By now you may have heard about this interesting video showing how many asteroids we’ve discovered since 1980. It’s pretty cool!
I have no idea how accurate it is, but the numbers seem about right; I know there are several hundred thousand known asteroids in the main belt between Mars and Jupiter [Note: the creator of the video talks about this in the comments below]. Note that a lot of the ones you see toward the end get close to Earth; according to the JPL Near-Earth Object site, almost 7200 near-Earth asteroids have been cataloged as of August 20, 2010! Of these, 815 are larger than about 1 kilometer in diameter, and 1137 are considered to be potentially hazardous; that is, have a chance (however small) of hitting the Earth.
It’s interesting to see where the asteroids are when discovered; usually in the opposite direction of the Sun, because that’s where surveys tend to look. Right at the end you’ll see two white patches at 90° from the direction of the Sun on either side. If I were a betting man — and I am — I’d wager those were from WISE, an infrared survey satellite. It scans the sky constantly, looking at right angles to the Sun, and I know it’s designed to find asteroids.
More interesting, to me, is how crowded the asteroid belt looks! But don’t be deceived. The distance between Mars and Jupiter is a bit roomier than depicted in the video. Remember, Mars is about 220 million km (130 million miles) from the Sun, and Jupiter is about 800 million km (480 million miles). That’s a whole lot of real estate: almost 2 quintillion square kilometers (670 quadrillion square miles)! Written out, that’s 2,000,000,000,000,000,000 square kilometers.
Yeah, a whole lot of real estate.
And that assumes those asteroids all lie in the same plane. In fact, many of their orbits are tilted, so we’re really dealing with volume. Even allowing that they may move above or below the plane of the solar system the paltry amount of a million kilometers, that means there’s really 2 septillion cubic kilometers: 2,000,000,000,000,000,000,000,000 cubic km! The volume of the Earth is only about a trillion cubic kilometers, so we’re talking a volume of space that could fit a trillion Earths in it!
So there’s plenty of room for these asteroids. The biggest, Ceres, is less than a thousand km across, so it’s small compared to Earth. Most of those asteroids identified in the video are roughly a few kilometers across, so they are positively tiny on this scale. The only reason the video looks crowded is because each asteroid is represented by a pixel that’s much, much larger than the actual asteroid size on that scale — even the Sun would be smaller than a single pixel at that scale! Displaying the asteroids actual size would be difficult; on my monitor a 10-km wide rock would only be about a nanometer across. A human hair is 100,000 times wider!
My friend Dan Durda — you’ll see lots of him on my TV show premiere Sunday night — studies asteroids. He once told me there are a billion asteroids in the main belt bigger than about 100 meters across. Even so, on average, there are millions of kilometers between them!
Space is big. Really, really big.
Despite what you see in this video and in movies, the asteroid belt is not a swarming mess of rocks going every which way. It’s actually mostly empty space. In fact, when we send probes to the outer solar system, the odds of even getting anywhere near one are incredibly small. Scientists have to physically aim the probe on purpose to get near enough one to get good images of it. The fact that we have, many times, is a testament to how good we’re getting at this sort of thing.
So anyway, the lesson here is twofold: we are getting better at finding asteroids, but there’s still plenty of room for them to exist in.
August 27th, 2010 at 7:17 am
Great post, Phil. Could you make an educated guess as to the mass of al the rocks in the asteroid belt and make a comparison to the Earth-moon system?
August 27th, 2010 at 7:30 am
No, I hadn’t yet seen that videoclip – & yes, yes it is. I’m impressed. Thanks.
So crowded in appearance there – and yet, as you nicely noted, so much empty space.
Is 2007 VN84 better known as the Rosetta spaceprobe counted among those?
(That was the one they mistook for an asteroid before realising what it was! I think the same thing happneed to an old Saturn V third stage or two.)
I take it they’re not including comets there – I couldn’t see any in cometary orbits. No Jovian or Neptunean trojans shown either & we know there’s quite a lot of *those* too!
Is there an asteroid (?numerals?) PhilPlait out among them somewhere yet?
