NEOs 2011 UL21 and 2024 MK passing Earth this week

[gary]

Story here :-
https://www.abc.net.au/news/2024-06-28/two-large-asteroids-passing-earth-this-week/104034960

[EpickCrom]

Hi Gary, thanks for this excellent post!

I will try to observe both these NEO's tonight. At around mag 11 they are within reach. Thanks again mate

[Dennis]

On the evening of 28th June 2024 from our back garden in Brisbane, I managed to grab 44 frames of 2024 MK as it sped across our Southern skies. There are a couple of gaps in the trail due to intermittent cloud cover.

I took 44x60 sec exposures (sidereal rate) from 7:09pm to 8:01pm AEST (UT+10).
UTC: 2024-06-28T09:09:00Z to UTC: 2024-06-28T10:01:00Z.

When I processed the frames in Pixinsight and took the result into Photoshop for finishing, I noticed that the trail appeared slightly curved.
Using the Photoshop “Line Tool” I drew a straight line along the trail and sure enough, this reveals a gentle curve to the recorded path of 2024 MK.

A plate solve for the frame recorded at 7:34pm AEST provided the following details.

Center RA (2000.0): 14h 34m 52.33s
Center Dec (2000.0): -47° 40' 38.1"
Scale: 0.6520 arcseconds/pixel
Size (pixels): 3124 x 2088
Angular Size: 0° 33' 57" x 0° 22' 41"
Position Angle: 179° 46' from north through east
FWHM: 3.72 pixels, 2.43 arcseconds


Later, from 8:04pm to 8:09pm AEST (UTC: 2024-06-28T10:04:00Z to UTC: 2024-06-28T10:09:00Z) I was able to grab 6 frames with the mount locked on NEO 2024 MK and you can see the “stepping” of the star trails when the frames were combined.

Celestron C9.25 Edge HD at F10, ZWO ASI2600MM Pro camera.

Dennis.

[gary]

Hi Dennis,

Fantastic!!!

Best Regards

Gary

[Dennis]

Thanks Gary, out of the 10 or 12 NEO’s that I have managed to record as trails, 2024 MK was the first (and only) one to display a curved orbital track in the composite image.

And, as fate would have it, we were clouded out of Saturday night for the closest approach.

Oh well, such is life.:)

Dennis

[gary]

Hi Dennis,

You taking the time to show the orbital track was curved was brilliant.

I also note that today is the anniversary of the Tunguska event which took
place on 30 Jun 1908.

Two things are worrying about the "near miss" of 2024 MK.

The first is that it was only discovered on 16th June 2024.
Essentially a "zero day" event with regards a deflection probe mission had it
been on a collision path with Earth.

The second was that the initial diameter estimates were between 122 and 256 metres.
Hopefully with the close pass that will be refined.

Nobody knows for certain what the diameter of the Tunguska event object
was but some estimates have it at around 50 metres.

If 2024 MK is a 200 metre diameter NEO and was discovered so late in
the piece, it clearly is a heads-up that the world should invest even
more in early NEO detection.

Some time back NASA had been tasked by the US Congress with detecting
and cataloging 90% of the NEO population of size 140 meters or greater.

You will recollect that the NEO survey Rob McNaught was doing at Siding
Spring was shut down by ANU.

Observatories in the south such as the Vera C. Rubin observatory were
then to take up some of that survey.

NASA is funding the NEO Surveyor spacecraft which is set to launch
in September 2027.

https://www.jpl.nasa.gov/missions/near-earth-object-surveyor

[Dennis]

Thanks for the back story, Gary.

Yikes, I had not realized that 2024 MK was such a recent discovery given its size and proximity to Earth, a sobering thought indeed.

Dennis