October 20, 2018

Review: Signatures of Life by Edward Ashpole

Out in July!

Where are they? That’s the central question that Enrico Fermi asked in what has now become known as the Fermi Paradox. For the past half century, scientists have attempted to answer that question, scouring the skies for searches for extraterrestrial intelligence. [Read more...]

Review: Rare Earth by Peter Ward & David Brownlee.

A controversial classic!

It is perhaps one of the greatest scientific questions of our time. How common are we? Is our existence here in time and space a widespread occurrence in the cosmos, or are we so unique that we are effectively alone? The topic of this week’s review represents a landmark paradigm shift and is an often quoted book that I’ve always wanted to get around to reading and reviewing. Rare Earth: Why Complex Life is Uncommon in the Universe by David Ward & Peter Brownlee posits that animal life in general and intelligence such as our own in particular is a rare, perhaps a singular event in our corner of the galaxy. Published in 2000, its interesting to see how the science of the day stacks up to current thinking. For example, in 2000 a handful of exoplanets were known; almost all were “hot Jupiters,” and the prospects for terrestrial planets looked slim. To date, 779 extra-solar planets have been discovered using a variety of methods, providing researchers with enough data to classify and characterize various types of planetary systems.

It should be noted that the authors do point out that while animal life may be a tough hurdle, simple bacterial life may be common in the cosmos. Our own story lends some credence to this supposition; once conditions in the early history of life on Earth stabilized about 3.5 billion years ago, simple life arose readily. For almost 90% of the span of life on Earth, however, life remained at the simple one-celled stage. It seems that at least in our own case, going to complex multi-celled life was the hard part; but yet in less than a billion years, the explosion of plant and animal life led to dogs, cats, humans, Ipads, etc. How common this tale is remains to be seen. Certainly, the discovery of bacterial life past or present within our own solar system may lend weight to the first half of the Rare Earth hypothesis.
Among the factors that the authors site as conducive to life as we know it;

-An orbit around a single relatively stable star that maintains a steady output for many billions of years, long enough for life to develop;

-A stable orbit within the habitable zone of said star, a place where water can exist in liquid state;

-Condensation from a proto-solar nebula with a high “metallicity” (remember, to an astronomer, the universe is hydrogen, helium, & metal!) full of lots of great but scarce raw materials such as carbon, silicon, nitrogen, etc.

-A single large Moon that acts to stabilize the tilt of the Earth;

-A large “goal tending” planet like Jupiter that deflects a good portion of the life extinguishing comets that come our way.

-A stable position in the galactic habitable zone, not too close to the radiation-riddled core and not in the outer metal poor ‘burbs. A good distance from any life extinguishing supernovae or gamma-ray bursters helps too, a sort of “may you live in mediocre times” curse/blessing.

-Active tectonic plates allowing for subduction and sequestration via a rock and carbon cycle.

To this end, the authors add some interesting twists to the famous Drake Equation, allowing for the events that brought us here in the mix. Certainly, if some of the scenarios such as the formation of our Moon are mandatory, chances for life are slim. One only has to look at the caveats offered by our neighboring worlds of Venus and Mars to see how different the Earth could be.

Still, a nagging hunch pulls at the back of our brain as we read Rare Earth… just how viable is a statistic of one? Are all of these happy accidents mandatory, or can life, once it’s started, make due even under drastically different conditions? One could also point out that these conditions aren’t exactly stable or permanent; the tilt of the Earth’s axis does vary, the output of the Sun is increasing and fluctuates with time, etc. It would be great to have a better understanding of the minimum and maximum criterion for life as it relates to these events. Carbon is probably crucial; no other element forms such long complex chains, although silicon is sometimes also cited as a possible alternative. Water also makes a great ‘universal solvent…” but might oxygen be poisonous to some forms of life? Would we recognize life drastically different from us if we saw it? I’m reminded of Arthur C. Clarke’s Report on Planet Three, where a Martian scientist gives a long and convincing discussion on why life on a hostile planet such as Earth couldn’t be possible.

Read Rare Earth as a very timely and still largely pertinent discussion on one of the biggest questions of our time. I would also recommend James Kasting’s How to Build a Habitable Planet as a great look at how the Earth came to be. Either conclusion has stunning implications; of course, most of us root for sentience and a cosmos teeming with diverse life with Klingons and Vulcans bickering about treaties in a Galactic Federation… but if we are truly  ”it” in our tiny niche of time and space, doesn’t that make us and the Earth all that much more precious and unique, a jewel worth safeguarding and preserving?

The Elusive Wow by Robert H. Gray.

On sale now!

Nothing fires the scientific imagination like the search for extraterrestrial intelligence. And likewise, no discovery would have further implications to our own existence and what it means to be human. Plus, it would just be darned interesting to get to know something about them. How unique are we?

[Read more...]

11.05.11: Voyager: The Humanoids Where Here.

Decoding the disk; are you smarter than a humanoid? (Credit: NASA/JPL).

