‘Oumuamua
'Oumuamua, discovered in October 2017 by the University of Hawaii’s Pan-STARRS1 telescope, holds the distinction of being the first confirmed interstellar object to visit our solar system. This strange visitor, named 'Oumuamua—which means "a messenger from afar arriving first" in Hawaiian—captivated scientists due to its unusual, elongated shape, reddish hue, and lack of a visible tail, distinguishing it from typical comets and asteroids in our solar system.
Measuring up to 400 meters in length and roughly ten times longer than it is wide, 'Oumuamua's shape is unlike anything observed before. The object likely consists of dense rock and possibly metals, with no water or ice, and has a surface reddened by cosmic rays over hundreds of millions of years. These properties, along with its rapid rotation, suggest that ‘Oumuamua is a relic from another star system, having wandered through the galaxy for eons before its accidental encounter with our solar system.
Following its discovery, telescopes around the world, including the Very Large Telescope in Chile, focused on observing 'Oumuamua to measure its orbit, brightness, and color. These observations revealed that the object varies in brightness by a factor of ten as it spins on its axis every 7.3 hours, indicating its elongated and possibly complex shape.
As 'Oumuamua travels out of our solar system at a speed of about 85,700 miles per hour, its path suggests it came from the direction of the bright star Vega in the constellation Lyra. However, due to its vast journey, Vega was not in that position when 'Oumuamua would have passed through the area some 300,000 years ago.
Despite its unique properties, 'Oumuamua's discovery hints that similar interstellar objects might pass through our solar system roughly once a year, though they are typically too faint to be detected. The significance of 'Oumuamua lies in its potential to provide new insights into the formation and composition of other solar systems.
For further details, you can explore more about ‘Oumuamua on NASA’s website.
