Posted on by Nancy Atkinson

Images, Video from Around the World of Asteroid 2005 YU55’s Close Pass

Animation showing Asteroid 2005 YU55 moving across the sky. Each image was a 2-second exposure, taken with the GRAS Observatory, near Mayhill, New Mexico. Credit: Ernesto Guido, Giovanni Sostero and Nick Howes

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A 400-meter-wide asteroid created a lot of “buzz” as it buzzed by Earth, with its closest approach on November 08, 2011 at 23:28 Universal Time (UT). The Near-Earth Asteroid 2005 YU55 passed within 319,000 km (202,000 miles or 0.85 lunar distances, 0.00217 AU) from Earth’s surface. Later, it safely passed our moon at distance of 239,500 km (148,830 miles ). Astronomers from around the world trained their telescopes on this object, hoping to capture images and learn more about this dark space rock.

Above is an animation from the team of Ernesto Guido, Giovanni Sostero and Nick Howes, remotely using the the GRAS Observatory near Mayhill, New Mexico USA with a 0.25-meter telescope, f/3.4 reflector and a CCD camera. The trio said that at the moment of their observing session the asteroid was moving at about 260.07″/min and it was at magnitude ~11. You can see more images and details on their Remanzacco Observatory website. A single image they took is below, along with other observations from various points around the globe, including an infrared image taken with the Keck Observatory.

This first infrared image of asteroid 2005 YU55 was captured by the Keck II telescope. Credit: William Merline, SWRI / W.M. Keck Observatory

The Keck Observatory hosted a live webcast of their observations of the asteroid, hoping to get infrared images and perhaps a three-dimensional view of the asteroid with one of the world’s largest optical/infrared telescopes. They also hoped to be able to look for moons around the asteroid, as about 20% of asteroids have “moons” orbiting them. Battling delays from fog at the summit of Mauna Kea, they team had to wait until conditions cleared, which unfortunately meant the asteroid was farther away when they were able to take a one-second infrared observation. Principal Investigator Bill Merline said it may take days to process this raw data, so look for a more refined image from the team soon. The webcast was a lot of fun, as they showed the events going on insides the observing rooms on both the summit and Waimea, and answered questions from viewers.

This video above is from Jason Ware from Plano, Texas USA who observed Asteroid 2005 YU55 with a 12 inch telescope to create the video.

Near Earth Asteroid 2005 YU55 on 11-08-2011 07:18pm E.S.T., a 10 second exposure. Credit: John Chumack

John Chumack of Galactic Images in Ohio took this image of the asteroid on 11-08-2011 at 07:18pm E.S.T., a 10 second exposure using a 16″ telescope and a QHY8 CCD. John also created a video, which is available on Flickr.

Peter Lake from Australia, has a telescope in New Mexico. He took a series of images at around 03:00 UTC on Nov. 9, using a 20-inch Planewave with a FLI PL11002M. The image field is 4008 X 2675 pixels and about 0.91 arc secs per pixel, so it passed at about 500 arc sec per minute, Lake said.

This video was taken by Steven Conard at the Willow Oak Observatory in Gamber, Maryland USA, with observations on November 9, 11 with the WOO C-14 telescope. This one has a special bonus–a satellite passes through the field as well.

We’ll add more images and video as they become available. Add your images to our Flickr group and we’ll post them.

Asteroid 2005 YU55’s flyby is the closest approach by an object of this size for the next 16 years. In August 2027, AN 10 is going to come within about one lunar distance from Earth. Astronomers estimate this asteroid is anywhere from 1/2 to 2 kilometers in diameter.

Just six months later, 2001 WN5, a 700-meter-wide asteroid will fly between the Earth and the Moon in June 2028, followed by Apophis on April 13, 2029.

