Record-Breaking Galaxy Cluster Confirms Dark Matter Universe
“But this new cluster is just 2.6 billion years old, and seems to be undergoing the very transition where a collection of galaxies falls into a bound structure for the first time, from a protocluster to a true galaxy cluster. This marks the first time astronomers have ever detected such an event: of the exact moment that a protocluster transitions to a true cluster. The fact that so many total galaxies (seventeen!) were discovered localized together at the same redshift (z=2.506) was a big hint, but the final piece of evidence came from the X-rays, where the diffuse emission engulfing the entire set of objects shows, beyond a shadow of a doubt, that this really is a galaxy cluster!”
There was once a time early on in the Universe where there were no stars, no galaxies and no clusters of galaxies at all. While stars and galaxies form very early on, after only tens or hundreds of millions of years, it takes billions of years for the first clusters to form. Yet even if we were to look back into the Universe’s past up to ten billion years, the clusters we see are already well-evolved and quiet. We had never seen a set of galaxies fall in and actively form a cluster before. We’d never seen the protocluster/cluster transition before. And we’d never found one from when the Universe was between two and three billion years old: when our dark matter theory predicts the first great clusters ought to form. Until, that is, now.
The North Celestial Tower : If you climbed to the top of this 13th century stone tower, it looks like you could reach out and touch the North Celestial Pole, the point at the center of all the star trail arcs. The well-composed image with scattered meteor streaks was recorded over a period of five and half hours as a series of 45 second long exposures spanning the dark of the night on July 7/8. The exposures were made with a digital camera fixed to a tripod near Marathon, Greece, planet Earth. Of course, the graceful star trails reflect the Earth’s daily rotation around its axis. By extension, the axis of rotation leads to the center of the concentric arcs in the night sky. Convenient for northern hemisphere night sky photographers and celestial navigators alike, the bright star Polaris is very close to the North Celestial Pole and so makes the short bright trail in the tower’s central gap. via NASA
Awesome summary of the year 1950, showing America’s race into space in by Dan Beaumont Space Museum. It details the German participation and joint-leadership in the U.S. space program. Note: the next posts will summarize 20 more posts for the years 1951 to 1970. Keep track on it.
NASA’s Juno spacecraft just completed a record-breaking flyby of Jupiter,snapping some incredible pictures as it soared over the tops of the gas giant’s clouds at speeds of around 209,200 km/h (130,000 mph).
Now that Juno has finally reached its destination, after spending the last five years and 2.9 billion km (1.8 billion miles) in transit, it’s scheduled to complete 35 more flybys of Jupiter over the next 18 months.