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Bill Merline / SwRI / W.M. Keck Observatory
An infrared image produced by the W.M. Keck Observatory in Hawaii shows the asteroid 2005 YU55 as it receded on Nov. 8. Measurements suggest that the space rock was not as wide as originally thought.
The asteroid that had everybody excited on Tuesday is just another space rock today, but 2005 YU55 brought a surprise or two to scientists as it passed by.
As expected, YU55 zoomed harmlessly past our planet at a distance of roughly 198,000 miles (319,000 kilometers) on Tuesday, and made its closest approach to the moon hours afterward.
If the asteroid were on a collision course, Tuesday would have been a very bad day, marked by a cosmic blast equivalent to a 4,000-megaton super-duper nuclear bomb. Instead, it was a very good day for astronomers. They can use the insights gained during this flyby to figure out how near-Earth objects might behave during closer, potentially more dangerous encounters to come.
Scientists tracked the receding asteroid from the Keck Observatory in Hawaii, using an adaptive-optics imaging system, and produced some great infrared pictures (including the one you see above).
Over the next few days, the full data set will be analyzed and perhaps turned into a time-lapse movie, similar to the sequence created from radar imagery during YU55's approach, said Larry O'Hanlon, spokesman for the Keck Observatory. The pictures confirm that the asteroid looks more like an elongated potato than a beach ball, with its side-to-side diameter estimated at 240 meters (787 feet).
"Note that this puts the asteroid at about half the diameter of what previous researchers thought it was," O'Hanlon wrote in an email.
'Puzzling' readings
Meanwhile, researchers are analyzing the radar readings gathered by the Goldstone radio antenna in California.
"The animation reveals a number of puzzling structures on the surface that we don't yet understand," radar astronomer Lance Benner, the principal investigator for the YU55 observations, said in a news release from NASA's Jet Propulsion Laboratory. "To date, we've seen less than one-half of the surface, so we expect more surprises."
Radar observations from the Arecibo Observatory in Puerto Rico will be factored in as well.
Well-equipped amateurs captured some great shots in the visible-light spectrum. Mike Renzi combined hundreds of images from his Starhoo Observatory in Massachusetts to create this video, showing YU55 as a fast-moving dot among the stars:
Asteroid 2005 YU55 captured at the Starhoo Observatory.
Rick Fienberg, press officer for the American Astronomical Society, snapped this time-exposure picture of YU55's track through the night sky:
Richard Tresch Fienberg / AAS
This time-exposure picture from Rick Fienberg shows 2005 YU55's track through the star field. The contrast has been boosted to emphasize the track.
Here's what Fienberg said about the picture:
"I shot this at Phillips Academy in Andover, MA, using my Canon DSLR and the school's 80mm Orion refractor piggybacked on a 16-inch telescope. Asteroid (in Pegasus) is moving lower right to upper left (north is up, east is left), and each streak is 1 minute long, separated by 1-minute gaps (during which the camera was making dark frames). This is a stack of three 1-minute exposures."
For more pictures of YU55, check out SpaceWeather.com's post-encounter roundup — and mark your calendar for June 26, 2028, when an even bigger asteroid, 2001 WN5, is due to even come closer to Earth.
Update for 10:15 p.m. Nov. 9: Asteroid-hunting can be hazardous to your health, even if the space rock is 198,000 miles away from causing a catastrophic cosmic collision. Just ask the six teenagers who said they were held at gunpoint in Marion, Ohio, while trying to catch a glimpse of YU55.
Update for 2:30 a.m. Nov. 11: A member of the Cosmic Log Facebook community, John Giroux, sent along this time-lapse picture of YU55 streaking across the sky. "Thirty-seven images stacked, contrast and brightness adjusted, color removed," Giroux writes. "Seven minutes worth of tracking, from right to left. Note how the brightness periodically varied. The time frame is from approximately 21:23 EST until 21:30 EST, in the constellation Pegasus."
John Giroux
Asteroid 2005 YU55 shows up as a series of short streaks in this picture from John Giroux.
More about the encounter:
- Passing asteroid puts on a show
- Your guide to the asteroid encounter
- How to save our planet from a killer asteroid
- Could the asteroid destroy the moon? (No)
- Why radar's the best for tracking near-Earth objects
- Interactive: Close encounters of the asteroid kind
Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or following the Cosmic Log Google+ page. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.
Leave a Comment:
Now all we need to know is what affect this close call and our gravity had on its orbit and the trajectory for the next trip around and if it is something that might smack into us in the foreseeable future
I'm no astrophysicist but just my $0.02 it seems like any adjustment to its trajectory from passing so close is going to throw it so far off course we'll never see it again rather than just a few million miles change... This is assuming the rock is in a regular orbit in the first place.
We need, say 3-6 dutchmen, going from asteroid to asteroid it would be the dutchmen's job to nudge the biggest into an orbit that will put them in a collision course with another celestial body! Mars, Venus, Jupiter, the Sun! 1) PUT IN PLACE, THEY WOULD INCRESE THE LIKELIHOOD WE COULD ACTUALLY INTERCEPT AN UP AND COMING COLLISION! 2) WE COULD PRIOR TO DEPARTURE CONDUCT RESEARCH REGARDING CONTENT AND PERHAPS COME UP WITH WAYS AND MEANS OF NUDGING A NEAR EARTH OUT OF A COLLISION!
