NEOviz: Uncertainty-Driven Visual Analysis of Asteroid Trajectories

TL;DR

NEOviz is introduced, an interactive visualization system designed to assist planetary defense experts in the visual analysis of the movements of near-Earth objects in the Solar System that might prove hazardous to Earth, and presents a novel approach for visualizing the 3D uncertainty region through which an asteroid travels, while providing accurate spatial context in relation to system-critical infrastructure.

Abstract

We introduce NEOviz, an interactive visualization system designed to assist planetary defense experts in the visual analysis of the movements of near-Earth objects in the Solar System that might prove hazardous to Earth. Asteroids are often discovered using optical telescopes and their trajectories are calculated from images, resulting in an inherent asymmetric uncertainty in their position and velocity. Consequently, we typically cannot determine the exact trajectory of an asteroid, and an ensemble of trajectories must be generated to estimate an asteroid's movement over time. When propagating these ensembles over decades, it is challenging to visualize the varying paths and determine their potential impact on Earth, which could cause catastrophic damage. NEOviz equips experts with the necessary tools to effectively analyze the existing catalog of asteroid observations. In particular, we present a novel approach for visualizing the 3D uncertainty region through which an asteroid travels, while providing accurate spatial context in relation to system-critical infrastructure such as Earth, the Moon, and artificial satellites. Furthermore, we use NEOviz to visualize the divergence of asteroid trajectories, capturing high-variance events in an asteroid's orbital properties. For potential impactors, we combine the 3D visualization with an uncertainty-aware impact map to illustrate the potential risks to human populations. NEOviz was developed with continuous input from members of the planetary defense community through a participatory design process. It is exemplified in three real-world use cases and evaluated via expert feedback interviews.

Figures (12)

• Figure 1: A systematic overview of NEOviz. NEO observations and their associated uncertainties are used to propagate trajectories into the future. These trajectories are then visualized as a collection using the Uncertainty Tubes and an Impact Map in the case of an impact. The results are presented in context to other solar system bodies and artificial satellites.
• Figure 2: Illustrations of the two different Uncertainty Tube representations: (A) sectioned uncertainty and (B) historical uncertainty. The timeline below each image shows the time ranges for each Uncertainty Tube.
• Figure 3: Ellipse slice computation and time stitching pipeline. At each time step, the trajectories are projected into a 2D space to calculate a minimum enclosing ellipse, which is used as an uncertainty representation. A consistent reference frame that is co-rotating with the NEO orbits is then used to connect adjacent ellipses and generate the Uncertainty Tube.
• Figure 4: Toggling the Uncertainty Tube into a wireframe mode enables the inspection of trajectory variants inside the tube in the case of nested uncertainty. The blue tube shows the uncertainty of all trajectories, the orange tube shows ones intersecting Earth.
• Figure 5: During asteroid (367943) Duende's close approach on Feb 15$^{\textrm{\small th}}$, 2013, the positional uncertainty increases due to the gravitational pull of Earth, while a second source of uncertainty, a lack of observations, decreases. NEOviz shows the transition accurately as the uncertainty shows a skew towards the Earth before the closest approach and a more uniform distribution after the encounter. The orange points in (a) correspond to the times at which figures (b), (c), and (d) were created. The trails around Earth show the Geostationary satellites at a distance of 36,000 km.