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he Asteroids Are Coming!Thursday November 3, 20112:55Daniel Strain: Hello to everyone who's tuning into this ScienceLive. We'll get started shortly.

2:59Daniel Strain: Hello and welcome to ScienceLive! Today well be talking about near-Earth asteroids, those are space rocks whose orbits bring them close to our planet. Theres a neat twist to this talk today since one such asteroid, which is called 2005 YU55, will be making a very rare flyby next week. With me to chat aboutthe science of asteroids is Scott Fisher a program director of the NSFs Divisionof Astronomical Sciences. And joining him is Don Yeomans, a NASA project scientist for the Hyabusa mission.

To get things started, Id like to ask Scott why 2005 YU55s appearance is an exciting event.

3:00Scott: This is particularly exiting since it is the first time since 1976 that an object of this size has passed this closely to the Earth. It gives us a great(and rare!) chance to study a near-earth object like this. In fact, we have several telescopes set up and ready to observe this event already.

3:01Comment From ptowngirlIs there any chance what-so-ever of the asteroid going off it's expected courseand hitting the moon or earth??

3:01

Donald Yeomans: The orbit of asteroid 2005 YU55 is very well known because of previous optical and radar observations so there is NO CHANCE that this object will collide with the Earth or Moon.

3:03Comment From JWhats the cheaper telescope I could buy to view this Asteroid and where should Ilook..? (in the Sky)

3:03Scott: Hi J, It turns out that YU 55 is going to be pretty faint when it flies by... It will not be visible to the naked eye, you will need a telescope that has

a mirror at least 6" in size to see it. To make it even more difficult to observe.. it will be moving VERY quickly across the sky as it passes.

3:03Comment From TonyIs yu55 in a circular orbit ?

3:03Donald Yeomans: The orbit of 2005 YU55 is elliptical extending from inside the orbit of Venus to just outside the orbit of Mars.

3:05Comment From mark

Does yu55 have orbiting satellites?

3:05

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Scott: Mark: No sir, YU 55 does not have any satellites in orbit. We believe that it is a 'lone wolf' in that sense. There are a couple of examples of asteroidsthat have satellites, but my understanding is that those are objects that are much larger than YU 55.

3:07Comment From dayoub

what is the current asteroid size, how did you determine asteroid size and how does this estimate alter during a possible entry into the earth's atmosphere whenbreak up can occur?

3:07Donald Yeomans: The diameter of this asteroid is about 400 meters, which was determined from 2010 radar observations. This object will not enter the Earth's atmosphere.

3:08Comment From susanbecause of Asteroid YU 55 close proximity to earth on nov 9,2011 is there a chan

ce it will be caught up in our planet's gravity,since it is coming closer to usthan our moon, that is something that concern's me and a few other people, thatour planet will pull that Asteroid down on us.

3:10Scott: Hi Susan, There is no reason to worry about YU 55 getting caught up in the gravity of the Earth. Through our observations of the object, we know that there is NO chance of it impacting either the Earth or the Moon for at least the next 100 years.

3:10Comment From BarryThe only image of YU55 I've seen makes it appear very spherical. Is that accurat

e and if so is that unusual?

3:10Donald Yeomans: Radar observation of this asteroid in 2010 showed it to be roughly spherical and while not many near-Earth asteroids are spherical, there are others that are spherical as well.

3:11Comment From regina petersen-danielsIs thier a relation to the Tsunami drill that is going to be happening at the same time that 2005YU55 is flying over us, a drill has never been done before at this scale~~why now? Is it possible that they are worried about the trojectory being affected by some variable?

3:11Scott: Hi Regina, There is no connection between the tsunami drill and the YU 55flyby. My understanding is that the large-scale nature of the tsunami drill islikely due to the fact that we (the Earth) has experienced two very large tsunami events in the last 5 years or so. We (the human race) are starting to recognize that we need to be prepared for these events, the large-scale drill is a way that we are starting to prepare.

3:13Comment From CaseyHow long has YU-55 been on it's current course in our solar system?

3:13Donald Yeomans: I think its safe to say that asteroid 2005 YU55 has been a near-

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Earth object on its current orbit for thousands of years but because the orbit is perturbed by neighboring planets from time to time, it is tough to say exactlyhow long it has been on its current orbit.

3:15Comment From Roger from BelmontWill this be able to be viewed in the northern hemisphere and if so, when will b

e the right time

3:16Scott: It turns out that YU 55 will be observable from the northern hemisphere,in fact, the radar telescopes that are going to observe the fly-by are in NorthAmerica. The best time to observe it would be in the early evening on November 8th from the east coast of the US. However! It is going to be VERY faint, even atits closest approach. You will need a decent sized telescope to be able to actually see the object as it flies by.

3:16Comment From Steve

Do we have any ideas about the chemical and material composition?

