Just about anything is possible in our remarkable universe, and it often competes with the imaginings of science fiction writers and filmmakers. Hubble's latest contribution is a striking photo of what looks like a double-bladed lightsaber straight out of the Star Wars films. In the center of the image, partially obscured by a dark, Jedi-like cloak of dust, a newborn star shoots twin jets out into space as a sort of birth announcement to the universe. Gas from a surrounding disk rains down onto the dust-obscured protostar and engorges it. The material is superheated and shoots outward from the star in opposite directions along an uncluttered escape route the star's rotation axis. Much more energetic than a science fiction lightsaber, these narrow energetic beams are blasting across space at over 100,000 miles per hour. This celestial lightsaber does not lie in a galaxy far, far away but rather inside our home galaxy, the Milky Way.
A seismic truck at Point 1 generated wave-like vibrations measured by EN/MME (Image: Sophia Bennett/CERN)
These measurements will help engineers understand how works could impact the LHC’s operation, and will provide crucial details about the site’s geology before construction begins.
The High-Luminosity LHC is a major upgrade to the Large Hadron Collider (LHC) that will increase its discovery potential from 2025.
From R&D into state-of-the-art magnets, to developing innovative, robust material capable of withstanding beam impact, the High-Luminosity LHC is a multi-faceted project involving many teams across CERN.
One of these teams has been mandated to measure vibrations at point 1 of the LHC ring where the ATLAS experiment is installed to see if civil engineering work for the High-Luminosity LHC can begin while the LHC is running. While civil engineering work for the LHC was carried out during Large Electron-Positron collider (LEP) operation, the LHC is much more sensitive to vibrations.
“While the main civil engineering work will, of course, take place during the long shutdown scheduled for July 2018, we would like to identify which parts of it could be carried out during LHC operation,” says Paolo Fessia, who is in charge of the HL-LHC integration. It is a tricky endeavour. Imagine a massive digger pounding away just 40 metres from the beam. Meanwhile, the LHC beam stability would need to remain within the micrometre level, that is, one millionth of a metre.
Could this be feasible?
The team in charge of the study began in an ATLAS tunnel, installing four sensors to measure vibrations in the ground. Further sensors were placed on the surface, and linked to the sensors underground.
“The first vibrations we studied were generated by a core-drilling machine, used to examine the site’s geological make-up,” says Paolo. “This information will be essential for designing and constructing the new underground caverns and technical galleries needed for the HL-LHC, as construction companies need to know exactly what they will find when they dig (hard rock, sand, water, etc.). While this is the main purpose of the drilling, it has also been used to study the effect of pulsed vibrations.”
A few days later, the seismic truck arrived. This unique, 24-tonne machine uses its entire weight to push down on the ground, generating wave-like vibrations up to 100 times per second.
“We created waves with a wide range of frequencies and looked at their attenuation,” says Michael Guinchard, who is in charge of the mechanical measurement lab. Measurements were also taken with the LHC beam and will provide a valuable data set for more detailed analysis.
So, while the HL-LHC is still many years away from operation, its impact on the LHC can already be felt… in this case, quite literally.
Earth's annual Geminid meteor shower did not disappoint, peaking before dawn on December 14 as our fair planet plowed through dust from active asteroid 3200 Phaethon. Captured in this southern hemisphere nightscape the meteors stream away from the shower's radiant in Gemini. To create the image, many individual frames recording meteor streaks were taken over period of 5 hours. In the final composite they were selected and registered against the starry sky above the twin 6.5 meter Magellan telescopes of Carnegie Las Campanas Observatory in Chile. Rigel in Orion, and Sirius shine brightly as the Milky Way stretches toward the zenith. Near Castor and Pollux the twin stars of Gemini, the meteor shower's radiant is low, close to the horizon. The radiant effect is due to perspective as the parallel meteor tracks appear to converge in the distance. Gemini's meteors enter Earth's atmosphere traveling at about 22 kilometers per second.
The next great space observatory took a step closer this week when ESA signed the contract with Arianespace that will see the James Webb Space Telescope launched on an Ariane 5 rocket from Europe’s Spaceport in Kourou in October 2018.
Euclid, ESA’s dark Universe mission, has passed its preliminary design review, providing confidence that the spacecraft and its payload can be built. It’s time to start ‘cutting metal’.
