You GO, Janey !
Posted on 09/06/2010 4:49:27 PM PDT by TaraP
Within the space of less than an hour on September 5, the Mount Lemmon Survey discovered two objects which will both pass by the Earth on September 8 at a distance closer than the Moon! This unprecedented coincidence provides an exciting observing challenge for amateurs although those observing from the UK will not have the best views.
The intrinsically smaller object, 2010 RF12, will be the more favourable observing target in that it passes closest at about 0.21 lunar-distance, i.e. about 80,000 km.
Tonight from the UK (Sep 6/7) this object will be 17th magnitude but by tomorrow (Sep 7/8) it will be brightening rapidly from 16th to 15th magnitude and be accelerating from an apparent speed of about 30 "/min to 50 "/min.
It passes closest around 2100 UT on the 8th but by then it will be difficult from any location on the Earth.
The larger object, 2010 RX30, only approaches to within about 0.66 lunar-distances of the Earth but will be more favourably placed for UK observers and should be able to be followed to within about 6 hours of closest approach which takes place around 1000 UT on the 8th. It will be visible all night on Sep 7/8 being 16th magnitude at first but then brightening to 15th mag.
The problem however is its apparent speed in that it will be racing across the sky at between 2-5 ARCSEC/SEC.
Observers with access to telescopes located in other parts of the world especially in the southern hemisphere could witness 2010 RF12 reach 13th magnitude around 1600-1700 UT on the 8th.
As seen visually in a large telescope (30-cm aperture or more), its motion across the sky would be very apparent in real time.
We will be lied to till the very end.
Bread, milk and batteries...maybe ammo.
Exactly....
When the one that hits comes, we won’t have a clue.
What, no zombie repellant?
I am not sure I want to know.
hey thanks for the info. not sure what a 15m asteroid would do if it made a direct hit in the middle of a city. My guess is there would be very limited damage and much would burn up before impact
Hmmm?
Reminds me of the sifi movie “Starship Troopers”, wasn't Buenos Aires a direct hit, and caught all by surprise...?
I hope one hits Mecca and the other one hits Medina.
We had a Huge Fireball that struck Columbia yesterday, what does it mean? Well for one earth’s changes are not due to Man-Made Glo-bull Warmng that warrants a *Carbon Tax*
Well if they hit, you’ll know it soon enough.
I think I read somewhere that there is an asteroid that will have a close pass to Earth sometime this decade, and if it passes through a well defined 600 mile-or-so area (threading the needle), it will definitely strike Earth (the Pacific) sometime in the 2030s on a later pass.
You GO, Janey !
I remembered it wrong - this describes Apophis, which will have a near miss in 2029 and if it threads the needle, will hit Earth in 2036.
UPDATE NOTES
2009-Apr-29:
This animation illustrates how the unmeasured physical parameters of Apophis bias the entire statistical uncertainty region. If Apophis is a RETROGRADE rotator on the small, less-massive end of what is possible, the measurement uncertainty region will get pushed back such that the center of the distribution encounters the Earth’s orbit. This would result in an impact probability much higher than computed with the Standard Dynamical Model.
Conversely, if Apophis is a small, less-massive PROGRADE rotator, the uncertainty region is advanced along the orbit. Only the remote tails of the probability distribution could encounter the Earth, producing a negligible impact probability. Although measurements in 2010-2011 may cut the size of the measurement uncertainty region greatly and result in an “all clear” using the Standard Dynamical Model, it may not be until Arecibo radar in 2013 provides a spin direction that Earth’s passage through the probability distribution center can be ruled out.
Only 8 meters in diameter? Might cause someone trouble if it hit, but would not be memorable.
We will have little warning about the one that gets us.
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