Really Hair Raisers - Missed again

[bigmasterdrago]

It appears that near April Fools Day we had a couple of small rocks pass inside 1/4 LD.

First rock 2022 GC, missed by 0.147825LD on March 31 2022, 20:47:12. When brightest (14.3), it was below my horizon and had not been discovered yet.

Then 2022 GQ flew by 0.12879LD on April 1 2022, 11:58:17CDT. Again, not yet discovered (inside our orbit). and when outside, too faint for me.

These close pass distances were topo for my location.

These rocks from space, once again show we can get clipped without even knowing it. Cool stuff.

[PMSchu]

Hi BMD,

Yes, we dodged a couple more impacts. Many of these rocks are only detected on the way out. 

Here's my Observing List (OL) showing the MPs that were predicted to be within 0.05 AU of earth on 2022 Apr 5 (today): [attachment=2313]

The OL was created using ST4v's Database Power Search (DBPS) on Apr 3 after I downloaded the MPC's NEAs at Today's Epoch data file to get the MPC's latest elements for the ~28,000 known NEAs. The OL is sorted on the Brief column at the far right that shows the peak brightness expected during the pass. MPs that were detected after close approach have PCA (=Past Close Approach) in the Brief. There are quite a few rocks with PCA in the list, although few as close as 2022 GC & 2022 GQ. Some objects like 2022 FY which came close ~Mar 25 were detected before that, so they're not tagged with the PCA label.

If I reran the DBPS today, there would be more objects on the OL as several MPs were detected yesterday & today & added to the MPC's data file.

Searching for these things is quite a challenge. It's a wonder that they're able to spot them at all.

Phil S.

[ledge1962]

Makes you want to put your insurance up.

Where is the size of the target?

[PMSchu]

Hi George,

I don't include the size of the MPs as part of the Brief & Note info but opening the Object Info (OI) dialog shows the estimated size range for any of these objects. If you've already downloaded the MPC's NEAs at Today's Epoch data file for today, just open the OI. It's on the right side of the dialog. See the post about 2022 GN1. That has an OI included for that object. The estimated diameter is 5 to 15m.

Phil S.

[ledge1962]

Thanks Phil

Is that measurement across the widest part?

[bigmasterdrago]

I see estimated diameters at both spaceweather.com and CNEOS https://cneos.jpl.nasa.gov/ca/

There are some interesting graphs of these two rocks at https://odassoastro.blogspot.com/2022/04...close.html

It's strange that for 2022 GC, the graphs for 'a' and 'e' are almost straight lines, whereas the graph for 'q' waves around a lot. It even includes significant changes that are not linked to close encounters. Wondering if something is out of whack. I may explore this more closely when I get the time.

[PMSchu]

I should have uploaded the Observing List to the forum. It's attached below for those who are interested in more information about these objects.

Phil S.

[bigmasterdrago]

Phil, do you run your DBPS for NEAs every evening? You seem to snag a lot more than I can using ST. I'm sure it involves something I'm intrinsically doing wrong. Especially in creating the observing list.

---

I cannot even get one rock to drop to a nightly planner observing list using your MPs WIthin 0.05 AU on 2022 Apr5.stx

---

   

[PMSchu]

Hi BMD,

Have you checked to be sure that these NEAs are in your MP database? Do you do the download of the MPC's NEAs at Today's Epoch to get the updated elements or do you download elements from HORIZONS? I would expect your MP DB to have at least some of these NEAs. You have the filters set to show these faint objects in the list. If I set ST4v to your Location on Apr 8 using my OL, all 45 objects are displayed. Does setting the Attachments folder to this OL make a difference?

Did the 2nd person who downloaded the .stx file have the same problem as BMD? Did you get all of the objects in the OL?

Greg does the .stx file include the elements for the MPs in the Observing List? If so BMD should have these MPs in his MP DB after downloading the .stx file. Am I missing something? When I downloaded Chamukuy's Red Stars .stx file, I got all of the objects without issues. I've never tried downloading a .stx file with MPs in it before.  

Phil S.

[theskyhound]

Greg does the .stx file include the elements for the MPs in the Observing List? If so BMD should have these MPs in his MP DB after downloading the .stx file. Am I missing something? When I downloaded Chamukuy's Red Stars .stx file, I got all of the objects without issues. I've never tried downloading a .stx file with MPs in it before.  

Phil S.

Yes, importing an observing list will import the objects plus all of the orbital elements assigned to each one.

Is he not running the Database Power Search though? I wonder if maybe he forgot to add the search results to the list?