger.org.ar - http://auger.colostate.edu

Chandra X-ray Observatory & Stellar Evolution: http://xrtpub.harvard.edu/edu


• Stellar explosion brightest supernova ever seen • Web links



This graphic gives a summary of the current understanding of the
evolution of stars, showing their birth, middle age, eventual demise.
Credit: NASA/CXC/M.Weiss