Lowell Observatory offers these tools to assist with asteroid observation planning and to faciliate data mining across multiple surveys. Orbital solutions are calculated in-house based on Minor Planet Center observations.

This website is in the process of being upgraded and as such is in beta status; some tools may experience bugs. If a bug is particularly important, please direct concerns to asteroid@lowell.edu.

Observational Tools


Interactive table of observable NEOs.


Asteroid and observatory-specific ephemeris generator.

Designation Linker

Return all known designations for a given asteroid.

NEO Observing Calendar

Calendar of ongoing NEO observing programs.


Observability chart for a given asteroid and observatory.


Calculate observations needed to result in numbering of asteroids.


Build finder chart for a given asteroid and time.


Plot field stars and asteroids at a given time and location.

Hierarchical Observation Protocol

Generate prioritized list of observable asteroids based on observability criteria.

Catalogs & Lists


List of asteroids whose orbits are near one or more of the major planets.

Critical List of Asteroids

List of asteroids in need of observation due to large ephemeris uncertainty.

Asteroid Orbital Elements

Access to, and information about, the astorb orbital elements database.

LONEOS Observations

Access the archived LONEOS asteroid observations database.

Star Catalogs

Query tool to access the USNO and PPM star catalogs.


January, 06, 2017,Reorganized home page. Updates to backend datbase hardware and schema.
November, 29, 2016 Improved Asteph page. Moved to new backend ephemeris tool. Now includes lunar elongation and airmass. Streamlined form fields. Made table generation faster. Removed multiple object option. UpObjects page now has dynamically adjusting table based on changing form fields.
August, 30, 2016 Improved UpObject performance and reliability. Multiple objects are now accepted for asteph (seperate with a ",")
April, 19, 2016 Improved reliability of Astplot and Astfinder. Fixed missing table export icon.
April, 6, 2016 Major UI updates. Fixed slow UpObjects load time. Fixed UpObjects plots being in wrong date order. HOP backend calculates daily.
February, 1, 2016 Airmass added to Ephemeris output on Asteph. Many popup plots for UpObjects parameters (click on a parameter).
December, 23, 2015 Ephemeris and Designation table now reference a JSON object which can be called directly. Minor UI and consistency updates.
December, 7, 2015 Added phase column option to UpObjects. Fixes sort by asteroid number on UpObjects. Optimized some code.
December, 1, 2015 New tool: NEO observing calendar. A publicly available summation of NEO observations.
November, 27, 2015 Fixed issue with negative phase angle object being improperly filtered on UpObjecs page
November, 18, 2015 Asteph object identifier links bring to prepopulated ephemeris page
November, 03, 2015 Fixed Asteph ephemerides. They used to be wrong. Now they are correct.
October, 29, 2015 Asteph timestep/duration combinations fixed. Can go past 100 steps. Email links fixed.
October, 22, 2015 UI updates to tables. Errors can be displayed in Asteph table.
October, 01, 2015 Public Beta Website Release
July 30, 2015 Landing page tiles
July 29, 2015 UI improvements