Physics & Astronomy News

<p>Mars’ Valles Marineris canyon, pictured, spans as much as 600 kilometers across and delves as much as 8 kilometers deep. The image was created from over 100 images of Mars taken by Viking Orbiters in the 1970s.</p>

<p>Image: NASA</p>

New Technique May Help Detect Martian Life
A novel interpretation of Raman spectra will help the 2020 Mars rover select rocks to study for signs of life.

<p>Simplification to represent PT (Parity-Time) symmetry. Imagine a situation where two cars are traveling at the same speed at some instant in time, but car A is speeding up, and car B is slowing down. In order to go at the same speed, you can jump from one car to the other (Parity reversal) and back in time (Time reversal). The cars are like the light waves inside the fiber, the speed of the cars is a representation of the intensity of light and the jump symbolizes a phenomenon called tunneling. (Graphics modified from freepiks).</p>

Stable Propagation of Light in Nano-Photonic Fibers
New model on how to achieve a more stable propagation of light for future optical technologies was published.

<p>Regime of a single 1D wire subband filled</p>

<p>Credit: Dr Maria Moreno</p>

Quantum Effects Observed in ‘One-Dimensional’ Wires
Researchers have observed quantum effects in electrons by squeezing them into one-dimensional ‘quantum wires’ and observing the interactions between them.

<p>This illustration shows a glowing stream of material from a star as it is being devoured by a supermassive black hole in a tidal disruption flare.</p>

<p>When a star passes within a certain distance of a black hole -- close enough to be gravitationally disrupted -- the stellar material gets stretched and compressed as it falls into the black hole. In the process of being accreted, the gas heats up and creates a lot of optical and ultraviolet light, which destroys nearby dust but merely heats dust further out. The farther dust that is heated emits a large amount of infrared light. In recent years, a few dozen such flares have been discovered, but they are not well understood.</p>

<p>Astronomers gained new insights into tidal disruption flares thanks to data from NASA's Wide-field Infrared Survey Explorer (WISE). Studies using WISE data characterized tidal disruption flares by studying how surrounding dust absorbs and re-emits their light, like echoes. This approach allowed scientists to measure the energy of flares from stellar tidal disruption events more precisely than ever before.</p>

<p>JPL manages and operates WISE for NASA's Science Mission Directorate in Washington. The spacecraft was put into hibernation mode in 2011, after it scanned the entire sky twice, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.</p>

<p>Image credit: NASA/JPL-Caltech</p>

Echoes of Black Holes Eating Stars Found
Astronomers now have new insights into tidal disruption flares, thanks to data from NASA's Wide-field Infrared Survey Explorer (WISE).

Individual Atoms Behavior Observed
For first time, researchers see individual atoms keep away from each other or bunch up as pairs.

Gaia’s First Sky Map
The first catalogue of more than a billion stars from ESA’s Gaia satellite was published – the largest all-sky survey of celestial objects to date.

Attosecond Science opens new Avenues in Femtochemistry
Attosecond Science is a new exciting frontier in contemporary physics, aimed at time-resolving the motion of electrons in atoms, molecules and solids on their natural timescale.

Science Facts

The Strange Spires of Callisto

by NASA Marshall Space Flight Center and ScienceIQ.com

Bright scars on a darker surface testify to a long history of impacts on Jupiter

When NASA's adventurous Galileo spacecraft skimmed a mere 138 km, (123 miles) above the surface of Jupiter's moon Callisto, onboard cameras captured the sharpest pictures ever of that moon's mysterious landscape. Scientists have since examined the images, and what they found is surprising. Callisto is peppered with strange icy features -- spires that seem to be slowly eroding on a world long considered changeless and dead.

Callisto's icy surface is the most heavily cratered place in the Solar System. There are no volcanoes or winds and rain to obliterate landforms. So, craters that form as the result of occasional impacts with meteorites are very long-lasting. Planetary scientists call terrains like Callisto's 'old.' Earth's much-weathered surface, on the other hand, is very 'young.' For billions of years, little has changed on Callisto other than the relentless accumulation of craters -- or so researchers thought. During the Callisto flyby, Galileo's camera saw spire-like 'knobs' jutting 80 to 100 meters (260 to 330 feet) high, consisting perhaps of material thrown outward from a major impact billions of years ago. The knobs are very icy, but they also harbor some darker dust. The dark material seems to be sliding down the knobs and collecting in low-lying areas.

The eroding spires of Callisto are just one of the moon's riddles. Indeed, with a diameter of 4,800 km, (2982 miles) -- nearly the size of Mercury -- Callisto is a bona fide world of its own with mysteries befitting a full-fledged planet.

A solar flare with an eruptive prominence on the limb of the sun.

Is There Weather In Space?

Space weather occurs in the area between the Earth and the Sun and refers to the disturbances and storms that swirl through space, which could have adverse effects on human activities. These disturban ...
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N81

NASA's Hubble Space Telescope has taken a 'family portrait' of young, ultra-bright stars nested in their embryonic cloud of glowing gases. The celestial maternity ward, called N81, is located 200,000 ...
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Sonic Boom

They sound like thunder, but they're not. They're sonic booms, concentrated blasts of sound waves created as vehicles travel faster than the speed of sound. To understand how the booms are created, lo ...
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Science Quote

'The most precious things in life are not those one gets for money.'

Albert Einstein
(1879-1955)