If we were to vanish from the cosmic scene tomorrow, what would be our most lasting impact? Would it be our monuments, our terrestrial relics, or our broadcasts of I Love Lucy and the Jerry Springer Show? Thankfully, researchers in the 1970’s designed a “message in a bottle” to be tossed out across the cosmic sea attached to the twin Voyager spacecraft. Launched in 1977, both spacecraft reconnoitered the outer planets before being flung on trajectories that will leave our solar system. [Read more...]

30.04.11: Pulling the Plug on Hat Creek; SETI on-hold?

Amidst news of royal weddings, birth certificate releases, and the usual celebrity goings on, troubling news recently came out of the University of California at Berkley. In a scene right out of certain Hollywood movie, the National Science Foundation’s funding for its Hat Creek Radio Observatory will be reduced to a tenth, effectively shutting down the Allen Telescope Array.

[Read more...]

27.04.11: MeerKAT & the Bid for SKA.

African radio astronomers are taking an innovative approach to a bid in hosting a unique proposal. The idea is known as the Square Kilometer Array, a radio observatory that will employ hundreds of dishes over a large area to scan and survey the radio sky in unprecedented detail. Much like the Allen Telescope Array being built in California, SKA’s strategy is to use the technique known as radio interferometry and go for many small dishes linked together rather than one large single antenna.

[Read more...]

December 2010: Life in the Astroblogosphere.

We’re back… December 2010 sees us here at Astroguyz wrapping up our 3-year plus quest for an online science teaching degree and a return to full-bore content creation.  And none too soon, as December is generally our busiest (and most intriguing!) month of the year…

[Read more...]

Review: How Did the First Stars and Galaxies Form? By Abraham Loeb.

One of the crucial questions in modern cosmology is: why is there anything at all? Why are we here to admire the cosmos, and create books and blogs about how clever we are to figure it all out? Why didn’t the early universe promptly annihilate itself in a massive matter/anti-matter collision? [Read more...]

13.06.10: Hayabusa: a Sample Return Update.

  14.06.10 Update: They got it… as of this writing, it looks like the sample return capsule safely touched down in the Australian desert intact!
A long trip home! (Credit: JAXA).  
A long journey home! (Credit: JAXA).
Earth looming as seen from Hayabusa. (Credit: JAXA).
Earth looming as seen from Hayabusa. (Credit: JAXA).
  (Note: As of this writing, the search for the sample return capsule is still underway in the Australian outback… expect updates here and on our Twitter feed as the day unfolds!) 

  Hayabusa returned to Earth today, lighting up the skies over the Australian outback and the Woomera restricted zone slightly before 10:00 AM EDT. Good captures of the fireball and the re-entry were confirmed, and the probe burned up after releasing the sample return capsule to plunge over the Australian desert. But the big mystery remains; did Hayabusa in fact capture and return a sample of asteroid Itokawa, and in doing so succeed in a first ever sample return from an asteroid? Of course, we may not truly know the answer to this long awaited tale for some time, as engineers must first recover and retrieve the capsule for further analysis. All indications were that the sample stirring pellet gun did not fire during the asteroid encounter, but there’s always the slim chance that material may have gotten stirred up and caught in the sample retrieval horn. Hayabusa slammed into the atmosphere today at a terrific speed of 27,000 mph, one of the fastest re-entries ever attempted. All space fans were present watching the action in the Australian night via Twitter and UStream, further evidence that the realm of new school media has in fact arrived. NASA & SETI’s joint reentry observation program was also aloft in a DC-8 for the event, watching to grab a spectroscopic analysis of the fireball as it plunged to Earth. The trail seen was quite bright, lighting up the thin scud of clouds as viewed from the surface.  Robin Whittle and his Wife Tina reported a fireball “brighter than Venus” from their locale 25 km west southwest of Port Augusta. Re-entry came at an angle of 10 degrees and had to endure temperatures of 5,000 degrees Fahrenheit during the decent. Toasts were raised worldwide as Hayabusa made its heroic return, a triumph for the Japanese Aerospace eXploration Agency (JAXA). Doubtless, it’ll be days to weeks for engineers to sort out the after action data; for example, scientists are still going over the Stardust aerogel returned from comet Wild years later.   A search of the Australian outback is underway and we’ll post more pics as we see em throughout the day… Kampai, Hayabusa! 


Video of the fireball in the Australian night… 

01:00 PM EDT: More dramatic pics have just come in via JAXA and the NASA/SETI team…

Image via JAXA's All Sky Observation System... (Credit: JAXA).

Hayabusa re-entry as seen by the JAXA Ground all-sky observation network. (Credit: JAXA).

  …and the most recent images from the joint SETI/NASA airborn observation program;

 Hayabusa re-entry...is that the sample return package flying formation to the right? (Credit: NASA/SETI).

Re-entry as seen from the air; is that a sample return capsule I see flying in formation to the lower right? (Credit: NASA/SETI).