Methinks, this would be even better if they then also showed the Edgeworth-Kuiper trans-Neptunian cometary disk from say 1992 QB1′s discovery onwards ..
Or / & started it from when Ceres was first discovered in 1801 although I guess it may make it too long. Something they could better do in a few parts perhaps?
I wonder if we’ll reach a point when there are just too many asteroids known for us to count & track them all?
August 27th, 2010 at 7:31 am
Off-topic, but I watched that video, then read the text, and the text continued swirling for another minute. The brain is awesome.
August 27th, 2010 at 7:32 am
I did notice that the discoveries tended to “surge” in time. I am going to assume that may have something to do with scheduling telescopes, the location of those telescopes on earth, funding, and weather?
August 27th, 2010 at 7:43 am
Since you mentioned Ceres: it’s a bit too late now that Dawn has already launched, but I strongly suspect that Ceres would have had its own flyby or mission if it had been known as a planet / dwarf planet all this time instead of an asteroid. Well, it was called a planet in the beginning but that was way before we had the capability to explore them.
One other interesting example are brown dwarfs: I make sure to call them brown dwarf stars whenever I write about them even though they’re technically sub-stellar objects, simply because your average person with little interest in astronomy will not be wowed by the idea of a sub-stellar object. A star is a very different matter, however…even if we’re talking about the same thing.
Anyway, back to asteroids: asteroids IMO need some better PR, and maybe this could come from articles giving their approximate surface area along with their diameter. I very often see comments asking whether a person could step off of Ceres if they’re not careful (because it’s an asteroid), and the answer is that no of course you can’t step off Ceres, but since it’s an asteroid and a 50-metre pile of rubble is also an asteroid it’s not that weird that they could be confused with each other. Say that Ceres has a surface area equivalent to Texas plus California plus Alaska though and now we know we’re talking about a tiny planet, which is much better than saying that it’s some 950 km in diameter…which means pretty much nothing to a person since we see size in terms of surface area and not the shortest distance from one side of an object to another.
Sorry for the rambly comment (I blame jet lag) but the point is this: to everyone who writes about asteroids, please give approximate surface area and a comparable location on Earth (equivalent to New York State, 100 football fields, etc.) when writing about asteroids. I think that would be the best way to give an idea of their actual size.
August 27th, 2010 at 7:50 am
@Messier:
165347 Philplait
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=165347&orb=1
August 27th, 2010 at 7:55 am
Reflecting on the emptiness of space, here’s a quote from British astronomer Sir James Jeans (http://en.wikipedia.org/wiki/James_Jeans ) :
“If you put three grains of sand inside a vast cathedral, that cathedral will be more densely packed with grains of sand than stars are found apart in space.”
- Page 28, ‘Skywatching’, David H. Levy, Ken Fin Books, 1995.
& here’s another to make you think :
“…about 40 supernovae are exploding somewhere in the universe every second. However, light from most of these events won’t reach Earth for billions of years, if ever.”
- Page 73, “Ask Astro” in ‘Astronomy’ magazine October 2008.
& just one more :
“Cosmology also tells us that there are perhaps 100 billion galaxies in the universe and that each contains roughly 100 billion stars. By a curious co-incidence, 100 billion is also the approximate number of cells in a human brain.”
- Page 237, ‘StarGazer’, Dr Fred Watson, Allen & Unwin, 2004.
PS. Here’s the link to the story of Rosetta‘s mistaken identity :
http://en.wikipedia.org/wiki/Rosetta_(spacecraft)#Misidentification_as_an_asteroid
& when it comes to scale this awesome Youtube clip / BA blogpost says it all :
http://blogs.discovermagazine.com/badastronomy/2009/06/12/scale/
Except that asteroids are too small to even mention there – so a little off topic sorry, but, still, I do recommend you watch to the end and enjoy!
August 27th, 2010 at 8:09 am
The visual of seeing more and more asteroids appear near Earth’s orbit is a bit disconcerting. Starting with just a few whose orbits took them very close to Earth was unsettling. And then there were more…and more…and more. Umm…eep?
