October 20, 2017

27.04.11: Detecting “Exo-Aurorae.”

Saturian aurora seen in the infrared via the Cassini spacecraft. (Credit: NASA/JPL).

Planetary Scientists may soon have a new technique in their arsenal in the hunt for exo-solar planets. Current tried-and-true methods involve measuring tiny radial velocity shifts, catching a gravitational lensing event, or watching and measuring a tiny dip in brightness as a planet transits its host star. [Read more...]

April 2011: Life in the Astro-Blogosphere.

The Best yet of our Quest… A “wing-transit!” (Photo by Author). 

Wow. April 2011 already… and what a year it’s already been in history, astronomy and science. This month sees a look at some celebrity astronomers, another shuttle retirement, and the return of the most photogenic planet to evening skies. Here is what’s on our astro-radar for the month of April 2011; [Read more...]

18.02.11: A Titan(ic) Flyby.

Titan (Lower Left) paired with Saturn as seen from Cassini last year. (Credit: NASA/Cassini/JPL/The Space Science Institute).

Far out in the depths of the solar system, one of our most distant orbiting ambassadors is completing a flyby of the largest known moon. On Friday, February 18th at 11:04AM EST NASA’s Cassini orbiter will skim the Saturnian moon at a distance of just 2,270 miles above the enigmatic moon Titan. [Read more...]

AstroEvent(s): A Week of Moons, Tri-Conjunctions, & Lunar Features!

Venus, Vesta, & Pluto in a 5 degree field of view. (Created by Author in Starry Night).

This week offers a grab bag of unique events, far from the humdrum wide conjunctions and difficult to see pairings. The action starts on February 8th with a rare chance to see Saturn’s moons in 1 -8 order. This occurs in a narrow window from 19:01-19:38 UT, and thus favors the Asian Far East. The planet currently rises around 11PM local, and a majority of the moons should still be in order from your corresponding latitude. [Read more...]

05.02.11: Postcards from Saturn.

Rhea and friends…(Credit: Cassini/NASA/JPL).

Ahhhh, but to be a fly aboard a Saturn-circling mission… this weekend, I want to turn your attention to some fairly amazing imagery coming from NASA’s Cassini spacecraft in orbit about Saturn. Cassini has just completed a flyby of several moons, including Enceladus, returned some first ever images of the tiny moon Helene, and on January 11th, took the close-up of Rhea pictured above. [Read more...]

February 2011: Life in the Astro-Blogosphere.

The Moon, the ISS, & Jupiter… Van Gogh would be proud! (Photo by Author).

The shortest month of the year is upon us. The month of February brings with it some curious moon alignments, a possible shuttle launch, and some rip roarin’ good Sci-Fi;

Coming to a Sky near You: February 1st kicks off with Jupiter’s moons arranged in 1-2-3-4 visual order. The 3rd sees a good occultation of a bright star by asteroid Irmintraud for the central Florida peninsula (re: Astroguyz HQ), and the 8th sees Saturn’s moons in order. [Read more...]

Review: 2001: A Space Odyssey

 

 

Original Theatrical Poster.

Original Theatrical Poster.

 

  This week, we here at Astroguyz are taking a look at a science fiction cinematic oldie but goodie. Stanley Kubrick’s 2001: A Space Odyssey makes the top of nearly every science geek’s short list of movies that bother to get the science right. And like its sequel, 2010, its just plain fun to look back now that those years have come and gone and see how well reality has held up. [Read more...]

AstroEvent: A Challenging Dawn Conjunction.

Saturn & Mercury on closest approach. (Created by the Author with Starry Night).

Saturn & Mercury on closest approach. (Created by the Author with Starry Night).

 

   Set your alarm clocks; one of the closest but most challenging planetary pairings of the year happens this week in the early dawn skies. Mercury and Saturn will be within 1° degree of arc separation the morning of October 8th. Saturn is fresh from superior conjunction behind the Sun, and Mercury is currently undergoing a dawn apparition. Both will fit well in a binocular field of view or a low power eyepiece. The pairing will rise about 45 minutes prior to local sunrise, which for middle northern latitudes will occur around 7:45 AM local. [Read more...]

