Thursday, March 15, 2018

The Drake Equation

American astronomer and exobiologist, Frank Drake, proposed a simple (if, rather lengthy) algebraic equation, back in the early 1960’s - for determining the potential number of communicating civilizations/societies/populations, in our Milky Way galaxy as represented by the variable, N. These would be civilizations that are both, capable of, and are communicating, at some wavelength via the Electromagnetic Spectrum (EMS). These parameters might be applied to any spiral, or barred-spiral galaxy in the universe, comparable in size and age to the Milky Way.

N = R* x Fp x Ne x Fl x Fi x Fc x L Graphic by Dale Alan Bryant
N = R* x Fp x Ne x Fl x Fi x Fc x L Graphic by Dale Alan Bryant

Radio Astronomy is an area of research which uses,  giant, dish radio-telescopes for monitoring the sky for potential EMS signals from extraterrestrial civilizations/societies/populations, emanating from planets in orbit around stars, other than the Sun. The SETI (Search for Extraterrestrial Intelligence) Institute is the largest organization devoted exclusively to this area of research. The EMS, is the natural source of radio, television, visible-light, infrared, ultraviolet, x-ray, gamma ray, cosmic, and other radiations, which continuously surround us, and in fact, pervade the entire Cosmos. It is presumed that any intelligent beings that have reached a certain technological level of existence, will have discovered the potential for the EMS to be used in long-distance communication, particularly, interplanetary and interstellar communications.

Here is the equation, in its entirety:

N = R* × fp × ne × fl × fi × fc × L

Where: N = the Number of galactic civilizations releasing detectable Electromagnetic Spectrum (EMS) signals into space. R* = the average annual Rate of solar-type star formation in the Milky Way galaxy. fp = the fraction of those stars, that form planets. ne = the average number of those planets, that lie in the star's ecological, or, habitable zone. fl = the fraction of those planets, that actually go on to develop life, at some point. fi = the fraction of those, life-bearing planets, that go on to develop intelligent life. fc = the fraction of those planets, that harbor intelligent civilizations/societies/populations, that are capable of developing a technology which releases detectable signs of its existence, through EMS emissions into space. L = the length of time, for which, a given civilization/society/population releases detectable EMS signals into space (the species, Longevity).

In 1961, when the Drake Equation was introduced, it was thought that very few stars harbored planetary systems, and the conservative value of N, generally, was placed at around 36 million. But as of January 2017, it is known that - almost all stars - have at least one, orbiting exoplanet. (Planets orbiting stars other than the Sun are called, 'exoplanets') As many as 8 exoplanets have been detected orbiting one star - and, one planet - orbiting as many as four stars! More than 4,500 confirmed exoplanets are known, to date. Most of these planets lie within one tiny sector of the sky; the only sector analyzed by the Kepler Orbiting Space Telescope, during the first phase of its mission: an area about the size of a postage stamp held at arm’s length! It lies just east of the constellation Cygnus, the swan (also known as the Northern Cross).

The number of new exoplanets being discovered through data which is still being reviewed from Kepler - is rising dramatically - and, so is our expectation for life elsewhere in our universe. Moreover - if algebraic equations are just not your cup of tea - I think you will find that, this one, just might be! - the only variables in the equation that are currently known, are, R*, and fp, so, you can modify the values of the other variables and play around with the equation, conservatively or radically, as I have, to your heart's content! I've obtained values for N, from, in the millions - all the way down to...3.

Here is a guide for plugging in quantities into the variables in the Drake Equation. I say, "guide", but only roughly: some of the variables are confirmed; some of them are assumed - and, still others are entirely unknown, so, as we progress down the line we become more and more unsure of their exact values. But this is where you come in! - YOU get to decide: the number of planets, where life, or even intelligence, has evolved, or, how many planets might lie in a sun's Habitable Zone - and so on.

I've given you some figures - that I input - the last time I played with the equation, but the numbers can vary wildly, depending on your level of conservativeness, radicalism, or liberality, at any given time (please remember, we are using multiplication throughout).

The values of the first two variables are given with some surety: R* (annual rate (whole number, in 'billions') of star formation in Milky Way galaxy) = 400 billion (400,000,000,000). Fp (fraction of those stars, that form planets) = .99 Ne (average number of those planets, that lie in a star's ecological zone) = 2

And now, the fun part (your input - see, I told you!): Fl (fraction of those planets, that actually develop some form of life) =. 01 Fi (fraction of those life-bearing planets, that go on to develop intelligent life) = .05 Fc (fraction of those planets bearing intelligent life, whose populations advance to form civilizations which are capable of communication, via the Electromagnetic Spectrum (e.g., radio, visible-light, etc. ) L (longevity, in years, of such civilization) = 800

My answer here, for the value of N - using extreme conservatism, throughout - was, of course - 95.04. That is: 95 communicating civilizations, within the Milky Way galaxy, alone. That is a rather poor number, comparatively, but it is a bit more than just, "something". In other, less pessimistic moods, I've come up with hundreds of thousands of living civilizations in our galaxy (including ourselves). Give it a try!...

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Saturday, February 24, 2018

Winter Break at SkyPi

While the snow has been falling at the high elevation of 7.800 ft. in Pie Town, New Mexico, there has not been much imaging time during the last week or two. Therefore we took advantage of the "down time" of the Astronomical Telescope for Educational Outreach (ATEO) to take care of some annual maintenance and upgrading. As we posted earlier, the crew at SkyPi Online Observatories successfully cleaned the 16" primary mirror of the remote telescope with a polymer solution. That was checked off our list!