August 27th, 2010 at 8:18 am
On sizing up asteroids – &/or comets – some are certainly bigger than others – see :
http://blogs.discovermagazine.com/badastronomy/2010/07/20/asteroid-comparison-chart/
This is the Lutetia asteroid & comet comparison article from last month but I’m figuring that some folks may not have seen it or may wish to see it again.
Hope this is interesting /enjoyable for folks here.
***
“To get a sense of the scale of the Jovian system, consider that if the Earth was placed at the centre of Jupiter, our Moon would lie inside the orbit of [Jupiter’s nearest large moon] Io, while distant [outer moon] Sinope would be a third of way to Mars.
- P. 186, Ferris, ‘Seeing in the Dark’, Simon & Schuster, 2002.
“Meteors plunge into the Jovian atmosphere at a rate that makes Earth’s 400 tons per day look paltry, and in the course of its long tenure Jupiter has ingested millions of comets.”
- P. 186, Ferris, ‘Seeing in the Dark’, Simon & Schuster, 2002.
“Few men realise the immensity of the vacancy in which the dust of the material universe swims.”
- Page 7, ‘The War of the Worlds’, H.G. Wells, first published 1898, this edition : Aerie books, 1987.
August 27th, 2010 at 8:23 am
http://www.watoday.com.au/wa-news/flu-vaccination-ban-goes-national-after-fever-convulsions-in-children-20100423-tglp.html
The Australian government has gone full derp. They are banning flu vaccines now.
August 27th, 2010 at 8:26 am
Actually be sure to watch it in 1080p. I wonder how many asteroids remain to be discovered? There is a size distribution among the asteroids and there must be an estimate of how many need to be discovered.
August 27th, 2010 at 8:44 am
The data is absolutely accurate and based on the MPCORB published regularly by MPC (Minor Planet Center) and more info can be found in the video’s description on youtube.
p.s. if anyone’s interested, the asteroid (165347) Philplait we discovered on 11 23 2000
August 27th, 2010 at 9:17 am
scibuff (12): I am not doubting it, but how do you know it’s accurate? Do you know who put it together? I’m curious how they did it; it’s a lot of work! On the YT page it says where he got the data, but not how he visualized it.
August 27th, 2010 at 9:44 am
It certainly is a cool video. As for discovering more asteroids – I think that’ll be going on ad infinitum.
It would be interesting to know of any discoveries of asteroid belts around other stars, in addition to exoplanets. Would it be possible from Earth-based telescopes? Has it been done already?
August 27th, 2010 at 9:46 am
I think the problem with finding all of the Asteroids is that they very in size some are so big that states would fit on them these are the ones we can see ,but others are about as big as my fist or the size of pebbles and some maybe microscopic these would be harder to find (unless we send a spacecraft out to spend 1000 of years looking ) . By the way Phil mentioned the Hoth astroid belt from The Empire Strikes Back in his book ,According to several Star Wars novels the resion it is so crowed is that it is the result of a collsion of two planets . Star Wars Triva : the system and planet Hoth is named after Lord Hoth a Jedi Kinght who led a battle against the Sith 1000 years before Episode 1 see the comic Jedi vs Sith for futher detales
August 27th, 2010 at 9:53 am
@Todd W:
It’s explained in the video comments that the objects are enlarged for visual purposes and it’s a 2D representation of 3D space. Lots of the near-Earth asteroids aren’t really all that near (if one crosses the Earth-dot, it may be even further from Earth than the moon) and they may be above or below the planet.
August 27th, 2010 at 9:56 am
@Drake (1), Wikipedia says this:
The total mass of the asteroid belt is estimated to be 3.0×10^21 to 3.6×10^21 kilograms, which is just 4% of the Moon. The four largest objects, Ceres, 4 Vesta, 2 Pallas and 10 Hygiea, account for half of the belt’s total mass, with almost one-third accounted for by Ceres alone. Ceres’s orbital distance, 2.766 AU, is also very close to the location of the belt’s center of mass, 2.8 AU.
