Space

Quasars are supermassive black holes that live at the center of distant galaxies. They are the most luminous beacons in the sky, and shine across the entire electromagnetic spectrum due to rapidly accreting matter in their gravitationally inescapable centers.

Quasars display a broad range of outward appearances when viewed by astronomers, reflecting the diversity in the conditions of the regions close to their centers. But despite this variety, quasars have a surprising amount of regularity in their quantifiable physical properties, which follow well-defined trends (referred to as the "main sequence" of quasars) discovered more than 20 years ago. 


The Milky Way galaxy is orbited by more than 150 globular star clusters - balls of hundreds of thousands of old stars dating back to the formation of the galaxy. In the constellation of Sagittarius (The Archer), the French comet hunter Charles Messier found one such cluster and it was given the designation Messier 54.

For more than two hundred years after its discovery Messier 54, was thought to be similar to the other Milky Way globulars, but in 1994 astronomers determined that it was actually associated with a separate galaxy — the Sagittarius Dwarf Galaxy. It was found to be at a distance of around 90,000 light-years, more than three times as far from Earth as the galactic center.

The minor controversy over whether the 38 foot wide gouge near Managua Nicaragua is a impact crater leads me to the question, how easy is it to tell by sight alone if something is an impact crater or not?  So let's play crater or not crater. 

To find the answer click the pictures and there will be a link to a source which shows that one image is a impact crater or not impact crater.  That is in cases where it's uncontroversially clear. 

The first candidate. 
1


2. Now the second one. 

The Orion Nebula. Image credit: NASA http://bit.ly/1rTTyeC

By: Marcus Woo, Inside Science

(Inside Science) -- Interstellar space can be a dusty place, filled with tiny flecks no bigger than a bacterial cell.

But now astronomers have detected particles as big as pebbles, possibly a previously unknown type of dust that may kick-start the production of planets. The presence of these big particles may also suggest that star formation is more efficient than previously thought.

Asteroid 2014 RC will buzz the Earth today. But don't be alarmed. 

The small asteroid was initially discovered on the night of August 31st by the Catalina Sky Survey near Tucson, AZ, and independently detected the next night by the Pan-STARRS 1 telescope, located on the summit of Haleakala on Maui, Hawaii. Both reported their observations to the Minor Planet Center in Cambridge, MA. Additional follow-up observations by the Catalina Sky Survey and the University of Hawaii 88-inch on Mauna Kea confirmed the orbit of 2014 RC. From its brightness, astronomers estimate that the asteroid is about 60 feet in size. 
2014RC is a 60 foot (or about 20 meter) wide asteroid detected at the last possible minute.  This small asteroid will not hit Earth.  What about the ones like it that eventually will?   I ask that question because it is a certainty the last time Earth was hit by an asteroid of this size wasn't the last time forever. If it was going to hit there are three things we could do about it. 

Some facts about 2014RC

By Tanya Hill, University of Melbourne 

Have you ever considered our cosmic address? It’s a fun device I’ve often used to help students get a grasp on our place in the universe.

For example, I work at the Melbourne Planetarium, 2 Booker St, Spotswood, Victoria, Australia, Earth, Solar System, Orion Arm, Milky Way Galaxy, Local Group, Virgo Cluster, Local Supercluster, the Universe.

You have a new galactic address; astronomers have determined that our own Milky Way galaxy is part of a newly identified enormous supercluster of galaxies - dubbed "Laniakea," which means "immense heaven" in Hawaiian.

This discovery broadens the boundaries of our galactic neighborhood and establishes previously unrecognized linkages among various galaxy clusters in the local Universe. How big are are talking? The Milky Way galaxy alone has 100 billion stars. We think. And then there are 1012 galaxies. So your address is now a lot bigger. Instead of being Earth, Sol, Orion arm, Milky Way, Local Group and Virgo cluster, you can now add Laniakea before Universe.




Observations made by the Kepler spacecraft have shown that Kepler-413b is a very wobbling exoplanet. The planet's orbit is unusual in that it is tilted 2.5 degrees with respect to the plane of the binary star's orbit.