On October 19, 2017, the Pan-STARRS telescope detected the first interstellar object, ‘Oumuamua.
'Oumuamua is the first confirmed interstellar visitor to our home solar system. Its visit has both excited and scared the scientists and the general public since it was first spotted. Surprisingly, our first interstellar guest appeared to be bizarre and unlike anything we have witnessed before. By the time scientists realized it, the visitor was already out the door with its image fading into the dark street, so they did not have a chance to get a second look at its mysterious qualities. Below is a list of five peculiarities exhibited by the distant visitor ‘Oumuamua.
Scientists have no idea where it came from
'Oumuamua entered our solar system from the rough direction of the constellation Lyra, but it is impossible to tell where it originally came from. Thousands of years ago, when 'Oumuamua started to wander from its parent planetary system, the stars were in a different position so it’s impossible to pinpoint its point of origin. It could have been wandering the galaxy for billions of years.
Scientists don't know what it looks like
The scientists have only been able to view 'Oumuamua as a speck of light through their telescopes. But its unique rotation leads the researchers to believe that it is elongated, more or less, cigar-shaped, about 10 times longer than it is width. Scientists know this because the interstellar object's brightness (or amount of reflected sunlight) varied by a factor of 10 every eight hours or so. This strongly suggests that 'Oumuamua has an extremely elongated shape.
'Oumuamua got a little speed boost as it approached our solar system
At some point during the visitor’s approach towards our solar system, 'Oumuamua appeared to have received a slight speed boost. Observations from the Hubble Space Telescope and ground-based observatories noticed that its acceleration increased which slightly altered its course from what was initially predicted. The high-precision measurements of ′Oumuamua’s position revealed that something was impacting its motion apart from the gravitational forces of the planets and the Sun.
Scientists had anticipated spotting an interstellar object
The discovery of an interstellar object has been anticipated for decades. Interstellar space likely has billions upon billions of roving objects like asteroids and comets. Scientists understood that it was an inevitability that some of these small bodies would eventually come for a visit. This interstellar visit by ‘Oumuamua reinforces the models of how planetary systems form.
Its composition is not known
Comets in our solar system kick off lots of dust and gas when they get close to the Sun, but 'Oumuamua did not, which led observers to consider defining it as an asteroid. But it could be giving off gases that are harder to see than dust, but it’s impossible to know at this point.
There is no doubt that the peculiar features of ‘Oumuamua have the potential to usher in a dramatic new era in space science.
