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Double black hole powers nearby quasar

View larger. | Artist's concept of a double black hole, at the heart of a quasar.

Artist’s concept of a double black hole, at the heart of a quasar. Image via NASA, ESA, and G. Bacon (STScI)

One black hole may be 4 million solar masses, about the same mass as our Milky Way’s central black hole. The other may be 150 million solar masses.

September 2015 guide to the five visible planets

Skywatcher, by Predrag Agatonovic.

Skywatcher, by Predrag Agatonovic.

At mid-northern latitudes, Saturn lords over the evening sky all by himself all month long! Mercury is hiding in the evening twilight for the Northern Hemisphere. Meanwhile, at southerly latitudes, two planets are visible in the evening, as Mercury presents its finest evening apparition of the year. The other three visible planets – Venus, Mars and Jupiter – are in the east before sunrise, with Venus pointing the way to Mars and Jupiter appearing in mid-month in predawn twilight. Follow the links inside to learn more about September planets.

Linked: Amazon wildfires, Atlantic hurricanes

This map of ocean surface temperatures shows how warm waters in the North Atlantic fueled Hurricane Katrina. NASA and UCI researchers have found that the same conditions heighten fire risk in the Amazon basin. Image credit: Scientific Visualization Studio, NASA’s Goddard Space Flight Center

This map of ocean surface temperatures shows how warm waters in the North Atlantic fueled Hurricane Katrina. NASA and UCI researchers have found that the same conditions heighten fire risk in the Amazon basin. Image credit: Scientific Visualization Studio, NASA’s Goddard Space Flight Center.

Years of data on storms and sea surface temps show a correlation between a warm North Atlantic Ocean – more destructive hurricanes – and a fire-prone Amazon.

Ethereal beach

View larger. | Cannon Beach, Oregon by Jeff Berkes Photography.

Cannon Beach, Oregon by Jeff Berkes Photography. He titled this photo Ethereal.

No photo in our social media last week had had as much positive feedback as this one, which Jeff Berkes posted at EarthSky Facebook. He wrote:

I still can not believe that I had the opportunity to witness a view as heavenly as this.

Neptune closest to Earth for year on August 31

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Neptune comes closest to Earth today – on August 31, 2015 – and reaches opposition less than a day later, on September 1. By closest, we don’t mean close. Neptune lodges in the outskirts of our solar system. At opposition, this giant world lies 29 times farther away from Earth than Earth lies from the sun.

Astronomy events, star parties, festivals, workshops

Here's the Texas Star Party in 2009, one of the biggest such events of the year, drawing about 500 deep-sky enthusiasts and their telescopes to the Davis Mountains of West Texas.  Image via Todd Hargis / Ron Ronhaar.  Used with permission.

Here’s the Texas Star Party in 2009, one of the biggest public astronomy events of each year, drawing about 500 deep-sky enthusiasts and their telescopes to the Davis Mountains of West Texas. Image used with permission, via Todd Hargis and Ron Ronhaar.

Interested in astronomy, but not sure where to begin? Seek out your local astronomy club, a roomful of willing and able amateur astronomers, whose telescopes may offer your first glimpse of the cosmos. The Astronomical League, an umbrella organization of 240 amateur astronomy clubs and societies in the U.S., helps us create and maintain the list of events on this page.

Record-breaking three Category 4 hurricanes in Pacific

Three Category 4 hurricanes on Sunday morning in the Pacific. Kilo (left), Ignacio (center) and Jimena (right).  Image via NASA.

Three Category 4 hurricanes on Sunday morning in the Pacific. Kilo (left), Ignacio (center) and Jimena (right). Image via NASA.


NASA’s Terra satellite just released this August 29 image of Hurricanes Kilo, Ignacio, and Jimena, all Category Four Hurricanes. According to the Weather Channel:

This is the first recorded occurrence of three Category 4 hurricanes in the central and eastern Pacific basins at the same time. In addition, it’s also the first time with three major hurricanes (Category 3 or stronger) in those basins simultaneously, according to hurricane specialist Eric Blake of the National Hurricane Center.

New Horizons’ potential next flyby target

View larger. | This perspective view shows the path of NASA's New Horizons spacecraft (yellow) through the outer solar system and the Kuiper Belt.  Read more about this image.

Path of NASA’s New Horizons spacecraft (yellow) through the outer solar system and the Kuiper Belt. Image via Johns Hopkins.

New Horizons will perform four maneuvers in October and November to veer toward 2014 MU69 – nicknamed PT1 (for Potential Target 1) – aiming for a January 1, 2019 encounter.

Moon swings to perigee – closest point – on August 30

The moon's apparent size in our sky depends on its distance from Earth.  The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left).  Image by Marco Langbroek of the Netherlands via Wikimedia Commons.

The moon’s apparent size in our sky depends on its distance from Earth. The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). Image by Marco Langbroek of the Netherlands via Wikimedia Commons.

The moon reaches perigee – nearest point to Earth in its orbit – on August 30, 2015 at 15:24 UTC. This perigee comes less than one day after the moon reached the crest of its full phase on August 29 at 18:35 UTC.

First of 3 full supermoons on August 29

Image credit: Stefano Sciarpetti

Image credit: Stefano Sciarpetti

Supermoon weekend! The full moon of August 29, 2015 will be the first of this year’s three full supermoons. It’s a full moon near perigee, or near its closest point to Earth for the month. Like it or not, modern skylore dictates that these sorts of moons are called supermoons.