Dave's Universe

On the road: Celestron Perspective

David Eicher — Mon, 17 Jun 2013 17:00:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-MISC/0131.PortofinoHotel_2D00_RedondoBeach.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-MISC/0131.PortofinoHotel_2D00_RedondoBeach.jpg"]The Portofino Hotel and Yacht Club. // Portofino Hotel[/caption]You may have noticed that I’ve been a little off on posting blogs lately. This has been an incredibly busy time, with a number of projects in midstream and several other big things cropping up for Astronomy magazine’s future. Just absolutely nonstop. But all good.

Tomorrow, Senior Editor Michael Bakich and I will be traveling to Los Angeles to participate in and help to emcee Celestron Perspective, a first-ever conference being put on by the telescope manufacturer. This two-day event begins Wednesday and will focus on astroimaging with Celestron telescopes. It will consist of about 100 imagers, Celestron dealers, and astronomy enthusiasts who have been invited to attend this unique meeting.

Bakich and I will speak about Comet ISON and emcee the awards dinner on Thursday night.

The whole event is taking place at the Portofino Hotel and Yacht Club in Redondo Beach.

It’s the first of its type as far as astronomy meetings go, and we hope to bring you some exciting coverage of the event during and afterward.

Stay tuned.

Comets and the distance scale of the solar system

David Eicher — Mon, 17 Jun 2013 14:49:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Comets/2627.Comet-Hale_2D00_Bopp_2D00_Stecker.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Comets/2627.Comet-Hale_2D00_Bopp_2D00_Stecker.jpg"]Comet Hale-Bopp // Michael Stecker[/caption]Here’s a comet exercise of the day, one that will help you appreciate the scale of the solar system. Take a ruler and mark 1 centimeter on a sheet of paper. That’s the distance between the Sun and Earth, 1 astronomical unit (AU), or about 93.0 million miles (149.6 million kilometers) — vastly farther than we have ever traveled in space as humans. You could also add other planets, too — Jupiter at 5 AU, Saturn at 9.5 AU, Uranus at 19 AU, and Neptune at 30 AU.

Now consider that on this scale, the Kuiper Belt exists between 30 and 50 AU, 30 and 50cm, and that the inner edge of the Oort Cloud begins 220 “yards” from the Sun. On this scale, the outer edge of the Oort Cloud, the “edge of the solar system,” would stretch 1,000 yards away from the Sun — a distance of 10 football fields end to end, with the distance between Earth and the Sun as just 1cm. The distance to the Oort Cloud’s outer edge represents 40 percent of the distance between the Sun and the nearest star system, Alpha-Proxima Centauri.

So when someone says confidently that they will be traveling from star to star, leisurely exploring the Milky Way in a spacecraft, you can begin to get an appreciation of why they very likely will never do that, regardless of technological improvements, simply because of the immense distance scale of the cosmos, even to the outer part of our own solar system or to the closest star to the Sun.

Memories of Comet West: an excerpt from my upcoming book

David Eicher — Mon, 03 Jun 2013 15:45:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Comets/6175.Comet_2D00_West.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Comets/6175.Comet_2D00_West.jpg"]Credit: ESO[/caption]My book, Comets: Visitors from Deep Space, will be published this fall by Cambridge University Press. Here’s a taste of chapter one, which describes my first adventures with viewing Comet West.

Enjoy!

When I was young, I fancied becoming a doctor. The allure of medicine, of diagnosing diseases, of understanding the complexity of the human body — it all seemed endlessly fascinating. It offered a universe of ideas and challenges you could lose yourself in that could help person after person through challenges with illness and health. And then, in the midst of that momentum, when I was 14, in my little southwestern Ohio town, I went to a so-called star party.

Someone had set up a Criterion Dynascope 6-inch reflector, one of those telescopes with a long white tube and with the eyepiece fixed high at the upper end, and I peered in to take my first telescopic look at Saturn. That moment changed my life. Seeing the radiant light from Saturn’s bright orange globe, encircled by golden orange rings and incised by a black gap, made me gasp. The pinpoint of a little saturnian moon hovered nearby. Everything just stopped. I was transfixed by the vision of another world — live, in real time — right before my eyes.

