Duck! Two Asteroids Pass Closer than Moon
Today is not a good day for the anxious among us. Two small asteroids — two in twelve hours — are passing the earth, both coming within the moon's orbit, one of them whipping by about 49,000 miles away.
In a spirit of calm, we ought to point out that NASA says close calls like these happen, on average, almost daily. The difference is that usually we never know. These two objects were both spotted Sunday by the Catalina Sky Survey at the University of Arizona.
The specifics:
–Asteroid 2010 RX30 is estimated to be 32 to 65 feet in size (10-20 meters) and passed within 154,000 miles of Earth at 5:51 a.m. EDT this morning. (The moon, by comparison, is 2,200 miles in diameter and respectfully stays about 240,000 miles away.)
–Asteroid 2010 RF12, about 20-45 feet in maximum width (6-14 meters), is passing within approximately 49,088 miles of us at 5:12 p.m. EDT. That’s a fifth as far away as the moon.
(NASA/JPL plot of asteroids' paths. Click to enlarge.)
A decade ago, this was the stuff of movies — think "Armageddon" and "Deep Impact" — but one of the more memorable lines from back then was that the planet would be whacked by something "the size of Texas." Asteroids the size of today's passersby enter the earth's atmosphere about once a decade, mostly harmlessly.
Of course, every now and then — remember the theory about the death of the dinosaurs — something hits us that is not harmless. The object believed to have ended the Cretaceous period is estimated to have been about six miles across. And that’s why the astronomers in Arizona didn’t have much of a Labor Day weekend.Update: Wayne Farley asks a good question: How quickly are either of these objects moving? The answer, according to the Near Earth Object program at NASA, is a maximum of about 6 km/second –about 13,400 mph — for 2010 RF12 and 10 km/second — 22,370 mph — for 2010 RX30, relative to us. (For comparison, a spacecraft in low earth orbit moves at about 17,000 mph relative to the earth's surface.) If you want to have some fun, the Jet Propulsion Lab has an interactive graphic of the orbit of 2010 RF12 and other objects HERE.
(Top: Asteroid Ida, imaged by the Galileo spacecraft on the way to Jupiter in August 1993. Click to enlarge. Courtesy NASA/JPL.)
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Posted by: tmak | September 8, 2010, 11:46 am 11:46 am
What is the speed at which these stteroids travel?
Posted by: Wayne FArley | September 8, 2010, 11:58 am 11:58 am
25 to 65 feet? Hardly something to get all worked up about. What would be left after the atmosphere finished with them would only make a moderate dent in the top soil. Enough to blow away a neighborhood or Congress.
Posted by: Wayne | September 8, 2010, 12:37 pm 12:37 pm
this is why we need to keep all of our nukes. We need to be on top of this for the future and be ready to blast one of those before it hits us.
Posted by: mothman | September 8, 2010, 12:40 pm 12:40 pm
I’ve always been of the opinion that its silly to worry over such things…near where I live there is a highway with signs posted, “Watch for falling rocks”. Um, OKAAAY. Not much you can do about said rocks should they happen to fall on you as you drive by, but I sure will “watch” for them. I suppose it’s a good thing someone is watching, but not too sure what could realistically be done if a rock big enough to do serious damage and on a direct collision course WERE spotted. Hollywood’s all very fine and well, but it’s not reality.
Posted by: Raven | September 8, 2010, 1:38 pm 1:38 pm
Force = Mass multiplied by Velocity
I could kill an elephant with a Tic Tac if I could throw it at 13,400 mph
Posted by: Birddog | September 8, 2010, 3:19 pm 3:19 pm
What would have been the damage if RX30 did enter our atmosphere and crashed in mid-America?
Posted by: Jim | September 8, 2010, 4:21 pm 4:21 pm
You’re dumb jim. Just wait for 2012 hahaha
Posted by: TMan | September 8, 2010, 4:32 pm 4:32 pm
Raven, that’s the formula for linear momentum.
Posted by: lithiumdeuteride | September 8, 2010, 4:39 pm 4:39 pm
“I could kill an elephant with a Tic Tac if I could throw it at 13,400 mph”
HAHHAHAHAAAA!!!!
Posted by: billy | September 8, 2010, 4:44 pm 4:44 pm
Note from Ned Potter–
Hello, Jim. Actually, there was a 2008 study from Sandia National Labs modeling the effect of a 30-50 meter asteroid, and showing that even if nothing hit the ground, there could be considerable damage as the object pushed air out of its way. The famous Tunguska crash in Siberia in 1908 may have been caused by something that size. But it’s hard to say what 2010 RX30 might do; we don’t even know, for instance, whether it’s solid, or a loose cluster of material traveling in the same orbit.
