What was 'Oumuamua made of?
Most likely: an ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without…Ahead on the evidence, not yet confirmed. It needs two reviews to be accepted.
Where it stands
Seven answers have been proposed. An ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without… leads, with evidence 3 for, 1 against: partly supported by its tests. Six are still possible. Of the two narrower questions under it, none is answered yet.
Answers 7
History
- European Southern Observatory puts forward: a dense, dry rocky or metal-rich body with no significant ice.
- European Southern Observatory: the discovery-era interpretation was a dense, possibly rocky or metal-rich body lacking water or ice.For: A dense, dry rocky or metal-rich body with no significant ice.
- Fitzsimmons et al. puts forward: an ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without…
- Bialy & Loeb puts forward: manufactured material, a thin artificial sheet.
- Trilling et al.: no water outgassing was ever detected.Against: An ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without…
- Fitzsimmons et al.: the red featureless spectrum fits an organic-rich mantle half a metre thick that could have kept interior ice…For: An ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without…
- Hsieh et al.: kinematics suggest an age of about 35 million years and a link to a young moving group.For: Mostly molecular hydrogen ice, formed in a giant molecular cloud core.
- Jackson & Desch: satisfies the acceleration, size, albedo and the CO/CO2/dust limits at once.For: Nitrogen ice, a surface fragment of a Pluto-like body.
- Levine et al.: formation and survival of an aggregate this size are not demonstrated.Against: An ultra-porous fractal aggregate of icy dust.
- Siraj & Loeb: the mass budget and fragment-size arguments weigh against it.Against: Nitrogen ice, a surface fragment of a Pluto-like body.
- Bergner & Seligman: the radiolytic-hydrogen model makes an ordinary water-ice body fit the acceleration.For: An ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without…
- Cordiner et al.: 2I/Borisov and 3I/ATLAS were both ordinary comets in composition, if unusually rich in CO or CO2.For: An ordinary comet-like planetesimal of water ice and dust under an insulating organic crust (with or without…
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