I am trying to use
get_body() to get position and motion data for solar system objects.
I’ve tried the following:
from astropy.time import Time from astropy.coordinates import solar_system_ephemeris, get_body t = Time('2019.5',format='jyear') mars = get_body('Mars',t,ephemeris='de432s') print(mars.ra) print(mars.dec) print(mars.pm_dec)
The first two print statements work fine. The last line throws this error:
TypeError: Frame data has no associated differentials (i.e. the frame has no velocity data) - represent_as() only accepts a new representation.
The same thing happens if I try any other solar system body as well.
Can I get motion data (such as the rate of change of the declination) using