Project Summary

• In this project we implemented a simulator which takes a 3D model of an object as an input, generates an animation of its rotation and produces it’s light curve, given the angle of observation.

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Asteroid “4 Vesta” rotational video through blender’s rendering system

What is a light curve?

• A light curve is the graph of a celestial body's brightness in respect to certain intervals and over a given period of time (hours, days, months...) or a given rotational phase.
• What we observe is Asteroids shining due to the Sun's light reflecting off their surface. Their brightness might vary due to one or more factors (asteroid distance, asteroid’s phase, irregularities in shape and texture, spinning pattern).

Our implementation

The control flow includes:

1. The use of the open source software “Blender” for rendering pictures of the asteroid. The outcome was a 3D animation of the asteroid reflecting sunlight, while spinning around the vertical axis.

Blender Environment

Render of “4 Vesta”

Our implementation

2. The implementation of a Python script, which calculates the average pixel brightness of each frame depicting a specific phase of the asteroid’s rotation, then collects the data and graphs the light curve.

Program Output

Real data comparison

• In order to validate the accuracy of our results we researched papers concerning the asteroids whose light curves we simulated. We attempted to imitate the actual conditions in which the light curves were measured (for example the phase angle of the observer to the sun). Where data was unavailable we made educated assumptions for the parameters.

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Simulated result compared to actual data

Problems we faced

The main problem we faced was in the research required for an accurate simulation and its documentation.

• The information available is targeted to experts on the field and requires prerequisite knowledge.
• Certain relevant information is either publically unavailable or remains unknown (for example the axial tilt of the majority of documented asteroids).

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The above problems make the replication of the real world data much more difficult to simulate.

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Future Prospects

1. Make the simulation more realistic
• Implementing more simulation parameters, such as axial tilt, orbital information, angular motion.
• Simulate the surface albedo of our model asteroids.

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• Inverse method applications (obtain asteroid information from observed light curves)
• Use the simulation results as a data creation method linking asteroid information (shape, chemical composition) with its light curve. This can be used as training data for a machine learning approach in order to improve predictions from actual observations.
• The simulation can also be used as a learning tool.

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