BULLET-PROOF

The Hawaii Observatory on Mauna Kea. Photograph: Roger Ressmeyer/Corbis



A team of Japanese astronomers using telescopes on Hawaii say they have seen the oldest galaxy yet discovered.


  The team calculates that the galaxy is 12.91bn light years away, and their research will be published in the Astrophysical Journal. The scientists with the National Astronomical Observatory of Japan used the Subaru and Keck telescopes on the summit of Mauna Kea.


  A light year is the distance that light travels in a year, about 6 trillion miles (9.66 trillion kilometres). Seeing distant galaxies is in effect looking back in time.


  Richard Ellis of the California Institute of Technology, an influential expert in cosmology and galaxy formation, said the latest work was more convincing than some other claims of early galaxies.


  He said the Japanese claim was more "watertight," using methods that everyone can agree on. But he said it was not much of a change from a similar finding by the same team last year.

Here it is, such as it is.



"It's the most distant bullet-proof one that everybody believes," Ellis said.


  In 2010, a French team using Nasa's Hubble Space Telescope claimed to have discovered a galaxy 13.1bn light years away and last year a California team using Hubble said it had seen a galaxy 13.2bn light years away. Both Hubble teams published findings in the journal Nature.

Vija Celmins sketching “Reverse Galaxy.”  The truth in her work has always amazed me.



However, the two Hubble teams have yet to confirm their findings with other methods, said Ellis. A team of Arizona State University astronomers this month claimed to have found a galaxy 13bn light years away using a telescope in Chile.


  Current theory holds that the universe was born of an explosion, called the Big Bang, about 13.7bn years ago. Astronomers using the most powerful telescopes available are peering deeper and deeper into that dawn of the universe.


• This article was amended on 12 June 2012 to change references to "light years ago" to "light years away".

A “space painting” by the great Chilean Surrealist painter, Matta.  I have always believed space looks like this.

City Lights of the Universe

If an alien civilization builds brightly-lit cities like those shown in this artist's conception, future generations of telescopes might allow us to detect them. This would offer a new method of searching for extraterrestrial intelligence elsewhere in our Galaxy. Photo: David A. Aguilar (CfA).

WASHINGTON, DC.- In the search for extraterrestrial intelligence, astronomers have hunted for radio signals and ultra-short laser pulses. In a new paper, Avi Loeb (Harvard-Smithsonian Center for Astrophysics) and Edwin Turner (Princeton University) suggest a new technique for finding aliens: look for their city lights.

"Looking for alien cities would be a long shot, but wouldn't require extra resources. And if we succeed, it would change our perception of our place in the universe," said Loeb. 

As with other SETI methods, they rely on the assumption that aliens would use Earth-like technologies. This is reasonable because any intelligent life that evolved in the light from its nearest star is likely to have artificial illumination that switches on during the hours of darkness. 

How easy would it be to spot a city on a distant planet? Clearly, this light will have to be distinguished from the glare from the parent star. Loeb and Turner suggest looking at the change in light from an exoplanet as it moves around its star.

As the planet orbits, it goes through phases similar to those of the Moon. When it's in a dark phase, more artificial light from the night side would be visible from Earth than reflected light from the day side. So the total flux from a planet with city lighting will vary in a way that is measurably different from a planet that has no artificial lights. 

Spotting this tiny signal would require future generations of telescopes. However, the technique could be tested closer to home, using objects at the edge of our solar system. 

Loeb and Turner calculate that today's best telescopes ought to be able to see the light generated by a Tokyo-sized metropolis at the distance of the Kuiper Belt - the region occupied by Pluto, Eris, and thousands of smaller icy bodies. So if there are any cities out there, we ought to be able to see them now. By looking, astronomers can hone the technique and be ready to apply it when the first Earth-sized worlds are found around distant stars in our galaxy.

"It's very unlikely that there are alien cities on the edge of our solar system, but the principle of science is to find a method to check," Turner said. "Before Galileo, it was conventional wisdom that heavier objects fall faster than light objects, but he tested the belief and found they actually fall at the same rate." 

As our technology has moved from radio and TV broadcasts to cable and fiber optics, we have become less detectable to aliens. If the same is true of extraterrestrial civilizations, then artificial lights might be the best way to spot them from afar. 

Loeb and Turner's work has been submitted to the journal Astrobiology and is available at arxiv.org.

  

Out Of Dream (Road)

Note:  Although nothing could be more "real world physical" than artist Gordon Matta-Clark's "building cut" works, his images (like Conical Intersect above, made in Paris in 1975) are as surreal and dreamlike as anything in the work of his father, the Chilean Surrealist painter Matta, or any of the artists one associates with Matta. The title of this post is a variation of one I used recently, Out Of Road (Dream), which was suggested by one of my own dreams.  I'm sure I have had dreams resembling Gordon Matta-Clark's images; I'm just not sure whether they came before or after seeing his work.  I'm sure seeing his images affected my future dreaming.

What Outer Space Actually Looks Like