October 21, 2017

Review: How to Build a Habitable Planet by James Kasting.

Some years ago, a book entitled Rare Earth was published amid much controversy. The central thesis of this work was that events that led to the eventual habitability and diversity of life and intelligence on Earth were so improbable, as be near to impossible to replicate elsewhere in our galaxy. The book marked a sort of change in thinking in the realm of exobiology, one from “intelligent civilizations are everywhere” championed by the late Carl Sagan to the concept that we may be the only ones, if not the first.

Out now from Princeton Press!
Out now from Princeton Press!

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26.04.10-Amateurs Scour the Solar System.


A stunning Martian panorama! (Credit:NASA/JPL Image Processing by Michael Howard & Glen Nagle).

   A quiet sort of revolution has been brewing online. Amateur astronomers have taken to the web on cloudy, light polluted nights and turned newly found computing power normally reserved for gaming and Second Life into something truly productive and phenomenal; the reprocessing of planetary images. This link includes more examples than you can shake a robotic camera arm at; the data is culled not only from the raw image archives of older spacecraft such as Mariner 10 and Voyager 2, but newer generation spacecraft such as the Cassini orbiter around Saturn and the Mars Exploration Rover Opportunity pictured above. These images frequently circulate the web and are processed and discussed long before even NASA engineers get to them. And with the mounting number of new missions out there and the transparency and access to public data increasing, the trend is likely to continue. But beyond just pretty pictures, the images dug up often have real scientific merit and value as well; for example, Philosophy professor Ted Stryk actually caught Neptune’s tiny moon Despina in the act of transiting as he sifted through old Voyager data! This makes one wonder; what else might engineers and scientists have missed? Emily Lakdawalla, web editor for the Planetary Society has contributed extensively to this growing revolution of online citizen scientists, taking advantage of Cassini’s equinox mission to produce some stunning images. So give it a try; put that ultimate power sitting idle on your desk to work doing something useful and productive… you just might spot that unknown moon or monolith!


A sight never before seen from Earth; the transit of Neptune’s moon Despina! (Credit: NASA/JPL Image processing & Copyright: Ted Stryk).

Satellite Spotting: A Quick How-to Guide.

Two objects you can see tonite; the Hubble Space Telescope & (if it's in orbit) the Space Shuttle! (Credit: Art Explosion).
Two objects you can see tonite; the Hubble Space Telescope & (if it’s in orbit) the Space Shuttle! (Credit: Art Explosion).

Go out any reasonably clear night around dawn or dusk and look up. Chances are, after a few minutes, a moving “star” will drift silently by. What you’ve just seen is a satellite in low Earth orbit, a symbol of our modern technological age. Many are truly surprised by this sight when I point it out at star parties; I always check for bright passes before I load the ‘scope in the car. Some are active; many are space junk or discarded boosters. A very few, like the Space Shuttle or the International Space Station, may have human eyes staring back at you; and an occasional rare spy satellite may even have electronic eyes of a more sinister nature.  This week, we’re going to discuss the astronomical sub-pursuit of “satellite spotting,” a pastime that anyone can quickly engage in with a minimum of gear and know how. All you really need is a set of eyes, patience, and knowledge of when and where to look. A good Internet connection (hey, you’re reading this, right?) and a pair of binoculars can up your game a notch, as you’ll soon see.

          Satellite spotting used to be a matter of national security. As recounted in Patrick McCray’s Keep Watching the Skies! Operation Moonwatch  recruited amateur spotters to keep tabs on the Russians, as our country found itself woefully unprepared for a potential “red menace from space”. This had its roots in pre-space age aircraft spotters placed along the U.S. coasts by the Civil Air Patrol. Moonwatch officially ended in 1975, but many aficionados liked what they saw, and kept up their skills via ham radio, home stapled newsletters, and various other pre-Internet modes of communiqué. Some can even still get the political goat of a space faring nation or two. For instance, in 1990 satellite spotters reported the classified shuttle deployed payload MISTY as alive and well, much to the chagrin of the U.S. government who had hoped to perhaps use the cover story of a failed launch to put the new breed of spy satellite in orbit.  Conversely, amateurs have been able to quickly confirm and/or deny such recent space age hopefuls as Iran and North Korea in their fortrays into space.

