The WISE Telescope
In 1964, Russian scientist Nikolai Kardashev suggested that in the long history of the universe, which began billions of years before the origin of our Sun and Earth, really advanced civilizations might have developed. Such civilizations might learn to control the total power of their stars -- and, ultimately, the total power of their galaxies.
Now, Jason Wright and Roger Griffith, a pair of scientists at Penn State University, have actually searched for this last kind of super-civilization. If such advanced beings have actually colonized and exploited the billions of stars within a galaxy, these civilizations could produce tremendous amounts of waste heat.
Just like your car and your computer produce waste heat while they are operating, so the thought is that large-scale civilizations will generate an unnatural amount of heat, beyond the heat that all objects give off.
A recent satellite called the Widefield Infrared Survey Explorer (WISE) has been collecting information on sources of heat energy around the sky. Wright and Griffith have looked at the output of 100,000 galaxies, to see if anyone of them might betray signs that the heat they produce is not natural, but comes from a super-civilization.
Although they did not find any obvious and definitive evidence, they did note some galaxies whose infrared energy was unusual in some ways. These are worth investigating further.
Of course no one really knows whether intelligent creatures can ever evolve to a level of technology where they take over an entire galaxy. So finding one by this method is a long shot. (But I asked Geoff Marcy, the world's leading planet hunter, and he pointed out that just about all our searches for intelligence in the universe so far have been "long shots" -- no one can be sure today what method will pay off. So Marcy feels we should explore as many different methods as possible.)
I also asked Jill Tarter, the U.S. leader of the search for extra-terrestrial intelligence using radio waves, and she also was excited about our adding more techniques to our SETI arsenal. She told me she was adding the unusual galaxies from the WISE survey to the list of places where they would point radio telescopes, just in case there were any intelligent radio signals to be found.
Indeed, the SETI institute organized a Google hangout about this survey, and included Jill Tarter and Freeman Dyson, who first suggested ways that an advanced civilization might betray itself with infrared waves. You can hang out and see what they said at: https://plus.google.com/events/cs8lq28m1ebd2bnukspml93njc8
I would like to invite all of you who live in or near the San Francisco area to a very special event this Sunday, at the Hyatt Regency Hotel near the San Francisco Airport, in the town of Burlingame. I will be moderating an afternoon discussion with three of my favorite astronomers (all excellent public speakers.)
Our topic will be "Beyond Earth: Planets, Life, and Intelligence in the Cosmos" and we will discuss the search for planets around other stars, for life on the worlds in our own solar system, and for intelligent life elsewhere in the universe. Geoff Marcy is considered the foremost planet hunter on our planet, having discovered more planets orbiting other stars than any other human being. Jill Tarter has headed the search for intelligent radio signals from ET for many years, and is the scientist whom Jody Foster was playing in the film "Contact." Chris McKay is one of the top Mars experts in the world and explores places on Earth that most resemble Mars.
The program is sponsored by the non-profit Astronomical Society of the Pacific, which is celebrating its 125th anniversary this year. The illustrated talks and panel will go from 1:30 to 5:30 pm at the Hyatt Hotel, 1333 Bayshore Highway, Burlingame, CA 94010. It's all free and open to the public, but the sponsors hope each attendee will make a donation of $10 to help pay for the expenses at the hotel. We expect big crowds, so come a little early to get a seat.
For more information and to RSVP, go tohttp://www.astrosociety.org/universe2014
With almost 2,000 planets now known to orbit other stars, and with many stars having more than one planet (just like our Sun does), this is the time that topics that seemed like science fiction only a few years ago are becoming an exciting part of science. Hear the latest from those at the forefront of this work.
If you know people living near San Francisco who might be interested, perhaps you can help me by sending this information on to them.
Astronomers using both the Hubble and the Spitzer space telescopes have gotten an indication of weather in the atmosphere of a kind of "failed star" called a brown dwarf. Stars are so far away that, in general, they look like points of light, even in our biggest telescopes -- so this is quite an achievement.
Brown dwarfs (a name coined by Jill Tarter, the scientist on whom Jodie Foster's character in the movie "Contact" was based) are large balls of hot gas that "ain't got what it takes" to be a star. They don't have the mass to continue making energy on their own, so after a brief period of glowing from how compressed they get at birth, they just fade away. (I like to compare them to all the actors that come to Hollywood with high hopes, maybe get a role as an extra in a TV show, but never make it to be real stars.)
This particular brown dwarf (which doesn't have a name, only a long catalog number) was observed not in visible light but in "infra-red" or heat rays, which allow us to see cooler glows. Both the Hubble and the Spitzer can detect and measure infra-red waves, but they "see" them from different depths in the atmosphere of the star. Daniel Apai, one of the astronomers doing the work, compared this to medical imaging, where different kinds of instruments can see different layers of your body.
As shown in the accompanying artist's interpretation (NOT a photograph!), there appear to be huge and deep clouds in the star's atmosphere, some of them as large as planet Earth! They move around in the atmosphere as the star spins every 90 minutes or so. They may somewhat resemble the largest regularly scheduled cloud we know in the solar system, the Great Red Spot of Jupiter (see the beautiful image below, from the Galileo spacecraft which orbited Jupiter.)
But the temperature in a brown dwarf is not cool like the atmosphere of Jupiter, so the clouds are likely to be made of different stuff from clouds on Earth and Jupiter. What might condense into clouds in a region which is 1100-1300 degrees Fahrenheit (600-700 degrees Celsius) in temperature? Mark Marley, another scientist on the team, suggests they are "composed of hot grains of sand, liquid drops of iron, and other exotic compounds."
Isn't it amazing that we can now do weather reports from a star?
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