NASA: Massive Asteroid will zoom near Earth on February 4th – at 76,000 mph

Asteroid 2002 AJ129 will make a close approach to Earth on Feb. 4, 2018 at 1:30 p.m. PST (4:30 p.m. EST / 21:30 UTC). It is expected to be the largest and speediest space object to whiz past the Earth in 2018. The 0.7-mile long body is larger than the tallest building on Earth, Dubai’s half-mile high Burj Khalifa skyscraper will zoom past Earth at 76,000 miles per hour.

At the time of closest approach, the asteroid will be no closer than 10 times the distance between Earth and the Moon (about 2.6 million miles, or 4.2 million kilometers). So, it will miss Earth, as seen in this animation below.

2002 AJ129 is an intermediate-sized near-Earth asteroid, somewhere between 0.3 miles (0.5 kilometers) and 0.75 miles (1.2 kilometers) across. It was discovered on Jan. 15, 2002, by the former NASA-sponsored Near Earth Asteroid Tracking project at the Maui Space Surveillance Site on Haleakala, Hawaii. The asteroid’s velocity at the time of closest approach, 76,000 mph (34 kilometers per second), is higher than the majority of near-Earth objects during an Earth flyby. The high flyby velocity is a result of the asteroid’s orbit, which approaches very close to the Sun — 11 million miles (18 million kilometers). Although asteroid 2002 AJ129 is categorized as a Potentially Hazardous Asteroid (PHA), it does not pose an actual threat of colliding with our planet for the foreseeable future.

“We have been tracking this asteroid for over 14 years and know its orbit very accurately,” said Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies at the Jet Propulsion Laboratory, Pasadena, California.  “Our calculations indicate that asteroid 2002 AJ129 has no chance — zero — of colliding with Earth on Feb. 4 or any time over the next 100 years.”

JPL hosts the Center for Near-Earth Object Studies for NASA’s Near-Earth Object Observations Program, an element of the Planetary Defense Coordination Office within the agency’s Science Mission Directorate.

More information about asteroids and near-Earth objects can be found at:

For more information about NASA’s Planetary Defense Coordination Office, visit:


91 thoughts on “NASA: Massive Asteroid will zoom near Earth on February 4th – at 76,000 mph

  1. I’m glad someone’s paying attention. It’s even better that they can spot those things far enough out that we can start taking pot shots at ’em, if need be. No sense in the world suffering through another mass extinction, if there’s something we might do to prevent it.

    • Start taking pot shots at them with what? Relative to us it’s doing 76000 mph. How fast does your fastest ICBM go, and can that actually escape earth orbit?

      • It would not be too hard to hit. It is fairly large and its position is known in advance to a high degree of precision.

      • We don’t need to hit this one. However, had we needed to, we would have had months to put something together.
        Secondly, had we needed to hit it, we wouldn’t have needed to hit it hard. The next pass isn’t for 100 years or so. A tiny nudge, over 100 years, results in a huge change in orbit. More than enough to turn a sure hit into a near miss.

        That’s why we are looking for asteroids and comets. So that we can spot the dangerous ones early.

      • Earth’s average orbital speed around the Sun is about 30 kilometers per second. In other units, that’s about 19 miles per second, or 67,000 miles per hour, or 110,000 kilometers per hour (110 million meters per hour).

        coincidence ?

      • Well it’s approaching at 76,000 mph so just throwing a missile into it’s path would do the trick. Course you’d have to do that early to affect it’s path enough. Or you could blow it up and hope for the best.

    • If you’ve read the Arthur C. Clark book, “Rendezvous With Rama”, This could sound like de je veux all over again.

      “Rendezvous with Rama” is a science fiction novel by British writer Arthur C. Clarke first published in 1973. Set in the 2130s, the story involves a 50-kilometre (31 mi) cylindrical alien starship that enters Earth’s solar system. The story is told from the point of view of a group of human explorers who intercept the ship in an attempt to unlock its mysteries. The novel won both the Hugo[4] and Nebula[5] awards upon its release, and is regarded as one of the cornerstones in Clarke’s bibliography. The concept was later extended with several sequels.