And of course, satellites have been the source of a good many UFO sightings over the years. Some, such as the ever-growing International Space Station, can appear brighter than Venus! Iridium flares are also splendid sights, often brightening up to magnitude -8 before fading out of sight.

Depiction of a Satellite Pass. (Created by Author).

Depiction of a Satellite Pass. (Created by Author).

So, you ask, how can I see these splendid sights? The best time is local dawn or dusk; even after the Sun has set on the Earth’s surface, it’s still shining and reflecting off of objects high over head. Anything that’s visible to the naked eye will be at least several meters across and in low Earth orbit about 50-200 miles up. At that height, things move around the Earth about once every 90 minutes. Fun fact: did you know that Sputnik I was invisible to the naked eye? The vision of folks gathering on their porches to witness this silent messenger of the Space Age now persists in our collective mythos; such a depiction was even shown in the movie October Sky. What most people saw was, in fact, the spent but much larger booster that put it there!

In any event, like much of astronomy, knowing what that moving dot is adds to the moment. At very least, it might help explain grandpa Jeb’s most current UFO sighting…. Here’s where ye ole Internet comes into play. Basically, you’ll need three pieces of information for a successful identification. What time an object is passing over, what’s its max altitude or elevation, and its position, or azimuth along the horizon. Match these up, and you’ve got yourself a successful sighting. Visual characteristics are handy; satellites do not blink (that’s a plane) or leave a fiery trail (that’s a meteor) unless, of course, the satellite itself is re-entering. Anyhow, when Astroguyz wants to know what’s up in the man-made sky, here’s where we turn;

Heavens-Above : This is the ultimate clearing house for online local astronomy; once you’ve got your local latitude, longitude and elevation preset in, it’ll predict passes in an easy to read format. This is a fine starting point and introduction to satellite tracking. The only drawback it has is they can be a bit slow on updates for recent launches.

Orbitron: this is an uber-cool applet that installs onto your computer; once configured, it’ll operate in the field, sans internet connection, a huge plus. The trick is to occasionally update the Two-Line Elements from time to time, as new stuff gets launched and old stuff decays; I find once a month is adequate or more frequently if it’s a rapidly evolving situation, like a recent Shuttle launch. Orbitron is the only true stand-alone, satellite simulation free-ware out there; you can even set it to chirp when a satellite enters or leaves the local sky! It’ll even take hand-loaded TLE’s with a little skill; the only objection would be the need for a possible addition of local constellations in overhead mode.   

Space Weather: If you want dirt simple, Space Weather’s simple satellite tracker is it; simply plug in your zip code for Canadian and US users, or  locale for international, and out comes the local flybys in a no fuss format. Even grampy Jeb could use it!

Spaceflight Now: A good place to track goings on in terms of recent and upcoming launches; Spaceflight Now publishes all worldwide launches right down to the communication satellite that currently brings such trailer park opuses as “Wife Swap” and “Monster Truck Mania” into your house. And their live chat and twitter feed  is indispensible for real time updates.

NASA: It can take some digging, but NASA publishes ground tracks for shuttle re-entries which can be copied and overlaid on Google Earth to aid with possible sightings.

So, what strange beasties are there in the satellite world? While not all inclusive, here’s a short list of what to look out for;

Manned missions: these are the ones that really stir the Buck Rodgers in all of us. It’s just plain neat to think that someone’s chasing zero-g M & Ms around the cabin, right over head. These days, most manned missions revolve around the International Space Station, but expect that to change as we return to the Moon later this decade.

Iridium and other flares: In the mid-90’s, Motorola launched a constellation of communications satellites designed for Sat-phone linkups. These sport three each solar panels that are refrigerator-sized and highly reflective, and if they catch the Sun just right, a brilliant flare will occur, sometimes up to -8 magnitude! Heavens-Above is a great site for predicting these, and you seldom have to wait more than a week to sight a flare from your locale.   

Space junk: After monitoring satellites a bit, you begin to realize just how crowded it’s getting up there. A great many objects in orbit are derelict, mostly boosters used to put satellites in odd or highly inclined orbits. And some can be downright unique, like the tool kit “dropped” by astronaut Heidi Stefanyshyn-Piper last year while working outside of the ISS!

