How was the asteroid spotted ?

Before being named "Oumuamua", the object was named C / 2017 U1, which means, according to the provisional comet designation rules, that the asteroid was observed for the first time during the third week of October 2017. On October 18, the Pan-STARRS1 telescope in Hawaii locates this visitor, after passing close to the Sun.

Immediately after its discovery, other telescopes around the globe, including the Very Large Telescope of the European Southern Observatory, in northern Chile, begin to observe the asteroid to determine its characteristics. Little by little, other telescopes are starting to track him down. Between 18 and 24 October, the asteroid is observed 34 times. His strange trajectory challenges.

Some high-powered terrestrial telescopes continue to follow the asteroid, while it quickly disappears away from the Earth. Two space telescopes from NASA, Hubble and Spitzer, also record all possible information about it. On November 20, the object was traveling at a speed of 38.3 kilometers per second and was about 200 million kilometers from Earth. Oumuamua passed into the orbit of Mars around November 1st and will cross Jupiter in May 2018 before continuing its journey beyond Saturn in January 2019. Then it will come out of our solar system to take the direction of the constellation Pegasus. Observations with large terrestrial telescopes will continue until the asteroid becomes virtually undetectable, after mid-December.