This image of the unusual asteroid Lutetia was taken by ESA’s Rosetta probe during its closest approach in July 2010. Lutetia, which is about 100 kilometres across, seems to be a leftover fragment of the same original material that formed the Earth, Venus and Mercury. It is now part of the main asteroid belt, between the orbits of Mars and Jupiter, but its composition suggests that it was originally much closer to the Sun. Credit: ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA
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According to data received from ESA’s Rosetta spacecraft, ESO’s New Technology Telescope, and NASA telescopes, strange asteroid Lutetia could be a real piece of the rock… the original material that formed the Earth, Venus and Mercury! By examining precious meteors which may have formed at the time of the inner Solar System, scientists have found matching properties which indicate a relationship. Independent Lutetia must have just moved its way out to join in the main asteroid belt…
A team of astronomers from French and North American universities have been hard at work studying asteroid Lutetia spectroscopically. Data sets from the OSIRIS camera on ESA’s Rosetta spacecraft, ESO’s New Technology Telescope (NTT) at the La Silla Observatory in Chile, and NASA’s Infrared Telescope Facility in Hawaii and Spitzer Space Telescope have been combined to give us a multi-wavelength look at this very different space rock. What they found was a very specific type of meteorite called an enstatite chondrite displayed similar content which matched Lutetia… and what is theorized as the material which dates back to the early Solar System. Chances are very good that enstatite chondrites are the same “stuff” which formed the rocky planets – Earth, Mars and Venus.
“But how did Lutetia escape from the inner Solar System and reach the main asteroid belt?” asks Pierre Vernazza (ESO), the lead author of the paper.
It’s a very good question considering that an estimated less than 2% of the material which formed in the same region of Earth migrated to the main asteroid belt. Within a few million years of formation, this type of “debris” had either been incorporated into the gelling planets or else larger pieces had escaped to a safer, more distant orbit from the Sun. At about 100 kilometers across, Lutetia may have been gravitationally influenced by a close pass to the rocky planets and then further affected by a young Jupiter.
“We think that such an ejection must have happened to Lutetia. It ended up as an interloper in the main asteroid belt and it has been preserved there for four billion years,” continues Pierre Vernazza.
Asteroid Lutetia is a “real looker” and has long been a source of speculation due to its unusual color and surface properties. Only 1% of the asteroids located in the main belt share its rare characteristics.
“Lutetia seems to be the largest, and one of the very few, remnants of such material in the main asteroid belt. For this reason, asteroids like Lutetia represent ideal targets for future sample return missions. We could then study in detail the origin of the rocky planets, including our Earth,” concludes Pierre Vernazza.
If you want to photograph something in space, what better way than to have a spacecraft take the picture? The Swift Telescope – better known for its study of high-energy outbursts and cosmic explosions – was able to observe the flyby of 2005 YU55, the asteroid that came within 324,600 kilometers (201,700 miles) of Earth this week, and captured its tumbling, rapid motion across the sky.
“Swift’s ultraviolet and X-ray capability gives scientists a unique perspective on comets and asteroids, expanding the spectral window beyond the radio, infrared and optical observations so well handled by big ground-based facilities,” said Sergio Campana, a Swift team member at Brera Observatory in Merate, Italy.” Campana requested that the spacecraft train its telescopes on the asteroid as a target of opportunity. Continue reading “Swift Satellite Captures Asteroid 2005 YU55’s Tumbling Flyby”
Dr. Randy Korotev at Washington University with the Conception Junction meteorite.
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Meteorite hunter Karl Aston finds meteorites not by digging in the ground, but by placing ads in local newspapers. He asked people who found unusual rocks to contact him. Most responses were bum leads, but in 2009 Aston heard from a farmer in the northwestern Missouri of Conception Junction, who found something interesting: An unusually heavy stone buried in a hillside. The overall size was similar to that of a basketball and had a mass of 17 kilograms (37 pounds). Its rusty exterior hid its true nature. When the farmer had sawed off one end, olive-green crystals embedded in a shining metal shone forth. It was one of the rarest types of meteorites, a pallasite, of which only 61 samples are currently known. Recently, scientists at Washington University in St. Louis have gotten involved in an attempt to discover the meteorite’s history.
Pallasites and other meteorites are relics of the formation of the solar system. The most commonly accepted story for their formation is that they represent a boundary region inside larger asteroids where the heat from formation melted the iron and nickel metal which sunk to the core. The lighter crystals would float, and near this transition, there would be some mixing which, when broken apart due to later impacts, would form the pallasites. These asteroids formed in the asteroid belt between Mars and Jupiter and similar layers would likely be found in larger asteroids still present as well as in planets like the Earth. An alternative theory is that the materials formed independently and were mixed more recently due to large impacts.