Spy and satellite constellations: Yes, there is some strange goings on in Earth orbit; satellite constellations, such as the NOSS series, are some of the weirdest (and rarest) things you’ll see in the manmade sky. These will look like a group of satellites moving in formation. I’ve seen this only once from North Pole, Alaska, and believe me, it’s a bizarre sight!     

Dumps, dockings and re-entries: If you’re persistent (and lucky) you may be able to witness a docking/undocking of the Shuttle or Soyuz with the ISS. Generally, these happen either two days before launch or landing… following the missions via streaming NASA TV  can come in handy to catch this. Does the Shuttle or ISS look a bit of a fuzzy halo or trail? You might have been lucky enough to catch a fluid dump, which can look pretty cool if you catch it just right. Re-entries of the Shuttle used to be common place, but after the Columbia disaster in 2003, are now less frequent. The shuttle now almost exclusively supports the ISS, which means it must match orbits with the station. Reentry now generally comes in over Central and South America. And of course, unscheduled reentries can happen any time!

So, you’ve seen the pretty moving dots and you want more? The sub genre of satellite spotting is always open to expansion and innovation;

Binocular spotting: A good many objects are out of naked eye visual grasp; a good pair of binocs will aid you in this task. To be effective, it’s helpful to know when a satellite is whizzing by a bright star. Simply aim at the star at the appointed time, and watch the object zip by. I successfully spotted the aforementioned errant tool bag this way! Wide field imaging around the Orion Nebula region some times of year can even turn up geosynchronous satellites, which give themselves away by their slow up and down nodding motion.  

Tracking and photography: A simple way to photograph a satellite pass or flare is to lock the shutter open as your quarry drifts by; a more difficult method is to video or photograph the target at higher magnification through the telescope. Setups can range from sophisticated computer tracking mounts to low tech manual setups; simply aim, keep the satellite in the crosshairs, and hope you nabbed a frame or two for later extraction. Both the Shuttle and the ISS are large enough to show telescopic detail. Another tried and true method is to fix on an object such as the Sun (with proper filter in place!) or Moon and let the satellite come to you. This has the advantage of being possible in the daylight, or when the satellite is not illuminated, although the object moves quick, less than ½ a second across the solar or lunar disk! CALsky can be configured to give you local e-mail alerts for transits in your area.  

Reporting: sure, these days, everybody’s got a blog; but it can also be a great way to get your sightings out. Also, Spaceweather is very approachable for amateur photography submissions, and their Spaceweather Flash routinely posts all things astronomical.

So there you have it, the wonderful and sometimes wacky world of satellite spotting. And unlike some exotic fields of amateur astronomy-dom, this is something you can do tonight with very little startup! Remember, the sky is waiting… and tracking the comings and goings of human and technological activity in orbit can be fun for the whole family to enjoy.

Drama in low Earth orbit! (Credit: STS-51A/NASA).

Drama in low Earth orbit! (Credit: STS-51A/NASA).

Carl Sagan: A Biography by Ray Spangenburg & Kit Moser.

(Editor’s Note; This post is part of our ongoing tribute to Carl Sagan, the man and scientist.)

Think you know Carl Sagan? The recently published Carl Sagan: A Biography by Ray Spangenburg & Kit Moser out earlier this year courtesy of Prometheus Books will show you otherwise. Don’t forget, long before there was Carl Sagan the media icon/spokesperson for humanity via PBS’s Cosmos series, there was Carl the PhD student, family man, and planetary scientist. Perhaps no modern scientific visage (with the exception of Hawking) is immediately as recognizable as Sagan’s, turtle neck, elbow-patched jacket and all. This biography traces his roots from his Brooklyn childhood in the 30′s up through his college and PhD years to his work as a scientist at JPL, to fame via Johnny Carson and publication. The book ends with Sagan’s untimely death, which came way too soon.

Many fascinating aspects of Sagan’s life are brought to light. Sagan found himself in the right place at the right time on many occasions. Attending the 1939 World’s Fair first sparked his interest in science. Like many of us, his childhood subsisted of a steady diet of Sci-Fi, only it was Pulp magazines and Edgar Rice Burroughs back then instead of Star Trek and Battlestar. Later in college he rubbed elbows with such 20th century greats as Urey & Miller, who performed the first seminal experiments on the origin of early life, and Gerard Kuiper, the great planetary scientist. How I would have loved to have been a fly on the observatory dome wall during Sagan’s and Kuiper pre-dawn discussions at the McDonald Observatory!