    • Waiting for the man who told us he invented the internet (Al Gore) to tell us that it’s due to increased CO2 and ‘climate change’ attracting these asteroids!

  2. The astro nutters definition of “near” is very very silly. It’s like suggesting that when I nip down to the local shop in my car I had a near miss with a car doing the same in Llanfairpwllgwyngyll (I live in England). The more reasonable definition of a near asteroid would be one passing through Earth’s orbital path within 2 hours of the Earth or within 100km.

    The reason they don’t use a more reasonable definition of “near” is that it would only generate one newsworthy bit of waffle every few thousand years. They need to grow up, be more realistic, consider the real world and stop this nonsense.

      • Yeah that’s pretty easy, we usually called it Llanfair PG, of course it’s missing the last half of the name any way.
        is slightly more tricky.
        Here’s a phonetic guide:

      • “Saint Mary’s Church in the hollow of the white hazel near a rapid whirlpool and the Church of St. Tysilio of the red cave.”

        Lovely language, Welsh… The words are long, true, but you really never need more than one or two for a complete sentence.

      • Writing Observer January 20, 2018 at 6:57 pm
        Lovely language, Welsh… The words are long, true, but you really never need more than one or two for a complete sentence.

        Agreed. Well the place names are long, there are lots of Llanfairs for example so they usually have a qualifier added (though not usually as many as in this case).
        Hwyl fawr am nawr!

      • Writing Observer January 20, 2018 at 6:57 pm
        Lovely language, Welsh… The words are long, true, but you really never need more than one or two for a complete sentence.

        On the other hand when I asked a Welsh friend why he called chips (french fries) ‘chippo’ he pointed out that to say ‘chip’ in Welsh would, in translation, be: ‘sliced and sliced potato fried deep in fat’ or thereabouts, there being no actual word for chip. Cuts both ways one might say.

      • Interestingly, I believe that the Welsh Language Society had sought – well before Brexit – an emergency air drop of vowels, from the EU [and a couple of sibilants and a terminal ‘R’ for effect, to taste, . . . .].
        No such air drop is confirmed – are the finances not audited?
        But England will, I gather, probably effect one very soon after Brexit.
        Estuary English, which seems to operate in a consonant-free zone, is thought not to be significantly threatened (as it has so many vowels, already).

        Mods – Please recalibrate – this IS Sarc. Seriously . . . . . .

    • I’d consider “near” to be anything close enough to have it’s orbit significantly modified by Earth’s gravity.

    • When I was a pup we had yearly books with tables of astronomical tables. They were darn accurate.

      Having said the above, I have no idea of how accurate is the prediction of this particular asteroid’s orbit. In any event, it’s not perfect. link In light of that, I would call a near miss anywhere within the margin of error.

      • We have been observing the orbits of the planets for hundreds of years. They have been refined to a very high degree of accuracy by now.

      • MarkW, CommieBob,
        I think you are both broadly right.

        A thought: –
        What we do not appear to have, at the moment, is a facility to pick up ‘new’ incoming rocks.
        I appreciate that they are all mostly billions of years old, but if they have not been sighted within 100/200/500 years, we will, very probably, not have orbital characteristics.
        These, then, may (might) be dangerous.

        Charles January 21, 2018 at 8:22 am
        Entirely right.
        I have no idea when we ‘should’ expect an anomalous atomising arrival.
        It might be next week – making all my pension contributions pretty irrelevant , in truth – but it may not be.

        Larry D January 21, 2018 at 9:38 pm : –
        To borrow a phrase from Instapundit “insufficient opportunities for graft.”

        Larry – plus + several shedloads!


    • Well, near is a relative thing in orbital relations. Some times its easier to think about it in time terms. While this asteroid poses no threat because its orbit is not in the same plane as ours and it crosses the ecliptic plane in an un-occupied orbit, as far as near this comes within about 1 day of us at our present orbital speed. We’ve had much closer near misses, like the earth was in that position not 5 minutes before where the asteroid crossed.

