The Tadpole Galaxy

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The Tadpole Galaxy
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Why does this galaxy have such a long tail? In this stunning vista, based on image data from the Hubble Legacy Archive, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation Draco. Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 - from right to left in this view - and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy's stars, gas, and dust forming the spectacular tail.

Checking Out the Center of Our Galaxy

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Checking Out the Center of Our Galaxy
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The Sagittarius Window Eclipsing Extrasolar Planet Search, or SWEEPS, was a 2006 astronomical survey project using the Hubble Space Telescope's Advanced Camera for Surveys - Wide Field Channel to monitor 180,000 stars for seven days to detect extrasolar planets via the transit method.

The stars that were monitored in this astronomical survey were all located in the Sagittarius-I Window, a rare transparent view to the Milky Way's central bulge stars in the Sagittarius constellation as our view to most of the galaxy's central stars is blocked by lanes of dust. These stars in the galaxy's central bulge region are approximately 27,000 light years from Earth.

Andromeda Has Far More Dark Matter Than the Milky Way

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Andromeda Has Far More Dark Matter Than the Milky Way
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The Milky Way is smaller than astronomers previously thought, according to new research. For the first time, scientists have been able to precisely measure the mass of the galaxy that contains our solar system. Researchers have found that the Milky Way is approximately half the weight of ou neighboring galaxy – Andromeda – which has a similar structure to our own. The Milky Way and Andromeda are the two largest in a region of galaxies which astronomers call the Local Group.

In this new study, researchers were also able to work out the mass of invisible matter found in the outer regions of both galaxies, and reveal their total weights. They say 90 per cent of both galaxies' matter is invisible. Scientists say that Andromeda's extra weight must be present in the form of dark matter, the little-understood invisible substance which makes up most of the outer regions of galaxies. They estimate that Andromeda contains twice as much dark matter as the Milky Way, causing it to be twice as heavy.

The Largest Particle Accelerator Is 4 Galaxies Slamming Together

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The Largest Particle Accelerator Is 4 Galaxies Slamming Together
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Five billion light-years from earth, there's a massive galactic pileup unfolding in slow motion. As four clusters of galaxies plow into each other, thousands of individual galaxies are colliding—creating huge amounts of cosmic chaos and a lot of energy.

New images of this phenomenon—one of the largest galactic mergers on record—suggest it's also producing more than just pretty pictures. It's also serving as quite possibly the largest particle accelerator of all time, besting the exquisitely engineered Large Hadron Collider one million times over.