An ancient globule

This image captures the stunning NGC 6535, a globular cluster 22 000 light-years away in the constellation of Serpens (The Serpent) that measures one light-year across.

NGC 6535 was first discovered in 1852 by English astronomer John Russell Hind. The cluster would have appeared to Hind as a small, faint smudge through his telescope. Now, over 160 years later, instruments like the Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) on the NASA/ESA Hubble Space Telescope allow us to capture the cluster close up and marvel at its contents in detail.

Credit: ESA/Hubble & NASA
Acknowledgement: Gilles Chapdelaine
Source: http://www.spacetelescope.org/images/potw1452a/

GOING DEAP:  Underground with the World’s Largest Dark Matter Detector

by Louisa Field

I feel a rush in my stomach as the cage drops and the pressure on my eardrums increases. I am travelling 2 km underground in a metal box that will carry me to the front line in the search for dark matter. I am eager to see DEAP, the world’s most sensitive detector before it is sealed off forever – but right now I wish I could stay at sea level.

My guide, Jack Dunger from the University of Oxford, reassures me. “The cage is much scarier than the tunnel,” he says. “Once you are down there you will feel more normal.”

The stuff Dunger’s colleagues are so keen to find is anything but normal. Dark matter accounts for about 80 per cent of the universe’s matter, yet only makes itself felt through gravity. It keeps galaxies from flying apart, but has never appeared in a detector.

DEAP, the Dark matter Experiment using Argon Pulse-shape discrimination, is based on the theory that dark matter is a weakly interacting massive particle. These antisocial WIMPs are difficult to detect because they are, as the name suggests, unwilling to play with other particles. However, physicists hope that the interactions are just rare, rather than non-existent…

(read more: New Scientist)

photograph by Snolab

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The Darkness Surrounds Us

New York University particle physicist Glennys Farrar explains what evidence clued in scientists to the existence of dark matter, and University of Michigan astrophysicist Katherine Freese discusses gravitational lensing, one of the mechanisms scientists use to find dark matter in the universe.

Watch the full Program Here: The Dark Side of the Universe

By: World Science Festival.
Support at: http://www.worldsciencefestival.com/support/

NASA Astronomy Picture of the Day 2015 April 26

Planetary Nebula Mz3: The Ant Nebula

Why isn’t this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round? Clues might include the high 1000-kilometer per second speed of the expelled gas, the light-year long length of the structure, and the magnetism of the star visible above at the nebula’s center. One possible answer is that Mz3 is hiding a second, dimmer star that orbits close in to the bright star. A competing hypothesis holds that the central star’s own spin and magnetic field are channeling the gas. Since the central star appears to be so similar to our own Sun, astronomers hope that increased understanding of the history of this giant space ant can provide useful insight into the likely future of our own Sun and Earth.

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Wonderful. Chromoscope:

Ever wanted X-ray specs or super-human vision? Chromoscope lets you explore our Galaxy (the Milky Way) and the distant Universe in a range of wavelengths from gamma-rays to the longest radio waves.

From top to down:

Quick Tour of Chromoscope

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Best of 2014!

January

February

March

April

May

June

July

August

September

October

November

December

Still not satisfied? Relive the previous year in science!

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The Shape of the Universe that Sends Chills Down your Spine

According to Einstein’s theory of relativity, gravity and energy effect the shape of space.

You can imagine this by looking at gravity not as a ‘force’ but as a downwards indentation in space. If you take a towel and have it pulled flat then drop a bowling ball in the middle, the area around the bowling ball will have been pressed down. The Moon orbiting Earth is just following a straight trajectory around this downward curvature of space.

Energy does the opposite of gravity. It makes a positive curvature.

When you look at the big picture, you’ve got a universe whose overall shape is dictated by whether or not it’s got an overall positive, negative or zero amount of energy.

We know, thanks to measuring the gravity of regular matter, dark matter and the strange anti-gravitational force called 'dark energy’, that we can make an equation with energy on one side and gravity on the other.

This equation will tell us the shape of the universe.

A negative answer means our universe is shaped like a saddle. A positive one means our universe is shaped like a globe (closed). An answer of zero means the universe has flat geometry.

Want the mysterious part?

Scientists have found that the universe is somehow, shockingly *perfectly tuned*. The measured amount of dark energy combined with the average density of matter is approximately zero. Our universe is flat.

With a flat universe, a universe with a net total of zero energy, we have a case of an entire universe being created out of nothing.

Somehow the matter and gravitational energies that otherwise cancelled each other out in a state of 'zero-ness’ were separated. Our universe may have in fact been created out of nothing.

It gets more odd. If you were to add (which we can’t) a single gram of matter (just one gram) it totally changes the entire shape of the universe. Our universe would be a closed one that would end in a 'Big Crunch’ where all things collapse and fall into a singularity: a perfect opposite of the Big Bang.

Scientists don’t like it when things seem to be fine tuned. It usually means we’re missing something. This means that our universe is many times more incredible and mysterious than you may have ever imagined before…

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NASA Astronomy Picture of the Day 2015 January 28

Comet Lovejoy in a Winter Sky

Which of these night sky icons can you find in this beautiful and deep exposure of the northern winter sky? Skylights include the stars in Orion’s belt, the Orion Nebula, the Pleiades star cluster, the bright stars Betelgeuse and Rigel, the California Nebula, Barnard’s Loop, and Comet Lovejoy. The belt stars of Orion are nearly vertical in the central line between the horizon and the image center, with the lowest belt star obscured by the red glowing Flame Nebula. To the belt’s left is the red arc of Barnard’s Loop followed by the bright orange star Betelgeuse, while to the belt’s right is the colorful Orion Nebula followed by the bright blue star Rigel. The blue cluster of bright stars near the top center is the Pleiades, and the red nebula to its left is the California nebula. The bright orange dot above the image center is the star Aldebaran, while the green object with the long tail to its right is Comet C/2014 Q2 (Lovejoy). The featured image was taken about two weeks ago near Palau village in Spain.

Big Bang May Have Created a Mirror Universe Where Time Runs Backwards

By Tim De Chant

Why does time seem to move forward? It’s a riddle that’s puzzled physicists for well over a century, and they’ve come up with numerous theories to explain time’s arrow. The latest, though, suggests that while time moves forward in our universe, it may run backwards in another, mirror universe that was created on the “other side” of the Big Bang.

Two leading theories propose to explain the direction of time by way of the relatively uniform conditions of the Big Bang. At the very start, what is now the universe was homogeneously hot, so much so that matter didn’t really exist. It was all just a superheated soup. But as the universe expanded and cooled, stars, galaxies, planets, and other celestial bodies formed, birthing the universe’s irregular structure and raising its entropy.

Continue Reading

NASA Astronomy Picture of the Day 2015 April 20

Total Solar Eclipse over Svalbard

Going, going, gone. That was the feeling in Svalbard, Norway last month during a total eclipse of the Sun by the Moon. In the featured image, the eclipse was captured every three minutes and then digitally merged with a foreground frame taken from the same location. Visible in the foreground are numerous gawking eclipse seekers, some deploying pretty sophisticated cameras. As the Moon and Sun moved together across the sky – nearly horizontally from this far north – an increasing fraction of the Sun appears covered by the Moon. In the central frame, the Moon’s complete blockage of the disk of the Sun makes the immediate surroundings appear like night during the day. The exception is the Moon itself, which now appears surrounded by the expansive corona of the Sun. Of course, about 2.5 minutes later, the surface of the Sun began to reappear. The next total eclipse of the Sun will occur in 2016 March and be visible from Southeast Asia.