It was early 1976, and the crisp winter air was not yet ready to surrender to spring. Infected with this new awareness of the universe around me, I needed to find out everything I could — to take many more looks through telescopes, or in my case, my dad’s pair of binoculars. Just as I was scrambling my first set of primitive equipment together, a friend called and gave me some promising news. “If you’re getting into astronomy, you’re in luck,” he blurted out. “There’s a bright comet that’s gonna be amazing soon, but you’ll have to get up early in the morning to see it!”

Along came another magic moment. Wandering out into the backyard, stepping across into the adjoining cornfield, and gazing up at the stars of Aquarius, I was thunderstruck at the sight. The icy cold air, dead silence of the early morning, and strange adventure of being out alone in a field before dawn added to the eerie, almost mystical sight that hovered over the planet. There, starkly visible in plain sight, like a shimmering sword hanging over Earth, was the bright glow of a comet with a fuzzy, starlike head and a long tail skirting upward and to the left. This was my first look at Comet West, the first look of many.

To someone who lived my whole life to that point on a “2-D planet,” like most of us beset by daily life, this was a dose of sudden magic. Who knew that you could simply walk out and so easily see such a range of incredible sights in the universe, far away from Earth? And not only was Comet West a spectacular sight, bright enough to be stunning in its odd and unexpected appearance, but it also showed me in just a day or two that objects in the heavens change rapidly. The comet changed appearance when viewed through a telescope and changed position in the sky from night to night. I was catching on that there’s a whole lot more to this universe than I might have believed a few days earlier.

Each day, the comet rose in the early morning sky in the east, the tail peeking above the horizon first and then finally the head clearing the trees and moving up to complete the stunning portrait. Each morning, it was fully visible in a dark sky before dawn finally moved in and broke up the show. Here was a daily adventure, one that revealed the universe around us as a dynamic and unpredictable place, and that we inhabit just one little tiny spot in it, indeed even a small corner of our solar system. That late winter and early spring, Comet West became one of the Great Comets of the 20th century, peaking at magnitude –3, making it brighter than the planet Jupiter.

Amateur astronomer captures gravitational streamers from galaxy

David Eicher — Tue, 28 May 2013 16:42:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Galaxies/7183.Splinter_2D00_Galaxy_2D00_and_2D00_tidal_2D00_effects.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Galaxies/7183.Splinter_2D00_Galaxy_2D00_and_2D00_tidal_2D00_effects.jpg"]NGC 5907 imaged with a TEC 140mm f/7 apochromatic refractor, a FLI ML 8300 CCD camera, Baader filters, and 21.5 hours of total exposure time on May 1, 3, 4, and 5, 2013, from WhistleStop Observatory, Grafton, Ontario, Canada. // Credit: Lynn Hilborn[/caption]Astroimager Lynn Hilborn of the WhistleStop Observatory in Grafton, Ontario, Canada, sent me this fantastic image of the galaxy NGC 5907 in Draco, which is sometimes called the Splinter Galaxy.

“Some time ago in an editorial, you requested astrophotographers to consider some of the rarer objects for possible inclusion in the magazine,” wrote Lynn. “I was delighted to pick up the extended stellar tidal stream around the galaxy after 21.5 hours of imaging with my modest TEC140 and FLI ML 8300 camera.”

The faint tidal stream is visible as a ghostly, C-shaped loop to the left of the galaxy.

That is an absolutely amazing shot — to capture the streamers of gas coming off the galaxy from gravitational interactions is fantastic. The galaxy lies at a distance of about 42 million light-years.

Congratulations, Lynn!!

A great new book: Sun Kwok’s "Stardust"

David Eicher — Wed, 22 May 2013 16:23:00 GMT

Longtime readers of Astronomy magazine undoubtedly know of our great friend and colleague Sun Kwok of the University of Hong Kong, one of the world’s leading experts on astrochemistry and stellar evolution.

I’m delighted to say that Sun’s new book is just out, Stardust: The Cosmic Seeds of Life (267 pp., paper. Springer-Verlag, New York, 2013, $39.95, ISBN 978–3–642–32801–5). This is one of the most entertaining books I’ve seen in astronomy in a while and fills a major gap in the popular literature of astronomy. The book’s chapters cover where life came from, cosmic dust and rocks, impact hazards from the solar system, the life cycles of stars, gems from heaven (in which Sun used a few examples of minerals from my collection as illustrations!), the possible celestial origin of oil, bacteria in space, and many other interesting topics.

This is a really fine and absorbing book you should know about. I urge you to seek it out and devour it!

