TRANSIT OF VENUS EXPLAINED

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WISE SKY

Credit: NASA/JPL-Caltech/UCLA.

  
In a great mapping milestone, NASA's WISE (Wide-field Infrared Survey Explorer) space telescope has compiled this mosaic image of the entire sky. 
  
That's more than 2.7 million images taken at four infrared wavelengths of light for a total of more than 15 trillion bytes of data in just over two years. 

As for what you're looking at, here's the WISE page description:
  

This map is centered on the Milky Way Galaxy. The plane of the Galaxy runs along the equator, and the center of the Galaxy is at the center of the map, where projection distortions are minimal. The distortions are most pronounced at the edges of the map. The right and left edges of this oval shape are the same location in the sky.

  

Credit: NASA/JPL-Caltech/UCLA.

  
There are 560 million objects in this view—many seen for the first time—stars, galaxies, planets, asteroids, and more:
  

WISE observations have led to numerous discoveries, including the elusive, coolest class of stars. Astronomers hunted for these failed stars, called "Y-dwarfs," for more than a decade. Because they have been cooling since their formation, they don't shine in visible light and could not be spotted until WISE mapped the sky with its infrared vision

 

And here's a zoomable version of the WISE map so you can boldly go where no one has gone before. Click here for humongous version.

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EARTH FROM AFAR

Click for larger view. Credit: NASA/JPL/Space Science Institute.

 
This view of Saturn eclipsing the sun is a composite assembled from 165 images taken by the Cassini spacecraft while 2.2 million kilometers/1.3 million miles from Saturn on 15 September 2006. The mosaics were captured over the space of about 12 hours as the spacecraft drifted in the darkness of Saturn's shadow.

Seen far in the distance, at the 10-o'clock position just outside the bright rings, is a tiny pale blue dot—Earth.

For a whole lot more on how this image was created and what its details reveal, check out the JPL Cassini page. Click here for a bigger version.

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MODELLING THE HISTORY OF THE UNIVERSE

Galaxies in Real and Simulated Universes from Risa Wechsler on Vimeo.

Seriously cool stuff. From the Vimeo page:

We see galaxies in the sky, but cannot see the dark matter clumps surrounding them. However, we can simulate them as they form in a model Universe. In this video we show how good the agreement is between the observed distribution of galaxies in the SDSS sky survey, and the predicted distribution of model galaxies associated with dark matter halos in the Bolshoi simulation. It's hard to tell them apart!  

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EARTH AND MOON FROM 6 MILLION MILES AWAY

Credit: NASA/JPL-Caltech.

NASA’s solar-powered spacecraft Juno captured this image of Earth and our moon from 6 million miles/9,656,064 kilometers away on 26 August 2011—three weeks into its 1.7-trillion mile/2.8-trillion kilometer 5-year voyage to Jupiter.

From the Jet Propulsion Laboratory page:

"This is a remarkable sight people get to see all too rarely," said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. "This view of our planet shows how Earth looks from the outside, illustrating a special perspective of our role and place in the universe. We see a humbling yet beautiful view of ourselves."

UPDATE:

You might have noticed what seems to be a great distance between Earth and our moon in the photo above. Here's a great short video explaining why we perceive it thus. Thanks to Jason R for pointing the way in his comment, below.



Plus, an image of Juno itself, intrepid wanderer of the solar system.

Credit: NASA/JPL.

 
Here's where Juno is currently.

Credit: NASA/JPL.

  
And here's its interplanetary trajectory.

Credit: NASA/JPL.

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CELESTIAL SEAS

The Mountain from TSO Photography on Vimeo.

Views of our beautiful Milky Way.

All images below cover the complete 360-degree celestial sphere, via a series of stitched frames forming a panoramic, with the Milky Way as the central line or arc. Except the last image, which is a close-up, relatively speaking.

Courtesy of Wikimedia Commons, from top to bottom: 1, 2, 3, 4.

It's well worth clicking on the images to see the larger sizes. If you have the bandwidth, clicking on the number 2 link (above) to see that image in its original too-big-for-blogspot size.

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FRIDAY BRAIN CANDY: THE COSMIC OCEAN

Seahorse Nebula. Via APOD. Credit: NASA, ESA, and M. Livio (STScI).

Lagoon Nebula. Via APOD. Credit & Copyright: Russell Croman.

Breaking waves in the Lagoon Nebula. Via the Hubbard Space Telescope. Credit: NASA, ESA.

Seagull Nebula. Via WISE (Wide-Field Infrared Survey Explorer). Credit: NASA/JPL-Caltech/UCLA.

Crab Nebula. Via the Hubbard Space Telescope. Credit: NASA and The Hubble Heritage Team.

Pelican Nebula. Via APOD. Credit: John Bally (U. Colorado) & Bo Reipurth (U. Hawaii), NOAO, AURA, NSF.

Prawn Nebula. Via APOD. Credit & Copyright: Martin Pugh.

