Interactions of Energy and Matter

What will we "see" when we get to Vesta and Ceres?

Dawn Mission Objectives

The mission's science goals are to understand the conditions and processes in place at the beginning of solar system formation. Scientists also hope to gain a new understanding of the role of water in asteroid evolution.

Objectives for Dawn's science instrumentation

Framing Cameras
Primary Objective—data mapping of the surfaces. Images will be used to characterize the geologic history and evolution of the asteroids; the size and shape, surface morphology, surface texture and regolith features of the asteroids.

VIR spectrometry
Primary Objective—determine the mineral composition of the asteroids' surface materials in the geologic context; identify spatial distribution of materials and mixtures, including silicates, hydrates and other minerals.

Gamma Ray and Neutron Detector (GRaND)
Primary Objective—measure the average surface composition of the asteroid; map compositional variations and assess the extent of heterogeneity on the surface of the asteroid; search for near-surface ices to depths of 1 meter.

Gravity Investigation
Primary Objective—measure mass/mass distribution of Vesta and Ceres.

Secondary Objective—establish pole positions, rotation rates, and precise orbit of the asteroids.

Electromagnetic radiation (EMR) will play a major role in accomplishing the goals of the Dawn Mission. All the Dawn spacecraft instrumentation utilizes the interaction of specific ranges of electromagnetic radiation with the matter that comprises Ceres and Vesta. The results of these interactions will enhance our knowledge of the physical characterization of the asteroids, as well as the surface composition and mineralogy, surface modification and the ages of these surfaces. When this information is incorporated with what is already known, it will either substantiate current scientific models of asteroid origins and morphology or it will form the basis for new models.

EMR interacts with matter, including electrons and neutrons, by absorption and emission only in wavelengths corresponding to particular discrete amounts of energy. These wavelengths can then be used to identify the components of a given substance.

Most science curricula emphasize how we use electromagnetic radiation in our everyday lives, using illustrations such as radios, x-ray machines, microwaves, ultraviolet and infrared lamps. The materials in this module will introduce students to the ways that scientists, engineers, and technologists "in the real world" design instrumentation that utilize the interactions between different frequencies/wavelengths of the EMR and matter to make scientific measurements and analyze data; specifically,

  • to detect the presence of elements and mineral content (compounds and mixtures);
  • to study topographical and surface mineralogy of asteroids; and
  • to determine the masses of the asteroids using gravity measurements.