New Horizons/Pluto Moon Tracker Help
This form enables you to generate a diagram showing the east-west motion of the inner satellites of Pluto across the planet's disk. The distance of each selected moon from the planet's axis is plotted in units of either arcsec or planetary radii. Positive values correspond to bodies on the "morning" side of the planet (moving toward the observer) and negative values by the "evening" side. In the diagram, the planetary limbs are indicated by a dark gray stripe down the middle. Time increases downward on the plot.
The Moon Tracker tool also allows you to download an ASCII table containing the numeric values that went into the diagram. The file contains a single header line followed by the numbers. Columns are as follows:
- Modified Julian Date (UTC)
- Year
- Month
- Day
- Hour
- Minute
- Projected equatorial radius of planet (arcsec)
- Distance of first moon from planet's axis (arcsec)
- Distance of second moon from planet's axis (arcsec)
- etc.
Change History
-
3.0 (August 2, 2022): The Moon Tracker has been newly expanded to support the Pluto system.
Time Limits
The start and stop times (UTC) of the table can be entered in a variety of formats. For example, the following all parse to 0:01:02 UTC on July 4, 1976:- 1976-JUL-04 00:01:02.00
- July 4, 1976 12:01:02 am
- 12:01:02 am July 4, 1976
- 1976-07-04T00:01:02Z (ISO format)
- MJD 42963.00071759259
- JD 2442963.50071759259
Interval: Enter the time interval to be used for the tabulation as a number in the box, and select the time unit from the choices provided. Start times and intervals are rounded to the nearest minute.
Moon Selection
Click on the box to the left of each moon that you wish to include in the diagram and in the tabulation.Plot Options
Scale: Enter the numeric range and units of the horizontal axis. The value you enter is actually half the width of the diagram; for example, if you enter 10 planetary radii, then the axis will run from -10 to 10. Zero always falls at the middle of the plot.
Title: Enter a title for the plot in this box. It will appear centered above the diagram.
Output
By default, when you click on "Submit", you are directed to a web page that lists the details of the request, a small preview of the diagram produced, and options to view or download that diagram as PDF, JPEG, Postscript, or as an ASCII table. Optionally, you can choose to bypass the web page and go directly to any one of these four formats.