    • Utter rubbish. It is inevitable, totally inevitable, that we will be hit at some point by a large rock. Could be next week. We have the technology to track and deflect these objects, yet we’d rather spend trillions on B/S like climate change. It is a testament to the stupidity of mankind that we have the power to solve this problem (one of the few really civilisation-threatening disasters we can do something about) and yet we don’t get on with it.

  3. Gee whiz, I thought I’d get a piece of that rock this time, but nooooooo….!

    Oh, well – maybe next year.

  4. These notices are getting almost routine. Like SpaceX deliveries to orbit.

    One wonders how many flew by without public notice in the past.

    • I was thinking the same thing. Have more asteroids been crossing Earth’s orbit lately, or are we just more aware of them?

      • This list from the Minor Planet Centre is always useful to get a feel of what’s passed by in the last couple of weeks and predicted for the next couple of weeks. Updated every day:

        I check it every day. As you can see, there are many that pass by at around the distance of 2002AJ129. However, it’s the size (up to 1.1km) that’s of interest here because that sort of size for this close approach distance is rare (roughly one every few years). We get many more 100-500m rocks within 4 million km, perhaps ten per year, although that’s subjective, from memory, I don’t keep a note.

        As you can see on the linked page (as of the date of this comment) five rocks passed with a close approach distance of less than 1LD in five days (15th-20th January 2018). This is definitely a record. All were discovered by the Catalina Sky Survey which is the most sensitive survey dedicated wholly to NEO detection. It had major upgrades in 2017 and this is probably why it’s now catching more (notice how all 5 rocks are very small, 2-10 metres).

        So, the increase in detection is due to tech advances. The flux of NEOs and their close approaches is the same as it ever was- we just missed them in the past.

    • Didn’t we have one that was visible to the naked eye a few years back. Passed between the earth moon orbit.

      • There are 5 PHAs that have passed within 1 Lunar Distance in the past week.
        2018 BW – 9m big, 0.4LD, 6.4km/s
        2018 BR1 – 4m, 0.3LD, 8.1km/s
        2018 BD – 3m, 0.1LD, 10km/s
        2018 BC – 5m, 0.7LD, 2.7km/s
        2018 BX – 6m, 0.7LD, 5.8km/s

    • This sort of mandates the following question:
      Given that we barely have the capability to intercept something hazardous and aren’t really sure how best to intervene anyway, what is the size and likelihood of impact that would have us hitting the panic button?

  5. E = 0.5 mv^2

    I leave it as an exercise to calculate the number of hydrogen bombs would equal the energy of an asteroid of that mass travelling at that velocity. hint

      • This happens a few times a year and your guess of 2-3 km/sec is very good.

        If the orbit of the incoming NEO has a perihelion distance of around 1AU and aphelion between say, 2 and 3 AU, its orbit will almost nest with the Earth’s circular orbit at perihelion. The other factor is the eccentricity (fatness) of the NEO’s ellipse which has to be fairly fat to nest but it usually is when the perihelion distance is 1AU. Also The inclination of the orbit has to be lowish (less than 5 degrees or so, also common in these cases).

        With this set up, the Earth and the NEO are travelling almost parallel at the NEO’s perihelion point. The Earth actually has to be in the vicinity which is of course a small chance.

        Since the NEO has a semimajor axis much bigger than 1AU it travels faster round the sun at the 1AU radius (it ‘drops’ in from 2 or 3 AU). This translates to around 33-36 km-sec as opposed to Earth’s 30km/sec. so the approach is directly from behind, catching up ‘in the same lane’. So the catch-up velocity is the same as the difference between the two orbital speeds. And this is usually 3 to 6 km/sec.

        Almost all other NEO closing velocities have a large vector component due to the crossover angle of the two orbits. 2002AJ129 has an approach velocity of 34km/sec due to the obvious large angle with the Earth’s orbit (due to high eccentricity and low perihelion distance).

        I’m putting this here because the JPL and science mag articles never explain how these rocks come in so we’re often left with bizarre descriptions of rocks whizzing past from South Pole to North Pole or straight from the direction of the sun as if its orbit is somehow diametrically across the solar system. This is because the orbital speeds of both the Earth and the rock are stripped out and we’re just looking at the geocentric approach radiant (direction). In reality, when viewed in the heliocentric reference frame (with Earth and NEO orbital speed added back in) it’s usually a very graceful crossing over of orbits. The geocentric version is akin to two cars on the freeway doing 70mph and one approaching apparently sideways towards you as it changes lane.

