Asteroid 2012 XE54 May Be Eclipsed During Close Flyby Tonight

The path of 2012 XE54 (in blue) during tonight’s close flyby.  At minimum distance, it will be about 139,500 miles away. Credit: NASA/JPL

Newly-discovered asteroid 2012 XE54 will fly by Earth tonight only 139,500 miles away or slightly more than half the distance to the moon. The rocky body, estimated at between 50-165 feet across (15-50 meters), was discovered only yesterday and will reach minimum distance tomorrow morning around 4:10 a.m. (CST) as it zips through northern Puppis southwest of Sirius. For a few hours before and after that, the asteroid should be visible in 8-inch and larger telescopes at around 13th magnitude. As with all these small bodies, 2012 XE54 will look like a starlight point of light on the move.

When brightest this evening at around 12.9-13.0 magnitude, the asteroid will be cruising through Orion and Monoceros. Positions are shown each hour starting at 9 p.m. CST. Created with Chris Marriott’s SkyMap software

According to Pasquale Tricarico, research scientist at the Planetary Science Institute, there’s a good chance the asteroid will be partially eclipsed by Earth’s shadow between 7:22 – 8 p.m. (CST), an unusual if obscure event. Amateurs and professionals watching at that time might see a drop in the 2012 XE54’s brightness.

It’s not often we get to see an asteroid eclipse. The first known case happened in 2008 when 2008 TC3 passed into Earth’s shadow for an hour before entering the atmosphere, where it shattered and dropped about 10 lbs. of meteorites over Sudanese desert.

Just so we’re clear, we’ve nothing to fear from tonight’s flyby. The asteroid will pass safely by Earth like so many others have in recent years. The map above gives you a general idea of 2012 XE54’s path across the sky. To create your own detailed map to find it in a telescope, click over to the JPL HORIZONS site. There you can set your location and time interval and then plot the asteroid’s positions on a detailed star map. Or you can input its orbital elements into your star-charting program. To see a very cool animation of the possible eclipse, check out Pasquale Tricarico’s website.

39 Responses

  1. Richard Keen

    Bob, thanks for posting that link to Pasquale Tricarico’s description of the eclipse. I ran the ephemeris on NASA Horizons, and their magnitudes show a slight BRIGHTENING during the eclipse, apparently due to opposition effect. It appears NASA doesn’t factor in the eclipse in their magnitude prediction algorithm.
    The event will be low in the trees here in Colorado, unless the wind (80 mph overnight, temperature 1 degree) blows them all down!

    1. astrobob

      Hi Richard,
      Yes, the asteroid continues to brighten during the eclipse according to the JPL ephemerides, so it appears they’ve not included the eclipse factor. Sounds like your conditions are downright wicked tonight. We might just get partly cloudy skies here in Duluth, so I’ll be watching.

      1. Richard Keen

        Bob, the winds have died down to 15 mph, the temperature has risen 10 degrees to +11, but alas, it’s cloudy and snowing. No eclipse here tonight.
        The DLH airport report has you in the clear, but the satellite image shows high clouds. How’d you do?

        1. astrobob

          Hey Richard,
          Darn it all. Well, we’re mostly cloudy with fairly thick cirrus. Jupiter and Capella look fine but if things don’t magically improve, I don’t think I’ll be able to reach 13-14 magnitude.

          1. astrobob

            Richard and all,
            It did clear up enough to see the little guy between 9-9:15 p.m. About 13 magnitude and moving at a steady pace in real time. Could see it at 142x in a 15-inch scope through light clouds. Maybe some brightness variations.

          2. Richard Keen

            Congrats, Bob, glad you got to see the space stone. I can occasionally spot Jupiter through the snowy sky, but that’s 15 magnitudes brighter than 2012 XE54. Guess I’ll have to settle for Toutatis, maybe tomorrow night.

          3. astrobob

            We got another clearing around 10 and I picked it up in Orion for a second time. Let us know if you see Toutatis. I’ll be out as well. That one will be much easier!

      1. Wayne Hawk

        Aloha astrobob!

        I’m constantly amazed at how short a time some of the closest “fly-bys” are discovered! I realize that finding anything smaller than a football field in the vastness of space is practically a miracle.

        See how your “humorous” comment pertaining to the ‘end of the world’ caused a small ripple of worry in your fanbase? With only 10 (or less) days to go until the end of the Mayan “long calendar”, I’m sure any and all asteroids, comets, meteors, etc. that are anywhere NEAR the earth will be labelled as “THE ONE”. Unfortunate as it is, the media has had a LOT to do with playing this false prediction way up.

        If TV shows and the like would only have reported what I believe is the truth, no one would be the slightest bit worried about this date. The truth? The end of this particular calendar only means (to the Mayan “civilization”) that an end was coming to one era and another era was beginning. What these differing “era’s” are I’ll leave to the experts. It certainly doesn’t mean the end of the entire planet and the existence of everything…sheesh!

        1. astrobob

          Hi Wayne,
          Thanks for sharing your thoughts on the matter. I agree about the hype and have tried in my small way to reassure folks the end isn’t near.

  2. rita murphy

    Hey Bob,

    Do you know if this asteroid will be visibe from Central Florida’s east coast? And, at what time, and what direction does one look? It has a condition code of 7. Isn’t that bad? Thanks.