August 27th, 2010 at 9:57 am
@Kevin
Yeah, I understand that. I picked up the point from Phil’s commentary that they aren’t all in a plane. It still is a sobering thing to think about, though, and I could see someone who either didn’t read that bit or got their info from someone else who left that important fact out (either innocently or intentionally) being rather overly frightened by the imagery.
August 27th, 2010 at 10:02 am
@4 (Larian):
The pulsing you see is mostly driven by the phase of the Moon. (In fact, you can, more or less, count 12-13 pulses for each time the Earth circles the Sun, corresponding to the dark of the Moon, when it’s easier to find faint asteroids.)
August 27th, 2010 at 10:33 am
Hi, great post.
One doubt, though, why don’t those asteroid stick closer to Jupiter?
August 27th, 2010 at 10:49 am
“I have no idea how accurate it is,”
As the guy that created the video I can assure you it’s pretty darn accurate, at least the rendering of the data from the original source elements is as accurate as I could make it. It took a few iterations to get things right, I had some old code from a decade ago and it turns out there were a couple of minor errors that crept in due to things like ‘how many days are in a year’ (that depends on how to define a year).
The one area of questionable accuracy is for the discovery dates, the Minor Planet Center has discovery dates for all numbered asteroids – that’s about 230,000 or thereabouts. The others have provisional designations in the format “2010 MN105″ which allow me to know which half month period they were discovered in based upon the letter code. For those the discovery dates are spread equally through the time interval so it’s possible those discovery dates are off by up to a quarter of a second in the video.
There’s also the question of accuracy of the orbital elements, and while Ted Bowell and associates are doing great work computing these it’s easy to see that in the WISE discoveries there are some systematic biases that produce the density bands. I hope with time that these will get corrected as new observations are made.
August 27th, 2010 at 10:52 am
@19 – moon phases explains the short term pulses. Wondering why there’s a long-phase pulse – very few asteroids seem to be discovered when the earth is in the lowest part of the orbit – there’s an annual lull in the pulses of discovery. Wonder what causes that?
August 27th, 2010 at 10:56 am
I see what you mean Phil, rather than saying that the data is not necessarily accurate, you say that there’s no way of knowing whether the data visualization accurately represents the actual data … fair enough.
… but I have to say that, although it doesn’t constitute any sort of proof of accuracy what-so-over, knowing what I know about asteroid discovery numbers (coming from LINEAR, Spacewatch and Catalina over the past decade) as well as the inclusion of WISE discoveries at the right time, strongly suggests that the visualization is quite accurate.
August 27th, 2010 at 11:19 am
Isn’t Ceres now classified as a Dwarf Planet along with Pluto? … I swore it was… I’ll check again.
edit: Yes, when Pluto got demoted, it got bumped up. Can’t wait for Dawn to get there in a few years.
August 27th, 2010 at 11:19 am
@James
Regarding the low discovery rate around the 5 O Clock position the most convincing theory I’ve come up with is that this corresponds to the monsoon season in Arizona which means that the prolific Catalina Sky Survey is clouded out and unable to make any discoveries.
August 27th, 2010 at 11:51 am
@Todd W:
Yeah – it’s kinda freaky at first, but then you realize how incredibly large a scale it is (1 million km to a pixel)
August 27th, 2010 at 11:57 am
I try and educate people regarding size relationships as an astronomer/presenter all the time. The Sci Fi movies, 100% of all science related TV programs, and indeed, this image presented above are grossly out of scale. I have begged in the past that Phil set things straight regarding this and present our solar system to scale on one of his TV ventures. I have never seen the scale of the solar system properly or adequately represented in the main stream media.