The Tunguska event: an excerpt from my upcoming book

David Eicher — Mon, 20 May 2013 15:21:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Comets/2117.Hale_2D00_Bopp.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Comets/2117.Hale_2D00_Bopp.jpg"]Credit: Michael Stecker[/caption]My book, Comets: Visitors from Deep Space, will be published this fall by Cambridge University Press. Here’s a taste of an introductory chapter that describes the impact dangers from near-Earth objects, and specifically, in this chunk, the famous Tunguska event of 1908 . . .

Enjoy!

What’s come to be known as the Tunguska event occurred along the Podkamennaya Tunguska River in central Siberia, in the present-day subject of Krasnoyarsk Krai, a region occupying 13 percent of Russia’s territory. Suddenly, on June 30, 1908, an enormous explosion thundered over the mostly uninhabited, forested landscape, flattening perhaps 80 million trees over 830 square miles (2,150 square kilometers). An enormous flash and bang were seen and heard over a huge area of the country, stunning hundreds of thousands of people. The shock wave from the blast would have registered about 5 on the Richter scale.

Tunguska was first noticed about 7:17 a.m. that morning when indigenous Evenks of the Russian North saw a blindingly bright column of bluish light sweeping across the sky. Some 10 minutes later came an immense flash of light and dull, heavy thudding akin to distant cannon fire. The sound rolled over the landscape in the direction of east to north. The air heated by the trail of the incoming object expanded and broke windows hundreds of kilometers distant. Fluctuations in atmospheric pressure were detected as far away as England. High-altitude ice particles floated, locked in suspension, and caused an eerie glow high in the night sky for several evenings after the event. Atmospheric transparency decreased for several months due to substantial dust kicked high into the atmosphere.

Eyewitness testimony was varied and recorded with enthralling details. The newspaper Sibir reported: “We observed an unusual natural occurrence. In the north Karelinski village the peasants saw to the north west, rather high above the horizon, some strangely bright (impossible to look at) bluish-white heavenly body, which for 10 minutes moved downwards. The body appeared as a ‘pipe,’ i.e. a cylinder. The sky was cloudless, only a small dark spot was observed in the general direction of the bright body. It was hot and dry. As the body neared the ground (forest), the bright body seemed to smudge, and then turned into a billow of black smoke, and a loud knocking (not thunder) was heard, as if large stones were falling, or artillery was fired. All buildings shook. At the same time the cloud started emitting flames of uncertain shapes. All villagers were stricken with panic and took to the streets, women cried, thinking it was the end of the world.”

The Tunguska event, blast, or explosion, as it was variously known, largely remained a mystery — substantially because of the then incredibly remote place where it occurred. Not until 13 years later did the Russian mineralogist Leonard Kulik (1883–1942) first visit the region. (Of course, delays also took place due to events that took precedence — World War I, the Russian Revolution, and the Russian Civil War.) When he arrived on scene in 1921, undertaking a survey for the Soviet Academy of Sciences, Kulik deduced the blast must have been caused by the impact of a giant object from space. Astonished by the enormity of the forest destruction and lured by the possibility of a large amount of recoverable iron from the offending meteorite, Kulik persuaded the academy to fund a proper expedition to investigate.

When his expedition returned in 1927, Kulik talked the local Evenks into taking him to the site of the central impact. The journey was long and difficult, and the locals would not pass all the way to the impact zone, fearful from freshly created superstitions. Kulik pressed on and found, amazingly, that he could not find a crater at all. Instead, he discovered a huge zone of scorched, upright trees whose branches had burned off; this spanned some 5 miles (8 kilometers) in diameter. (The surrounding trees for many kilometers in every direction were flattened like matchsticks.) More than 30 years later, researchers determined the blast created a butterfly-shaped zone of devastation whose “wings” stretched across 43 miles (70 kilometers) and whose “body” covered 34 miles (55 kilometers).

Over the next decade, Kulik led three more expeditions to the remote Siberian forest. He found holes and bogs he attributed to meteorite strikes but later discovered stumps in some of them, ruling out meteoritic craters. The first aerial images of the blast zone were taken in 1938. Later research trips uncovered tiny silicate and magnetite spherules in the soil. The high percentage of nickel found in some of these spheres strongly suggested a meteorite as the impactor. With no impact crater, however, it seemed clear that whatever whizzed into Earth from space exploded in the air above the Siberian woods, raining debris down violently from above.