    1. astrobob

      Hi Rita,
      The asteroid will miss Earth completely. It will be visible from Florida BUT you will need at least an 8-inch telescope to see it and a very precise map to locate and track it.

    2. Kevin Heider


      An Uncertainty Parameter U (condition code) of 7 is more than adequate to make a 2 day prediction (Dec 9-11) of the asteroids position given that it will pass Earth at a distance of roughly 0.0015 AU (220,000 km; 140,000 mi).

      Also make sure not to confuse the Uncertainty Parameter U (condition code) with the Torino Scale. 2012 XE54 is not even listed on the Sentry Risk Table for a future potential impact.

  3. MBZ

    Cold front blew through last night. Sky is good. The Clyde (my 8″) is already outside and pointed at Orion’s spot in my late evening sky. Thanks for the additional challenge.

    1. astrobob

      This will be a challenge. Check the JPL emphemeris for magnitudes. It starts at around mag. 14 at 0 U.T and rises through the evening to mag.13. Not bright but not impossible. A great chart will be the key to finding it. Good luck!

  4. stephanie

    Hi bob I just seen about this astroid on nbc news and they have it all scary looking and saying stuff like it won’t hit but if it did we all would be screwed… not what I needed to read… what is ur take on the situation? And when will it be closes to earth? After that will it be flying by the rest of the way where ppl can see it? Thanks a lot bob what would I do without ya lol

    1. astrobob

      This asteroid has already passed by Earth and it’s on its way outta here. It’s also MUCH too small to cause any significant damage. Perhaps you’re referring to the larger asteroid Toutatis that passes nearest to us tonight (see today’s blog on the topic). It’s a few miles across – IF that one hit, it would cause massive devastation. Fortunately, it’s not predicted to do that anytime soon. Not in the cards.

  5. Layla

    Hi bob what time is this one suppose to pass? Can I see it from buffalo ny? And if it poses no threat why is the media making a big deal about it ? And did one fly by last year about this time bob that they showed online as well?

    1. astrobob

      No threat for anyone. It will be visible across most of the world for weeks but it’ll be brightest the next few nights. I can’t recall offhand which particular asteroid flew by last year since there were several close ones. The media is probably hungry for a cool space story, otherwise there’s no danger in this one.

      1. Kevin Heider

        I am fairly confident the reader is commenting about 2005 YU55. On 8 November 2011 at 23:28 UT “2005 YU55” passed 0.8453 LD (324,900 km; 201,900 mi) from Earth.

  6. stephanie

    Are u gonna be watching it tonight ? The nbc news said closes approach would be at 1:40am eastern time does that sound right to u bob? And once it’s at its closest approach the rest of the time its just moving away right? Thanks

    1. astrobob

      I’ll take a look tonight if it clears. Snowing right now. That close approach time sounds right. After that, Toutatis heads out and away as its distance from Earth increases.

  7. Layla

    Bob I have to ask you I just seen online that a 65 foot asteroid just passed close by earth earlier today 2012 XE54 how come no one said anything about that ? Wow that’s crazy!!! Did u hear anything about it?

  8. Layla

    I’m always the last to know lol but still I’m glad u wrote ur blog about tonight I’m a lil uneasy but if u say its ok than its ok lol but for the future would an asteroid break up in our atmosphere? If one where to pose a threat? Or at least NASA have a back up plan?

    1. astrobob

      Small asteroids break up in our atmosphere at least several times a year. If we’re lucky, they deliver meteorites to a place we can find them. There are some great ideas to get the asteroid on a new course if a bigger one were expected to hit Earth, but since there is no imminent threat, these ideas have yet to be tested in a real situation.

  9. Alex

    hi my name is Alex and Im 12 yrs old I was just wondering if ur sure nothing bad will happen tonight cause Im a little scard to sleep…..I dont wanna believe all the stuff I been reading and i read ur whole page and u seem truthful I just wanna make sure cause im gonna be a teenager in the summer and been waiting my whole life for this I know Im a kid but thank you for ur help. I also read ur 2012 page and what u wrote makes sence cause in school we did a chart and without leap year it would be 2013 already is my teacher correct? thank you

  10. It is amazing just how much concern is caused by these objects.
    We have come so far in our understanding of NEO’s and mapped so many more of the in the time I have been involved in Astronomy and Space Science (last 10 years) I believe that we (bloggers and science broadcasters) have a responsibility to spread the truth, with all the sensationalist stories about these very natural events, in the mainstream media. Good on you Astrobob !

  11. Wayne Hawk

    I totally agree with you Ian and astrobob. It really breaks my heart to read posts like the one from Alex above who can’t get to sleep some nights because of the hype from various media sources that make false claims out of just about anything that has an “apocalyptic” feel to it. Not only does it sadden me, if I dwell on it, it angers me as well.

    I realize that all most of us with an above average knowledge of the universe cannot put every person who is this anxious at ease about this situation. We can only post our comments on all the various websites that allow us to with hopes that those that are stressing out over this will read them and take what we say not only as the truth, but the honest and comforting truth that it really is.

    Alex and all others that have been made afraid by all the sensationalistic media out there: REST EASY. NOTHING WILL HAPPEN ON 12/21/12 LIKE THEY ARE REPORTING. OK? OK! TRUST US.

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