        Even experts don’t visualise this lane-changing approach enough. At the Planetary Denfense Conference in Tokyo in 2017 the hypothesised NEO impact was going to hit Tokyo. The models showed the meteor explosion 200km west of Tokyo. They thought this was a mistake and ignored it because they weren’t thinking in the geocentric reference frame. So they evacuated Tokyo north, south east…and west *into the path of the meteor fireball*.

      • Thank you.

        From a planetary defense standpoint, it’s “interesting” to see the prejudices – almost physical revulsion – against using nuclear weapons on these smaller rocks. The most probable impactors.

        That Nukes are claimed to be ineffective – which they are against very large asteroids or comets.
        That nukes need to be dug-in (drilled into the rock like in the movies) to break the impactor up into small bits.
        That residual radiation in the rocks would be deadly.
        That nukes are not allowed into space, so they can’t be used in space.
        That warning time limitation prevent nukes from being launched out into space early enough.
        That we could not hit a asteroid with a nuke.

        …. Then, when all these arguments are made, the same astronomer who opposes any thought of nuclear weapons proposes sending a manned vehicle (which doesn’t exist even in designs!) or unmanned probe (which doesn’t exist in designs either!) out to the inbound rock, finding the rock, landing on it and mounting some sort of drilled and clamped tether on the centerline of mass and rotation of an irregular mass tumbling irregularly in 3D space for a magical shroud or solar parachute to pull the tumbling rock out of earth’s orbit. Or attach a solar-power/electronic rocket to drive the irregularly tumbling rock out of earth’s orbit using a few pounds thrust for years.

        Instead, the nuke – not efficiently but merely practically – need only impact the tumbling rock, blast a few tons off or break it up into smaller bits – each bit with a side motion of only a few meters per day that will clear the earth’s orbit. Or, failing to clear, will break the single large destructive rock into 2 or 3 smaller rocks that further break up in the atmosphere – if they hit at all.

        If the first large nuke fails, or misses, use the backups. It is not as if we do not have ballistic-capable large weapons designed. Pick a site, hold a few missiles on standby for planetary defense. If the first three nuclear weapons are not enough, use a few more. If the radiation deposited in the any of all of the in-space nuke blasts does not move it from the earth orbit, then the tremendous blast and heat damage from a 10000 tons of rock impacting WILL make the residual radiation from a 25 megaton nuclear blast 3 months previous to impact immeasurable.

    • Seems you’ve published half a differentiation there. Wouldn’t e = mv^2 differentiate to kg-m = 0.5 mv?

      Been a long time since my calculus classes, but that’s how I remember it being done.

      • Classic Newtonian physics holds kinetic energy = 1/2 mv^2.
        Potential energy is m*(delta h)*g for a mass elevated between two distances in a constant gravity field.
        But both require a very large numbers of assumptions. The energy exchanged between two colliding masses is proportional to their difference in the velocity vectors of the center of mass of each other. Not the absolute velocity of either.
        But is either (or both) is spinning, you need to account for that inertia as well.

  6. Its next approach is quite a bit closer;
    “On February 8, 2172, the asteroid will pass about 0.00458 AU (685,000 km; 426,000 mi) from Earth.[2] The 2172 Earth approach distance is known with a 3-sigma accuracy of ±4000 km.”

  7. The question, as always, becomes: “OK, It missed the earth this time. Now, how was its orbit changed so we can predict it will CONTINUE to miss the earth’s position the next 16 times? ”

    I’d much prefer the massive computer power now making mistakes with 1000 year runs of chaotic climate models based on assumed minute conditions of dust, gas, and winds be applied to “simple” Newtonian physics of mass, time, velocity, and distance of a six body problem: The earth, the moon, the asteroid itself, Jupiter, Mars, and Venus.

  8. If asteroid scientists followed the lead of climate scientists, they’d be scaring the sh*t out of everybody and demanding billions to save the world from asteroidmeggendon.