The rusting fusion crust on the outside of the Conception Junction meteorite disguises it as just another rock, but one glimpse of the interior gives the game away. The olive-green crystals set in lustrous metal are unique to pallasites. Image credit: Dave Gheesling
Within the United States, 20 pallasite meteorites have been discovered. The majority of them belong to a single family of “main group” pallasites due to a similar chemical composition of their olivine crystals. When compared to other samples, the Conception Junction meteorite was unique. Because of this, the sample was given a unique designation this past August, named after the location of discovery. Before the Meteoritical Society recognizes a designation, it is required that a museum or other institutional collection houses a “type specimen” which will make the material available for scholarly research. As such a portion of the sample will be housed at UCLA where the chemical analysis on the metal was performed (the olivine was examined at Washington University).
The rarity of pallasite meteorites makes them uncommonly valuable. Some slices of the Conception Junction meteorite are still available for sale or trade, but don’t expect it to be an impulse buy. While more common stony meteorites sell for a few dollars per gram, pallasite meteorites sell for a few hundred dollars per gram. The overall price is also determined by the condition (some are unstable in Earth’s atmosphere) and whether or not it has a unique history. Meteorites for which the fall was observed are especially prized.
Wondering if the discovered meteorite was part of a larger body, Aston and other meteorite collectors including Robert Ward and Dave Gheesling conducted an extensive search of the region. They looked for 16 months in concentric circles centered on the original discovery location, but did not find any other specimens.
Concept for a possible gravity tractor. Credit: JPL
With asteroid 2005 YU55 passing close by Earth yesterday, this rather unsettlingly near flyby has many people wondering if we would be able to divert an asteroid that was heading for an intersection with Earth in its orbit.
Of course, as natural disasters go, an asteroid strike on Earth would be extremely bad. Even relatively small space rocks could wipe millions of people off the face of the planet, and for the really big asteroids – like the one that caused the Chicxulub event 65 million years ago – it’s unlikely that humanity would survive. And yet, for all their devastation, asteroids offer a glimmer of hope. An asteroid strike is preventable, given we have the time to deal with it.
“Today no known asteroid is on a collision course with the Earth,” said Dr. David Morrison from NASA’s Near Earth Object (NEO) Program, in a report a few years ago from the Spaceguard Survey that looks for close passing objects. “The Spaceguard Survey does not expect to find any large asteroid that directly threatens us. If, however, such a rock is discovered on a collision course, then we anticipate that we would apply appropriate technology to deflect it before it hits. Asteroid impacts are the only natural hazard that we can, in principle, eliminate entirely.”
There are a few different ways to change an asteroid’s orbital path, but what’s the best way to do it?
First, let’s talk a little about what we’re dealing with. A Near Earth Object is an asteroid or comet whose orbit enters the Earth’s neighborhood – anything that orbits within 195 million kilometers (120 million miles) of Earth’s orbital vicinity. Some objects have been traveling with us for millions years, weaving in and out of our orbital path. Eventually, one of these objects is going to be at the wrong place at the wrong time and impact the Earth.
This chart shows how data from NASA's Wide-field Infrared Survey Explorer, or WISE, has led to revisions in the estimated population of near-Earth asteroids. Credit: NASA/JPL-Caltech
Astronomers everywhere are aware of the problem, and there are several surveys underway to discover and catalog all of the potential Earth crossing asteroids, such as the Spaceguard Survey, working to discover all of the near Earth asteroids larger than 1 km in diameter. Rocks above this size have the potential to end civilization as we know it, so it would be good to know if any of them are heading our way.
But objects as small as 140 meters across will cause regional damage, and even the death of millions if one happens to strike a major city. These smaller rocks are a priority too.
As of November 03, 2011, 8,421 Near-Earth objects have been discovered. Some 830 of these NEOs are asteroids with a diameter of approximately 1 kilometer or larger. Also, 1,262 of these NEOs have been classified as Potentially Hazardous Asteroids that have the potential to make close approaches to the Earth, with a size large enough to cause significant regional damage in the event of impact.
Additionally, recent results from NASA’s Wide-field Infrared Survey Explorer, or WISE spacecraft – which with the other surveys has helped find about 90 percent of the largest near-Earth asteroids — astronomers now estimate there are roughly 19,500 mid-size near-Earth asteroids out there, meaning the majority of these mid-size asteroids remain to be discovered. These are objects between 100 and 1,000 meters (330 and 3,300-feet) wide.