But Carl’s personal life was as complex as the ponderings of the man himself. Married three times, he frequently fell prey to the same marital dilemmas that plagued Einstein and Gandhi; its just plain hard to be a “great” public persona while being a great father and husband! He was also vexed with achalasia, an esophageal condition that made swallowing difficult. Some of the behind the scenes portraits of Sagan’s work on the Cosmos series paint him as difficult to work with and uncompromising; but perhaps its this quality that has made the series itself so timeless and enduring.

For the record, Sagan got his PhD in 1960 in Astronomy from the University of Chicago for his thesis entitled: “Physical Studies of Planets”. It was a heady time for science, as the Russians had recently thrown down the technological gauntlet in the form of Sputnik. Science may not have been at the forefront of politicians’ minds as they eagerly funded the race to space, but men like Sagan assured that some science did indeed get done. Ironically, it was during the first flyby of another world, Mariner 2 past Venus, that his first marriage dissolved. Sagan was also crucial in bridging the gulf between Soviet and American scientists, no mean feat in beleaguered Cold War climes. He was also key to perhaps one of the greatest planetary exploration legacies of the 20th century; the Grand Tour of the outer planets, first with Pioneer, and then the Voyager space probes past Jupiter, Saturn, Uranus and Neptune, utilizing the post-Apollo technologies to their best advantage. When Vikings I and II touched down on Mars, Sagan was there in JPL eagerly awaiting the images of his childhood world of Barsoom.

But it was for is later era of his life as a elder scientist & skeptic that he was best known. It seems as if a true sign of “making it” as a science writer is when the “cranks” start filling your inbox. It’s truly astounding the number of concocted-in-the-basement, alternative theories of cosmology and what not that have filled loose leaf notebooks over the years. After his first book, The Cosmic Connection, Sagan was introduced to this alternate world. Rather than dismissing it, Sagan carefully brought these folks in and introduced them to real science. His era as a celebrity properly began with his appearances on the Johnny Carson Show, who was himself an avid amateur astronomer. How many scientists make late night TV today?

It was via Cosmos that Sagan entered most of our households, explaining science and the state of man. I was enthralled by the show as a teenager; it was like a real life Star Wars! I especially remember how effectively Carl would convey how long and torturous a path our road to knowledge was, and still is. Scientific knowledge is not easy to come by; many obstacles had to be overcome throughout the ages.

Alas, Carl’s time with us proved to be much too short after his success as a science popularizer. Throughout the 1980′s he could be seen warning against nuclear winter, a term he himself brought into popular focus. He wrote several outstanding books, and continued to advocate the Search for Extra-Terrestrial Intelligence (SETI) in a new era of meager science funding. He also founded the Planetary Society, still one of the largest grassroots citizen science organizations.

Carl’s diagnosis and passing from pneumonia due to his battle myelodysplasia came as a blow to all. Carl had just turned 62 when he passed away on December 20th, 1996; next month, he would have been 75. He missed the opening of the movie Contact based on his only science fiction novel by mere months. One sees the whirlwind of scientific progress and the dilemmas we face and wonder what insight Carl would have, were he still with us.

Read Carl Sagan: A Biography to get a true feel for the man that shaped much of our thinking in the late 20th century. Few scientists have cast such a long shadow in not only the scientific, but political and cultural arenas. We still miss you Carl!



The Moon joins a Planetary Three-Way.

Early risers this week will awaken to a fine sight; a three way dance between Mercury, Saturn, and Venus, joined by the waning crescent Moon on the 16th. Look towards the east, about a half hour before local sunrise. Mercury has just passed greatest elongation on the 6th of this month, and thus will be swiftly sinking back to the horizon morning by morning. Venus will continue to shine high in the east at dawn, and Saturn, fresh from conjunction with the Sun last month, will be the faintest and slowly slide upwards past the pair of inferior planets this week.

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July09: News & Notes.

- Teenage Supernova Discovery: Ah…who says you can’t engage kids in science anymore? Supernova 2008ha was recently discovered by Caroline Moore of Warwick, New York. Discovery actually occurred back in November 7th of last year, and buzz has just passed around the Internet as this is one of the weakest supernovas to be discovered. Perhaps that’s why the big guys missed it…

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AstroEvent of the Week: 04.20.09: A Morning of Moons and Meteors!

