Comet 3I/ATLAS, a newly discovered interstellar comet, has generated significant interest in the astronomical community. This comet, identified only five and a half months ago, is the third interstellar object recorded in our Solar System. Recent studies indicate that 3I/ATLAS is exhibiting non-gravitational acceleration, a phenomenon that needs clarification to dispel misconceptions about its nature.
Understanding Non-Gravitational Acceleration of Comet 3I/ATLAS
Non-gravitational acceleration refers to a change in the motion of a celestial body that is not caused by gravitational forces from other objects. In the case of comets, this acceleration is typically a result of outgassing. As comets approach the Sun, their icy cores heat up, causing frozen gases, such as water and carbon dioxide, to turn directly into gas. This process releases jets of material, which can alter the comet’s trajectory.
Characteristics of Comets
Comets are often described as “dirty snowballs,” composed of ice and rock. As they travel close to the Sun, their nuclei experience sublimation, which leads to the formation of a coma and a tail made of gas and dust. The dynamics of these jets contribute to the non-gravitational acceleration observed in comets like 3I/ATLAS.
Measurement and Findings
Researchers utilized several Earth-based and space telescopes, including the Hubble Space Telescope, the European Space Agency’s Trace Gas Orbiter, and NASA’s Psyche mission, to measure the effects of non-gravitational acceleration on 3I/ATLAS. The studies indicate an acceleration of about half a micron per second squared.
- This acceleration is relatively small compared to gravitational forces.
- However, it can result in significant deviations in the comet’s predicted orbit over time.
While this change in speed might not reflect an artificial object, it does provide valuable insights into the comet’s characteristics. One exciting finding from the research is an estimate of the comet’s mass before its close approach to the Sun. It is estimated that 3I/ATLAS had a mass of approximately 44 million metric tons in September, equivalent to over seven times the mass of the Great Pyramid of Giza.
Size Estimation
If the mass estimate is accurate, the nucleus of 3I/ATLAS is likely smaller than previous assumptions, measuring around 375 meters (1,230 feet) in size. This study was published in the journal Research Notes of the American Astronomical Society.
As more observations are conducted, scientists hope to gain further understanding of 3I/ATLAS and its behavior. This comet serves as a fascinating subject for ongoing research into the dynamics of celestial bodies beyond our solar system.
