Monday Night’s Asteroid Passage the Closest/Largest in Next 12 Years

January 25th, 2015 by Roy W. Spencer, Ph. D.

Artist's concept of a near-Earth asteroid (ESA).

Artist’s concept of a near-Earth asteroid (ESA).

Tomorrow night an asteroid the size of a small mountain will pass about 3 Moon distances from the Earth, and will be in perfect position for binocular viewing in the U.S. Details and a tracking chart are available at Sky and Telescope. I also use their interactive sky chart to find the locations of constellations, clusters, planets, etc., for specific nights and my location.

Asteroid 2004 BL86 will be moving at about 2.5 deg. per hour generally northward and pass right next to the Beehive Cluster (M44) between 11 p.m. and midnight CST. It is estimated to be over 500 meters in diameter, which is like 5 football fields long (and high and wide).

From what I’ve been able to find on the energy equivalent if one of these bad boys hit the Earth, this one would easily wipe out the entire New York City metro area. (The resulting climate impact would likely be cooling for years, but I don’t believe in the nuclear winter scenarios where most life is wiped out — dust settles out of the atmosphere relatively fast).

For those of us in the central time zone, the asteroid should be visible in binoculars with a fairly dark sky, brightest around 11 p.m. till midnight (when it will be fully illuminated by the sun on the other side of the Earth), and will be almost directly overhead. If the clouds move out of N. Alabama in time, I’ll be doing time lapse photography and will post a video if weather permits. I’ll be using a 200 mm f/2.8 lens at f/4.0, 30 sec exposures, ~ISO 2000, and star tracking with an AstroTrac on my tripod. Those settings provided this view of the Pleaides (about the same size as the Beehive Cluster) last night from my backyard:

16 Responses to “Monday Night’s Asteroid Passage the Closest/Largest in Next 12 Years”

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  1. boris says:


    It’s probably worth mentioning that we are technologically equipped to destroy an asteroid of 500 meters cubed should the need arise. Of course that is unless the environmentalists stop us from interfering with the “natural” process of orbital degeneration of asteroids because we would necessarily be polluting space with “unnatural” ionizing radiation.

    Since we wouldn’t be able to jump on our X-box Perseus and zap it out of its orbit by hurling make believe mystical forces we would be doomed!

  2. Walter Cox says:

    Hi Roy,

    I have a friend who insists that “global” includes our oceans, which are “rapidly warming.”

    He even cites studies that show the total heat content of Earth’s oceans has multiplied. Is he right? How can this be measured accurately?

    I am not qualified to rebut his points. Can you?



    • The oceans have warmed, depending upon the depth, by hundredths of a degree over the ~50 years they have been monitored, that’s all. It’s questionable whether the deep ocean warming is even real because it is so small, and the error bars on the measurement are large. The surface warming is larger than deep ocean warming, and likely real…but still less than the land warming.

      So, maybe what your friend is referring to is the fact that hundredths of a degree of warming, averaged over the entire ocean, would require trillions upon trillions of Joules, which is the amount of heat required to raise 1 gram of water by 1 deg. C. So, they plot ocean heat content rise in these terms, which makes the numbers seem astronomical…even though the average ocean warming has been only hundredths of a degree.

      • Alan says:

        But now we have the 3,000 ARGO buoys taking lots of measurements, but hampered by the difficulty of measuring temperature with accuracy and precision. Any idea how long of a time baseline will be required before these devices give us an accurate idea of we how much heat is really being stored in the ocean despite the error bars?

      • Cunningham says:

        Thank you, Dr. Spencer… It’s amazing how a couple paragraphs can clear up so much misconception.

        • dave says:

          Dr Spencer says oceans have been monitored for ~50 years. It is actually longer. Since the “Challenger” voyages of the early 1870s, which accurately measured ocean temperatures at depth, the annually-mixed layer (i.e. to about 100 meters down) has warmed by (best estimate) 0.69 C. That is a rate of 1/200 hundredth C per year. Anybody can call that “rapid warming,” if they want, or “rather slow,” and speculate whether the increase has or has not been “uniform” over time. The description is merely a gloss. The fate of most of the “extra stored heat” will be to mingle into the large, lower volume, of almost freezing water, over the next century or so, and raise the temperature of the bottom water by 0.10 C. In Cretaceous times, the bottom water was about 15 C warmer than now.

    • geran says:

      Walter, tell you friend that the “guardian” is not a source for reliable science. In fact, ask him/her if they can even spell “science” correctly.

  3. boris says:

    to keep the image going we have to jump on our Pegasus with Perseus. Damn spell check won’t stop you from using the wrong proper name.

  4. DMA says:

    Off Topic
    There are several posts (Jo Nova, Paul Homewood) showing GISS 2014 for South America showing much warming that wasn’t shown in the original data. Can you show a map of the satellite derived temp. anomalies for South America to compare or better yet a brief post to compare the data sets for South America?

  5. Gary says:

    Looking forward to your video. I’ll be watching two feet of snow accumulate her in southern New England.

  6. Dr. Spencer, maybe the asteroid SHOULD hit us; the cooling is exactly what the AGW alarmists seem to want! They are always talking about geoengineering to cool the planet…

    By the way, a recent study damaged the “nuclear winter” hypothesis by showing that firestorms were very unlikely when the asteroid hit Yucatan at the time of the K-T extinction event.

    Thanks for the info on the big rock up there!

  7. Alan says:

    I wonder how far away you would be able to feel the impact if something of this mass hitting the earth?

    Changing gears, AFP came out with a call for more funding for ocean science which included this:

    “These include more research on how climate change will impact the marine food web, and improved forecasting of tsunamis and earthquakes — which along with other extreme weather events will become more frequent as the planet warms.

    So now AGW is also responsible for increasing frequency of tsunamis and earthquakes! Who knew? 🙂

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