CERN Open Data Portal: LHC experiments open to the Public

The web-based CMS event display, accessible through the CERN Open Data Portal, shows a proton-collision event recorded by the CMS detector. 

Credit: CMS /Open Data Portal

CERN today launched its Open Data Portal where data from real collision events, produced by experiments at the Large Hadron Collider (LHC) will for the first time be made openly available to all.

It is expected that these data will be of high value for the research community, and also be used for education purposes.

"Launching the CERN Open Data Portal is an important step for our Organization. Data from the LHC programme are among the most precious assets of the LHC experiments, that today we start sharing openly with the world."

"We hope these open data will support and inspire the global research community, including students and citizen scientists," says CERN Director-General Rolf Heuer.

The principle of openness is enshrined in CERN's founding Convention, and all LHC publications have been published Open Access, free for all to read and re-use.

Widening the scope, the LHC collaborations recently approved Open Data policies and will release collision data over the coming years.

The first high-level and analysable collision data openly released come from the CMS experiment and were originally collected in 2010 during the first LHC run.

This data set is now publicly available on the CERN Open Data Portal. Open source software to read and analyse the data is also available, together with the corresponding documentation.

The CMS collaboration is committed to releasing its data three years after collection, after they have been thoroughly studied by the collaboration.

"This is all new and we are curious to see how the data will be re-used," says CMS data preservation coordinator Kati Lassila-Perini.

"We've prepared tools and examples of different levels of complexity from simplified analysis to ready-to-use online applications. We hope these examples will stimulate the creativity of external users."

In parallel, the CERN Open Data Portal gives access to additional event data sets from the ALICE, ATLAS, CMS and LHCb collaborations, which have been specifically prepared for educational purposes, such as the international masterclasses in particle physics benefiting over ten thousand high-school students every year. These resources are accompanied by visualisation tools.

"Our own data policy foresees data preservation and its sharing. We have seen that students are fascinated by being able to analyse LHC data in the past and so, we are very happy to take the first steps and make available some selected data for education" says Silvia Amerio, data preservation coordinator of the LHCb experiment.

"The development of this Open Data Portal represents a first milestone in our mission to serve our users in preserving and sharing their research materials. It will ensure that the data and tools can be accessed and used, now and in the future," says Tim Smith of the CERN IT Department.

All data on OpenData.cern.ch are shared under a Creative Commons CC0 public domain dedication; data and software are assigned unique DOI identifiers to make them citable in scientific articles; and software is released under open source licenses.

The CERN Open Data Portal is built on the open-source Invenio Digital Library software, which powers other CERN Open Science tools and initiatives.

NASA ICESat-2 satellite Box structure under construction

An engineer checks ICESat-2's box structure, shortly after its arrival in a NASA clean room in May. 

Over the next two years, engineers and technicians will attach electronics, optics, lasers, a telescope and more to the box, testing its function at each step. 

Credit: NASA's Goddard Space Flight Center /Kate Ramsayer

To build a satellite that will measure all the bumps and dips of our dynamic Earth, engineers started with a black box, built of a composite honeycomb material to make it as light as possible.

The structure was precisely manufactured with an opening to allow lasers to beam to Earth, and other windows sized for a telescope that will capture photons that bounce off our planet and return to the satellite.

The box was measured and marked to denote where the assembly of aligned mirrors, electronics, lasers and photon detectors would be attached.

It must be tough enough to handle the rigors of a rocket launch and years in a harsh space environment; here on Earth, the box structure must be hardy enough to withstand tests engineers use to simulate those conditions.


The box structure at the core of the Ice, Cloud and land Elevation Satellite-2 (ICESat-2), instrument was delivered to a clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland, in May.

A team of 250 engineers, fabricators and scientists has now started the official integration and testing stage of the laser instrument.

"There's lots of activity, we're moving from looking at all the different subsystems, to looking at the overall system coming together."

"It's really exciting to move forward into that realm," said Cathy Richardson, instrument manager with the ICESat-2 mission. The team will have a half-dozen components ready for delivery in June.

"It's not just a drawing. It's an actual, real piece of hardware, that's getting tested and showing that it's meeting requirements."



ATLAS Assembly
ICESat-2's instrument, called the Advanced Topographic Laser Altimeter System (ATLAS), will measure the elevation of Earth's surfaces, from ice sheets to forests to oceans.

Its six beams will generate a more detailed elevation portrait than single beam of original ICESat-2, which flew from 2003 to 2009, and with the beams paired, scientists will be able to measure surface slope and better calculate height changes.