  9. Oumaumau, the Giant Turd from Interstellar space, also had a similar elongated shape when it whizzed through our solar system last fall.

    Coincidence? I think not. There must be an alien shape-ship hiding in the shadow.

    • Now, take that irregular shape, assume it is spinning on some axis, and attach a drive motor or solar parachute to the surface of the rock on the center of the spin axis directed exactly through the center of mass of the asteroid so the drive motor can “push” the asteroid away from the earth’s orbit in some controlled manner.
      Assuming you have a couple of years’ of thrust available.

  10. Buy the time it does pose a direct threat to earth, we will have the technology to alter it’s trajectory…
    All of us will be long gone by that time, so why even worry about it. I am worried whether the Eagle will beat the Vikings..,.and other stuff so much more important…
    Who cares if the government is shut down…

  11. I wonder how dense that thing is? What is it’s mass? Seems pretty important information to know in calculating it’s orbit and how it may be perturbed by the gravity of other masses it passes by. Also nice to know how it may perturb the orbits of smaller asteroids it passes by. Be a good thing to know before it hits something in our part of the solar system neighborhood.

  12. I like my odds. The planets have been pulling debris from near space for billions of years. Not much left up there. Last known big hit tens of thousands of years ago.

    Man’s problem is the lack of a paradigm for the vastness of space. We can’t comprehend it. ‘Near Earth’ headlines don’t help.

    • You are forgetting about Tunguska, that was about 100 years ago. It was big enough to have destroyed an entire city.

      • I don’t consider the Tunguska Event to be ‘big.’ We are looking at a ‘0.7-mile long body.’

        “big enough to have destroyed an entire city”

        Mt. St. Helens was big enough, too. But as I say we are protected by the vastness of space, we are also protected from actual Tunguska sized object impacts by the vastness of the Earth. 500,000,000 square kilometers, of which very little is populated.

        A ‘0.7-mile long body’ impact would affect all of Earth, regardless of where it hit. We didn’t even know about Tunguska for many decades.

        [Rather, the blast was seen (or felt) over wide areas of Russia and recorded that day, and unusual lights the next evening were seen over most of north Europe. But, true, the area itself was not reached until the 1921-27 expeditions. .mod]

  13. In case of impact: 1.5*10^18 Jule or 48GW in a whole year. No chance of that though. But it could have replaced large number of power stations :-)

  14. [reporter Tom Foreman, CNN] “[during 2013 Federal Government shutdown] for more than two weeks, NASA reportedly stopped monitoring potentially dangerous asteroids. A big one, by the way, is expected to brush by Earth on February 4th.”

    70 years into the Atomic Age and 50 years into the Space age “the Gub’mint” still has no credible asteroid intercept mission ready to fly, that’s the real news story here. Modern reporters would stop short and recite this alarming fact to their viewers as a coda to every such story, had news reporting not been bred out of them.

    I find comments like one previous in this thread, “The astro nutters definition of “near” is very very silly.” outright offensive. Here we have a class of threat that is demonstrably existential. We have well-preserved craters on the Moon, evidence of mass extinctions and catastrophe on Earth, plenty of ongoing near encounters of various sizes, an incomplete NEO catalog. The nearby Asteroid Belt is yet to be charted down to the fine resolution with which we chart space debris in Earth orbit, as are the paths of eccentric long term comets.

    There is an emerging human pathos in which everything is reduced to statistical probability regardless of its effect and consequence, and action is taken (or not) based on probabilities alone. It is a distorted view of reality. This is an abuse of statistics on the same level as the use of Newtonian physics by Astrologers to give superstition a patina of science.

    In fact what I describe is pretty much ‘Statistical Astrology’. The idea that our presently calculated low probability of asteroid impact is ‘actionable’, as in ‘no action’ — no need for urgent action, just cool 3am documentary stuff — is like deference to a supernatural force. Like entering a casino to pull the handle just once because “God is with me today.”

