May 15, 2015
An artist's impression of a 'super-impact,' in which a very large asteroid, about 800km in diameter, strikes the Earth. Image courtesy of NASA/Science Photo Library.
A major incident during the Syrian civil war is helping to pin down the seismic signature of distant bombs.
Although seismologists have long monitored nuclear explosions, any nuclear tests since 1980 have taken place underground. Measurements of smaller, conventional explosions on or near the surface are relatively rare.
Accurate models of such blasts could help interpret seismic readings and allow rescuers to deal with incidents in war zones or industrial accidents. "Knowing the yield and depth of large, shallow explosions is useful to government agencies from an emergency response perspective," says Michael Pasyanos of Lawrence Livermore National Laboratory.
Working with colleague Sean Ford, Pasyanos added a dampening effect to existing models to account for how shallow seismic waves are weakened when they pass from the ground into the air. To do this, they used data from controlled explosions at the U.S. Army White Sands Missile Range in New Mexico.
This image shows the remnant of Supernova 1987A, seen in light of very different wavelengths. Data (in red) shows newly formed dust in the center of the remnant. Credit: ALMA (ESO/NAOJ/NRAO)/A. Angelich/Hubble Space Telescope/Chandra X-Ray Observatory
New results from the NASA NuSTAR telescope show that a supernova close to our galaxy experienced a single-sided explosion.
A team of scientists including Lawrence Livermore researchers found that X-ray emissions taken with the Nuclear Spectroscopic Telescope Array (NuSTAR) show that the Supernova 1987A explosion was highly asymmetric. NuSTAR observations, including those of 1987A, provide strong and compelling observational evidence that supernovae are not symmetric.
Supernova 1987A in the Large Magellanic Cloud provides a unique opportunity to study a nearby (170,000 light years) core collapse supernova explosion and its subsequent evolution into a supernova remnant.
Steve Yakuma holds the remains of a ripped heavy duty tie-down, evidence of the powerful South Pacific storm the team encountered aboard a U.S. Navy ship. Photo by Jeff Bonivert/LLNL
Despite heavy storms and rough seas, a Lawrence Livermore team captured critical missile flight data during a mission off of Saipan in the South Pacific.
ICBM test flights are regularly launched from Vandenberg Air Force Base to a target location in the southern Pacific Ocean, where diagnostics-laden rafts are deployed to record the data from the missile splash.
Livermore researchers were responsible for verifying the performance of the instrumented reentry vehicles employed in these two tests, using the LLNL Independent Diagnostics Scoring System (LIDSS). Designed, fabricated and fielded by an LLNL team, the LIDSS data acquisition systems collect data from flight test reentry vehicles landing in the deep ocean. The systems include high-speed cameras and video cameras, neutron detectors and hydrophones installed on more than a dozen raft-mounted, GPS-controlled sensor platforms.
NIF’s 192 laser beams converge at the center of this giant sphere to make the tiny hydrogen fuel pellet implode. Image by Damien Jemison.
Most nuclear power plants around the globe currently work via a process called nuclear fission. This involves splitting up large atoms into smaller parts and harvesting the vast amounts of energy that are produced in the process.
But what if there was an alternative method of generating similar amounts of energy, without any of the negative consequences?
Scientists at the National Ignition Facility (NIF) believe they may have passed a milestone in nuclear fusion development. In November 2013, the team at NIF successfully used the strongest laser known to man to fuse hydrogen atoms, and although the energy yield still did not outweigh that which was expended upon the process, the team believe this was more due to inefficiencies in the technique, rather than the technique itself.
It is hoped that once these inefficiencies are ironed out, fusion ignition will be one step closer to reality.
Lawrence Livermore researchers have made graphene aerogel microlattices with an engineered architecture via a 3D printing technique. Illustration by Ryan Chen/LLNL
Researchers have printed inks containing nanoscopic graphene flakes to build macroscopic, three-dimensional objects that could benefit numerous fields, including energy storage and bioengineering.
A team at Lawrence Livermore National Laboratory has 3-D printed porous, highly compressible aerogels using a graphene oxide ink.
This is not the first example of graphene inks. However, scientists are still searching for formulations that fully capitalize on the atomically thin material’s remarkable properties. For example, some existing inks sacrifice mechanical properties for high electrical conductivity.
“We were really trying to avoid making compromises,” says Marcus Worsley, who, along with his colleague Chen Zhu, led the Livermore researchers. Their goal was to devise a 3-D printing process that allowed conductive flakes to controllably coalesce and ultimately form aerogels: spongelike materials that are about as light as air yet mechanically robust.