Jellyfish Nebula. Via APOD. Credit & Copyright: Bob Franke.

Phytoplankton bloom in the North Atlantic. Via the Earth Observatory. Credit: NASA, Jeff Schmaltz, MODIS Rapid Response Team.

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ILLUSTRATED: THE CRAB NEBULA THROUGH TIME

M1: The Crab Nebula, captured by the Hubble Space Telescope, 2009. Credit: NASA, ESA.

Towards the end of my book DEEP BLUE HOME I wrote about the cave paintings of Mexico's Baja Peninsula—truly a wonder of the world—including an image of the Crab Nebula supernova from the year 1054.

[O]ne of the most modest paintings on view anywhere in Baja California: a small depiction in ochre of a childlike sun, with lines radiating from a circle, nestled beside the outline of another circle more than half filled with ochre pigment.

North American rock art depicting the Crab Nebula supernova, circa 1054. Illustration: Harry W. Crosby, from The Cave Paintings of Baja California.

  
You can see the art I'm describing on the far left in the image above: 

The story of this image has a long lineage, and the starting place for its rediscovered meaning dates back to the year 1054, when Chinese astronomers noted a guest star in the constellation Taurus and recorded that its glow was visible in the daytime sky for twenty-three days and in the nighttime sky for six hundred fifty-three days.

Little more thought was given to this celestial light for a long time. It was not noted in 1731 when the English doctor and astronomer John Bevis first observed a nebulous cloud within our own Milky Way galaxy nor, more than a century later, when another English astronomer named it the Crab Nebula. The visit of the guest star was nearly forgotten until the early twentieth century, when—working backward in time to calculate the rate of expansion—astronomers surmised that the Crab Nebula was the remains of the 1054 supernova observed by ancient astronomers.

The crablike sketch made in 1844 by William Parsons, 3rd Earl of Rosse, for which the nebula was named. Image courtesy Wikimedia Commons.

And:

Later the American astronomer William Miller calculated that the 1054 supernova appeared in western North America in dazzling conjunction with a crescent moon. He correlated this sight to two pieces of prehistoric rock art in Arizona, each depicting a star beside a crescent moon. Later astronomers found strikingly similar rock art of conjunct stars and crescents at other sites in the American Southwest. In 1971 the explorer Harry Crosby, traveling by mule in the Sierra de San Francisco, came upon this image of a star and a moon—the only painting of its kind in the murals of Baja California, which he later surmised was also an image of the 1054 supernova.

Chaco Canyon, 1054 supernova rock art. Photo via.

Astronomy Picture of the Day (APOD) describes the Crab Nebula as "the mess left after a star explodes," filled with mysterious filaments:

The filaments are not only tremendously complex, but appear to have less mass than expelled in the original supernova and a higher speed than expected from a free explosion. In the nebula's very center lies a pulsar: a neutron star as massive as the Sun but with only the size of a small town. The Crab Pulsar rotates about 30 times each second. 

Crab Pulsar Wind Nebula, 2008. Credit: NASA.

  
This deep x-ray image of the Crab Pulsar taken from the orbiting Chandra Observatory provided the first clear view of the ghostly edges of the pulsar's wind nebula. From APOD:

The pulsar's energy accelerates charged particles, producing eerie, glowing x-ray jets directed away from the poles and an intense wind in the equatorial direction. Intriguing edges are created as the charged particles stream away, eventually losing energy as they interact with the pulsar's strong magnetic field.

It's astonishing to think how much we've seen—and learned to see—in less than the blink of a universe. Of course the real timeline of events is even more profound. Back to my excerpt:

The 1054 supernova occurred 6,300 years before anyone on Earth witnessed it. The explosion dismantled a star more than 37,000 trillion miles away from us. The blast radiated as much energy as our sun will emit in the course of its life, and its light traveled at the fastest speed possible, the speed of light itself, yet it still took more than sixty centuries to get here.

Credit: Danny LaCrue & the ESA/ESO/NASA Photoshop FITS Liberator.

 

The beautiful mess of the Crab Nebula.

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THE JELLYFISH NEBULA

(Image Credit & Copyright: Bob Franke)

From APOD:

Normally faint and elusive, the Jellyfish Nebula is caught in this alluring, false-color, telescopic view. Flanked by two bright stars, Mu and Eta Geminorum, at the foot of a celestial twin, the Jellyfish Nebula is the brighter arcing ridge of emission with dangling tentacles below and right of center. In fact, the cosmic jellyfish is seen to be part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded. Light from the explosion first reached planet Earth over 30,000 years ago. Like its cousin in astrophysical waters the Crab Nebula supernova remnant, IC 443 is known to harbor a neutron star, the remnant of the collapsed stellar core. Emission nebula Sharpless 249 fills the field at the upper left. The Jellyfish Nebula is about 5,000 light-years away. At that distance, this image would be about 300 light-years across. The color scheme used in the narrowband composite was made popular in Hubble Space Telescope images, mapping emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors.

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