The terrestrial telescopes have not been able to see directly the shape of this small body due to its remoteness, but if you ask how we know its approximate shape, it is easy: in the same way that it is estimated with most asteroids, that is, seeing its light curve.
Oumuamua has a rotation period of 7.34 hours, a value that is not uncommon in asteroids of this size, but the high contrast of the light curve implies a very elongated shape or a dramatic albedo difference. Occam's razor makes astronomers opt for the first option, since it is easier to explain a homogeneous surface composition, although evidently the light curve could be the result of both factors. In any case, we must insist that we do not know the true form of Oumuamua and we can only work with estimates. Of course, if it really is a kind of very long cosmic splinter, it would have to be formed predominantly by rock and metal in order to withstand the structural tensions.
Oumuamua has a rotation period of 7.34 hours, a value that is not uncommon in asteroids of this size, but the high contrast of the light curve implies a very elongated shape or a dramatic albedo difference. Occam's razor makes astronomers opt for the first option, since it is easier to explain a homogeneous surface composition, although evidently the light curve could be the result of both factors. In any case, we must insist that we do not know the true form of Oumuamua and we can only work with estimates. Of course, if it really is a kind of very long cosmic splinter, it would have to be formed predominantly by rock and metal in order to withstand the structural tensions.
The VLT together with the Hawaii CFHT telescope (Canada-France-Hawaii Telescope) have provided fundamental information about the nature of this visitor to the stars. The first and most important thing is that its interstellar nature is confirmed. The'Omuuamua orbit - which in Hawaiian means 'messenger that comes from afar and arrives first' - has an eccentricity of 1.188 with a very high statistical confidence (300σ). Second, neither the VLT nor the CFHT, nor the GST (Gemini South Telescope), have been able to detect a comma around the body despite its enormous resolution, so it is also confirmed the absence of volatiles -hols- in the surface of Oumuamua. That is, it is a body rich in rocks and metals
We are free, this time, from visits of a heavy visit at home