“DARK MATTER CAPTURED IN FIRST-EVER…

“DARK MATTER CAPTURED IN FIRST-EVER PHOTO”

 Astronomers at the University of Waterloo in Canada have produced what they say is the first ever composite image of a dark matter filament that connects galaxies together. Making up around 27 percent of the universe, dark matter is a substance that has eluded the eyes of astronomers for a long time due to it being almost virtually impossible to detect (it does not give off, reflect or absorb light).
 In their work, Mike Hudson and co-author Seth Epps, a professor of astronomy and a master’s student respectively at Waterloo, employed a technique called weak gravitational lensing – tiny measurements of the slight bends that occur when light passes near a mass – to capture the photo. This effect had produced photos of galaxies that appeared slightly warped – all due to the presence of dark matter.
 By taking a catalogue full of galaxy cluster pairs that were lensed and another catalogue full of background source galaxies, the duo ‘stacked’ more than 23,000 pairs to create a composite image that showed the presence of dark matter between galaxies.
 “By using this technique, we’re not only able to see that these dark matter filaments in the universe exist, we’re able to see the extent to which these filaments connect galaxies together,“ Epps said in a statement.

Read more about this fascinating story at: http://www.space.com/36495-astronomers-capture-the-first-image-of-the-dark-matter-that-holds-the-universe-together.html

Cassini Looks on as Solstice Arrives at Saturn NASA’s…

Cassini Looks on as Solstice Arrives at Saturn

NASA’s Cassini spacecraft still has a few months to go before it completes its mission in September, but the veteran Saturn explorer reaches a new milestone today. Saturn’s solstice – that is, the longest day of summer in the northern hemisphere and the shortest day of winter in the southern hemisphere – arrives today for the planet and its moons. The Saturnian solstice occurs about every 15 Earth years as the planet and its entourage slowly orbit the sun, with the north and south hemispheres alternating their roles as the summer and winter poles.

Reaching the solstice, and observing seasonal changes in the Saturn system along the way, was a primary goal of Cassini’s Solstice Mission – the name of Cassini’s second extended mission.

Read more at: NASA

ASTRONOMY & ASTROPHYSICS