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IDProjectCategoryView StatusLast Update
0001599SkyChart1-Softwarepublic17-01-13 22:05
ReporterSasa Assigned ToPatrick Chevalley  
PrioritynormalSeverityminorReproducibilityalways
Status resolvedResolutionno change required 
PlatformLinux 32-bitOSKubuntuOS Version16.04
Summary0001599: Asteroid data - unexpected download limitation
DescriptionNewly found asteroid 2017 AG13, almost hit the Earth few days ago...

http://www.space.com/35265-newfound-asteroid-buzzes-earth-2017-ag13.html
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2017%20AG13

In any event, after attempt to update asteroid list from "Update -> Asteroid elements", I have notice download is limited to 5000 objects, even checkbox "Load only the first" 5000 in this case asteroids is not checked. Report after download indicate that only 5000 asteroids is updated.

After "Setup -> Solar System -> Asteroid -> Load MPC file" and trying again gives the same result. After changing 5000 to 10000, checking or not the checkbox, result is the same...

Examining raw downloaded file MPCORB-2017-01-12.DAT shows there is exactly 5000 rows. I believe you have script at your server which download, prepare and split data from file(http://www.minorplanetcenter.org/iau/MPCORB/MPCORB.DAT).

It seems that there is some problem...
TagsNo tags attached.

Activities

Patrick Chevalley

17-01-13 00:01

administrator   ~0003514

You must select the file you want to download from Setup/Internet/Orbital elements
see: https://www.ap-i.net/skychart/en/documentation/internet#orbital_elements

The default is to get only the first 5000 from my server because most people do not want much overhead with asteroids.

I just update the full mpcorb and it work fine, download is 41MB, 144MB unzipped. Contain 726263 asteroids and 2017 AG13 is there:
Asteroid
2017 AG13
Magnitude: 26.4
Phase: 147 °
Distance: 0.0308au
Solar distance: 0.9575au
Velocity: 30.5km/s
Date: 2017-01-12 23h49m25s
ref: E2017-A76/2017-02-16
Hourly motion: 02'41.9" PA:64° dRA:14.19s dDec:01'11.6"

But for better precision with a near earth object you must use the method described here:
https://www.ap-i.net/skychart/en/documentation/display_of_neos

Sasa

17-01-13 01:51

reporter   ~0003516

I have full MPCORB, however that is far too large. Anyway, I do not know what first 5000 object are in it (low RAM and slow computer to examine), but obviously among theme are not recently found asteroids...

For me (as an amateur), there is no sense to have all nor far, but simply near asteroids in database.

What is your opinion to use this as a default instead:
http://www.minorplanetcenter.net/iau/MPCORB/NEA.txt

There is only around 15000 NEAs.

Sasa

17-01-13 01:57

reporter   ~0003517

BTW, I have notice now duplicated note...
Please delete first one and this. I do not see edit nor delete button any more.

Patrick Chevalley

17-01-13 08:45

administrator   ~0003518

To select NEA.txt and a few other interesting bodies click the button "First 5000 NEO + TNO" in Internet/Orbital elements.

You can also change the URL list as you want, as long you get files with the right MPC format.

There is no recent asteroid in the first 5000 but this is the brighter anyone can observe because the list is in discovery order and brighter where found first.

Sasa

17-01-13 14:40

reporter   ~0003519

Thank you for clearance.

In PDF help is wrote than Default is "First 5000 NEO + TNO", but obviously it is only first 5000 from your site, that makes a bit of confusion here.

Patrick Chevalley

17-01-13 22:05

administrator   ~0003523

Yes, the documentation was a bit outdated here.
I have fixed the text for asteroid and comet elements.

Issue History

Date Modified Username Field Change
17-01-12 21:57 Sasa New Issue
17-01-13 00:01 Patrick Chevalley Assigned To => Patrick Chevalley
17-01-13 00:01 Patrick Chevalley Status new => feedback
17-01-13 00:01 Patrick Chevalley Note Added: 0003514
17-01-13 01:49 Sasa Status feedback => assigned
17-01-13 01:51 Sasa Note Added: 0003516
17-01-13 01:57 Sasa Note Added: 0003517
17-01-13 08:45 Patrick Chevalley Note Added: 0003518
17-01-13 14:40 Sasa Note Added: 0003519
17-01-13 22:05 Patrick Chevalley Status assigned => resolved
17-01-13 22:05 Patrick Chevalley Resolution open => no change required
17-01-13 22:05 Patrick Chevalley Note Added: 0003523