Posted on by Ray Sanders

Absorption Lines Shed New Light on 90 Year Old Puzzle

Gemini North Observatory, Maunakea Hawaii. Image Credit: Gemini Observatory/AURA

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Using the Gemini North Telescope, astronomers studying the central region of the Milky Way have discovered 13 diffuse interstellar bands with the longest wavelengths to date. The team’s discovery could someday solve a 90-year-old mystery about the existence of these bands.

“These diffuse interstellar bands—or DIBs—have never been seen before,” says Donald Figer, director of the Center for Detectors at Rochester Institute of Technology and one of the authors of a study appearing in the journal Nature.

What phenomenon are responsible for these absorption lines, and what impact do they have on our studies of our galaxy?

Figer offers his explanation of absorption lines, stating, “Spectra of stars have absorption lines because gas and dust along the line of sight to the stars absorb some of the light.”

Figer adds, “The most recent ideas are that diffuse interstellar bands are relatively simple carbon bearing molecules, similar to amino acids. Maybe these are amino acid chains in space, which supports the theory that the seeds of life originated in space and rained down on planets.”

“Observations in different Galactic sight lines indicate that the material responsible for these DIBs ‘survives’ under different physical conditions of temperature and density,” adds team member Paco Najarro (Center of Astrobiology, Madrid).

The discovery of low energy absorption lines by Figer and his team helps to determine the nature of diffuse interstellar bands. Figer believes that any future models that predict which wavelengths the particles absorb will have to include the newly discovered lower energies, stating, “We saw the same absorption lines in the spectra of every star. If we look at the exact wavelength of the features, we can figure out the kind of gas and dust between us and the stars that is absorbing the light.”

Spectra of the newly discovered Diffuse Interstellar Bands (DIB's).
Image Credit: Geballe, Najarro, Figer, Schlegelmilch, and de la Fuente.

Since their discovery 90 years ago, diffuse interstellar bands have been a mystery. To date, the known bands that have been identified before the team’s study occur mostly in visible wavelengths. Part of the puzzle is that the observed lines don’t match the predicted lines of simple molecules and can’t be traced to a single source.

“None of the diffuse interstellar bands has been convincingly identified with a specific element or molecule, and indeed their identification, individually and collectively, is one of the greatest challenges in astronomical spectroscopy, recent studies have suggested that DIB carriers are large carbon-containing molecules.” states lead author Thomas Geballe (Gemini Observatory).

One other benefit the newly discovered infrared bands offer is that they can be used to better understand the diffuse interstellar medium, where thick dust and gas normally block observations in visible light. By studying the stronger emissions, scientists may gain a better understanding of their molecular origin. So far, no research teams have been able to re-create the interstellar bands in a laboratory setting, mostly due to the difficulty of reproducing temperatures and pressure conditions the gas would experience in space.

If you’d like to learn more about the Gemini Observatory, visit: http://www.gemini.edu/
Read more about RIT’s Center for Detectors at: http://ridl.cis.rit.edu/

Source: Rochester Institute of Technology Press Release

Posted on by Ray Sanders

Are Black Holes Planet Smashers?

Light echo of dust illuminated by nearby star V838 Monocerotis as it became 600,000 times more luminous than our Sun in January 2002. Credit: NASA/ESA

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Some supermassive black holes are obscured by oddly shaped dust clouds which resemble doughnuts. These clouds have been an unsolved puzzle, but last week a scientist at the University of Leicester proposed a new theory to explain the origins of these clouds, saying that they could be the results of high-speed collisions between planets and asteroids in the central region of galaxies, where the supermassive black holes reside.

While black holes are a death knell for any objects wandering too close, this may mean even planets in a region nearby a black hole are doomed — but not because they would be sucked in. The central regions of galaxies just may be mayhem for planets.

“Too bad for life on these planets, ” said Dr. Sergei Nayakshin, whose paper will be published in the Monthly Notices of the Royal Astronomical Society journal.

In the center of nearly all galaxies are supermassive black holes. Previous studies show that about half of supermassive black holes are obscured by dust clouds.

Nayakshin and his team found inspiration for their new theory from our Solar System, and based their theory on the zodiacal dust which is known to originate from collisions between solid bodies such as asteroids and comets.

