#!/usr/bin/env python
# coding: utf-8

# # A Simple Solar System Simulation
# 
# This notebook demonstrates some basic controls of the [pywwt] Jupyter widget in its 3D (really, 4D) Solar System mode.
# 
# [pywwt]: https://pywwt.readthedocs.io/
# 
# First, we import the necessary modules:

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from pywwt.jupyter import connect_to_app
from astropy.coordinates import SkyCoord
from astropy import units as u
from astropy.time import Time


# Next, we connect to the WWT app:

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wwt = connect_to_app()


# Turn on the 3D Solar System mode and adjust a few view parameters, including significantly exaggerating the size of the planets to make them more visible:

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wwt.set_view('Solar System')
wwt.solar_system.scale = 99  # scale up the planet size very unrealistically!
wwt.solar_system.track_object('sun')


# Choose a nice angle that will show several planets:

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wwt.center_on_coordinates(SkyCoord(339.32980758, 20.78999814, unit=u.deg), fov=.6*u.deg)


# Finally, set the time of WWT's internal clock and adjust its rate to make the planets move at a nice pace:

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wwt.set_current_time(Time('2019-07-01'))
wwt.play_time(rate=300000)  # 300,000 times faster than real time


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wwt.get_current_time()


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wwt.pause_time()


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wwt.set_current_time(Time('2020-07-01'))


# ## Credits
# 
# This notebook was prepared by O. Justin Otor with contributions from Thomas Robitaille and Peter K. G. Williams.