Astronomers are working to create a comprehensive list of every dangerous space rock out there. What if there’s an asteroid with our name on it? What action can we take to reach out and destroy it, or at least change its trajectory away from a collision with the Earth?
We’re not talking about an Armageddon or Deep Impact scenario here; there’s no way to stop an asteroid that’s going to impact us in just a few months — we don’t know how and don’t have the technology. But let’s say we’ve got a few decades warning.
How could we stop it?
NASA's Deep Impact probe hits Comet Tempel 1 (NASA)
Former Apollo astronaut Rusty Schweickart has talked with Universe Today numerous times, and emphasizes that the technology needed to divert an asteroid exists today. “That is, we do not have to go into a big technology development program in order to deflect most asteroids that would pose a threat of impact,” he said. “However, that technology has not been put together in a system design, and not been verified, tested or demonstrated that it could actually deflect an asteroid. So, we need to test everything – test the very sequence we would use for a deflection campaign.”
The best way to test it would be to have NASA, or perhaps a consortium of space agencies, carry out an actual mission to test the entire system.
“Not with an asteroid that threatens an impact,” said Schweickart, “but with an asteroid that is just minding its own business, and we’d have the opportunity to show we can change its orbit slightly in a controlled way.”
Schweickart described two types of “deflection campaigns” for a threatening asteroid: a kinetic impact would roughly “push” the asteroid into a different orbit (a bigger version of what happened with the Deep Impact spacecraft) and a gravity tractor or space tug would slowly pull on the asteroid to precisely trim the resultant change course by using nothing more than the gravitational attraction between the two bodies. Together these two methods comprise a complete deflection campaign, using existing technology.
What are some other options?
Blow it up with nukes
Every Hollywood story dealing with asteroids always involves packing nuclear warheads on board a spaceship and then flying out to blow up the asteroid. Kaboom! Problem solved? Not exactly. The science in these movies is misleading at best, and probably just plain wrong.
Plus, as Schweickart stresses, this is probably a really bad idea. He believes that there the problem of creating many smaller and just as deadly pieces of rock by blowing up a large asteroid (and it might actually increase its destructive power.) But in a report put out by the National Research Council in 2010, scientists admit that nuclear explosions are the only current, practical means for dealing with large NEOs (diameters greater than 1 kilometer) or as a backup for smaller ones if other methods were to fail.
There’s one additional legal catch. Article IV of the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies prohibits countries from using nukes in space. Conventional explosives are permitted, but they just aren’t as effective. But Schweickart worries that NASA may be open to manipulation to put forward the proliferation of space-based nuclear weapons under the guise of international “safety.”
*Update: That said, another mitigation plan also involves nuclear weapons, and is called Nuclear Ablation. This would involve detonating a nuke in close proximity to an asteroid and the radiation vaporizes its surface generating an explosive thrust and a change in velocity in response.
In their 2007 NEO Workshop Report NASA’s Program Analysis and Evaluation determined that such an approach would be 100 times more effective than a kinetic impactor.
Use a Solar Sail
For a more elegant idea rather than blowing it up, physicist Gregory Matloff has studied the concept of using a two-sail solar photon thruster which uses concentrated solar energy. One of the sails, a large parabolic collector sail would constantly face the sun and direct reflected sunlight onto a smaller, moveable second thruster sail that would beam concentrated sunlight against the surface of an asteroid. In theory, the beam would vaporize an area on the surface to create a aerojet of materials that would serve as a propulsion system to alter the trajectory of the NEO.
Tie them Up
Back in 2009 David French, a doctoral candidate in aerospace engineering at North Carolina State University, had the idea of attaching ballast to an asteroid with a tether. By doing this, French explains, “you change the object’s center of mass, effectively changing the object’s orbit and allowing it to pass by the Earth, rather than impacting it.”
Mirror Bees
Another more elegant technique also uses concentrated light to gently move an asteroid. This project, which has been sponsored by the Planetary Society, is called “Mirror Bees.” This uses many small spacecraft — each carrying a mirror — swarming around a dangerous asteroid. The spacecraft could precisely tilt their mirrors to focus sunlight onto a tiny spot on the asteroid, vaporizing the rock and metal, and creating a jet plume of super-heated gases and debris. Alternatively, the satellites could contain powerful lasers pumped by sunlight, and the lasers could be used to vaporize the rock. The asteroid would become the fuel for its own rocket — and slowly, the asteroid would move into a new trajectory.
Artist concept of the Mirror Bees. Credit: The Planetary Society
Lasers
Another interesting technique from the University of Alabama in Huntsville would involve placing a laser system into space, or at a future Moon base. When a potential Earth-crossing asteroid is discovered, the laser would target it and fire for a long period of time. A small amount of material would be knocked off the surface of the asteroid, which would deflect its orbit slightly. Over a long period of time, the asteroid course correction would add up, turning a direct hit into a near miss.
