Super-Earth Found Hiding in Gliese 581 Star System After All

Gliese, or GJ, 581 - a star 20 light years from here

The Gliese 581 star system is roughly 20 light years away from Earth. If we could travel at the speed of light as a species, Gliese 581 is a place a human could visit in a single human lifetime. It is an M3 dwarf star, which is to say it is a Red Dwarf star. This means that its light is relatively faint compared to our Sun (which is a Yellow Dwarf star) and considerably smaller than our Sun, too. Scientists once felt that red dwarfs weren't places you would expect to find habitable worlds, but now - considering that red dwarfs make up maybe 70% of the Milky Way Galaxy - scientists are reconsidering. The Gliese 581 system is a good example of this change in attitude. Previous to the most recent news, Gliese 581 is suspected to contain up to 4 exoplanets (Vogt et al 2010). 

Now a new paper out by Steven S. Vogt, R. Paul Butler, and Nader Haghighipour re-examines the previous HARPS data for the Gliese 581 system. They found that previous attempts to examine the system (Forveille et al 2011) excluded outlying data points. Re-examination of the numbers by Vogt's team confirmed the same 4 planers previously known as well as some additional worlds, including confirmation of the now famous Gliese 581g:

"The periodogram of the residuals to a 4-planet all-circular-model reveals significant peaks that suggest one or more additional planets in this system. We conclude that the present 240-point HARPS data set, when analyzed in its entirety, and modeled with fully self-consistent stable orbits, by and of itself does offer significant support for a fifth signal in the data with a period near 32 days."

The Signatures of Intelligence

Blue Marble 2012 - Can you detect life in this picture? 

Looking for lifeforms out there in the Milky Way Galaxy is a very difficult task. Why so hard? You might say to yourself, "Well, I'll know a living thing when I see it." And generally, with the exception of a sea sponge or a slime mold, that is basically true. But, try recognizing something hundreds of millions of miles away, as is the case with Mars, or hundreds and hundreds of light years away, as is the case with most of the exoplanets we are discovering. In light of such a complication, the business of looking for life comes down to looking for signs of life. In order to do this, one must understand what kinds of life signatures can exist. A knowledge of all the different ways that lifeforms can alter their environment can give us an itemized list of what to look for on other worlds.

So, when scientists get a whiff of an alien atmosphere, as is the case sometimes when an exoplanet is detected by Astronomical Transit, they breakdown the light via spectroscopy and sift through the results looking for key atmospheric gases like oxygen or methane. These kinds of gases are signs of life, as far as LAWKI is concerned (Life As We Know It)...these gases in particular are waste products of the living metabolisms of millions upon millions of creatures. Another sign of life for LAWKI is water, and indeed water is being sought after like the holy grail as far as exoplanet discoverers and astrobiologists are concerned. Just recently, there has been chatter about how to discover exo-oceans - oceans on other worlds - by understanding how light from the parent star can reflect off of that ocean. It is crude to look for life in such a way, but at the moment our options are quite limited. What we need is to broaden our thinking on how particular biological patterns leave particular signatures in the environment they inhabit.

MSL Curiosity to Land in 20 Days

For those of you who might not have heard, the Mars Science Laboratory Curiosity - the most advanced human-made object ever sent to another world - will be landing on Mars Aug 6 2012 at approximately 1:31AM Eastern Daylight Time, or if you prefer, 10:31 pm Aug 5 2012 on the West Coast (or, more appropriately 5:30 am UTC).

While its true that we've been to Mars before, gigantic questions still linger unapologetically in our faces...Questions like, "Did Mars ever have life?" or "Was Mars truly ever a wet planet?" or "Can Mars support Human colonization?" or "What happened to Mars, to its magnetosphere, to turn a perfectly good world into a cold, barren platform for the political maneuvers of the Baron Vladimir Harkonnen?"

The fact is, we know very, very little still about our nearest planetary neighbor. What we can tease out of Mars over the next few years with Curiosity is going to add much to the Search for Life, to our understanding of what is required of a rocky planet to support the creation of life. Mars and Earth are so very similar in many ways, so much so that it appears now, in this pre-Curiosity period, that we are dealing with a kind of Tale of Two Planets. Earth and Mars both seemingly started in the same situation billions of years ago and took two different paths in their planetary lives - Earth headed for the whole teeming-with-life gig while Mars got the Tatooine treatment.