Has anybody paid any attention to the fact that it came MUCH closer to the moon, and if the moon was ever wiped out, it would be catastrophic for the Earth???
So true. Maybe a precursor to a prophecy. After all, it is predicted that "...and there fell a great star from heaven, burning as it were a lamp, and it fell upon the third part of the rivers, and upon the fountains of water; and the name of the star is wormwood..."
It will happen. Just a matter of when. It's coming.
True, but a rock this small would merely cause a very large crater and light show on the moon. It would take a pretty significantly sized asteroid to destroy the moon or knock it out of orbit.
And Lucille, there have been quite a few meteorites that have hit the Earth since revelations was written. Just sayin.
Heck, I wish it had hit the moon. (And I bet the scientific world feels the same way!)
I wonder how visible such an impact would have been here on Earth?
First, it didn't come closer to the Moon, it came closer to the Moon's orbit. The Moon wasn't in the vicinity.
Second, it would not have wiped out the Moon. However, it would have been a spectacular Lunar show.
It's all out there
Ok, so a space rock roughly the size of the superdome hits the moon. Then what?
It makes a humongous crater, throws up some moon dust and small bits of moon.
And?
Is it big enough/strong enough to knock the moon out of it's orbit? Or cause the moon to break up?
I'm serious, what's the big deal?
I guess that depends on the size of the chunks it throws up and when and if they would begin to enter our atmosphere. We've never seen something like that happen, but we know it does. Such a close flyby of such a big rock is a great opportunity to take some really good numbers - not just for curiosity - this thing will be back and so will others like it.
As you say, Skip, an asteroid of the size of YU55 hitting the Moon would be no big deal.
The Moon will continue to orbit has it has for billions of years.
An asteroid hitting the Moon would have the same "impact" (pardon the pun) as would a bullet striking a mountain - the mountain won't move at all.
It's like saying that a bug hitting the windshield of a bus would smash the bus and throw it off the road; ain't gonna happen.
Where people are getting this idea is beyond me.
you do realize the asteroid weighs in at multiple million tons and is travel at hundred of thousands mph?
My quesiton in another topic was more could a glancing blow send the rock itself or a piece of the moon to earth, and if so how big would it need to be. Maybe that seems like a silly question. It isn't my area of expertise, but the distances made me curious with things going between earth and the moon.
2005 YU55 has a mass of about 55 million tonnes, and its velocity when near the Earth was just shy of 29,000 mph / 47,000 kph (not "hundred of thousands mph" as you state, but still haulin').
So yes, I do realize - what's your point Kyle?
.
Hey thanks Michael, that's kind of what I thought with my tiny monkey/lizard brain but I wanted to toss the question out to you kids with the great big giant brains to comment on.
The rock making a bank shot off the moon and into the earth is another interesting point. I would'nt think it would "glance" off the moon, it would be more likely to plow into the moon and explode. But, again, my tiny monkey/lizard brain isn't qualified to respond. Just speculate.
If such a trick shot were possible I would think the moon would slow it down and absorb a lot of it's energy and even cause it to break up. Depending on the size of the chunks, a lot of them might burn up in the atmosphere, but again, I"m not qualified to say.
Interesting thoughts though.
Your post is all aces Skip - I can not imagine as asteroid "glancing" off the Moon and THEN happening to hit the Earth. MAYBE in the most extreme billiards shot imaginable an asteroid could somehow >just barely< skim the surface of the Moon, but at that point it would almost certainly be captured by the Moon, and will come back down to create a new lunar crater.
"I'm not qualified to say." - your common sense answers prove that statement wrong; you've got a better than average grasp on this.
Hey thanks Michael, I appreciate your kinds words. Always a pleasure to read your posts. Take care and have a great weekend.
Thanks for the responses. Just curiosity...
Now it's behind you... oop ...it's beyond you ...oop behind you ...beyond you... it's behind you...
What I would like to know is, if this asteroid had come closer but not hitting the earth or if another does later on. What then? What would it leave in its path? Would passing particles come to earth? Is it just a rock or is there possibility it could have unhealthy bacteria? How far away is enough not to be worried of contamination?
O2 - we have not yet found any signs of life beyond the Earth. With the exception of some very thin evidence from a Mars meteorite that made its way to Earth, we have found no signs of life in any meteorites - which are the smashed debris from asteroid collisions. I am not worried in the least about an asteroid bringing bacteria to Earth.
Unlike comets, asteroids do not leave a debris trail behind them (unless they were recently hit by something else). We have not seen any debris trailing behind asteroid 2005 YU55.
Small pieces of rock are being passed around the Solar System all the time. I recall a report several years ago about a meteorite that was discovered. Analysis showed that it originally came from Mars and hit the Moon. Then it was knocked around several times on the Moon by other hits, and finally blasted BACK into orbit, and eventually landed on Earth. What a trip...