Later scientific analyses of bog areas in the region also uncovered evidence of an extraterrestrial impact. Layers of sediment in the bogs were analyzed and found to contain different amounts of various carbon, hydrogen, and nitrogen isotopes than the layers from before and after 1908. The layer corresponding to the year 1908 also contained much larger amounts of iridium than normal, in an analogy to what would later be found in the K-Pg sedimentary rock.

So if the Tugunska event was caused by an impact, what happened to the body that struck Earth? Researchers could never find any evidence of solid bodies, meteorites, recovered from the site. Clearly, a significant object came hurtling in from space, exploded violently, and left almost no trace of itself save for the widespread damage that it caused. From 1908 onward, scientists were left with quite an impact puzzle.

In 1930, British astronomer Francis J. W. Whipple (1876–1943) — unrelated to the American Fred Whipple — proposed that perhaps the Tunguska impactor was not an asteroid but a comet. In contrast to an iron-nickel or rocky meteorite, a predominantly icy comet may have largely vaporized as it slammed into the lower part of the atmosphere, most of it disappearing into gas. The fact that Europeans saw a brighter than normal sky for several nights after the impact might also support this idea, the icy particles, water vapor, and dust scattered by the decomposition of a comet lingering in the upper atmosphere before being dispersed.

Since then, the idea that Tunguska was a comet that exploded in an airburst has washed back and forth, generally finding support but also coming into question. In 1978, Slovak astronomer Ľubor Kresák (1927–1994) linked the Tunguska impactor to the well-known periodic comet designated 2P/Encke, the parent body of an annual meteor shower called the Beta Taurids, which peaks in intensity during the last days of June. Kresák pointed out that the Tunguska event occurred during that shower’s activity and that the orbital trajectory of the impactor would have matched a stray fragment from that meteor shower.

A 1983 paper by American astronomer Zdenĕk Sekanina argued that the Tunguska object could not have been a comet because a comet would have disintegrated long before it approached the ground. American astronomer Christopher Chyba suggested that a stony asteroid could enter the atmosphere at high velocity, encounter a force that flattens and pancakes the leading edge, and create an explosion that blows the object apart, releasing nearly all its energy and leaving no crater. And a team led by Italian physicist Giuseppe Longo found that resin trapped in the trees of the Tunguska impact region contained grains typical of stony asteroids and atypical of comets. They also identified Lake Cheko, a small body of water in the region, as a possible crater tied to the Tunguska event. This may have been caused by a small fragment sent reeling downward by the Tunguska airburst.

The comet hypothesis received a boost in 2010 when Russian-American physicist Vladimir Alexeev studied the Suslov Crater, one of the bog-like holes found by the Kulik expeditions, this one spanning 105 feet (32 meters). Alexeev’s team concluded this crater was indeed formed by the impact of a body from above. The surface was covered by permafrost, but lower layers revealed disturbed ice and, at the lowest levels, icy debris that may have come from the impactor itself, supporting the comet hypothesis.

Planetary scientists still debate whether the Tunguska event was caused by a cometary nucleus that shattered in an airburst or an asteroid that violently exploded and left little trace — and, of course, the lines between comets and asteroids are becoming increasingly blurred. What’s clear is that a small body of the solar system some 330 feet (100 meters) across fell rapidly toward the Siberian forest and, 3 to 6 miles (5 to 10 kilometers) above the ground, exploded violently with the force of 1,000 Hiroshima bombs.

Never before or since have humans recorded such an event of exactly this type.

Michael Bakich and Dave Eicher to attend Celestron Perspective

David Eicher — Mon, 13 May 2013 15:33:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-MISC/2425.Antares.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-MISC/2425.Antares.jpg"]Antares region. // Ivan Eder[/caption]Some 60 people will attend an event next month in Los Angeles that is the first of its kind. Telescope manufacturer Celestron will put on an event called Perspective in which they host an invitation-only audience of telescope dealers and astroimagers at a fancy oceanfront hotel in Redondo Beach. The two-day conference, slated for June 19 and 20, will include talks and seminars by well-known astrophotographers including John Davis, Christopher Go, and Warren Keller.

The event also will feature workshops by telescope and imaging experts, a Celestron factory tour, hands-on demonstrations, new product announcements, special awards, and camaraderie.

Not only will Michael and I be attending, but we’ve also been asked to emcee the awards dinner on the final evening. So I can only warn you that we’ll be invoking the spirits of George Carlin and Rodney Dangerfield.