New King of the Galaxy Crowned

The Bad Astronomer (found at Google+, Twitter, Facebook and of course the Bad Astronomy Blog) leads on the story of the star HD 10180, which is a star you can't see with the naked eye, but is readily seen with a telescope. It is in the Hydrus constellation, if your are familiar with your constellations (Hydrus has four stars with planets!). According to a reassessment of the data concerning this star, it seems it possesses nine planets. If you are counting, that is one more planet than our own solar system (or Sol System, if you prefer) contains, if you accept Pluto's current status (RIP Pluto). So, the score so far on the solar system with the most planets is...

HD 10180         9 Planets          Status: King of the Galaxy
Solar System    8 Planets           Status: Runner-up
Kepler 11          6 Planets           Status: Never wins at anything

Horizontal Gene Transfer

Eastern Emerald Elysia - a sea slug. Photo by Patrick Krug of the
Encyclopedia or Life

Everyone knows the usual story of evolution. An organism wishes to pass on its genes to the next generation must do so by surviving and reproducing in a dynamic environment. It must evade predation, avoid the pitfalls associated with weather, find enough food to make it to the next day and convince a partner (if the organism reproduces sexually) to mate in order to pass on those genes. If the genes are well-suited to the context in which it evolved, then the next generation will be given the necessary tools to continue the same struggle. If the genes are not well-suited for some reason, or the environment or competition is too harsh, then the survival of the organism becomes questionable. This story works because of a mechanism we will call Vertical Gene Transfer (VGT). This is where genes are passed from parent to offspring through reproduction.

So, in light of this scientific truth, it may be surprising to know that VGT isn't the only game in town. There is a thing in the world called Horizontal Gene Transfer (HGT). Certain organisms are capable, it seems, of exchanging genes in ways that DO NOT involve the standard sexual or asexual reproduction model. There are several different ways in which HGT can happen:

Thoughts on Life’s Diaspora

Here is a continuation of the discussion regarding Panspermia, which is the idea that life can move from one planetary body to another, in effect seeding a lifeless world. It is a claim that is passed off as science fiction conjecture, in some circles; as perhaps a claim not entirely worthy of scientific investigation. Others, both scientists and laypeople, helpfully counter that the idea of panspermia, as it concerns the origins of life on Earth, is just passing the problem from one place to another without answering the fundamental question, which is "How did life first arise?"

I disagree with the first point, and largely agree with the second. The search for life outside of the Earth IS a goal worthy of scientific investigation. Due to the very reasons that the origins of life are, thus far, inexplicable, so should we regard with seriousness the search for extraterrestrial life as part of the effort to understand the mystery of life's origins. We have no clear answers as to why life arose here on Earth. Even if we do find that mysterious genesis and it sheds some light on the process, we will probably not have a clear understanding of the events that transpired in life's first steps. That will be the case until we have a clear, unambiguous example of non-Earth life with which to compare us to.

Optimism at SETICON 2 and Beyond

The SETICON 2 event happened this past weekend in Santa Clara, California. The SETICON is a "unique, entertaining and enlightening public event where science and imagination meet." Speakers such as SETI pioneer Frank Drake, astronauts Mae Jemison and Tom Jones, Star Trek veteran Robert Picardo, SETI director Jill Tarter, exoplanet explorer Geoff Marcy among many other notable people attended and mingled, marinating in the ideas and the presence of influential personalities.

It seems that everyone is excited. There is a palpable post-SETICON 2-buzz filling the internet this week as a result of all that scientific and creative merging. What is the general theme that the rest of us sense? Optimism. 

The reason is this: we can't possibly be living in more interesting times. The entire planet, in one way or another, is connected via planetary, near-instantaneous computer network that is having profound impacts across all aspects of life. The rate at which we solve problems is increasing exponentially, which seems to be leading to the abundant future recently described by Peter Diamandis. And most intriguingly, we've been discovering hundreds of planets outside of our solar system at an intense rate.