The central point of Nayakshin’s theory is that not only are black holes present in the central region of a galaxy, but stars, planets and asteroids as well.

The team’s theory asserts that any collisions between planets and asteroids in the central region of a galaxy would occur at speeds of up to 1000 km/sec. Given the tremendous speeds and energy present in such collisions, eventually rocky objects would be pulverized into microscopic dust grains.

Nayakshin also mentioned that the central region of a galaxy is an extremely harsh environment, given high amounts of deadly radiation and frequent collisions, both of which would make any planets near a supermassive black hole inhospitable well before they were destroyed in any collisions.

While Nayakshin said the frequent collisions would be bad news for any life that may exist on the planets, he added, “On the other hand the dust created in this way blocks much of the harmful radiation from reaching the rest of the host galaxy. This in turn may make it easier for life to prosper elsewhere in the rest of the central region of the galaxy.”

Nayakshin believes that a greater understanding of the origins of the dust near black holes is important to better understand how black holes grow and affect their host galaxy, and concluded with, “We suspect that the supermassive black hole in our own Galaxy, the Milky Way, expelled most of the gas that would otherwise turn into more stars and planets. Understanding the origin of the dust in the inner regions of galaxies would take us one step closer to solving the mystery of the supermassive black holes.”

Source: University of Leicester Press Release

Posted on by Ray Sanders

Are Pluto and Eris Twins?

Artist's rendering of the distant dwarf planet Eris. New suggests that Eris is almost exactly the same diameter as Pluto. Eris is very reflective - possibly due to the frozen remains of its atmosphere. Image Credit: ESO/L. Calçada

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Back a couple of weeks ago, I wrote an article highlighting the debate between scientists on which dwarf planet is bigger, Pluto or Eris. During a planetary science conference earlier this month in France, word “leaked” out that Eris was still more massive, but likely smaller in diameter.

Today, the latest findings were published in Nature, and as such are now “official”. There’s also some additional information, so I’d like to revisit this topic and include some new details which may help answer the question:

Could Eris and Pluto actually be twins?

Before we answer the pressing question, let’s revisit my prior post at: http://www.universetoday.com/89901/pluto-or-eris-which-is-bigger/.

Bruno Sicardy of the Paris Observatory and his team calculated the diameter of Eris in 2010. The technique they used took advantage of an occultation between Eris and a faint background star. Sicardy’s results provided a diameter of 2,326 kilometers for Eris, slightly less than his 2009 estimate of Pluto’s diameter at 2,338 kilometers.

Combining the diameter estimate with mass estimates yielded a density estimate for Eris which suggests, and is supported by its extra mass, that its composition is far more rocky than Pluto, with Eris being only 10-15% ice by mass.

In this week’s announcement by the European Southern Observatory, additional information was presented which sheds new light on cold, distant Eris.

Regarding the new density estimates, Emmanuel Jehin, one of Sicardy’s team members mentions, “This density means that Eris is probably a large rocky body covered in a relatively thin mantle of ice”.

Further supporting Jehin’s assertion, The surface of Eris was found to be extremely reflective, (96% of the light that falls on Eris is reflected, making it nearly as reflective as a backyard telescope mirror). Based on the current estimate, Eris is more reflective than freshly fallen snow on Earth. Based on spectral analysis of Eris, its surface reflectivity is most likely due to a surface of nitrogen-rich ice and frozen methane. Some estimates place the thickness of this layer at less than one millimeter.

Jehin also added, “This layer of ice could result from the dwarf planet’s nitrogen or methane atmosphere condensing as frost onto its surface as it moves away from the Sun in its elongated orbit and into an increasingly cold environment. The ice could then turn back to gas as Eris approaches its closest point to the Sun, at a distance of about 5.7 billion kilometers.”

