6 replies to this topic

[PeterSurma]

I recently observed the 13.2mag PHA 363027 during its encounter with earth on Oct 11th, 2024 (nearest encounter on Oct 12th). 20" f/4 scope used under pretty bad 19.6mag/sas skies due to moonshine (60% illuminated, @30° angular distance).

 

Angular velocity: 0.96"/second
Distance to earth   0.02393968 au (3,581,326 km)

 

Just google- translate my report to read the story, if you like:

https://eyes4skies.d..._10_11_LAHA.htm

 

I already tried before to catch it on Oct 5, at 15mag, though no luck and orbital elements too bad, well regrettably:

https://eyes4skies.d...Z.htm#pha363027

 

JPL infos on this PHA available at

https://ssd.jpl.nasa...l#/?sstr=363027

 

Regards,

Edited by PeterSurma, 14 October 2024 - 11:59 AM.

[Tapio]

Strange that it's going so fast (0.96"/second) and yet it's 3,5 million kilometers away.

Checked that it's going 25.8km/s.

[PeterSurma]

Did not know solar escape velocity straightforwardly by heart, so google told me (which sounds reasonable):

 

Escape velocity from the sun without the influence of Earth is 42.1 km/s. In order to reach this speed, it is highly advantageous to use as a boost the orbital speed of the Earth around the Sun, which is 29.78 km/s.

 

So yes the PHA's speed is similar to earth's speed on its orbit. That sounds completely reasonable, doesn't it ? And we're far from solar escape velocity here, so no matter to worry about speeds too high, I'd reckon.

 

Looking at the path on a large scale chart you see it moves 16° southwards in one day from Oct 11 to 12. Check it out for plausibilty on my guide 9.1 simulated map here

https://eyes4skies.d...027_Okt2024.PNG

 

And yes, I could very well see it moving + passing by the surrounding stars, live and realtime. That's the thrill of observing this PHA passage events, after all. Very recommended to watch. You need accurate orbital elements though, see in the report text for MPC links...

 

Recommended software: guide 9.1 from projectpluto.com - performs pretty accurate orbit calculations and provides you all the charts you need to do it.

Edited by PeterSurma, 14 October 2024 - 09:26 AM.

[Tapio]

It's always fascinating to watch space objects move in real time.
My first one was back in 2007 when asteroid 2006vv2 (about 2km in size) was about 4 million km from Earth.
Even in 5s exposure it made a short streak.
https://www.ursa.fi/...6vv2_010407.htm

Fun fact - camera used then was Atik 1 HS, which I bought from Damian Peach.

[PeterSurma]

Cool !

You know about Apophis on April 13th, 2029 !? Looking forward to THIS one. Hope we THEN have good weather all over Europe.

 

But I really need to see such stuff visually,  I'm actually into visual DSO...

 

Kind regards to Finland,

Edited by PeterSurma, 14 October 2024 - 01:05 PM.

[Urban Uraniborg]

 

4 minutes 

This is the fastest space rock I have observed!! 
 

I had been apprehensive for trying to push to one of these targets because my FOV° is around 30 arc minutes wide. PHA (363027) 1998 ST27 took just over a half hour to zip all the way across my FOV°

Edited by Urban Uraniborg, 14 October 2024 - 08:22 PM.

[PeterSurma]

The fastest I have seen was back in/on 2002-08-18 this one:

2002 NY40

running at 8"/second 

 

https://ssd.jpl.nasa...2 NY40&view=OPC