Plastic Wrap
One extremely inventive concept involves using a satellite to wrap an asteroid with ribbons of reflective Mylar sheeting. Covering just half of the asteroid would change its surface from dull to reflective, possibly enough to allow solar pressure to change the asteroid’s trajectory.
Mass Drivers
This idea involves the use of multiple landers to rendezvous and attach to a threatening asteroid, drill into its surface, and eject small amounts of the asteroid material away at high velocity using a mass driver (rail gun or electromagnetic launcher). The effect, when applied over a period of weeks or months, would eventually change the heliocentric velocity of the target asteroid and thereby alter its closest approach to Earth.
Civil defense (evacuation, sheltering in place, providing emergency infrastructure) is a cost-effective mitigation measure for saving lives from the smallest NEO impact events and would also be necessary part of mitigation for larger events.
The key to deflecting a dangerous asteroid is to find them early so that a plan can be developed. Schweickart said making decisions on how to mitigate the threat once a space rock already on the way is too late, and that all the decisions of what will be done, and how, need to be made now. “The real issue here is getting international cooperation, so we can — in a coordinated way — decide what to do and act before it is too late,” he said. “If we procrastinate and argue about this, we’ll argue our way past the point of where it too late and we’ll take the hit.”
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.
The Keck telescopes, located atop Mauna Kea, Hawaii. Credit: W.M. Keck Observatory
Astronomers from the Keck Telescope in Hawaii will be trying to observe Asteroid 2005 YU55 as it flies away from Earth. A live webcast from Keck starts about the same time this article is being published, starting no later than 9 pm U.S. PST on Nov. 8, or Midnight EST/ 0500 UT on Wednesday, Nov. 9. Indications are the webcast might start a little late because of fog on Mauna Kea.
Their hope is to get infrared images and perhaps a three-dimensional view of the asteroid with one of the world’s largest optical/infrared telescopes. The observing run is being webcast live on UStream from the Keck II Remote Operations room in Kamuela, Hawaii. They also are hoping to be able to look for moons around the asteroid. About 20% of asteroids have “moons” orbiting them.
At the helm of the 10-meter Keck II telescope and using Keck’s pioneering adaptive optics to view YU55 will be asteroid investigators William Merline and Peter Tamblyn of Southwest Research Institute, in Boulder, Colorado, and Chris Neyman of Keck Observatory.
Here’s a short movie of Asteroid 2005 YU55, created from data collected from the 70-meter Deep Space Network antenna at Goldstone, California. The video was generated from six frames, and each of the six frames required 20 minutes of radar data collection. They are the highest-resolution images ever generated by radar of a near-Earth object. Continue reading “First Movie of Asteroid 2005 YU55’s Flyby”
This radar image of asteroid 2005 YU55 was obtained on Nov. 7, 2011. Credit: NASA/JPL/Caltech.
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NASA’s Deep Space Network antenna in Goldstone, California has captured new radar images of Asteroid 2005 YU55 as it begins its close pass by Earth. The image above was taken on Nov. 7 at 11:45 a.m. PST (2:45 p.m. EST/1945 UTC), when the asteroid was approximately 1.38 million kilometers (860,000 miles) or about 3.6 lunar distances away from Earth. It’s not a great image, but there should be better images available as the asteroid gets closer. Several telescopes will be tracking of the aircraft carrier-sized asteroid throughout the pass. Goldstone’s 230-foot-wide (70-meter) antenna has been keeping an eye on it since Nov. 4, and the Arecibo Planetary Radar Facility in Puerto Rico will begin observations on Nov. 8, as the asteroid will make its closest approach to Earth at 3:28 p.m. PST (6:28 p.m. EST/1128 UTC).
The Slooh telescope will be hosting a live webcast of the flyby on Nov. 8, 2011. Find out more at the Slooh Events page. Keep track of the latest images gathered by astronomers at the Asteroid and Comet Watch website.
Starmap is an astronomy/planetarium app for the iPhone and iPad. A companion app, called Spacemap is an extended orrery that lets you view the phases, motions, and positions of items in the Universe all from your iPad. If you’re hoping to track down Asteroid 2005 YU55 as it comes close to Earth on Nov. 8, you might want to check out both Starmap and Starmap. You can see this asteroid in both apps, but Spacemap is the only application available in the iTunes store that displays 2005 YU55’s orbit in 3D animation.
UPDATE: The contest is now closed and the winners have been notified.