Raven, you raised an important point — can we do anything? All sorts of schemes have been discussed for sending a probe to an asteroid and gently nudging it away from a path that would hit the earth — if you had advance notice. That’s why NASA says it pays to keep a lookout. But three days is not much warning.
Posted by: Ned Potter | September 8, 2010, 4:44 pm 4:44 pm
If there’s another extinction will the universe notice? Microbes will survive and it will all return to normal and we’d be back if not as we are then as something else and if not here somewhere else so don’t worry about it. Enough time has passed since the last strike for humans to arise and be able to deflect a big one so just thank your lucky stars you’re here in the first place.
Posted by: Amiman | September 8, 2010, 4:47 pm 4:47 pm
So, I’m just wondering *really* how much warning we have with lethal CMEs (the so called “kill shot” from the sun or a large asteroid impacts? I get the sense we’d have about 72 hours to get our affairs in order before we all died..
Really question is would they tell us it was coming at all?
Posted by: Sean | September 8, 2010, 5:02 pm 5:02 pm
Raven,
Force = Mass multiplied by Acceleration.
So let`s say the elephant is 20 feet away, it takes the TicTac about 1ms to hit. The mass of a TicTac being around 0.5grams the Force on impact would only be 3000 Newtons or 675 lbs. I doubt that will kill or even injure an african elephant weighing in at over 15,000 lbs.
Nevertheless good comment.
Posted by: dimplez | September 8, 2010, 5:03 pm 5:03 pm
Our solar system is enshrouded in clouds of intensely dense debris field of galactic clouds we’re passing thru, as foreseen by the remote view of Jimi Hendrix and explained in the book Rock Prophecy. When Obama was informed of the 2 new asteroids on Monday he went to Milwaukee and quoted Hendrix “Stone Free” in his speech – “Stone” as in ROCK rolling free in space (google: obama hendrix labor day). The ENTIRE “2012″ fad is a TOTAL RIP OFF of the 1995 book Rock Prophecy, which is being concealed and suppressed by the Microsoft founders who persecute the author of that book. They ordered their DreamWorks media empire to instigate the craze for “2012″ as the END of the Maya calendar because Rock Prophecy book explains the START of the Maya calendar with an asteroid impact. The Rock Prophecy.com website is surfacing all of the evidence that MSM is ordered to censor and suppress.
“Electric Love penetrates the sky, the Mountain falls in the sea, the Sun refuses to shine, the story of the asteroid belt in our solar system is explained, continental size graves…” – Jimi Hendrix
Posted by: PROPHETJIMI | September 8, 2010, 5:37 pm 5:37 pm
Well…There is nothing we can do now. If it hits, it hits but I think we should all petition the government to get cracking on getting a defence system in place. The “big one” will come some day. You don’t need to be a statistician to figure the odds out – we’ve been lucky for a LONNNG time. In the meantime….I guess if you think it helps, say a prayer.
Posted by: Shakinginmyboots | September 8, 2010, 5:41 pm 5:41 pm
Enough to blow away a neighborhood or Congress…Wayne..Sep 8, 2010 12:37:12 PM….Congress, only if intelligent life exists out there and it overheard any sessions of congress, then it would have sent it on a proper trajectory, knowing intelligent life didn’t exist here.
Posted by: Ken | September 8, 2010, 5:46 pm 5:46 pm
drat and all that cooling down for nothing once the big one finally hits
bwhwhahahahahaha
Posted by: oleironleg | September 8, 2010, 5:47 pm 5:47 pm
IMHO, NASA should scrap manned space missions and focus on implementing detection and interdiction systems for protecting the planet from asteroids. Perhaps even form an international effort. For the first time in Earth’s history, a specis has the opportunity to protect itself from planet-killing asteroids. We should take advantage of that fact.
Posted by: NewsForNASA | September 8, 2010, 5:57 pm 5:57 pm
Hi Ned, it was interesting to read your statement about Tunguska and the impact of air “displacement”. It never made sense to me that entire forests were “pushed over” but not burned/decimated in any other way. Thanks!
Posted by: puppyfeet217 | September 8, 2010, 6:01 pm 6:01 pm
“If there’s another extinction will the universe notice?” Who cares if the universe notices? I’m pretty confident that the extinction of the human race would be a pretty big deal, especially when we haven’t determined yet if we’re the only sentient life in the universe. In the entire history of the millions of species on our planet, we’re the only ones that ever evolved beyond the basic ‘eat, sleep, reproduce’ mechanic. The mere survival of microbial life is not enough considering how obviously rare sentience is.