Astro-Challenge: See Saturn’s Moons in 1 to 7 Order.

Saturn's moons on July 31st. (Created by the Author in Starry Night).

Saturn's moons on July 31st. (Created by the Author in Starry Night).

 

    This week’s challenge may also give you a unique photographic opportunity. On the evening of July 31st (my birthday!) Saturn’s moons will be in 1 to 7 order. This will occur from 6:45 to 11:15 Universal Time, and favor viewers in Australia and the Far East. Later in the evening over North America, only speedy Mimas and Enceladus will be out of order… now is the time to brush up on and perhaps nab some of those hard to spot moons; in descending magnitude, difficulty, and order number (#)  they are: [Read more...]

Astro-Event: A Planetary-Galactic Pairing.

An interesting pairing of Saturn & NGC 4073. (Created by the Author in Starry Night).
An interesting pairing of Saturn & NGC 4073. (Created by the Author in Starry Night).

 

   This week’s astro-challenge may test your skills as a “visual athlete;” a close visual conjunction of the planet Saturn and the galaxy NGC 4073.  This unique event comes to us via the computations of reader Ed Kotapish. On the evening of July 25th, both planet and galaxy will be in a 1 degree field of view. The challenge is twofold; Saturn sits at magnitude +1.1, while NGC 4073 is about 10,000 times fainter at magnitude +11.4. Add into the mix a Moon just a day from Full, and you’ve got a definite challenge… telescopes of 6” inches aperture or larger need only apply. [Read more...]

Review: Voyager by Stephen J. Pyne.

Out July 23rd from Viking Press!

Out July 23rd from Viking Press!

 

   Ours may be an age of discovery like no other. This week, we look at Voyager: Seeking Newer Worlds in the Third Great Age of Discovery, by Stephen J. Pyne, out July 26th, 2010 from Viking Press. This fascinating work delves into the Voyager series of spacecraft missions from a unique perspective, juxtaposing it as a symbol of the third great age of exploration and drawing historical parallels and contrasts with past great expeditions of discovery. [Read more...]

08.06.10: Titan and the Case of the Missing Acetylene.

Titan as imaged by Cassini in 2007. (Credit: NASA/ESA/Cassini).

Titan as imaged by Cassini in 2007. (Credit: NASA/ESA/Cassini).

  

   It started with two papers… as of late, much good and bad science journalism has been committed to the mysteries of Saturn’s largest moon, Titan.  A photochemical smog shrouded world, Titan is a dynamic place, and would easily qualify as a planet in its own right if it were in a solo orbit about the Sun. Titan has only begun giving up its secrets in the past decade; a close flyby of Voyager 1 in 1980 revealed an orange-brown disk devoid of detail. The arrival of the joint ESA-NASA Cassini Huygens mission has led to a wealth of data, as Cassini has performed a series of close mapping flybys of the moon and even deposited the successful Huygens probe on the surface in early 2005. Now, two papers from the Journal Icarus and the Journal of Astrophysical Research describe a curious anomaly; some process is consuming expected acetylene (HC2H) on the surface of Titan. Or something… but wait, let’s not got shouting, “Scientists find life on Titan!” We’re talking an indicator to a possible form of life. The studies site data gathered by Cassini’s infrared spectrometer and ion and neutral mass spectrometer as it swept by the moon. As a matter of fact, Cassini has just completed a 1,270 mile pass recently on June 5th. The process in question is the accumulation of hydrogen molecules high in the atmosphere and raining down to the lakes of methane and ethane coating the surface.  Evidence supports the idea that Titan should be coated with organic molecules, not to be confused with full fledged life itself (old school media take note!). Clearly, something is sequestering the expected acetylene that should be forming… could it be methane-based life? Keep in mind, Titan is a cold place; daytime temps reach a balmy -290 degrees Fahrenheit. Perhaps there may be warmer, as of yet undiscovered pockets of geological activity, but the very idea of methane based life is very hypothetical. Such life forms would be vastly different than what we know here on Earth, and acetylene is on the short list of oxygen-metabolism substitutes. Mark Allen at NASA’s Astrobiology Institute points out that the lack of surface hydrogen and acetylene may have a non-biological cause; “Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed.” Other processes, such as bombardment by radiation or cosmic rays (remember Titan doesn’t have an ozone layer) or the chemical action of minerals could play a role.