31.03.10- S.E.T.I. Turns 10!

Tired of waiting for E.T. to call? Late last year, the distributed computing program that started it all, http://setiathome.berkeley.edu/, turned ten. One of the most scientifically ambitious programs run before bedtime, SETI@Home showed us that computers could do more than display flying toasters in their spare time.  In fact, word of the first SETI@Home way back in ’99 initially convinced us here at Astroguyz that we probably should get a home computer, and we’ve been hooked ever since. Sure, the Vulcan home world has yet to present itself, but this is one of those experiments that even one confirmed positive hit would have some amazing implications!

In 2001, SETI@Home essentially became the world’s largest collective super-computer. But what you may not realize are the changes that have been made, and the ones that are in store. In 2006, a multi-beam sky survey was introduced. Then in 2007, the Astropulse Survey was launched. Further upgrades to come are a Near-Time Persistency Checker, searches beyond the current 2.5MHz Band, and new methods of limiting terrestrial radio interference, as well as a means for users to share new data. What we’d also like to see is a dedicated SETI@Home platform, perhaps via the Allen Telescope Array. SETI currently piggybacks off of Arecibo data, which itself spends most of its time staring at extra-galactic sources, not prime alien country. Anyway, if you haven’t, now’s the time to donate that idle CPU time for what could be the discovery of this or any other century!

Review: Confessions of an Alien Hunter by Seth Shostak.

Seth Shostak has a unique tale of scientific inquiry to tell. At its heart are questions that some of the greatest thinkers of our time such as Jill Tarter and Carl Sagan have pondered; are we alone? Why are we here? How common or unique are we as a species?

Only very recently has the topic and field of exobiology become a respectable science, and Confessions of an Alien Hunter by Mr. Shostak and out by Nation Geographic Press reflects on how far we’ve come in this very elusive field and where we might be headed. [Read more...]

17.10.09: Pondering the Possible Fate of the Earth.

Colossus-The Forbin Project: a Sci-Fi classic that kicked off the talks!

What’s the future of humanity and life on Earth? Will we have a good multi-billion year run until our Sun swells into a red giant boiling away our atmosphere, or will we first do the job of snuffing ourselves out? Earlier this year, some of the leading thinkers of our time gathered near Harvard University at the Arrow Theater to discuss just these weighty concepts. Dubbed Crossroads: The Future of Human Life in the Universe, each talk in the series was 30 minutes long and solicited an avalanche of enthusiastic questions. Some of the highlights:

-Gerrit Verschuur discussed the Drake equation and just how prevalent any interstellar neighbors might be; at a guesstimated 2,500 light years, we may be pretty, well, spaced out!

-Maira Zuber discussed the future of space travel in the solar system and the difficulties of overcoming probably the biggest engineering problem; prolonged radiation exposure.

-Astronomers Dimitar Sasselov, David Charbonneau, and paleontologist Peter Ward of Rare Earth fame discussed the slew of recent exoplanet findings and the quest for the true coin of the realm; Earth-like worlds around other stars. Most interestingly, the idea was proposed that a “super-Earth” may be more conducive to the development of life, and our own planet may represent the bottom rung of habitability; indeed, as Ward notes, “Rare does not mean unique!” Another interesting proposal by Ward is what he termed the Medea Hypothesis, a sort of anti-Gaia Hypothesis, were the Earthly biosphere may actually occasionally become detrimental to life, and thus fuel mass extinctions. The name comes from perhaps the worst Mom in mythological history!

-Finally, big time elder thinker Freeman Dyson of Princeton urges that our very search methods for life might be flawed, and that we should be looking for “what is detectable, rather than only whats probable.” he also proposed missions targeting such possible abodes for life such as Europa, the icy large moon of Jupiter.

Whatever the future of humanity is, one gets the impression from the visionary speakers presented that it is NOT endless consumerism. The message in the history of life on Earth is clear; evolve or die. No one will save us but ourselves, and the future is collectively ours to choose!

Beyond UFO’s by Jeffrey Bennett.

The topic of extra-terrestrial life is a controversial one. Indeed, it’s only been in the last decade or so that the subject has moved from the realm of science fiction into that of mainstream science. In Beyond UFOs: The Search for Extraterrestrial Life and Its astonishing Implications for Our Future, (Princeton Press), author Jeffery Bennett covers a wide swath of science, leading up to our present day understanding of the emerging field of exobiology.

[Read more...]

The Drake Equation: A Primer.

Nothing fires the ol’ mental juices like the Search for Extraterrestrial Intelligence. Only recently has the very idea of alien life moved from the realm of science fiction to a possible science reality in our lifetimes.

[Read more...]

Astro-Event of the Week: 19-25 August 2008; Spot the globular cluster M13.

As the Moon wanes from the evening night, thoughts here at Astroguyz turn towards the wonders of the deep sky.

One of the finest sights in the northern hemisphere is the globular cluster M13  in the constellation Hercules. [Read more...]