Some “Facts of Note” to try and get your head around:
If the Sun were scaled down to a bowling ball in size, the Earth would be a very small 2mm diameter bead orbiting 26 Yards from the bowling ball, Mars is a 1mm bead 40 yards away, and Jupiter is a 22mm diameter marble orbiting 135 Yards from the bowling ball sun. Neptune is a pea sized object 777 Yards out, close to half a mile. On this scale, there would be 10 amazingly small specks of dust representing asteroids per square yard between Jupiter and Mars. Assuming as Phil has that they are about a foot deep, this would be about 1 Asteroid in every cubic foot of space for the 500,000 Asteroids covering an area the size of 10 football fields. If there are 2 million Asteroids, this would still just be 4 specks of dust in a cubic foot of space.
From what I understand, when NASA sends a spacecraft through this “Crowded” asteroid belt beyond Mars, they completely disregard any chance of anything hitting the spacecraft or vice versa, because the probability is so remote.
BTW, let me bounce this off you, if the Earth were a basketball, the crust we live on, and 99% of the atmosphere would each be about 3 sheets of paper thick on average covering the basketball. Earth and Sky are 6 sheets of paper thick. A chicken egg shell is 6 times thicker to scale than our earths crust, food for thought.
August 27th, 2010 at 12:18 pm
@James – I’m pretty sure that’s the direction of the Galactic Center. You can see a persistent gap in the same place in plots of known Kuiper Belt Objects.
August 27th, 2010 at 12:24 pm
Scott (21): Thanks for the note! I’m glad you cleared that up. I was not trying to cast aspersion on what you did at all, just saying up front that *I* wasn’t sure how accurate it was.
So congrats on doing this, and I’m glad to see it getting so much attention. It’s very cool.
August 27th, 2010 at 12:28 pm
From this video it kind of seems like there’s a small, thinly populated asteroid belt between Earth and Mars… obviously nowhere near as dense as the “real” asteroid belt.
Either that, or it’s kind of an asteroid cloud with the orbits of Mars and Earth swept clean.
August 27th, 2010 at 12:34 pm
“2 septillion cubic kilometers”
Uh. That’s completely incomprehensible. Wouldn’t AU^3 be a better unit? I mean, I can at least imagine a 1AUx1AUx1AU cube, while counting zeros is not exactly my thing.
August 27th, 2010 at 1:01 pm
So it never occurred to me that you can only look away from the sun (duh, nighttime), until I saw it manifested as the sweeping ring of discovery, but I noticed in 2010 the bands weren’t just perpendicular to our orbit, they were parallel (in front of/behind us, as it were), meaning they would have been discovered in local twilight.
My question (for anyone) is what technological or observational advancements have been made in the last 12 months or so that don’t require darkness to find asteroids?
Just curious.
August 27th, 2010 at 1:05 pm
@Messier – I see lots of Jupiter’s trojan asteroids in the video. Hundreds, if not thousands. I didn’t see them very well until I watched it in 1080p fullscreen, then they are easy to see.
There are no neptunian trojans shown, because Neptune’s orbit doesn’t fit on the screen.
@Angus – read the article. Phil says “Right at the end you’ll see two white patches at 90° from the direction of the Sun on either side. If I were a betting man — and I am — I’d wager those were from WISE, an infrared survey satellite. It scans the sky constantly, looking at right angles to the Sun, and I know it’s designed to find asteroids. ”
Keith
August 27th, 2010 at 1:42 pm
@Kris – I don’t think that humans have any way to comprehend volumes as large as this.
2 septillion cubic kilometers would be 0.6 cubic AU… 1 cubic AU is about 3.35 x 10^24 cubic km.
Or we could take the volume of a sphere with a radius equal to 1AU, which is about 1.4 x 10^25 cubic km, I think this would be easier to visualize than a cubic AU.
2 septillion cubic kilometers would be about 0.14 spherical AU.
And just to take this to the ridiculous, how about a cubic light year
, a massive cube a light year across on a side, that would be 8.47 x 10^38 cubic km. At least this one could be abbreviated CLY.
2 septillion cubic kilometers would be about 2.36 femto CLY, which really gives you no perspective on how big it would actually be.
And I hope I didn’t screw up any of my formulas in excel, because that would be rather embarrassing.