So, what should the man on the street take away from this? That Titan is a fascinating and dynamic place, a place in our solar system where things are happening. Clearly, there is more to Titan’s methane- fueled hydrologic cycle than we currently understand, and a spacecraft such as the proposed Titan Survey mission that would put a dirigible-based probe in the atmosphere would go a long way towards solving the “Life on Titan” puzzle. For now, it’ll just have to go on our “Mars-Europa” short-list of interesting places to visit… but don’t believe the “Aliens found on Titan!” news hype just yet!

26.04.10-Amateurs Scour the Solar System.

marshorizon_opportunity

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!

neptune_despina_transit_combo_despinabrightened

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

22.04.10-The Exotic World of Prometheus.

(Credit: NASA/ESA/Cassini).

(Credit: NASA/ESA/Cassini).

 The tiny shepherd world of Prometheus.

    The moons of Saturn continue to astound. The count now stands at 61, and one by one, NASA’s Cassini orbiter is giving us a close up look at these unique worlds, some for the first time. Last year, Cassini passed within 36,000 miles of Prometheus just the day after Christmas. Discovered by Voyager 1 in 1980, this shepherd moon dips within the F-ring once every 15 hour orbit. This fact is apparent as the oblong cratered surface on the 74 mile long moon is coated with a fine layer of dust, giving it a smooth appearance. The constant “plowing” of these moons through Saturn’s rings cause the grooves that we see, and also confines the F-ring. These images are especially satisfying to Carolyn Porco, lead scientist of the Cassini research team who was also on hand for the tiny moon’s initial discovery by Voyager in 1980. It’s likely that we won’t get another look at this bizarre shepherd moon for some years to come!

17.04.10- The Case of the Vanishing Moon: Solved.

(Credit: NASA/ESA/STScI/AURA)

(Credit: NASA/ESA/STScI/AURA)

The scale of the enormous and thin Phoebe Ring as recently imaged by Spitzer.

 

   Since its discovery by Giovanni Cassini in 1671, Saturn’s moon Iapetus has confounded astronomers. Even early on, observers knew something curious was going on with this far off moon; Iapetus varies in brightness between +10 & +12th magnitude as it orbits the ringed planet, nearly vanishing from sight for half its orbit! Late last year, NASA’s Cassini spacecraft and the Spitzer Space Infrared Telescope fingered the culprit; a tenuous outer ring of material now known as the Phoebe Ring that is raining down material on its surface. Like our own Moon, Iapetus is tidally locked in its 79 day orbit. As a consequence, the leading edge plows through this dusty stream of debris. This also causes sunlight to warm and sublimate icy material on the leading side, which streams and re-condenses on the trailing end. This nicely explains the sharply defined and complex boundary seen between the two hemispheres. Alas, no monolith as depicted in Clarke’s original 2001 novel adaptation. .. but perhaps a fine site one day for a cosmic ski resort!

14.03.10-Record Lightning Storm Spotted by Cassini.

The shadow of Titan as viewed by Cassini. (Credit: NASA/JPL/Space Science Institute).

The shadow of Titan as viewed by Cassini. (Credit: NASA/JPL/Space Science Institute).

