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Monthly Archives: October 2013

A journey across the Red Planet – movie

From the highest volcano to the deepest canyon, from impact craters to ancient river beds and lava flows, a new showcase of images from ESA’s Mars Express takes you on an unforgettable journey across the Red Planet.

Credit: Medialab, ESA 2001

Mars Express was launched in June 2003 and arrived at Mars six-and-a-half months later. It has since orbited the planet nearly 12,500 times, providing scientists with unprecedented images and data collected by its suite of scientific instruments.

The data have been used to create an almost global digital topographic model of the surface, providing a unique visualization and enabling researchers to acquire new and surprising information about the evolution of the Red Planet.

The images in this movie were taken by the High Resolution Stereo Camera and it was released by DLR, the German Aerospace Center as part of the ‘10 years of Mars Express celebrations’ in June 2013. Credits :ESA/DLR/FU Berlin (G. Neukum).

Titan: a land of lakes

A newly released image of Titan, Saturn’s largest moon reveals details of seas or lakes near its northern pole.

Credit: NASA/JPL-Caltech/U. Arizona/U. Idaho

The false-color mosaic, made from infrared data collected by NASA’s Cassini spacecraft, reveals the differences in the composition of surface materials around these hydrocarbon lakes. Titan is the only other place in the Solar System that we know has stable liquid on its surface – but its lakes are made of liquid ethane and methane rather than liquid water. While there is one large lake and a few smaller ones near Titan’s south pole, almost all of Titan’s lakes appear near the moon’s north pole.

The image data suggest parts of Titan’s lakes and seas may have evaporated and left behind the Titan equivalent of Earth’s salt flats. They appear orange in this image against the greenish backdrop of Titan’s typical bedrock of water ice.

Launched in 1997, Cassini has been exploring the Saturn system since 2004. A full Saturn year is 30 years, and Cassini has been able to observe nearly a third of a Saturn year. In that time, Saturn and its moons have seen the seasons change from northern winter to northern summer.
Links: press release from Cassini imaging team; annotated image from NASA’s Cassini mission homepage.

IRIS: Looking deep into the Sun’s atmosphere

Earlier this year, NASA’s Interface Region Imaging Spectrograph (IRIS) spacecraft captured its first observations of a region of the Sun that is now possible to observe in detail: the lowest layers of the Sun’s atmosphere, the solar interface region.

Credit: NASA Goddard

The first images from IRIS show the solar interface region in unprecedented detail. They reveal dynamic magnetic structures and flows of material in the Sun’s atmosphere and hint at tremendous amounts of energy transfer through this little-understood region. These features may help power the Sun’s dynamic million-degree atmosphere and drive the solar wind that streams out to fill the entire Solar System.

The energy flowing through the interface region powers the upper layer of the Sun’s atmosphere, the corona, to temperatures greater than 1.8 million degrees Fahrenheit (1 million K). That is almost a thousand times hotter than the Sun’s surface. Understanding the interface region is important because it drives the solar wind and forms the ultraviolet emission that impacts near-Earth space and Earth’s climate.

IRIS is a NASA Small Explorer mission that was launched on June 27, 2013. Its instrument is a combination of an ultraviolet telescope and a spectrograph.

Links: NASA press release and IRIS mission homepage.

A particle accelerator in heart of the Van Allen radiation belts

Using data from NASA’s Van Allen Probes, scientists have discovered a massive particle accelerator in the heart of one of the harshest regions of near-Earth space, the super-energetic, charged particles surrounding the globe known as the Van Allen radiation belts.

Credit: NASA/Van Allen Probes/Goddard Space Flight Center

Local bumps of energy kick particles inside the belts to ever-faster speeds, much like a well-timed push on a moving swing. Knowing the location of the acceleration within the radiation belts will help scientists improve predictions of space weather, which can be hazardous to satellites near Earth. The results were published earlier this year in the journal Science.

The twin Van Allen Probes fly straight through this intense area of space. By taking simultaneous measurements with their instruments, the satellites were able to distinguish between two broad possibilities of what accelerates the particles to such amazing speeds, deducing that the particles are undergoing local acceleration, rather than radial acceleration.

The data showed an increase in energy that started right in the middle of the radiation belts and gradually spread both inward and outward, which implies a local acceleration source. The research shows this local energy comes from electromagnetic waves coursing through the belts, tapping energy from other particles residing in the same region of space.

The challenge for scientists now is to determine which waves are at work. The Van Allen Probes, which are designed to measure and distinguish between many types of electromagnetic waves, will tackle this task, too.

Links: NASA press release and Van Allen Probes mission page.

NRAO’s Jansky Very Large Array – movie

The National Radio Astronomy Observatory has released a new video about the Karl G. Jansky Very Large Array (VLA), narrated by actress Jodie Foster, for their Visitor Center near Socorro, New Mexico. (See Section 3.8d and Section 15.4.)

Credit: Wikipedia

Credit: Wikipedia

Called Beyond the Visible, the 24-minute movie tells the behind-the-scenes story of the operation and scientific achievements of the VLA, which has been at the forefront of astrophysical research since 1980. Spectacular ground and aerial footage of the iconic radio telescope is augmented by first-person interviews with staffers who keep the telescope working and scientists who use it to discover exciting new facts about the Universe. The documentary also depicts many of the technical tasks needed to keep the array functioning at the forefront of science.

Links: The NRAO has made the video available for viewing online here. An earlier movie “Into Deepest Space” tells the story of the Atacama Large Millimeter/submillimeter Array (ALMA).

François Englert and Peter Higgs awarded the 2013 Nobel Prize in Physics

François Englert and Peter W. Higgs have been awarded the 2013 Nobel Prize in Physics “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, at CERN’s Large Hadron Collider.” The announcement by the ATLAS and CMS experiments took place on July 4 last year. (See Figure 19-15, p. 523.)

DSCN4110

Credit: Vince Higgs

The Brout-Englert-Higgs (BEH) mechanism was first proposed in 1964 in two papers published independently, the first by Belgian physicists Robert Brout (now deceased) and François Englert, and the second by British physicist Peter Higgs. Among other things, it explains the mechanism that endows fundamental particles with mass. A third paper by Americans Gerald Guralnik and Carl Hagen with their British colleague Tom Kibble contributed to the development of the new idea, which now forms an essential part of the Standard Model of particle physics. As was pointed out by Higgs, a key prediction of the idea is the existence of a massive particle of a new type, dubbed the Higgs boson, which was discovered by the ATLAS and CMS experiments at CERN in 2012.

The Standard Model describes the fundamental particles from which we, and all the visible matter in the Universe, are made, along with the interactions that govern their behavior. It’s a remarkably successful theory that has been thoroughly tested by experiment over many years. Until last year, the BEH mechanism was the last remaining piece of the model to be experimentally verified. Now that the Higgs has been found, experiments at CERN are eagerly looking for physics “beyond the Standard Model”.

Links: the CERN press release, a Higgs boson poster courtesy of the Institute of Physics; an introductory cartoon explaining the Higgs field, courtesy of the New York Times; and Sean Carroll’s op-ed article, also in the New York Times.