Based on the new information on surface composition and surface reflectivity, Sicardy and his team were able to make temperature estimates for Eris. The team estimates daytime temperatures on Eris of -238 C, and that temperatures on the night side of Eris would be much lower.

Sicardy concluded with, “It is extraordinary how much we can find out about a small and distant object such as Eris by watching it pass in front of a faint star, using relatively small telescopes. Five years after the creation of the new class of dwarf planets, we are finally really getting to know one of its founding members.”

Source(s): ESO Press Release , Universe Today

Posted on by Nancy Atkinson

Latest Images of Comet Elenin: Not Much to See

Screenshot of a video of images from the GRAS telescopes in Mayhill Station, New Mexico on Oct. 21, 2011, showing what might be a diffuse blob of material, all that's left of Comet Elenin. Credit: Ernesto Guido, Giovanni Sostero and Nick Howes.

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A series of images of Comet Elenin taken on October 21, 2011 might show an “extremely faint and diffuse blob of light,” according to Ernesto Guido, Giovanni Sostero and Nick Howes, who used two remote telescopes in New Mexico to image again the field of view where Comet Elenin should be. Their first observing session with a 10” reflector showed no obvious moving object in the telescope’s field of view, while the second session a 0.1 meter refractor showed a hint of something moving in the background when images taken 2 hours apart were “blinked,” but interference from moonlight hasn’t been ruled out.

The trio of astronomers encourage other observers to confirm or refute this view with additional observations/images. “We suggest the use of wide-field, fast focal ratio scopes, possibly under very good sky conditions,” they said.

You can see more at the Remanzacco Observatory website, including a video of the “blinking.”

Posted on by Nancy Atkinson

All-Sky Camera Captures Mysterious Flashes

Every couple of weeks or so a strange flash appears on an all-sky camera that searches for meteors. What could it be? Take a look at the video above and maybe you can help solve the mystery.

“They are not iridium flares because they are stationary,” said James Beauchamp, an amateur astronomer who hosts the meteor camera for Sandia National Labs and New Mexico State University, and who posted this video on You Tube. “And they are not geosynchronous satellites because the azimuth/elevation are too far North. They are reflective because they always happen just prior to or after sunrise/sunset. Whatever it is, it’s slow and BIG.”
Continue reading “All-Sky Camera Captures Mysterious Flashes”

Posted on by Ray Sanders

Why is Tonight’s Full Moon the Smallest of the Year?

Moon at Perigee and Apogee. Credit NASA

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Think we can only see half of the Moon’s surface from Earth? Not always.

Over the course of the year, observers on Earth can view a bit less and a bit more than half of the lunar surface. Additionally, the Moon appears smaller in the sky during some months compared to other times of the year.

Due to the processes at work, tonight’s full Moon is an opposite of the “Supermoon” that made headlines earlier this year.

What causes our Moon to change apparent size throughout the year, and how do we notice this phenomenon?

While it would be difficult to judge the apparent size of the full Moon each month with our eyes, the phenomenon of Lunar librations is readily apparent in the animation below.

There are three forces at work that help produce the “dancing” effect as shown in the video above.

There are three types of lunar libration:

First, the Moon doesn’t orbit Earth in a perfectly circular orbit. An eccentric orbit will cause our Moon to lead and lag in its orbital position while its rotational speed stays the same. This causes a libration in longitude.

Secondly, the Moon’s rotational axis is slightly inclined to its orbital plane, with respect to Earth. The Moon’s orbit is also inclined with respect to the ecliptic, allowing the Moon to be illuminated from above and sometimes from below. The illumination from above and below allows some of the lunar surface beyond the poles to be visible from Earth.

Last but not least, there is a small daily oscillation due to Earth’s rotation. This oscillation changes the perspective at which an observer views the Moon. Imagine a straight line connecting the center of Earth with the center of the Moon. Over time an observer would be on one side of this imaginary line and then the other, which would allow the observer to look first around one side of the Moon and then around the other. This is because an observer on Earth is on the surface and not at the center of Earth.