The ATEO patiently waits for the snow and skies to clear-up in the high elevation of New Mexico.
The ATEO patiently waits for the snow and skies to clear-up in the high elevation of New Mexico.

Muir Evenden, Insight Observatory's Systems Engineer, sent down to the staff at the New Mexico site a few adaptors to install for reaching the "Sweet Spot" of the CCD cameras field of view. This allows the coma in the outer area of the field of view to diminish. Muir also sent along an Astrodon brand "V" filter to replace the Ha filter that had been in the CCD camera filter wheel since its installation last May. The purpose of this filter is to allow users of the telescope to perform real scientific research. The projects included can be studying variable stars and their magnitude changes as well as recording the changing magnitudes of asteroids.

The black Wall Mounted Flat Frame Light Box (left) to be mounted in Gamma Observatory   at SkyPi Online Observatories where the ATEO resides. Photo by Dustin Smith.
The black Wall Mounted Flat Frame Light Box (left) to be mounted in Gamma Observatory 
at SkyPi Online Observatories where the ATEO resides. Photo by Dustin Smith.

This telescope maintenance period also convinced us it would be a convenient time to purchase a Wall Mounted Flat Frame Light Box for creating flats for image processing of data taken by the telescope. The light source is an electroluminescent panel housed behind a sheet of translucent white acrylic, providing perfect even illumination of the field edge-to-edge. A dimmer will be included so we can easily adjust the panel brightness to fit our needs. The alternative to purchasing this built-to-order device was to rush through twilight to shoot all of our flat frames. The light box will be mounted in a position inside the observatory where the telescope park position is so we can take flats anytime. With the beta version of Insight Observatory's remote telescope access portal being released within the next few weeks, we thought the timing of delivery of the flat field box to Gamma Observatory where the telescope is housed to be more than ideal.

Last but not least, Muir successfully installed and tested the latest updated version of TheSkyX software by Software Bisque remotely from his home office. This software application runs all of the telescope and imaging equipment with a Linux operating system installed on a Raspberry Pi. We will be sending notice out to of our subscribers and social media followers when the online beta portal is released.

Once again... Many THANKS to the wonderful staff at SkyPi Online Observatories for all of their hard work and assistance with the maintenance and upgrades on the Astronomical Telescope for Educational Outreach (ATEO).
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Friday, February 23, 2018

Comet Hunters

Main-belt comets are a recently discovered population of small bodies residing in the Solar System's asteroid belt exhibiting distinctive tails that we typically associate with comets. Very little is known about main-belt comets as only about 10 have been discovered to date, but with a larger sample we could probe the origins of the Solar System and the active processes occurring in today's asteroid belt.

View of Mauna Kea (one of the best astronomical observing sites in the world) from the Subaru Telescope Cat Walk - Image Credit: M. E. Schwamb

Zooniverse.org has initiated the Comet Hunters project to try to greatly increase the discovery rate of these objects. Some main-belt comets were first known as inactive main-belt asteroids, and then were only found to have cometary activity in later observations. Asteroids frequently appear by chance in wide-field astronomical observations, and so by scanning through these images, we may have a chance of finding more active objects. We have extracted images of known main-belt asteroids from the public archives of the Subaru Telescope, one of the largest telescopes in the world (at 8.2 meters, or 27 feet, across), located on Mauna Kea in Hawaii. None of the objects we are targeting have been previously known to show activity, but most have so far only previously been studied using small telescopes that may have missed faint activity.

Discovery image of comet-like activity in bright main-belt asteroid Griseldis taken on the Subaru Telescope on Mauna Kea - Image Credit: Adapted from figure by D. Tholen, S. Sheppard, C. Trujillo
Discovery image of comet-like activity in bright main-belt asteroid Griseldis taken on the Subaru Telescope on Mauna Kea - Image Credit: Adapted from figure by D. Tholen, S. Sheppard, C. Trujillo - original image

This is important because we believe we can discover many more main-belt asteroids if we can detect fainter activity, and the way to detect fainter activity is to use larger telescopes like Subaru. Detecting comet-like activity is not easy. Comets can have a wide variety of appearances, and it is difficult to design automated routines to detect all the different types of cometary behavior that might exist in telescope images. In contrast, the human eye can easily spot tails of many different shapes and size that indicate cometary activity.

This is where you come in. By reviewing asteroid images on the Comet Hunters website to identify whether the asteroids has a tail or not, you can help find new candidate main-belt comets that the Comet Hunters science team will then follow up with ground- and space-based telescopes. Most of these chance asteroid observations have never been reviewed for cometary activity before. You just might be the first to discover that an asteroid is really a comet!

Zooniverse.org would love to see Comet Hunters incorporated in the classroom:

A wide variety of ages should be able to perform the task we are asking volunteers to do in the main classification interface in order to help identify new comets residing in our Solar System’s asteroid belt.

You might find some resources on NASA's Asteroid and Comet Watch page helpful. If you are interested in building a scale Solar System to show students where the asteroid belt is located, you can find a guide here.

The Comet Hunters Blog is also a great place to keep up with the latest science results and news from the project. Comet Hunters is currently showing images of previously discovered asteroids with well characterized orbits.

If you develop a lesson based around Comet Hunters, please consider sharing it by uploading it to the Zooniverse Zoo Teach platform. Also check out the Zooniverse's Education Talk discussion board to interact with the Zooniverse Education Team and other teachers interested in utilizing citizen science in the classroom.

Learn more at https://www.zooniverse.org/projects/mschwamb/comet-hunters/about/research
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