    I consider this use of statistics to whitewash confirmed existential threats to be an intellectual crisis. And that crisis has reached its peak in this ‘science’ piece by Ethan Siegel purportedly for children but actually unfit for them. In it he takes the gambler’s fallacy to a new level, encouraging children to “go gently into the good night” by imagining their whole species as a fait accompli, an interesting yarn while it lasted. There is nothing actionable in this. Yet he goes further to present a series of smaller catastrophes made fun by statistics, introducing ‘city-killers’ which will presumably (statistically!) only obliterate those in ‘other’ cities. These concepts are like training wheels for young minds who, as they mature, become ready to ignore the ultimate threat of mass extinction. Or in our case, a possibly preventable threat.

    Existential threats are a special case and must be treated as such, not bargained away with probability until they drop below the threshold of action. And by that I mean any useful action whatsoever.

    If you’ve ever heard someone mentioning some threat and realized, Hey! This has been mentioned regularly since I was a kid time and again, they always bring up the same points and recommend something, yet the cycle has repeated itself dozens of times and decades later we are not even a single step closer… you know what I mean by “below the threshold of action.”

    There is scarcely a moment to lose. Every disaster scenario we DO throw money and resources at is pretty much an *IF*. Asteroid impact is a *WHEN*.

    • Oh dear, I have offended someone on an internet blog. Must be a first! Is there a prize?

      Seriously though, Hocus Locus, my “very very silly” comment is because the definition of “near” is too far. It needs to be more realistic, I’m not disagreeing with the potential threat of asteroids which ARE really “near” or the inevitability of a big hit sometime or the sense in thinking about planning for it or mitigating it. The “near” definition just needs to be much much more sensible numerical figure.

    • “There is an emerging human pathos in which everything is reduced to statistical probability regardless of its effect and consequence”

      It’s worked for us so far.

  15. Since asteroids can’t be taxed, it’s not a threat. Move along. Same thing happened to the dinosaurs, they were so wrapped up with meat eater violence, plant eater coexistence, size guilt, and evolution that they forgot to look up.

    • But asteroid protection can betaxed. In true government fashion, they can fudge the data, hand out grants to political friends, skim off the top, build bureaucratic empires , create grandiose yet utterly useless plans and put off any real action as long as possible.
      And blame their predeessor for the asteroids “aggressive” behaviour.

      • “Unfortunately the course of XB234-HG-7 is no longer as predicted last week. It appears that the gravitational pull of the distant but exceptionally heavy XB235-HG-77i has MOVED THE GOALPOSTS”

      • Okay, but it must not be part of the low hanging fruit among various options like CO2, mean corporations, sugar, and the rich.

      • Didn’t some reporter ask if the CO2 was the reason why the Earth has been hit by a lot of asteroids recently?

  16. In Minnesota, this is known as a SIGN. The Vikes will be at the Super Bowl, and they will WIN. (Between this and the SNOW in the Sahara 2 weeks ago, how can we not “believe”.)

  17. Now that NZ is a Space Nation, leave it to us. We will drop-kick any asteroid to Alpha Centauri. Or not.
    Very proud, so I went to the pub yesterday after the launching to celebrate. Any excuse will do. The rockets are Carbon Fibre tubes with metallic wire laser printed Rutherford engines. Three cubesats in 500km orbits. Americas Cups, plastic yachts, hydrofoils, and now we have really gone crazy.

  18. On a slightly different tack —
    I find it interesting that American Meteor Society reports goes from less than a hundred per year in 2005 to over 5,000 per year in 2017. Why the BIG increase — better reporting, or more verified reporting in recent years, or maybe just more fireballs? Who can say?
    All I can say is if you see one of these rare fireball events , please report it to

  19. Yes the big one misses
    Or at least if it was going to hit would you all really think the world would tell us months or days before hand.
    As humans would act irrational riot and loot people would start going crazy if they felt they only had seconds to live. Much like the missile alerts that happened in Hawaii recently, the public response would be crazed. Did the Russians warn their people when the metor struck its land a few years ago? No they didnt how ever they were quick to reapond.
    If the big one misses us great its the Debris floating alongside it that i worry about.
    Imagine what new rare element’s this thing could be made of. Possable element’s that doesnt exist here on earth. Assuming we all live a chance to hit this thing and study the rock could prove valuables unknown.

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