3:17Donald Yeomans: 2005 YU55 is a so-called C-type asteroid that means it is blacker than charcoal and likely composed of carbon-based materials and perhaps silicate rock. Spectroscopic observations of the asteroid during its upcoming close Earth approach should provide additional clues as to its composition.

3:21Comment From BobWhat do you expect that scientists will be able to observe or learn from this close approach that we couldn't otherwise easily do?

3:21Scott: Bob: it turns out that this close approach gives us a great chance to study this kind of object! One thing we are going to do is obtain radar images of the object as it flies by. I've read that we will be able to see details down toa size of about 15 feet across on the surface of the asteroid. THIS IS AWESOME.Additionally, telescopes on the island of Hawaii are going to obtain spectroscopy of YU 55 to try to give us an idea of what it is made of.3:22Comment From mohamadaccording what asteroid classified3:22Donald Yeomans: The number of asteroids depends upon what sizes you are considering. If we talk about small asteroids of a few meters, there are billions of them. Each time asteroids collide, more and more fragments are produced and hence more and more small asteroids are produced.3:22Daniel Strain: Oops, we're sorry. I posted the wrong question from mohamad.3:22Comment From mohamadwhat are number of asteroids in our solar system

3:23Comment From TBarWill any efforts be made to observe YU55 as it passes SOHO at less than 300,000km?

3:23Scott: Hi TBar - unfortunately not... YU 55 is moving pretty quickly and I do not believe that SOHO has any means of 'tracking' it as it flies by. However, as I

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mentioned above, we will be making lots of observations from other telescopes during the event.

Scott: Hi Scott! - We do have high-resolution pictures of YU 55, the picture from Arecibo, a NSF-funded telescope in Puetro Rico, made the image that has been presented many places online. Arecibo will be observing YU 55 as it fliesby and at the time of closest approach we will be able to see detail on the object down to a size of roughly 15 feet.

Here is a link to the picture I am talking about here:http://www.examiner.com/astronomy-in-national/asteroid-2005-yu55-photo

3:30Comment From StephWhat time and date will it come closest to the earth?3:31Donald Yeomans: The closest approach will occur on November 8 at 23:28 Greenwichtime and the close approach distance will be about 201,000 miles.

3:31

Comment From drjpsWhat is the future for planetary radars used to image NEOs-- specifically what is the latest on the fate of the Arecibo radar that took the 2010 image featured?3:31Scott: drjps: Good question. I am happy to say that Arecibo is going to be aliveand well for this type of research for the near-term future. In addition to theastronomy research done at Arecibo there are other new types of research beingconducted. For example, the telescope is now being used to study our own atmosphere, and in particular the ionosphere of the atmosphere.3:33Comment From MaureenWill the radar images be able to provide you with a 3-D model of the asteroid, or just take images from the side facing the radar? What kind of information will

you be able to extract from these images?3:33Donald Yeomans: Yes, the radars can observe the object over several days, over several rotation periods, so that a 3-D shape model can be formed.3:34Comment From NorthernWhat's the difference between these NEO's and the ones in the asteroid belt ? Are these rogues that broke out from the belt at some point, or are there billionsof rock type objects flying around our solar system ? And if so, do we know where some of them originate from ?3:34Scott: Northern: It turns out that this near-earth object (NEO) and the other NEOs that we have observed all come from the asteroid belt, so their compositionsare roughly the same. These objects are 'nudged' by the gravity of Jupiter (andSaturn) onto orbits that make it into the inner solar system and therefore closeto Earth.

3:37Comment From Andre HeathWhat plans are being made to go beyond the observation of asteroids? Are there any future plans to actually interact with these objects?

3:39Donald Yeomans: Yes, NASA has plans to visit asteroid 1999 RQ36 in 2020 (OSIRIS-REx mission) and return a surface sample three years later. The Japanese Space A

gency has plans to visit 1999 JU3 in 2018 and return a surface sample as well. Each of these target asteroids are of the same C-type as 2005 YU55.

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3:39Comment From ZLooking back to the recent past, a time without telescopes, or humans, how oftendid asteroids as large as 2005 YU55 make such close passes?

3:39Scott: Hi Z: We believe that a close pass like this one happens even few decades

, so once every 30 years or so. We firmly believe that this these sorts of events have been happening for most of the lifetime of the Earth, about 4.5 billion years. In fact, early in the life of the Earth we went through a time that astronomers have named the "Era of Heavy Bombardment" where close passes and massive impacts happened much more frequently then now.3:40Comment From BonnieSince it will not hit the earth or the moon, will it have any impact on the earth whether from tides, earthquakes, volcanoes, or anything else.

3:41Scott: Hi Bonnie. So it turns out that YU 55 is way too small to have any effect

on our tides, or earthquakes, or anything like that.

3:42Comment From DrewHow fast is this asteroid traveling?

3:42Donald Yeomans: The speed of the asteroid varies as it moves in its orbit aboutthe sun. It travels fastest when nearest the sun and slowest at its greatest distance from the sun.

3:44Comment From GZ

Is there anything NASA is doing to prevent future approaches that might get to close to earth?

