Tom Hanks And Meg Ryan Are Beyond Sleepless In Seattle

The 11-mile long asteroid Gaspra, photographed by the Galileo spacecraft en route to Jupiter is a typical stony, main belt asteroid. Credit: NASA

Tom Hanks zoomed just 151 million miles from Earth Monday and Meg Ryan will make a pass at us from 191 million miles later this month.  How did these celebrities travel so far from Earth without a single mention in the tabloids? Well, they’re living second lives as asteroids of course!

12818 Tomhanks, the 12,818th asteroid to have its orbit determined and name assigned, was discovered on April 13, 1996 by the Spacewatch program at Kitt Peak in Arizona and named after the famous actor for his role in the movie Apollo 13. 8353 Megryan was picked up earlier on April 3, 1989 by E. W. Elst at the European Southern Observatory. Both are small main belt asteroids orbiting between Mars and Jupiter. They’re dim at just 17th and 18th magnitude respectively, so few of us will ever view them in a telescope. Guess we’ll just have to see a movie instead.

The name a newly discovered asteroid receives comes only at the end of a long process that can carry into years. Assuming it’s a unique object and not a re-discovery of an older asteroid, it first receives a temporary designation based on the year and half-month of its discovery, ie. 2011 MD. When the asteroid has been observed long enough that its position can be predicted well into the future, it then gets a permanent number like 12818. At that point, the discoverer is asked to suggest a name. As of September 2011 there are 297,233 numbered minor planets out of the millions that must be out there; only some 16,000 of them have been given both numbers and names.

A special committee within the International Astronomical Union assigns both numbers and names. Naturally there are naming guidelines:

1. 16 characters or less in length
2. preferably one word
3. pronounceable in some language
4. non-offensive
5. not too similar to an existing asteroid or planetary moon name

And ix-nay on the names of individuals or events known for political or military activities until 100 years after the event or death of the person. And no commercial names either. Sadly, pet names are discouraged.

Their discoverers must have admired the actors to honor them with an asteroid. Many gods, goddesses, scientists, artists, musicians and hard-working amateur astronomers have also been given a touch of immortality with an asteroid name.  I’ll leave you with words of wisdom from 20th century American novelist Kurt Vonnegut (asteroid 25399 Vonnegut), whose every book I devoured back in high school: Laughter and tears are both responses to frustration and exhaustion. I myself prefer to laugh, since there is less cleaning up to do afterward.”

A quintet of Saturn's moons come together in Cassini's field of view for this portrait taken on July 29, 2011. Saturn is out the frame to the right. From left are: Janus (111 miles across), Pandora (50 miles), bright Enceladus (313 miles), and Mimas (246 miles) which is partially blocked by Rhea (949 miles). Credit: NASA/JPL-Caltech/SSI

Just kidding. I’m not going to leave just yet. Not without sharing this family portrait of five of Saturn’s moons that was recently released by the Cassini probe imaging team. If you like that, take a minute to fly by the planet in the short video below created using nothing but real images taken by the Cassini spacecraft. My favorite segment is crossing through the planet’s ring plane in the final, hi-res clip. Awesome!

7 Responses

  1. MBZ

    Wow. Awesome clip. Goosebumps.
    (I’m betting you roared through Asimov, Heinlein, Clarke, Sagan et al, in addition to Vonnegut 😉 We must be the same age.
    Great post, much enjoyed.
    Got a semi-decent view of M101 just before the moon messed me up last night. Keeping fingers crossed for the SN in the next few nights.

    1. astrobob

      Hey MBZ,
      Yes, I sure did read Asimov, Clarke and Sagan though never cared much for Heinlein at the time. By the way, the supernova’s mag. is 9.9.

    1. astrobob

      Either haze and humidity or depending on where you live, it might also be forest fire smoke. We’ve had a lot of that in my neighborhood lately. The color is most pronounced when the moon is low in the sky, because it shines through a longer column of thicker, dustier air than when viewed higher up in the sky.

  2. paul contant

    Thanks for the great post. After the announcements by the chinese government the past few weeks, looks like Clarke wasn’t really doing fiction when he wrote that they would be the firsts to put a man on Europa.

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