Lowell Observatory offers these tools to assist with asteroid observation planning. The orbital solutions used within these tools are independently calculated from Minor Planet Center observations. Asteroid.lowell.edu is in the process of upgrading and in a Beta status. Functionality should generally be available. However, some tools may experience bugs. If a bug is particularly important, please direct concerns to asteroid@lowell.edu.

Target Generation

Hierarchical Observation Protocol

Generate an observationally prioritized list of asteroids based on the capabilities of the user's instrument and other generic requirements.


View a list of asteroids whose orbits are very near the orbit of one or more of the major planets. These asteroids can have rapidly changing orbits due to perturbations by the large planets.

LONEOS Observations

Access the archived LONEOS asteroid observations database.

Critical List of Asteroids

View a pre-selected lists of asteroids in need of observation. These lists are based entirely from parameters related to ephemeris uncertainties.

Observational Aids

Up Objects

Generate a table of NEOs based on severable filterable parameters.

Asteroid Ephemeris

Generate an asteroid ephemeris by selecting the asteroid by name, the start time, duration and interval.

Designation Linker

Return all known asteroid designations given any of its designations.

NEO Observing Calendar

View a summary of observing nights on large aperature (>2m) facilities allocated to observers who study near-Earth objects

Asteroid Observability Chart

Build a chart indicating when an asteroid is observable. It is based on the user's instrument, and location and the asteroid's declination, uncertainty, solar elongation, magnitude, and galactic latitude.

Asteroid Observing Strategy

Calculate the dates for a 'small' number of observations that will result in the numbering of an asteroid. It is based on the user's instrument and location.

Asteroid Finder Chart

Build a chart showing the position of a selected asteroid and the surrounding stars. The motion vector and the line of variation are indicated.

Asteroid Plot

Build a plot that depicts the position of stars and asteroids within a defined region.

Catalog Access

Asteroid Orbital Elements

View a list of asteroid orbital parameters and physical properties. The orbital parameters are updated daily.

USNO-A2.0 Star Catalog

Create a list of stars that meet various positional and brightness criteria. The base catalogs include USNO-A2.0, USNO-SA2.0, and PPM.


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

Lowell Observatory | MANOS | Flagstaff, AZ