August 27th, 2010 at 1:43 pm
I still think it’d be a cool idea to send something out into the asteroid belt and disrupt the area just enough to induce accretion into a new (dwarf?) planet.
August 27th, 2010 at 2:04 pm
[...] thousand known asteroids in the main belt between Mars and Jupiter [Note: the creator of the video talks about this in the comments below]. Note that a lot of the ones you see toward the end get close to Earth; according to the JPL [...]
August 27th, 2010 at 2:04 pm
Based on the low number of asteroids discovered in summer, I’m glad to see that astronomers do take holidays sometime
Thanks for this nice video.
August 27th, 2010 at 2:08 pm
Disruptions prevent accretion. Part of the reason things don’t get very big in the asteroid belt is because of disruptions from Jupiter.
It is believed the asteroid belt once held much more mass, but the effects of Mars and Jupiter (mostly Jupiter) caused most of it to be swept up or ejected.
August 27th, 2010 at 2:13 pm
@37
Summer also has the shortest nights, of course.
August 27th, 2010 at 3:18 pm
@34 fetchbeer:
“we could take the volume of a sphere with a radius equal to 1AU”
So we imagine a sphere around the Sun with a 1AU radius, and Earth skirting on the surface. What’s the problem with that? We now have a reference.
“2 septillion cubic kilometers would be about 0.14 spherical AU.”
And there is no problem in comparing a sphere with the size of 0.14 to a sphere with the size of 1 we have visualized previously. (BTW — 0.14 is the volume, or radius?)
And, the space where the asteroids are is actually a toroid. But again, once we have imagined a reference 1 AU sphere, a toroid with the inner radius of 1.8 and the outer radius of 4 (or whatever) can be easily visualized, and it’s volume calculated.
To explain that the space is mostly empty, just give the combined volume of asteroids in cubic AU, and compare to the previous number.
“And just to take this to the ridiculous, how about a cubic light year”
For describing volume of a star cluster, a cubic ly is a perfectly reasonable unit.
August 27th, 2010 at 3:33 pm
@32. Phil mentions it – it’s due to WISE.
August 27th, 2010 at 4:33 pm
@38. Material being ejected due to the gravity of Jupiter. Does this mean that it has added to the Oort cloud. With that thought, are the two areas exchanging material.
August 27th, 2010 at 4:45 pm
Keith Hearn @ 33: You beat me to the comment about Trojans.
Messier Tidy Upper @ 2: I first see the jovian Trojans from late 1996 on the right side of the animation. Neptune is 6 times further out than Jupiter…
Somebody in the YouTube comments was complaining that all the Kuiper Belt objects shown in the animation, were all theoretical and not observed. I seems like that somebody might need a better map of the Solar System so he can find the actual Kupier Belt :-, Would probably not bee able to find the Earth either
Cheers,
Regner
August 27th, 2010 at 5:39 pm
On item 27, the best general release scale solar system I’ve seen to date in the Opera Web Browser widget, “PlanetWerks”.
Doesn’t show everything of course, and doesn’t go over automatically on a zoom in on a planet to something like Google Earth, Moon or Mars, (or Google Sky for a background) but use the orbit tracking feature, center on the sun, which then becomes merely the brightest star in the field and set it so the entire orbits of even the most distant TNOs are on the screen, and it does give one a strong sense of the emptiness of even Solar system Space.
August 27th, 2010 at 5:39 pm
“By now you may have heard about this interesting video showing how many asteroids we’ve discovered since 1980.”
My God — it’s full of rocks!
Seriously, that video is an impressive piece of work. And I understand that the true spaciousness of the asteroid belt makes even close approaches very rare at this late date. The same is true for the debris we’ve left in Earth orbit, which seems to swarm as menacingly in representations.
August 27th, 2010 at 5:47 pm
Are the objects depicted as being on Keplerian orbits, or is this an n-body simulation? (Presumably you can get away with treating the asteroids as test particles to reduce the computing power needed to do such a thing)
August 27th, 2010 at 7:53 pm
@21. Scott Manley :
Love your work here! Thanks.