It should be a really fun night and a fun event, and I’ll keep you posted about further plans as I hear of them.

Eclipse report from Jay Pasachoff

David Eicher — Fri, 10 May 2013 18:25:00 GMT

[caption image="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Eclipses/3302.2013_2D00_Australian_2D00_annular_2D00_eclipse_2D00_Kier.jpg" position="right" targeturl="http://cs.astronomy.com/cfs-file.ashx/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-72-Eclipses/3302.2013_2D00_Australian_2D00_annular_2D00_eclipse_2D00_Kier.jpg"]Credit: Ruben Kier[/caption]Today’s annular eclipse was visible widely across Australia and other areas of the South Pacific, and early reports have it as a big success. I take pleasure in sharing the report sent by Jay Pasachoff, astronomer at Williams College and a longtime contributor to Astronomy:

We can report good success in observing 4 minutes 20 seconds of annularity at the eclipse today, about 62 miles (100 kilometers) north of Tennant Creek, Northern Territory, Australia. On one side of the road, there was a turnoff to a hill that carried a radio repeater, and about 100 people had gathered there in the very early morning in anticipation of the 8:05 a.m. annularity, not to mention the beginning of the eclipse at 6:55 a.m. A wide variety of telescopic and photographic equipment was on view. Most of the people present were Australian amateurs or tourists. Several teams of Japanese amateur astronomers also were deployed north of Tennant Creek, though not at this location.

There were clouds in the sky, and much of the eclipse was viewed through thin clouds, though rarely after the first few minutes was the Sun obscured. The clouds thinned considerably before annularity, which were observed in a pretty clear sky. The air cooled noticeably when the Sun was almost entirely covered, and the shadows sharpened because they were being cast by a thin crescent of Sun.

We now look forward to the next total eclipse of the Sun, which will be visible from Gabon, Africa, on November 3. Another annular eclipse, on April 29, 2014, will have its annularity visible only from an inaccessible ocean spot off Antarctica, but Australia will see about 60 percent coverage.

If you have any images from the annular eclipse, submit them to the Astronomy.com Reader Photo Gallery or email them to readergallery@astronomy.com.

Another Brian May 3-D image of Comet PANSTARRS!

David Eicher — Tue, 07 May 2013 19:41:00 GMT

Yesterday, I shared a cool 3-D image of Comet PANSTARRS sent by Ph.D. astronomer, Queen guitarist, and Astronomy Editorial Advisory Board member Brian May. Today, I have the good fortune to share another image Brian sent me.

You may know that Brian is very much into stereo photography (see “Brian May’s world of stereo astro imaging,” Astronomy, January 2012), and he has produced these very cool shots with images taken by a number of astroimagers. You can view them by relaxing your eyes, at the right distance, until the images blend together and you see the comet floating in front of the starry background.

You can also use an OWL viewer to do this properly, without having to defocus your eyes. See the London Stereoscopic Co. website for more info on OWL viewers (which were designed by Brian) and on astronomical 3-D photo sets. (Hey, you might want some of the 3-D Queen shots taken by Brian and others, too.)

This impressive picture shows PANSTARRS was shot by Jamie Cooper of Northampton, United Kingdom (And happy birthday, Jamie! — May 6.)

Enjoy!

Brian May’s amazing 3-D image of Comet PANSTARRS

David Eicher — Mon, 06 May 2013 19:31:00 GMT

Ph.D. astronomer, Queen guitarist, and Astronomy Editorial Advisory Board member Brian May sent some 3-D images of Comet PANSTARRS (C/2011 L4) the other day. These are absolutely incredible and will blow your mind when you see them in the right way.

You may know that Brian is very much into stereo photography (see “Brian May’s world of stereo astro imaging,” Astronomy, January 2012) and he has produced these very cool shots with images taken by a number of astroimagers. You can view them by relaxing your eyes, at the right distance, until the images blend together and you see the comet floating in front of the starry background.

You can also use an OWL viewer to do this properly, without having to defocus your eyes. See the London Stereoscopic Co. website for more info on OWL viewers (which were designed by Brian) and on astronomical 3-D photo sets. (Hey, you might want some of the 3-D Queen shots taken by Brian and others, too.)

This impressive picture shows PANSTARRS with a wide fan-shaped tail and was shot by Ignacio Diaz Bobillo in mid-February 2013.

Enjoy!