Vulcan found?

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Scientists have found a super-earth orbiting 40 Eridani-A, a star located sixteen light years away and proposed by Gene Roddenberry in 1991 as the home star for his race of logical Vulcans.

It turns out the letter authors’ prediction was right — a world really does orbit the primary star of the three-star 40 Eridani system. (Whether it’s home to a logic-based alien society, though, is anyone’s guess!)

The world is a super-Earth, the most common type of planet in the galaxy (though a type that’s missing from our solar system). At twice Earth’s radius and eight to nine times its mass, 40 Eridani b sits on the line that divides rocky super-Earths from gaseous ones. The planet orbits its star every 42 days, putting just inside the system’s habitable zone — in other words, where it’s nice and hot. At 16 light-years away, it’s the closest super-Earth known and therefore a good potential target for followup observations.

The discovery was made by a survey taking place using a relatively small telescope right here in the Tucson area, on top of Mount Lemmon. Most cool!



  • Orion314

    Vulcans, now that is an illegal alien invasion I could get behind , VLM :}

  • wayne

    on a serious Note:
    ref: “At twice Earth’s radius and eight to nine times its mass…”
    What, is the force of gravity at the surface?

    on a more historical Note:

    “On Jan 2, 1860 Urbain Le Verrier announced the discovery of Planet Vulcan, orbiting between the sun and the planet Mercury.” [“This astonishing discovery finally solved the question of why Mercury orbited so strangely… the only problem was that it was totally wrong…”]

  • Andrew_W

    “At twice Earth’s radius and eight to nine times its mass…”
    What, is the force of gravity at the surface?

    Twice Earths.

  • Col Beasabre

    Given the gravity on Vulcan, Spock must be a Klingon imposter! They’re not tall and thin, but squat and powerfully built.

  • Andrew_W

    “On Jan 2, 1860 Urbain Le Verrier announced the discovery of Planet Vulcan, orbiting between the sun and the planet Mercury.”

    That was my first thought on reading the title, though finding it again seemed improbable.

  • wayne

    Thank you. Can you show your work? I’m having trouble conceptualizing that.

  • Andrew_W

    Inverse square law, double the radius you double the distance to the center, so gravity from a given mass drops to a quarter, with 8 times the mass the strength of gravity is 8 x 0.25 = 2
    Probably some of the physics and math experts here could put it better.

  • Edward

    You phrased it well.

    However, if that wasn’t clear, then try this longer explanation:
    For a planet, we can model the gravity as a point source at the center. Gravity decreases as the inverse square of the distance from the center, the radius, so a planet with twice the radius ( 2r ) and the same mass would have a gravitational force a quarter ( 1/[2r]^2 = 1/4 ) of the gravitational force of the first planet. Since the mass of the second planet is eight or nine times greater, and gravity is directly proportional to mass, then the math is:

    8g x 1/4 = 2g (Andrew_W used the estimated eight times Earth’s mass), or

    9g x 1/4 = 2.25g (using the estimated nine times Earth’s mass)

  • wayne


    Thank you.

  • pzatchok

    I can’t help but think that by the time the human race is able to travel to another habitable planet even a marginally habitable one we would not need to to.

    But for those who want to, I think we would be at the point that we could genetically change humans to better fit the environment.

    And I bet that we would be capable if this inside of 200 years. Unless something very bad happens.

    Any planet with liquid water and land to grow crops on. We don’t want a water world either.

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