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<p>This map of dark matter in the Universe was obtained from data from the KiDS survey, using the VLT Survey Telescope at ESO’s Paranal Observatory in Chile. It reveals an expansive web of dense (light) and empty (dark) regions. This image is one out of five patches of the sky observed by KiDS. Here the invisible dark matter is seen rendered in pink, covering an area of sky around 420 times the size of the full moon. This image reconstruction was made by analysing the light collected from over three million distant galaxies more than 6 billion light-years away. The observed galaxy images were warped by the gravitational pull of dark matter as the light travelled through the Universe.</p>

<p>Some small dark regions, with sharp boundaries, appear in this image. They are the locations of bright stars and other nearby objects that get in the way of the observations of more distant galaxies and are hence masked out in these maps as no weak-lensing signal can be measured in these areas.</p>

<p>Credit:</p>

<p>Kilo-Degree Survey Collaboration/H. Hildebrandt & B. Giblin/ESO</p>
Dark Matter May be Smoother than Expected
Analysis of a giant new galaxy survey suggests that dark matter may be less dense and more smoothly distributed throughout space than previously thought.
<p>Interference pattern created by neutron holography.</p>

<p>Credit:</p>

<p>NIST</p>
Holograms from Neutrons Created
For the first time, scientists have used neutron beams to create holograms of large solid objects, revealing details about their interiors in ways that ordinary laser light-based visual holograms cannot.

<p>An artist’s conception of this unusual system, courtesy of Jonathan Holden/Disk Detective.</p>
Oldest Known Planet-Forming Disk Found
Scientists find a star surrounded by the oldest known circumstellar disk—a primordial ring of gas and dust that orbits around a young star and from which planets can form.
<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.


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.
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.
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).

Science Facts

An Old Science Experiment On The Moon

by NASA Marshall Space Flight Center and ScienceIQ.com

The Apollo 11 lunar laser ranging retroreflector array.: Image Courtesy NASA The most famous thing Neil Armstrong left on the moon 35 years ago is a footprint, a boot-shaped depression in the gray moondust. Millions of people have seen pictures of it, and one day, years from now, lunar tourists will flock to the Sea of Tranquility to see it in person. Peering over the rails ... 'hey, mom, is that the first one?' Will anyone notice, 100 feet away, something else Armstrong left behind? Ringed by footprints, sitting in the moondust, lies a 2-foot wide panel studded with 100 mirrors pointing at Earth: the 'lunar laser ranging retroreflector array.' Apollo 11 astronauts Buzz Aldrin and Neil Armstrong put it there on July 21, 1969, about an hour before the end of their final moonwalk. Thirty-five years later, it's the only Apollo science experiment still running.

University of Maryland physics professor Carroll Alley was the project's principal investigator during the Apollo years, and he follows its progress today. 'Using these mirrors,' explains Alley, 'we can 'ping' the moon with laser pulses and measure the Earth-moon distance very precisely. This is a wonderful way to learn about the moon's orbit and to test theories of gravity.' Here's how it works: A laser pulse shoots out of a telescope on Earth, crosses the Earth-moon divide, and hits the array. Because the mirrors are 'corner-cube reflectors,' they send the pulse straight back where it came from. 'It's like hitting a ball into the corner of a squash court,' explains Alley. Back on Earth, telescopes intercept the returning pulse--'usually just a single photon,' he marvels. The round-trip travel time pinpoints the moon's distance with staggering precision: better than a few centimeters out of 385,000 km, typically.

Targeting the mirrors and catching their faint reflections is a challenge, but astronomers have been doing it for 35 years. A key observing site is the McDonald Observatory in Texas where a 0.7 meter telescope regularly pings reflectors in the Sea of Tranquility (Apollo 11), at Fra Mauro (Apollo 14) and Hadley Rille (Apollo 15), and, sometimes, in the Sea of Serenity. In this way, for decades, researchers have carefully traced the moon's orbit, and they've learned some remarkable things, among them: (1) The moon is spiraling away from Earth at a rate of 3.8 cm per year. Why? Earth's ocean tides are responsible. (2) The moon probably has a liquid core. (3) The universal force of gravity is very stable. Newton's gravitational constant G has changed less than 1 part in 100-billion since the laser experiments began.



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Ancient Planet

Long before our Sun and Earth ever existed, a Jupiter-sized planet formed around a sun-like star. Now, almost 13 billion years later, NASA's Hubble Space Telescope has precisely measured the mass of t ...
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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

'Beauty is a harmonious relation between something in our nature and the quality of the object which delights us.'

Blaise Pascal
(1623-1662)


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