Lecture Notes: A Mua Mua - The First Interstellar Object

Introduction

• A Mua Mua
  • First interstellar object detected in our solar system in 2017.
  • High-speed object, first spotted on its way out of the solar system.
  • Its behavior defies known physical laws, leading to speculations about its nature.

Frequency of Interstellar Objects

• Potentially 10,000 objects pass within Neptune's orbit daily.
• Solar System Dynamics
  • Extends beyond Neptune, including the Kuiper Belt and Oort Cloud.
  • Oort Cloud may contain trillions of comets, influenced by other stars.
  • Solar system's movement causes interactions with interstellar objects.

Characteristics of A Mua Mua

• Initial classification as a comet, then reclassified as an asteroid.
• Physical Attributes
  • Possibly 100m-1000m in size, unusual cigar or disc-like shape.
  • Tumbling motion rather than a stable axis rotation.
• Trajectory
  • Hyperbolic trajectory, indicating an interstellar origin.

Mysterious Behavior

• Passed closest to the sun at 87 km/s.
• Unexpected acceleration observed against solar gravitational pull.
• Lack of detectable outgassing, typical of comet behavior.

Theories and Explanations

• Alien Technology Hypothesis
  • Proposed by Avi Lobe, suggesting a light sail structure.
• Hydrogen Iceberg Theory
  • Proposed by Darryl Seligman, suggests sublimated hydrogen causing acceleration.
• Dark Comet Theory
  • Collaboration of researchers indicating reconfigured ice releasing hidden gases.

Other Mysterious Objects

• Identified six other objects with unexplained acceleration within the solar system.
• Ongoing missions like the Japanese Hayabusa 2 to study such objects.

Efforts to Study A Mua Mua

• Limited data due to rapid exit from the solar system.
• Project Lyra
  • Proposes missions to catch up with A Mua Mua using gravity assists.
  • Considering both long and shorter trajectory options.

Future Prospects

• Detection and Observation Improvements
  • Upcoming Vera C. Rubin Telescope could spot interstellar objects sooner.
  • ESA's Comet Interceptor mission planned for 2029.
• Economic and Technological Viability
  • Challenges related to cost and feasibility of missions to interstellar objects.
  • Debates on whether investing in such missions is worthwhile.

Conclusion

• Ongoing debates and studies aim to unravel the mystery of A Mua Mua.
• Future discoveries may validate or refute current theories.
• The pursuit of understanding interstellar objects continues to pique scientific curiosity.