A slight bit of Lunar trivia: Lunar librations helped notable British astronomer Patrick Moore investigate the edge regions where librations provided extra coverage. Moore’s investigations lead him to discover a large circular feature, which he named “Mare Oriental”. Once studies of the Lunar farside were performed from space, it was discovered that Mare Oriental was a lava filled impact crater.

Posted on by Jason Rhian

Book Review: The Space Shuttle: Celebrating Thirty Years of NASA’s First Space Plane

The Space Shuttle: Celebating Thirty Years Of NASA's First Space Plane is chocked full of great imagery and works to cover each of the shuttle's 135 missions. Photo Credit: Zenith Press

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The space shuttle program is over. The orbiters are being decommissioned, stripped of the components that allowed them to travel in space. For those that followed the program, those that wished they did and those with only a passing interest in what the program accomplished a new book has been produced covering the entirety of the thirty years that comprised NASA’s longest human space flight program. The Space Shuttle: Celebrating Thirty Years of NASA’s First Space Plane is written by aerospace author Piers Bizony and weighs in at 300 pages in length.

Bizony is a prolific author who has focused a lot of his work on space flight. Some of the books that he has written include (but definitely are not limited to) include: One Giant Leap: Apollo 11 Remembered, Space 50, The Man Who Ran the Moon: James E. Webb, NASA, and the Secret History of Project Apollo and Island in the Sky: The International Space Station.

Bizony pulls out all the stops in detailing the shuttle era. From thunder and light - to tragedy, the full spectrum of the shuttle program is highlighted here. Photo Credit: NASA

The book contains 900 color images, detailing the entire history of NASA’s fleet of orbiters. From the first launches and the hope that those initial flights were rich in, to the Challenger tragedy and the subsequent realization that the space shuttles would never be what they were intended to be.

The next phase of the book deals with the post-Challenger period and how NASA worked to find a balance with its fleet of orbiters, while at the same time worked to regain the trust of the America public. The path was both hindered and helped by a single payload – the Hubble Space Telescope.

The Space Shuttle: Celebrating Thirty Years of NASA’s First Space Plane - has stunning imagery on every page, allowing the reader to once again view the majesty that the shuttle program provided. Photo Credit: NASA

When the images the orbiting telescope beamed back turned out fuzzy, NASA was a laughing stock. Hubble would become a sensation and NASA redeemed its name after the first servicing mission to Hubble corrected the problem with the telescope’s mirror.

Hubble was not the only telescope or probe that the shuttle placed in the heavens. It would however, be the only one that NASA’s fleet of orbiters would visit during several servicing missions. Besides Hubble the shuttle also sent the Chandra X-Ray telescope, Galileo probe to Jupiter and the Magellan probe to Venus during the course of the program’s history.

It is currently unknown when the U.S. will launch crews into orbit again. Some aerospace experts have even suggested that the shuttles be pulled out of retirement to help fill this gap - but this is highly unlikely to happen. Photo Credit: NASA

NASA was now on course to begin construction of the most ambitious engineering feat in human history – the International Space Station. The Space Shuttle: Celebrating Thirty Years of NASA’s First Space Plane details this period, as well as the tragic loss of the shuttle Columbia in 2003 with great care and attention to detail. Many never-before-seen images are contained within and Bizony uses them to punctuate the history that the space shuttle accomplished with every flight.

With a chance of catastrophic failure estimated by some as being as high as one chance in 53 - the shuttle was a risky endeavor. However, given all of the program's accomplishments - it is not a stretch to say that the shuttle made fact out of last century's science fiction. Photo Credit: NASA

The book also contains a detailed diagram of the orbiter (it is long and therefore was produced as a pull-out section. This element is included near the end and acts as a nice punctuation mark to the stream of imagery contained within.

