First-Known Interstellar Object Looks…Pretty Weird

By Nathaniel Scharping | November 20, 2017 2:27 pm
An artist's impression of the asteroid . It is around ten times as long as it is wide. (Credit: ESO/M. Kornmesser)

An artist’s impression of the asteroid `Oumuamua. It’s around ten times as long as it is wide. (Credit: ESO/M. Kornmesser)

Scientists now have an idea of what the first recorded extra-solar asteroid looked like.

The hunk of rock of that whipped through the solar system in October looks like no other asteroid we’ve seen before, they say, long and thin like a javelin and colored red from millions of years of accumulated radiation exposure. The coloration wasn’t surprising, but the shape was, say astronomers from the European Southern Observatory. Most objects astronomers observe in our solar system are roughly spherical, drawn into a ball by gravity. This asteroid, now named `Oumuamua, is about 10 times as long as it is wide, according to research published Monday in Nature.

`Oumuamua is also spinning rapidly, something that helped clue astronomers in to its shape. During the few weeks when it was visible, it varied wildly in brightness, consistent with an elongated object that’s rotating about its axis. Further observations with the Very Large Telescope in Chile revealed that `Oumuamua is made of dense metal or rock and completely inert, meaning that no clouds of dust or ice surround it. The roughly quarter-mile-long asteroid was initially thought to be a comet, but the absence of water ice as it neared the sun dismissed that theory.

Though this was the first time astronomers have spotted an interstellar visitor, they’re likely not uncommon. Estimates range from one to ten per year, and with new, more powerful telescopes, astronomers hope to see more of them in the near future. These objects, usually identified by the highly angled paths they take through our solar system, could provide clues about the composition of far-off solar systems.

Planetary systems, our own included, will occasionally cast out comets and asteroids as a result of gravitational interactions with larger bodies, and they can travel through interstellar space for millions of years before encountering another system.

These visitors usually only stay for a few weeks at most, careening around the sun and speeding back out into the cosmos; a brief moment of contact and another ten million years of silence.

CATEGORIZED UNDER: Space & Physics, top posts
  • Andrew Worth

    Obviously a derelict alien spaceship.

    • ES Prado

      spaceship hiding in as a giant space turd – genius!

    • Haruki Chou

      Who knows, could be, but now it’s gone, and we’ll never know.

    • disqus_atlq8Zmtsd

      Derelict, or in stealth mode on an information gathering mission? It must have amazing heat sinks for us to not recognize something was amiss.

    • MSBassSinger

      Perhaps it was looking for humpbacked whales. :)

  • juju_nantes
  • Lawdy! Lawdy! Lawdy!

    Just another interstellar turd

  • Paul Smith

    anyone else think this is a slingshot maneuver??

    the orbit, distance from Sun etc, couldn’t be better way to pick up some speed, has anyone put a thought into where its heading? or now possibly aimed at?

  • Uncle Al

    “a 10:1 axis ratio and a mean radius of 102±4 m” There is no way to randomly assemble something like that by aggregation or collision/fragmentation. It’s either a grown natural crystal (e.g., Cave of the Crystals, selenite; not bloody likely) or constructed. If you are doing serious high speed traveling, you want a shielded nose to clear the way for the rest of the vessel.

    We let a starship slip through our fingers.

    • Zed

      There is no way THAT YOU KNOW OF to randomly assemble something like that. This is just an argument from ignorance.

      • Uncle Al

        Argument from physics, engineering, and chemistry. I’ve solved high aspect ratio problems – drilling 500 micron holes 5 microns wide through a methacrylate contact lens. A single crystal diamond drill won’t do it, nor will any other engineering cleverness. 100:1 aspect ratio.

        I asked the VP R&D if 7 micron diameter holes were OK. A week later I delivered a 10-inch long Plexiglas rod with hundreds of uniform 7-micron diameter holes down its long axis, an aspect ratio of 36,000:1. They fabricated lenses.

        How did I do it, wooly thinker?

  • ordersixty6

    A test volley from Planet Klendathu that missed?

  • ThreeLeftFeet

    The ‘top’ in the image looks flattened.

    Stellar surfboard?

  • The Beard Eye

    Hello, Rama. Don’t worry it will come back 2 more times. 😉

  • donaldwestington

    Off topic: AGW is BS.

    I don’t read replies.

  • Eric Delzard

    So basically, Clarke and Bear were right… :p


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


See More

Collapse bottom bar