Got interstellar asteroid?

[Quantum]

It would be quite interesting to find out what it's physical composition is.

In a paper submitted to Astrophysical Journal Letters, they argue that its size, rotation, and reddish colour are similar to those of asteroids in our Solar System.

Measuring about 180m by 30m, it resembles a chunky cigar.

"The most remarkable thing about ['Oumuamua] is that, except for its shape, how familiar and physically unremarkable it is," said co-author Jayadev Rajagopal from the US National Optical Astronomy Observatory (NOAO).

If planets form around other stars the same way they did in the Solar System, many objects the size of 'Oumuamua are predicted to be slung out in the process.

"U1 may provide the first direct evidence that planetary systems around other stars ejected objects as they formed," said Dr Rajagopal.



(Interstellar asteroid is given a name
http://www.bbc.co.uk/news/science-env...)

[Ian]

Every solid object is made from the same elements, formed in novae and supernovae (or maybe neutron star collisions) and the proportions of the elements are the same, more or less, from each source. The most common elements formed are oxygen, carbon, neon, nitrogen, silicon, magnesium, iron, then there is a fairly big fall-off to the rest. Accretion of solids inside the snow lines invariably involves magnesium/iron silicates (olivines and pyroxenes) and iron itself, with "other stuff" making up the residue. Other stuff includes water, and in a certain zone, carbonaceous stuff.

As Dr Rajagopal points out, this is exciting because it shows the concept that newly forming planetary systems can play gravitational billiards and throw stuff out is most likely right. It also confirms the belief that what is out there will not be that different from what is here, provided the initial conditions were the same

[Matthew]

The new estimates place its length at 400 m, which means it is especially elongated. This press release, and the study that its based on, was put out by the ESO earlier today:

http://www.eso.org/public/news/eso1737/

[Ian]

There is an image of what an artist thinks it looks like on the ESO site http://www.eso.org/public/news/eso1737/ (the same link that Matthew got. - I got it independently this morning and didn't notice Matthew's until I posted. Sorry, Matthew.

It really seems to be a long skinny object, almost as if it fragmented off something else in some sort of collision (assuming the image is correct).

[Matthew]

Ian wrote: "There is an image of what an artist thinks it looks like on the ESO site http://www.eso.org/public/news/eso1737/ (the same link that Matthew got. - I got it independently this morning and didn't no..."

Hey, no skin off my butt ;)