To measure elevation, ATLAS beams light with a green laser that pulses 10,000 times a second. Only a few photons will bounce off the surface and return to the satellite, but an incredibly sensitive detector counts those that do come back.

Using the time of the photons' return trip, the speed of light and some geometry, scientists can determine the distance the photons traveled and, therefore, the height of Earth below the satellite's orbit.

ATLAS will provide scientists with measurements that create a global portrait of Earth's elevation, and will gather data that can precisely track change, including melting glaciers and thinning sea ice.

Credits: Satellite image courtesy of Orbital Earth image illustrating AMSR-E sea ice courtesy of the NASA Scientific Visualization Studio

"ICESat-2 will revolutionize our understanding of ice sheet and sea ice changes and processes," said Thorsten Markus, ICESat-2 project scientist.

"I think it's one of the most exciting missions out there. There's so much opportunity for real discoveries."

The satellite will observe Earth in a new way, he said, which makes it technically challenging. But this also opens the door for discoveries not yet imagined.

After years of calculations and computer models and discussions, Markus said, it's exciting to see the hardware come together.

NASA MABEL: Laser Lidar technology reveals how ice measures up

NASA's Multiple Altimeter Beam Experimental Lidar flew over Southwest Greenland's glaciers and sea ice to test a new method of measuring the height of Earth from space. 

Credit: NASA/Tim Williams

New results from NASA's MABEL campaign demonstrated that a photon-counting technique will allow researchers to track the melt or growth of Earth's frozen regions.

When a high-altitude aircraft flew over the icy Arctic Ocean and the snow-covered terrain of Greenland in April 2012, it was the first polar test of a new laser-based technology to measure the height of Earth from space.

Aboard that aircraft flew the Multiple Altimeter Beam Experimental Lidar (MABEL), which is an airborne test bed instrument for NASA's ICESat-2 satellite mission slated to launch in 2017.

Both MABEL and ICESat-2's ATLAS instrument are photon counters – they send out pulses of green laser light and time how long it takes individual light photons to bounce off Earth's surface and return.

ICESat-2's ATLAS instrument

That time, along with ATLAS' exact position from an onboard GPS, will be plugged into computer programs to tell researchers the elevation of Earth's surface – measuring change to as little as the width of a pencil.

This kind of photon-counting technology is novel for satellites; from 2003 to 2009, ICESat-1's instrument looked at the intensity of a returned laser signal, which included many photons.

So getting individual photon data from MABEL helps scientists prepare for the vast amounts of elevation data they'll get from ICESat-2.

"Using the individual photons to measure surface elevation is a really new thing," said Ron Kwok, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"It's never been done from orbiting satellites, and it hasn't really been done much with airborne instruments, either."

Ron Kwok

ICESat-2 is tasked with measuring elevation across Earth's entire surface, including vegetation and oceans, but with a focus on change in the frozen areas of the planet, where scientists have observed dramatic impacts from climate change.

There, two types of ice – ice sheets and sea ice – reflect light photons in different patterns.

Ice sheets and glaciers are found on land, like Greenland and Antarctica, and are formed as frozen snow and rain accumulates.

Sea ice, on the other hand, is frozen seawater, found floating in the Arctic Ocean and offshore of Antarctica.

MABEL's 2012 Greenland campaign was designed to observe a range of interesting icy features, said Bill Cooke, MABEL's lead scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

With the photon counts from different surfaces, other scientists could start analyzing the data to determine which methods of analyzing the data allow them to best measure the elevation of Earth's surface.

MABEL, short for "Multiple Altimeter Beam Experimental Lidar," serves as an ICESat-2 simulator. 

Credit: NASA /Kelly Brunt

"We wanted to get a wide variety of target types, so that the science team would have a lot of data to develop algorithms," Cooke said.

"This was our first real dedicated science mission."

The flights over the ocean near Greenland, for example, allowed researchers to demonstrate that they can measure the height difference between open water and sea ice, which is key to determining the ice thickness.

MABEL can detect enough of the laser light photons that bounce off Earth surface and return to the instrument, and programs can then make necessary elevation calculations, Cooke said.

Bill Cooke

"Part of what we're doing with MABEL is to demonstrate ICESat-2's instrument is going to have the right sensitivity to do the measurements," Cooke said. "You can do this photon counting if you have enough photons."