@6. EG : @Messier: 165347 Philplait
Thanks. ..
THX too to :
@12. scibuff :
That long ago – well before his books were published (2002 Bad Astronomy & 2008 Death from the Skies) & before this blog was started or such a hit? I’m surprised but glad to hear the BA had “his” asteroid that far back.
@ 33. Keith Hearn :
&
@43. Regner Trampedach :
Okay, thanks, I’ll have to look a bit closer for the Jovian ones. I know Neptune doesn’t fit in this scale – I’m thinking they could add it as a later zoom-out or do a separate video for the Edgeworth-Kuiper cometary belt region maybe?
August 28th, 2010 at 12:48 am
“Space is big. Really, really big.”
If you think it’s a long way to the chemist’s on the corner…
Any prize for catching the HHGTTG ref?
This video is totally amazing! Great job Scott!
August 28th, 2010 at 3:19 am
The only problem I have is that with that scale for distance and the dots marking asteroids not being to scale, some people might get the impression that the asteroid belt is just like what’s portrayed by Hollywood and not the mostly empty space that it actually is. So, thanks for pointing out the problem with scale. I fume and scream whenever I see portrayals like that on documentaries and with no interpretation of the image.
August 28th, 2010 at 5:27 am
Glad YOU find it ‘cool.’ Personally, it scares the holy bejezuz out of me.
August 28th, 2010 at 6:43 am
Great work, Scott!
I like how the the music makes an uptick around the 2:09 mark, which coincides with a flurry of discoveries around the 9 O’Clock position.
I wonder what the relative impact hazard is for Mars.
August 28th, 2010 at 9:32 am
AFAIK impact hazard for Mars is significantly higher. Unfortunately I do not know/remember details.
August 28th, 2010 at 1:04 pm
Mithridates,
figuring out the surface area of asteroids is difficult since relatively few are spherical or of other regular shapes. Look at some coarse grains of sand to get an idea of all the irregular shapes asteroids have. Now consider that our telescopes aren’t very good at capturing fine details and most asteroids will just come across as diffuse blobs of mass. Very difficult to get a grasp on their surface area. Stating the maximum length and breadth of an asteroid already overstates its size.
August 28th, 2010 at 1:11 pm
Wow! But let me throw out a nit pick. What is with “quintillion”? Please at least throw in scientific notation for a bicycle mechanic who has no idea what that means and is impatient with counting zeros but has no trouble comparing 10^12 to 10^15.
August 28th, 2010 at 1:27 pm
For a second, I was actually wishing for a new planet out there to sweep those suckers up
but then I realized that would certainly perturb enough of them to send a few thousand more rocks hurtling down to our orbit at breakneck speed. 
Best to have them stay in their zone, peacefully shepherded by Jove and Mars…
August 28th, 2010 at 5:41 pm
@Scott_Manley:
Absolutely stunning video. The one question, not asked here but several times on the You-Tube site, is what did you use for music? I love it. Composer and album, please. I’ll buy it soonest. Also notable is the difference in quality of the comments between here (good) and You-Tube (you gotta be kidding me!). Also, where can we get a (preferably 1080pHD) copy of the video? I’ll buy that too.
August 28th, 2010 at 8:00 pm
@Dave Yes the quality of the comments is…. worthy of comment.
The music is ‘Transgenic’ from the band ‘Trifonic’ (Amazon Linky:
http://www.amazon.com/Emergence-Trifonic/dp/B0013MTJUQ/ref=sr_1_2?ie=UTF8&s=music&qid=1283047098&sr=8-2 )
I have ‘pristine’ versions available to media and educators on a case by case basis, it’s on my webspace and I need to watch the bandwidth usage, so shoot me a message on youtube if you really want a high quality source version.
August 29th, 2010 at 1:48 am
Since someone mentioned asteroid (165347) Philplait and I’ve had a few beers I threw this together to give you an idea of where it is
http://www.djsnm.com/philplait.png
Doesn’t come near any of the planets, which is good because it means it’s unlikely to get ‘lost’ anytime soon.
