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JPL Solar System Dynamics
=========================
SSD provides information related to the orbits, physical characteristics, and discovery circumstances for most known natural bodies in our solar system.
* * *
Lookup the Specified Small-Body
#### Quick Links
* [Horizons System](/horizons/)
* [Gravity Field Visualization](/tools/gravity.html)
* [Small-Body Database Lookup](/tools/sbdb_lookup.html)
* [Small-Body Database Query](/tools/sbdb_query.html)
* [Small-Body Satellites](/sb/sats.html)
* [Astrodynamic Parameters](/astro_par.html)
* [Glossary](/glossary/)
* [FAQ](/faq.html)
Solar System Objects
Count
Classification
8
Planets
421
Planetary Satellites (includes satellites of Earth and dwarf planet Pluto)
773,916
numbered
668,368
unnumbered
1,442,284
Asteroids (includes KBOs, TNOs, and dwarf planets)
589
numbered
3,413
unnumbered
4,002
Comets (includes fragments)
Last updated: 2025-03-21 10:07:03 UTC
Statistics
340,633
orbits computed last month (Feb, 2025)
2,297,812
orbits computed last 12-months
### Prior Announcements
[
#### TLS/SSL Encrypted Connection for Horizons Command-line Interface 2024-09-13
A new TLS/SSL encrypted and PKI authenticating port option is available for the Horizons command-line interface, port 6770.
](/announcements/an20240913.html "click to read the complete announcement")[
#### SSD Server Upgrade Notice 2023-01-25
The SSD server (ssd.jpl.nasa.gov) supporting the website and Horizons will be upgraded starting at 8am PST (16:00 UT), Monday February 13.
](/announcements/an20230125.html "click to read the complete announcement")[
#### Updating to Horizons v4.90 Next Week 2021-09-29
Horizons version 4.90 will go into effect on the server late Monday, October 4 PDT, along with updated documentation. This e-mail is advance notice of new output options, redefinition, and format changes some might need to accomodate.
](/announcements/an20210929.html "click to read the complete announcement")
If you're looking for earlier announcements, [all announcements](/announcements/) are available on a separate page.
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