3:45Scott: One thing that we (NASA and NSF) are doing with an eye towards the futureis that we are funding and building telescopes that search the sky for this type of object. With respect to your questions about what we are doing to prevent an impact... in many ways there is nothing that we can do to actually prevent animpact, but we can try to give ourselves a long lead time by discovering any object that may be on a collision course.

3:45Comment From ireneany idea how many telescopes will be observing the asteroid on the 8th? Will Hubble any any other space observatories be used, or will it be too close?

3:45Donald Yeomans: Thousands of amateur and professional astronomers will observe this object near it closest approach to Earth. However, it is moving too fast onthe sky for Hubble to observe it.

3:47Comment From RosaI am just curious that. why in national tv last night there were saying if this asteroids lands in the ocean will make a tsunami of 70ft hight why there are specu

lating to this extreme if there is not worries!

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Scott: Hi Rosa. This is a good question. I believe that the national news favorsthe dramatic side of an event like this. Although myself, Don, and MANY peoplearound the globe are excited about this idea of learning more about YU 55, asteroids in general, and what they can tell us about how our solar system formed, however, that sort of story does not pull in the ratings that a story about a 70 FOOT TSUNAMI does.

3:49Comment From GuestWhy do you believe there are so many fears over NEO such as YU55 and Elenin in recent times?

3:51Donald Yeomans: Recently there have been many posts on the internet concerning disasters concerning comet Elenin (now disintegrated into a cloud of dust), Nibiru (never existed), Planet X (never existed) and any number of phenomena for which there is NO EVIDENCE whatsoever. There are no filters for internet blogs. People can, and do, say whatever they like so readers have to ask themselves whetherthere is any evidence for the claims being made. It used to be that editors cou

ld filter nonsense before it was published but the internet is largely uneditedmaterial so readers have to think whether or not there is evidence to support the claims being made.3:52Comment From GeorgeA lot of recent movies have led people to believe that NASA would not warn the public immediately if a RISK factor was identified, whats your view on this?3:52Scott: Hello George, good question. Hey, I loved "Deep Impact" and "Armageddon"as much as everyone else, but they are just movies. I know that NASA and most ofthe observatories around the globe have a standard procedure already in place for a major discovery like a large asteroid impact. In a nutshell, the scientificcommunity believes that there is no way to keep such a discovery a secret. Nor

is it really ethical to consider keeping such information a secret.:51Donald Yeomans: Recently there have been many posts on the internet concerning disasters concerning comet Elenin (now disintegrated into a cloud of dust), Nibiru (never existed), Planet X (never existed) and any number of phenomena for which there is NO EVIDENCE whatsoever. There are no filters for internet blogs. People can, and do, say whatever they like so readers have to ask themselves whetherthere is any evidence for the claims being made. It used to be that editors could filter nonsense before it was published but the internet is largely uneditedmaterial so readers have to think whether or not there is evidence to support the claims being made.3:52Comment From GeorgeA lot of recent movies have led people to believe that NASA would not warn the public immediately if a RISK factor was identified, whats your view on this?3:52Scott: Hello George, good question. Hey, I loved "Deep Impact" and "Armageddon"as much as everyone else, but they are just movies. I know that NASA and most ofthe observatories around the globe have a standard procedure already in place for a major discovery like a large asteroid impact. In a nutshell, the scientificcommunity believes that there is no way to keep such a discovery a secret. Noris it really ethical to consider keeping such information a secret.3:55Comment From claudiawill YU55 come near to hitting any of the satellites orbiting Earth?

3:55Scott: Hi Claudia.... we do not think that any satellites, the Moon, the space s

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tation, or any object will be impacted by YU 55. Luckily for us we have really dedicated observers watching this object quite closely and we know its orbit veryaccurately... so no worries, our GPS and cell phones will be working after thefly by!

3:56Comment From Sheridan

What is the risk that Earth will be hit by one of these asteroids?

3:57Donald Yeomans: There are vastly more small asteroids than large ones so we aremostly likely to be hit by a small one. Baseball sized object hit the Earth's atmosphere daily. Volkswagen sized objects hit every few weeks but are too small to cause any ground damage. On average, a 30 meter sized object , the smallest that could cause significant ground damage, would be expected to hit every few hundred years, and a larger object of a kilometer in diameter would not be expectedto hit but every few hundred thousand years.

3:58

Comment From LoriEarlier, you said we would not have to worry about Yu55 for 100 years. Are you seeing impact potential in 100 years?3:58Scott: Hi Lori... when I said there is no chance of an impact for 100 years, that is because the folks that have done the research on the orbit of YU 55 have 'projected' it into the future for only 100 years or so... We do not think that itwill ever impact the Earth (or Moon), it is just that we only have its orbit calculated for the next 100 years...3:59Daniel Strain: Okay, it looks like we're drawing to an end. I was curious, whatwill the two of you be doing on the night of the flyby?

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