August 29th, 2010 at 5:31 pm
On the scale of the solar system: I have heard a rumour that there is a scale model of the solar system in Regents Park in London. Apparently, at this scale, Mars is on the South coast of England near Brighton, Jupiter is in New York and Saturn in Buenos Aires. I have not been able to confirm this rumour. Anyone know any more?
August 29th, 2010 at 10:20 pm
[...] via [...]
August 30th, 2010 at 1:44 am
this video took 30 years in the making
August 30th, 2010 at 6:44 am
@Scott Manley: Nice work man!
Just curious, did you only use astorb.dat or other datasets as well (ie. MPCORB)?
What software did you use to read/render the dataset? Please enlighten me.
August 30th, 2010 at 8:43 am
35. 24601
Being all broken up is the neatest thing about the asteroid belt. It allows for a LOT of accessible volume, potential life storage space equivalent to tens of thousands of planet earths. Earths total surface area is around 5 x 10^8 square kms. A hollowed out asteroid 100 meters in diameter would provide 4 x pi x r^2, or about 30,000 square meters. Lots of living space in that.
With possibly one billion such 100 meter asteroids,well, you get the picture. About 60,000 planets earths worth of equivalent surface area.
Gary 7
August 31st, 2010 at 1:23 am
@Gary Ansorge:
Interesting concept, but you’re thinking two dimensionally. There’s no effective gravity on a 100M diameter object, so you’d have maybe 85 or 90% of the entire interior volume available. That works out to about 0.524 x D^3 or 85% of 524,000 cubic meters or 445,400 M^3. That’s a lot of space!
August 31st, 2010 at 2:42 am
@james (#22) @scott (#25) Apart from the monzoon season which affects CSS there’s another thing to smaller discovery rates in “summer months” (June-August). The ecliptic is at relatively low altitudes (around -20 in declination) at that time, and the vast majority of telescopes actively looking for asteroids are in the northern hemispehere, which means that when scopes are pointed in the direction of the ecliptic, they are looking through more airmass thus bringing down the limiting magnitude.
August 31st, 2010 at 2:20 pm
[...] post: 30 years, a half million asteroids | Bad Astronomy | Discover Magazine Pretty crazy stuff! Most of us are going to be alive when the most exciting Apophis gets close to [...]
September 8th, 2010 at 10:50 am
I keep crashing the stellarium beta ’cause I’m trying to observe p-mcnaught-2006 or some such. I don’t have any net dl so don’t tell me i need to upgrade, K? What prompted me to post was the lack of credit given to Saturn as a collector of ‘roids….
September 9th, 2010 at 4:14 am
[...] my very close and personal friend whom I’ve never met, Phil Plait, explain why that is (from this post at his blog Bad Astronomy): The distance between Mars and Jupiter is a bit roomier than depicted in [...]
September 16th, 2010 at 2:29 pm
I guess I missed the boat on this discussion. Really I wanted to incite someone to elaborate on whether the crazy behavior I’ve managed to observe the ’2006 object presenting in Stellarium is anywhere near accurate, and if there are any other similar objects to be observed within the Stellarium program?
September 29th, 2010 at 6:57 am
@59 Keith-
List of scale models….. there’s one in my home town (Melbourne, Australia), which I have not yet done, but with the weather improving as summer approaches here, will be on my list of things to do!
http://en.wikipedia.org/wiki/Solar_system_model
October 3rd, 2010 at 1:41 pm
Gary,
I think you did your math wrong. The 60,000 earth surface areas happens when you divide the total asteroid area in square METERS by the Earth’s area in square KILOMETERS. By dividing the areas when using square meters, you end up with a total surface area of less than one Earth surface area.
October 18th, 2010 at 12:32 am
[...] [7]: http://www.jpl.nasa.gov/asteroidwatch/newsfeatures.cfm?release=2010-332 [8]: http://blogs.discovermagazine.com/badastronomy/2010/08/27/30-years-a-half-million-asteroids/ [9]: [...]