Posted by: ponytailjones | September 8, 2010, 6:13 pm 6:13 pm
if this is not a serious why post it on the internet? i think this matter is very serious infact this asteroids can do alot of damage if this asteroids were to decide to go another route like hitting the earth
Posted by: stephen | September 8, 2010, 6:15 pm 6:15 pm
The really big one will hit us in 2012.
Slightly offshore on the west coast of Canada, midway between Wash. and Alaska
6 miles in diameter traveling a million miles an hr.
Posted by: stan | September 8, 2010, 6:41 pm 6:41 pm
where on earth could the 2 sept 8 asteroids been seen from? what hemisphere?
Posted by: lori | September 8, 2010, 7:18 pm 7:18 pm
dimplez.. ok the momentum at .5grams X13.4kmph or 20kfps is defined by m*v^2.
so it is the equiv of 50 grams at 2kfps. Even if the air takes the momentum, the shock from the projectile plus air is on the order of a 50 cal sniper rifle.
Posted by: Storm | September 8, 2010, 7:49 pm 7:49 pm
Correction tic-tac hitting elephant
impact force = mass x deceleration
F = M x dv/dt
deceleration = dv/dt
dv = velocity change
dt = change in time
If the tic-tac is going 100 ft/sec
and slows from 100 to 0 in 0 seconds
We have dv/dt = 100/0 or infinite force
What is critical here is time dt
Posted by: stan | September 8, 2010, 8:18 pm 8:18 pm
I DON’T WORRY ABOUT SUCH THINGS, I BELIEVE IN GOD :)
Posted by: WAYNE | September 8, 2010, 11:37 pm 11:37 pm
what kind were they?
Posted by: mugahi | September 9, 2010, 7:56 am 7:56 am
From what I read, the Siberian 1908 blast occurred when the object entered the atmosphere at a shallow angle of descent. If the angle was steeper, the object would have hit the ground instead of blowing up in the atmosphere.
So we’re still pretty much green horns when it comes to determining what will happen if a NEO hits the Earth. I always had thought that the bigger the NEO, the more damage it will create. Yet, they’re saying now that even small NEOs can cause huge damage as the Siberian 1908 blast.
Gee, now we have to be concern even with small rocks falling from the sky.
Posted by: GWP | September 9, 2010, 8:38 am 8:38 am
Reverend Jones, The University of Arizona just called. They think they’ve found your balls.
Posted by: Senator McCain | September 9, 2010, 10:17 am 10:17 am
The Tunguska event that happened and knocked down the forest trees happened because it exploded over the area and never made contact with the ground. Just like we do when a nuke is fired at a country. The greatest effect is to explode it over the top of an area.
Posted by: jerald | September 9, 2010, 11:17 am 11:17 am
30-50 meters is roughly 3 times the size of someting 30-50 feet, which is what these asteriods were. So while the Tunguska impact was certainly an event to behold, it isn’t a fair comparison
Posted by: Jordan | September 9, 2010, 12:14 pm 12:14 pm
The momentum of a 0.5 g tic-tac moving at 13,400 mph (6,000 m/s) is about the same as a 5 g bullet moving at 600 m/s, but the kinetic energy of the tictac is 10x greater.
It’s lethal.
Posted by: Bill | September 9, 2010, 12:25 pm 12:25 pm
Raven has it right with the tic-tac.
But we need to use Kinetic Energy here.
KE=1/2mv^2.
A 9mm bullet can kill a man (115 gr bullet 1300 ft/s ==>431.45 ft-lbs of force.)
The tic-tac at .5 grams at 13000 mph looks like this:
13000mpg = 19000 ft/sec
.5 grams is 8 grains in bullet lingo.
so we have an 8 gr bullet going 19000 ft/sec ===>6411.36 ft-lbs…
More than enough to kill a pachyderm.
Posted by: Gidian | September 9, 2010, 3:22 pm 3:22 pm
sorry Jordan…didn’t see your comment…
Posted by: Gidian | September 9, 2010, 3:28 pm 3:28 pm
Force = Mass x Acceleration
Momentum = Mass x Velocity
Kinetic Energy = .5 * Mass * Velocity * Velocity
Posted by: hsgrad | September 9, 2010, 4:56 pm 4:56 pm
We are all doomed!
Posted by: Slim Shady | February 9, 2011, 5:20 am 5:20 am