How do we know that some galactic bodies have interacted with each other?

Question

Spallation caused particle exchange.
Some bodies appear inhabitable.
Most orbits are elliptical in shape.
Low confidence intervals are observed.

Answer 1

There are several ways we can determine that galactic bodies have interacted with each other:

1. Spallation caused particle exchange: When galactic bodies interact, they can collide or come close enough to exchange particles. This can be observed through various methods, such as studying the isotopic composition or elemental abundance in certain astronomical objects. Spallation reactions occur when high-energy particles from one body collide with the nuclei of atoms in another body, resulting in the production of different isotopes or elements.

2. Inhabitable conditions: One way to infer interaction between galactic bodies is by observing if they have habitable conditions. For instance, if a planet or moon shows signs of having a stable atmosphere, liquid water, or the presence of basic organic molecules that could support life, it may indicate that it has interacted with another body in the past. Such interactions might have supplied the necessary conditions or ingredients for life to develop.

3. Elliptical orbits: The shape of an orbit can provide clues about interactions between galactic bodies. Most orbiting objects in a galaxy, such as planets around a star or satellites around a planet, follow elliptical paths rather than perfectly circular ones. Elliptical orbits can be a result of gravitational interactions with other celestial bodies in the system. For example, the orbits of comets or asteroids can be elongated or disturbed if they encounter other massive objects during their journey.

4. Low confidence intervals: When studying the dynamics of galactic bodies, scientists often use statistical methods to calculate various parameters and predict their behavior. If the confidence intervals for certain predictions are low, it suggests that there might be interactions or perturbations causing uncertainties in the calculations. This can happen due to gravitational interactions among galactic bodies, which can influence their movements and make accurate predictions more challenging.

These various observations and analyses help astronomers and astrophysicists to understand the interactions and dynamics of galactic bodies and provide evidence for their past or ongoing interactions.