Want to win a copy of either Starmap or Spacemap? Universe Today has a two copies of each to give away to the first four readers to answer this question correctly: What year was the last time an asteroid as big as 2005 YU55 passed by Earth?
Answer in the comment section, and indicate which app you’d like. We have two of each to give away. First four commenters to answer correctly wins. Make sure your contact info on Disqus is correct, as that is you’ll be contacted.
Passage of of 2005 YU55 near Altair from 6:03 p.m. – 6:12 p.m. EST (11:03 – 11:12 UTC)
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It’s already been stated several times here on Universe Today that 2005 YU55, a 400-meter-wide roughly spherical asteroid, will not pose any threat to Earth as it passes by on Tuesday, November 8… even though it will come within 80% of the distance to the Moon. Many experts have come forward to state this fact, including Don Yeomans of JPL’s Near-Earth Object Observation Program and Lance Benner, a radio astronomer with the Deep Space Network in Goldstone, CA. But it will still be a notable event, being the first time since 1976 such a large object will pass so closely by our planet. So, with the eve of YU55’s approach upon us, let’s turn our curiosity toward another aspect of this cosmic visitation: how can we see it?
Unfortunately there are a couple of factors working against the casual observer being able to witness YU55’s pass. One: it’s a dark object. A very dark object. 2005 YU55 is a C-type asteroid, which means it is composed of carbonaceous material and is thus effectively darker than coal, reflecting less than 1% of the sunlight that it receives. It probably won’t be brighter than magnitude 10. (On the backwards-ranked scale of apparent magnitude, 6 is the limit of best visibility to the average human eye, while -1 or 0 would be a very bright star. Jupiter is about -3 right now, while the full moon would be -12.7. In a typical suburban neighborhood 3 or 4 is the limit of naked-eye visibility.)
And two: the Moon will be close to full on the night of the 8th, and YU55 will be headed in its direction. That sure won’t help visibility.
But, should you be located in a dark area, and should you have a 6″ or larger telescope at your disposal, you may want to give a go at spotting the asteroid that’s caused quite a fuss over the past few months for yourself. It won’t be a simple task, but it’s not impossible – and to help you out teacher, writer and astronomy enthusiast David Dickinson has posted an article about it on his blog, Astro Guyz.
Here’s an exerpt:
Closest approach to Earth occurs at 11:29 UTC/06:29 EST at about 202,000 miles distant, placing it high to the southwest for observers on the US Eastern Seaboard. At its closest approach, 2005 YU55 will glide along at one degree every 7 minutes, easily noticeable after a few minutes of observation at low power. I plan to target selected areas with my GOTO mount, sketch the field, then watch for changes. I may also take some wide-field piggyback stills with the DSLR, but mostly, this one will just be fun to watch.
Visually tracking a Near-Earth asteroid can be thrilling to watch; for example, I’ve actually seen 4179 Toutatis years ago show discernable movement after tracking it for a few moments in the eyepiece!
– David Dickinson
Wide field finder of 2005 YU55 from sunset until 8:30PM EST.
The asteroid will pass through the constellations Aquila, Delphinus, and Pegasus as it heads westward. Interestingly, 2005 YU55 passes within a degree of Altair centered on 6:07:30PM EST only 27 minutes after local sunset, and also makes a very close pass of the star Epsilon Delphini during closest approach. These both make good visual “anchors” to aim your scope at during the appointed time and watch. Keep in mind, the charts provided are rough and “Tampa Bay-centric…”
On an approach as close as this one, two factors muddle the precise prediction coordinates of the asteroid; one is the fact the gravitational field of the Earth will change the orbit of 2005 YU55 slightly, and two is that the position will change due to the position of the observer on the Earth and the effect of parallactic shift. Many prediction programs assume the Earthly vantage as a mere point in space, fine for positioning deep sky objects but not so hot for ones passing near the planet. A good place to get updated coordinates is JPL Horizons website which lets you generate an accurate ephemeris for your exact longitude latitude and elevation.
David goes on to add:
2005 YU55 will pass our Moon at 8 AM Universal Time on November 9th at a distance only marginally closer than it did the Earth, at 140,000 miles. Interestingly, it also transited Sun on November 3rd as seen from the Moon, but would have appeared <1” in size, a tough target for any would-be lunar-based observer. Its next close predicted passage of the Earth won’t be until 2056 at nearly 3 times the distance.
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Excellent information… many thanks to David for sharing with us! (You can read the full article on his website here.) And if you do witness the pass of this asteroid and somehow manage to get some photos of it, you can share them on the Universe Today Flickr group… they may be featured in an upcoming article!