There are two reasons to set your alarm this week; one is the annual Lyrid meteor shower, and the second is the lunar/planetary action in the dawn sky. First, the shower. The Lyrids break the lull we’ve had in meteor showers for a few months; this showers’ radiant is located in the constellation Lyra near the star Vega (of Contact fame!) and can be expected to produce about 10 meteors per hour around the mornings of April 22nd.

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April 2009 News & Notes.

The Successful Launch of Kepler: The Kepler space telescope launched successfully last month on March 6th, during a spectacular night launch. Sporting one of the biggest CCD imagers ever to leave Earth, Kepler is bound for an Earth-trailing, heliospheric orbit. Kepler will spend several months staring at a patch of sky in the direction of Cygnus looking for one of the holy grails in astronomy; Earth-sized, terrestrial planets. Stay tuned! This could be one of the potential discoveries of the year!

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Astro-Event of the Week:03.23.09:Can you spot Venus at Inferior Conjunction?

Warning: Do not attempt this weeks’ astro-feat unless the Sun is properly blocked, preferably just below the horizon! Sweeping the area near the Sun with optical equipment introduces the very real possibility of momentarily pointing at the Sun, which can cause optical damage!

This week’s observing challenge is a unique attempt, and will put you in league with a handful of skilled observers that even realize this is possible. It is not generally appreciated that Venus’s orbit is tilted 3.4 degrees in relation to our own, as represented by the ecliptic.

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Astro-Event of the Week; February 23rd-March 1st; A Close Conjunction.

Lots of happenings in this last week of February… the pick for the astro-event of the week was a toughie. I choose the Friday close conjunction/occultation of Venus and the Moon, as it’s one of the closest of the year! And it’s easily observed with the naked eye, and highly photogenic to boot!

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AstroEvent of the Week: February 2nd-8th, 2009; Spot a Daytime Venus!

A Daytime Venus Shortly After Occultation. (Video by Author).


Astronomy isn’t just restricted to a night time activity. Many folks do not realize that objects such as the Moon can be spotted even in broad daylight. This week, I give you a fun daytime naked eye challenge; spotting Venus in the daytime.  No special equipment is required; just a sharp set of eyes and persistence. [Read more...]

Astro-Event of the Week: 1st-7th December, 2008: A dusk tri-conjunction.

This week’s astro-event requires absolutely no gear to observe, just a clear sky. Look westward into the dusk, just after sunset the evening of Monday, December 1st. Venus and Jupiter will be joined by a thin, waxing crescent Moon for a spectacular tri-conjunction . [Read more...]

Astro-Event of the Week, September 9th-15th, 2008: Mercury Reaches Greatest Elongation.

Mercury is an elusive world.

Legend has it that Nicholas Copernicus himself never spotted the fleeting world. This week, Mercury reaches greatest elongation, and provides us with a chance to top one of the greats. [Read more...]

Astro event of the Week, August 12-18, 2008: See a Triple Conjunction!

Alas, poor North America! We miss out of both this months’ eclipses! But I give you as an Astro consolation of sorts; a rare triple planetary conjunction!

On the evening of August, 15th, the planets Mercury, Venus, and Saturn will span an area of less than 2 degrees, a nice binocular view. [Read more...]

UFOs – is ET phoning home?

(Note: As of yesterday, Astroguyz has been live for a year! Let it never be said that we’ll join the legions of “also ran” blogs!)

Next clear night, go outside, away from the street lights, and look up.

On virtually any evening, the casual observer will notice a bewildering menagerie of phenomena. Meteors. Aurora. Even the usual, such as Venus low in the twilight sky, can look unusual at first glance. Venus, in of itself, has been mistaken by air traffic controllers for an approaching aircraft. Imagine their frustration as it refused to answer repeated hails! [Read more...]

Viewing a Low Altitude Occultation

This past Thursday, I got an e-mail from Sky & Telescopes’ automated alert system; Monday, the 18th of June, there would be an occultation of Venus by the Moon visible from extreme northern New England and the Canadian Maritimes.  This occultation would also span the Atlantic, Europe, and into Asia, but would be especially difficult to spot from the continental US (what we in the miltary refer to as ConUS) due to its extremely low elevation in the day time sky.

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