Observing Geometry for the 2021 Apparition

The plots presented here are for general planning purposes. If you need more detailed values for the different geometric conditions, use the JPL Horizons routines to compute the values for your specific situation.

Geometry was computed using the orbital solution JPL#17.

Geometry Data File

The geometric data plotted below is included in ASCII format in this Data File.

Right Ascension and Declination

Note that the width of the line reflects the objects estimated brightness, which is plotted below.

2021 Plot of the object's RA And Dec positions
PDF Version

Heliocentric and Geocentric Distances

2021 Plot of Heliocentric and Geocentric Distances
PDF Version

Solar Elongation and Solar Phase Angle

2021 Solar Elongation and Phase Angle
PDF Version

Expanded view of the angles around close approach:

2021 Solar Elongation and Phase Angle - Expanded view
PDF Version

Predicted Brightness

2021 Predicted Brightness
PDF Version

True Anomaly

Notice that the true anomaly may have a discontinuity at close approach, which is caused by the changes in the asteroid's orbit from the gravitational effects of the Earth.

2021 True Anomaly
PDF Version

Rate of Motion

2021 Rate 2021 Rate

Rise, set and visibility from different latitudes

The asteroid rises and sets at different times depending on the observer's latitude and longitude. The plots below provide information for approximating when the asteroid will be visible, and how long it will be observable from a given location on a given date.

Plots are given for latitude intervals of 5°, which is usually close enough for general planning purposes. Rise and set times are given in UTC for 0° longitude. For other latitudes, these times will be approximate to the local time, which should again be sufficient for basic planning purposes. Note, however, that there will be an offset (typically < 1/2 hr) for different longitudes, so if more accuracy is needed, then you should obtain a more detailed ephemeris.

How to read these plots

We provide a more detailed description of the Rise/Set and visibility plots, and an example of how to read the information here (PDF).

Asteroid visibility (TimeUp) and Rise/Set plots

If there is another major observatory for which you'd like to see details, please let know.

Goldstone (+35.4) Timeup Rise/Set
DCT (+34.7) Timeup Rise/Set
Spacewatch (+32) Timeup Rise/Set
La Palma (+28.8) Timeup Rise/Set
MKO (+19.8) Timeup Rise/Set
Arecibo (+18.4) Timeup Rise/Set
La Silla (-29) Timeup Rise/Set
CTIO (-30.2) Timeup Rise/Set
SAA (-32.4) Timeup Rise/Set