While it required the combined effort of 16 different nations to make the International Space Station work - the space shuttle made the orbiting laboratory a reality. Photo Credit: NASA

The book is not perfect (but what book is). If one did not know better, upon reading this book one would assume that the Delta Clipper (both DC-X and DC-XA) flew once and upon landing caught fire. DC-X flew eight times – not once. Bizony also describes the lunar element of the Vision for Space Exploration (VSE) as being a repeat of Apollo. Apollo 17 was the longest duration that astronauts roamed the Moon’s surface – they were there for about three days. The VSE called for a permanent crewed presence on the moon.

For those out there that consider themselves “shuttle huggers” this book is simply a must-have. It is perfect to take to autograph shows to be signed by astronauts (as every mission is detailed, it is a simple matter to have crew members sign on the pages that contain their missions). It is also a perfect gift for space aficionados this holiday season. Published by Zenith Press and retailing for $40.00, The Space Shuttle: Celebrating Thirty Years of NASA’s First Space Plane is a welcome addition to your home library.

How will the shuttle be remebered? According to Bizony, given the technological restraints and the numerous accomplishments that the orbiter accomplished - it will be remembered in a positive light. Photo Credit: NASA
Posted on by VirtualAstro

Did The Draconids Perform?

Draconid Meteor Over Somerset UK Credit: Will Gater www.willgater.com

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After weeks of speculation of its intensity, the Draconid/Giacobond meteor shower finally arrived. Some astronomers predicted that this normally quiet meteor shower would deliver up to 1000 meteors per hour at its peak – Were they right?

At approximately 20:00 BST (21:00 UT) on October 8th 2011 the shower started in earnest and many in the UK and Europe looked forward to an evening of meteor watching.

Unfortunately, many people were under thick clouds and missed the display, but there were a few places where the clouds cleared and observers were treated to a memorable spectacle.

I have done many meteorwatch evenings in the past, but this one got exciting very quickly and the uncertainty of the amount of meteors was soon doused.

Many people including myself were popping outside and trying to glimpse meteors through the clouds, but most of the time the Meteorwatch Meteor Live View was being used.

Everything was fairly sedate apart from us all moaning about the weather, but then all of a sudden at approximately 20:30 BST (19:30 UT) The Meteor Live View app on the Meteorwatch website went crazy!

Meteor Live View Credit: meteorwatch.org/ Norman Lockyer Observatory UK

Many people started to get good breaks in the clouds including myself and there were reports of dozens of meteors in just a few short minutes, much to the envy and disappointment of those still clouded over.

At this time the International Meteor Organisation (IMO) reported observations of just over 300 meteors per hour (319 ZHR).

The evening continued and to everybody’s delight (to those who could see meteors), there were many. I saw 3 within a couple of seconds and this continued for about an hour.

Eventually rates started to decline, people saw less and the Meteor Live View started to show less activity.

At approximately 22:00 BST (21:00 UT) meteor activity dropped substantially – The show was over!

The IMO results were posted on their website with rates of just under 350 meteors per hour at the peak of the shower, reported by their observing stations.

Credit: IMO

Did the Dracondids/ Giacobonids live up to expectations in the end? I would say yes, a fairly heavy meteor shower, maybe it could be called a mini storm!

Posted on by Nancy Atkinson

Stunning Timelapse Video of Earth and Sky, Volume 2

Almost a year ago we featured a timelapse video by videographer Dustin Farrell that showed the beauty of our Earth and sky. He’s now completed a second video which is just absolutely beautiful. Of particular interest to Universe Today readers is how Farrell was able to capture the stunning shimmering of stars at night and he even got several long-trailing meteors to make a cameo. Farrell says every frame of this video is a raw still from a Canon 5D2 DSLR and processed with Adobe software. “In Volume 2 I again show off my beautiful home state of Arizona and I also made several trips to Utah,” he writes on his Vimeo page. “This video has some iconic landmarks that we have seen before. I felt that showing them again with motion controlled HDR and/or night timelapse would be a new way to see old landmarks.”

Just gorgeous. Watching in HD with a big screen is recommended. Farrell adds that part 3 may be on the way. (Yay!)