Oumuamua

'Oumuamua, first spotted in October 2017, is the first known interstellar object to pass through our solar system. Its name, of Hawaiian origin, means "scout" or "messenger from afar arriving first". Detected by the Pan-STARRS1 telescope in Hawaii, its high speed and hyperbolic trajectory confirmed its interstellar origin.

Characterized by its unusual shape, 'Oumuamua is elongated, roughly 800 meters long but only 80 meters wide. Its reddish hue suggests a metal-rich composition, potentially resulting from cosmic rays over millions of years.

One of the object's most puzzling features was its acceleration as it moved away from the Sun, not solely accounted for by gravitational forces. This led to multiple hypotheses. Some scientists proposed that 'Oumuamua is a hydrogen iceberg, with sublimating hydrogen providing the necessary thrust. However, its behaviour also reignited discussions about potential artificial, non-natural origins, although this remains highly speculative.

'Oumuamua's brief visit, lasting only a few weeks in our inner solar system, has left astronomers with more questions than answers. Its discovery has emphasized the importance of monitoring interstellar objects for both understanding the cosmos and assessing potential threats or opportunities they may pose.