In an article recently published in the Journal of Atmospheric and Oceanic Technology, Kwok and his colleagues showed how to calculate elevation from MABEL data, and do so over different types of ice – from open water, to thin, glassy ice, to the snow-covered ice.

CERN ATLAS experiment: Higgs boson decays to two tau particles

The ATLAS detector, open during a recent technical stop. 

Credit: Maximilien Brice /CERN

The ATLAS experiment at CERN has released preliminary results that show evidence that the Higgs boson decays to two tau particles.

Taus belong to a group of subatomic particles called the fermions, which make up matter.

This result – measured at 4.1 sigma on the 5-point scale particle physicists use to determine the certainty of a result – is the first evidence for a Higgs decay to fermions.

On 4 July 2012, the ATLAS and CMS experiments at CERN announced the discovery of a new particle, which was later confirmed to be a Higgs boson.

For physicists, the discovery meant the beginning of a quest to find out what the new particle was, if it fit in the Standard Model, our current model of nature in particle physics, or if its properties could point to new physics beyond that model.

An important property of the Higgs boson that ATLAS physicists are trying to measure is how it decays.

The Higgs boson lives only for a short time and disintegrates into other particles. The various possibilities of the final states are called decay modes.

So far, ATLAS physicists had found evidence that the Higgs boson decays into different types of gauge bosons - the kind of elementary particles that carry forces.

The other family of fundamental particles, the fermions, make up matter. The tau is a fermion and behaves like a very massive electron.

Graphical representation of a Higgs boson decaying to two tau particles in the ATLAS detector. 

The taus decay into an electron (blue line) and a muon (red line) 

Credit: ATLAS

The Brout-Englert-Higgs mechanism was first proposed to describe how gauge bosons acquire mass but the Standard Model predicts that fermions also acquire mass in this manner, so the Higgs boson could decay directly to either bosons or fermions.

The new preliminary result from ATLAS shows clear evidence that the Higgs boson indeed does decay to fermions, consistent with the rate predicted by the Standard Model.

This important finding was made possible through careful analysis of data produced by the LHC during its first run.

Only with new data will physicists be able to determine if the compatibility remains or if other new models become viable.

Fortunately, the next LHC run, which begins in 2015, is expected to produce several times the existing data sample. In addition, the proton collisions will be at higher energies, producing Higgs bosons at higher rates.

Advanced Humanoid 'Atlas' Robot Unveiled - Video

Boston Dynamics developed the robot for DARPA. It will compete in the DARPA Robotics Challenge Trials at the Homestead-Miami Speedway in December 2013. 

Advancing the technology to assist humans in disaster response is the goal.

NEO Asteroid Detection: NASA's Arecibo now and ATLAS in the future

Arecibo Radio Telescope

The NEO program at NASA currently detects and tracks Earth-approaching asteroids and comets with land-based and orbiting telescopes. Scientists estimate their mass and orbit to gauge whether they pose a danger.

With this system, the Arecibo radio telescope in Puerto Rico, which has an antenna 305 meters in diameter, can observe with great sensitivity a third of the night sky and detect asteroids that are on the large side.

All asteroid observations made anywhere in the world by telescopes, even by amateur star gazers, must be passed on to the Minor Planet Center, which is financed by NASA and run by the Smithsonian Astrophysical Observatory for the Paris-based International Astronomical Union.

But in times of tight budgets like these, NASA is trying to develop other systems specifically capable of tracking small objects in space.

NASA is financing to the tune of $5 million a project at the University of Hawaii called Atlas, or Asteroid Terrestrial-Impact Alert System.

Researchers say ATLAS, which will monitor the entire visible sky every night, will be able to detect objects 45 meters (yards) in diameter a week before they hit our planet.

For those measuring 150 meters (yards) in diameter, the system -- which could be operational in late 2015 -- will give a three week heads up.

The goal is to find the objects and give enough advance warning for measures to be taken to protect people, said John Tonry, the principal investigator at ATLAS.

The system has enough sensitivity to detect a match flame in New York City when viewed from San Francisco, for instance.

"That's enough time to evacuate the area of people, take measures to protect buildings and other infrastructures and be alert to a tsunami danger generated by ocean impacts," according to the ATLAS website.

ATLAS will complement the Institute for Astronomy’s Pan-STARRS project, a system that searches for large “killer asteroids” years, decades, and even centuries before impact with Earth.

Whereas Pan-STARRS takes a month to complete one sweep of the sky in a deep but narrow survey, ATLAS will search the sky in a closer and wider path to help identify the smaller asteroids that hit Earth more frequently.