Friday, February 4, 2011

2011 CQ1 - Very Close Approach

The newly discovered object, officially designated 2011 CQ1, will make a close Earth approach today February 04, 2011 around 19:40UT at ~0.03(LD)/0.00008(AU) or 11855 km.

2011 CQ1 has been discovered by R. A. Kowalski few hours ago in the course of the "Catalina Sky Survey" with a 0.68-m Schmidt + CCD. The object was moving at roughly 6 "/min and it was of magnitude ~19. According to its absolute magnitude H=32 this is a very small object, in the order of 2-3 meters.

Just few hours after his discovery, we have been able to follow-up this object using remotely a 0.35-m f/3.8 reflector + CCD of "Tzec Maun Observatory" in New Mexico. At the moment of our images (on February 04.46), "2011 CQ1" was moving at 23"/min and its magnitude was ~18.

Here you can see our image (stacking of 20 unfiltered exposures, 10 seconds each). Click on the image for a bigger version:

While this is an animation showing the object movement in the sky:

According to Bill Gray (Findorb developer): "That perigee value is solid to within a few kilometers. So no chance of an impact, but still _very_ close!!"

The orbital element published here, are very interesting:

2011 CQ1
Perigee 2011 Feb 4.818749 TT = 19:38:59 (JD 2455597.318749)
Epoch 2011 Feb 4.8 TT = JDT 2455597.3 Find_Orb
q 11855.6869km (2000.0) P Q
H 32.1 G 0.15 Peri. 156.15870 -0.32177738 -0.84067340
Node 92.60696 -0.92360962 0.17747398
e 1.7936521 Incl. 25.85075 -0.20833766 0.51163581
From 11 observations 2011 Feb. 4 (6.3 hr); mean residual 0".362.

As shown by the ephemeris, 2011 CQ1 will be visible for a few hours. It would be really interesting to follow-up this object in the next few hours, during its very close approach when it will reach the magnitude 14!

UPDATE - February 04, 2011 - 19:35UT

On mpml mailing list, Andrew Lowe pointed out that "that 2011 CQ1 will transit the sun shortly after its close approach. Based on astrometry up to MPEC 2011-C14, its "centre line" will start to cross the earth at Feb. 4.831 UT around N11 E160, with mid-transit at Feb 4.844 (S24 W125; south Pacific) and ending at Feb 04.858 (S29 W30)"

Andrew has supplied three coordinates on the centerline:

First contact: Feb 4.831 UT 11N, 160E (west of the Marshall Islands,
near Enewetak)

Mid-transit: Feb 4.844 UT 24S, 125W (French Polynesia, east of
Pitcairn Island)

Final contact: Feb 4.858 UT 29S, 30W (south Atlantic, off the coast
of Brazil)

Following this suggestion, Bill Gray calculated a transit line plot showing the path over South America. You can see the charts below:

Credit: B. Gray

UPDATE - February 05, 2011 - 09:30UT

According to a press release by NASA/JPL, 2011 CQ1 is "the closest non-impacting object in our asteroid catalog to date. It passed to within 0.85 Earth radii (5480 km) of the Earth's surface over a region in the mid-Pacific"

Prior to the Earth close approach, this object was in a so-called Apollo-class orbit that was mostly outside the Earth's orbit. Following the close approach, the Earth's gravitational attraction modified the object's orbit to an Aten-class orbit where the asteroid spends almost all of its time inside the Earth's orbit.

NASA press release contains this diagram where is evident how the close Earth approach changed the asteroid's flight path by about 60 degrees:

Credit: Nasa/JPL

By Giovanni Sostero & Ernesto Guido


tommie'somebody said...

Will the moon's gravity affect 2011CQ1 trafectory?

Anonymous said...

Give it to us in English. How many miles or Kms will it be it's closest point to earth, and when will that be in Greenwich mean time? and what part of the world will that be over?

Anonymous said...

It will be more affected by the closer approach to the earth's larger gravity well. The moon close apprach is tomorrow (UT) at a much greater distance with a much less massive object.

Team said...

Closest approach will be on February 04, 2011 around 19:40UT at roughly 11855 km. At present UT time and Greenwich Time (GMT) are the same.


Rob Matson said...

Andrew Lowe has recently reported on the Minor Planet Mailing List (MPML) that 2011 CQ1 will ~also~ transit the sun starting in less than an hour, from 19:57-20:35 UT. Purely of celestial mechanical interest since the angle subtended by the asteroid in silouette will be less than 0.05 arcseconds.

Anonymous said...

Closest approach is right now, at about 5482 +/- 26 km above the earth's surface

Meteor Wayne said...

Team gave the distance from the earth's center, I gave the distance (5482 km) above the earth's surface


Team said...

Hi @Rob, thanks we have updated the blog with the news of the transit on the Sun.


Team said...

Hi @Meteor, yes 11855 km is the distance from the earth's center. As you pointed out, the distance from the Earth's surface is only roughly "5482" km.


Belle said...

I'm calling Bruce Willis.

Anonymous said...

how close was it to the keyhole ? any future encounters ?

Anonymous said...

Will it hit the earth?

Anonymous said...

Four metres is *interesting*. Forty metres calls for further tracking. Four hundred metres would be scary...

Prissy- Booth said...

Wow! that is so interesting to know, about this scenario,particularly that we just recently learnt about "Asteroids".I couldn't help but constantly visualize this, evening's, event.I wished I had the opportunity to be amongst the viewers(Astromers)today. Looking forward to getting more data from Prof West, on monday.
Thanks for informing us.

Team said...


No, this object will NOT hit the Earth!!

It's so small (roughly 2 meters) that even in case of impact, it would explode high in the atmosphere and do essentially no damage.


Erik Bryssinck said...

Great job! Not easy to image this fast moving object of that magnitude, with 10 sec exposuretime!
thanks for the quick informing! keep up the great work

Anonymous said...

great work V.