The first known interstellar object was found in 2017 by the Pan-STARRS1 telescope in Hawaii, and named 'Oumuamua', a Hawaiian word for 'messenger from afar arriving first'. This unusual object, moving at inexplicable speeds, and occasionally adjusting its own path, like something with independent thought, has intrigued both scientists and the public. It has a cigar-like appearance, is roughly the size of a football field, and has an unusually bright appearance.
The object lacks the characteristic dust tail of comets and is too small to be anything other than an asteroid. Oumuamua likely originates from interstellar space, propelled by either massive collisions or the gravitational pull of gas giant planets in other systems. Observations indicate a brightness that changes every twelve hours, suggesting it falls on its ends, and a slight acceleration away from the sun, characteristic of comets.
The trajectory of Oumuamua, discovered to be hyperbolic while it was already within the solar system, suggests that it was moving at such high speeds that the Sun's gravity could only slightly bend its route. Current calculations suggest that Oumuamua has left Neptune's orbit and is now headed towards Pegasus. It is not expected to return.
While its exact origin remains unknown, theories suggest it could either be a block of nitrogen ice displaced from a Pluto-like body by a massive impact, or that it contains hydrogen gas, potentially released when the crystalline structure of its ice was altered by the Sun's heat. Neither theory, however, has been definitively proven.
The research into, and debate over, the nature of Oumuamua continues to advance our knowledge of interstellar objects. Identifying more such objects, which could roam the Galaxy from far away planetary systems, could provide scientists with critical insights into the makeup of our solar system during its early stages and the formation of other planets.
