NASA AIM Spacecraft Mission - UPSC Notes | Testbook.com

About the AIM Spacecraft Mission

Image courtesy: www.nasa.gov

The AIM spacecraft, a mission by NASA, was launched on April 25, 2007. Its primary purpose is to study the noctilucent clouds and the mesosphere.

• The mesosphere is a layer of Earth’s atmosphere situated between 50 and 85 kilometers above Earth’s surface.
• This region remains largely unexplored, and the AIM spacecraft was developed to investigate the dynamics and composition of this layer.

Noctilucent Clouds: A Brief Overview

• Noctilucent clouds, also referred to as polar mesospheric clouds (PMCs), are thin, wisp-like clouds that form at high altitudes in the mesosphere during the summer season in the polar regions.
• These clouds are the highest in Earth’s atmosphere and are composed of ice crystals. Scientists are interested in these clouds as they provide insight into the connections between Earth’s atmosphere and the space environment.

Key Components of the AIM Spacecraft

The AIM spacecraft is equipped with three specialized instruments that enable it to study noctilucent clouds and the mesosphere effectively.

• The Cloud Imaging and Particle Size (CIPS) instrument captures high-resolution images of the clouds and measures their particle size.
• The Cosmic Dust Experiment (CDE) measures the quantity and size distribution of micrometeoroids in the mesosphere.
• The Solar Occultation for Ice Experiment (SOFIE) measures the composition and temperature of the mesosphere.

Significant Scientific Discoveries

• The presence of noctilucent clouds has been steadily increasing over the past decade.
• Factors such as global warming, rising levels of water vapor, and decreasing upper-atmosphere temperatures, which are consequences of greenhouse gases, may be contributing to the increased presence of PMCs.
• Ice crystals in noctilucent clouds form on tiny microparticles when meteors burn up in Earth’s atmosphere.
• The AIM spacecraft has been successful in tracking heat movement in the upper atmosphere, indicating that heating in the mesosphere is more likely linked to heat circulation in the atmosphere rather than direct heating from the sun.
• The AIM spacecraft has made significant contributions, providing scientists with unprecedented information about the mesosphere and noctilucent clouds.
• The insights gathered from this mission have enhanced our understanding of the connections between Earth’s atmosphere and the space environment and improved our knowledge of the dynamics of the mesosphere.