 

Saturn is turning out to be a very electrified place. Last year, NASA’s Cassini orbiter spied a massive storm that broke the solar system record; beginning in January 2009, this storm raged on for 7 ˝ months, the longest recorded. This marks the ninth storm on Saturn thus recorded; these behemoths tend to be around 1,900 miles in size. It’s been known since the initial Voyager flybys of the ringed world in the 1970’s that an ionization differential of x100 exists in favor of the daytime side of Saturn over its night side, but routine observations by Cassini are revealing what a turbulent world Saturn really is. Cassini utilizes its antennae aboard its Radio and Plasma Wave Science instrument to analyze the powerful radio emissions.   Tantalizingly, the storms almost always originate in a region known as “Storm Alley” at latitude 35° south. The reason for this isn’t entirely clear. Scientists also took advantage of a passage of Cassini behind Saturn’s largest moon, Titan, to confirm the source of these radio emissions. Surely enough, when Titan occulted the body of Saturn, the emissions disappeared, only to return when Saturn came back into view. This was yet another proof that Saturn is still an active and mysterious place.

Astro-Challenge: Spotting Two-Faced Iapetus.

Iapetus

 The wacky orbit of Iapetus. (Created in Starry Night & Paint).

As the majestic planet Saturn approaches opposition on March 21st, I’d like to turn your telescopic attention to one of the most bizarre moons in the solar system; Iapetus. It was way back when in the 17th century that Italian astronomer Giovanni Cassini noted that he could only see Iapetus when it was to the west of the ringed planet, but never to the east. He correctly deduced that Iapetus must not only be tidally locked, that is, holding one face towards Saturn, but must be correspondingly dark on one hemisphere and brighter on the other. In fact, Iapetus is known to vary from magnitude +10 to magnitude +12 over its 79 day orbit, a variation of 6 times in terms of brightness. the Cassini space probe has confirmed the duality of Iapetus, showing us a dark leading hemisphere with an albedo of 5% (think fresh asphalt) and a trailing hemisphere with an albedo of about 50% (think dirty snow). The third largest of the Saturnian moons, Iapetus is a “walnut shaped” world, with a large ridge running the equator of this twisted moon. Discovered by Cassini on New Year’s Eve 2004, no satisfactory explanation for the ridge is known, but the little world must have had a tumultuous history. [Read more...]

27.01.10: As Titan Turns.

Sequence showing an evolving storm on Titan. (Credit: Gemini Obs/AURA/H. Roe/E. Schaller).

Sequence showing an evolving storm on Titan. (Credit: Gemini Obs/AURA/H. Roe/E. Schaller).

 

Think that this winter is brutal here on Earth? As February is about to set in, we here at Astroguyz invite you to contemplate the seasons on Titan, the largest moon of Saturn. At over 3,000 miles in diameter, Titan is larger than some planets, and possesses an opaque hydro carbon smog veil of an atmosphere. There, a balmy summer day might reach 290°F on the thermometer, and sunshine is a dim murk at best. Scientists have recently found out that this seemingly dismal world is in fact a dynamic place, and a world well worth further scrutiny. The Cassini spacescraft has already conducted fly-bys of the mysterious moon since its orbital insertion in 2004, and even deposited the Huygens probe, which still stands as the most distant soft landing of a manned spacecraft ever made. Now, scientists Emily Schaller of the University of Hawaii and Henry Roe of the Lowell Observatory have been successful in tracking storms in Titan’s turbulent atmosphere. Like Earth, Titan is one of the very few rocky worlds in the solar system that possesses a hydrological cycle and weather. On Titan, however, it rains liquid methane and pools of ammonia dot the surface of this bizarre world. Using the 3-meter Infra-red Telescope Facility, Schaller and Roe monitored Titan 138 nights over 2.2 years in the 2.1 micron range, using the much more sensitive Gemini North telescope also on Mauna Kea for follow up observations when things started to look interesting. Titan is a tough target to image; at its best, it presents a disk no more than 0.8” in diameter. The 2008 storm pictured about demonstrates that Titan is indeed a changing world, one that deserves further examination. Cassini has already performed another flyby of Titan earlier this month on January 12th as part of its mission extension.