Thursday, April 10, 2014

I is for Ida (Planets Aren't The Objects in Space with Moons)

Dactyl and Ida
Many planets have moons. But guess what. So do some asteroids.
 
Just as 17th century astronomer Galileo Galilei was first to see moons around another planet, the 20th century spacecraft named in his honor was the first to discover a moon orbiting an asteroid.
 
In 1993 while on its way to Jupiter, NASA’s Galileo spacecraft flew right by an asteroid called Ida. It’s 19 miles wide and has a small one mile wide moon orbiting it called Dactyl. These were the first binary asteroids discovered.
 

Spacecraft Galileo
Since then more asteroids with a satellite (formal name for a moon) have been discovered:

In 1999, astronomers using Earth-based telescopes found that 135-mile-wide Eugenia has an eight-mile-diameter moon, which they dubbed Petit-Prince.
 
• In 2000, 90-mile-wide Pulcova was discovered to have its own moon, about nine miles wide.
 
• In 2001, scientists found Linus orbiting Kalliope, and another moon around asteroid Sylvia.
 
Many more binary asteroids have been confirmed as Near-Earth Objects, in the asteroid belt between Mars and Jupiter, and in the trans-Neptunian area, or beyond the farthest planet (sorry Pluto) from our sun.
 
Astronomers used radar to observe some of the closer asteroid-moon pairs. Most of the others were discovered in visible light, using ground-based telescopes with adaptive optics. (These systems use computer-controlled deformable mirrors to compensate for the blurring effects of Earth's atmosphere, creating sharper images.) Scientists are able to calculate an asteroid's mass and density by observing the moon orbiting the asteroid. Reference

23 comments:

  1. cool, always interesting to discover a little more about the universe we live in. do check out my blog at www.angiecreativeink.com/blog. thanks :)

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  2. Astroids have moons? Wow, I'd never have guessed that.

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  3. I didn't know asteroids had moons! Does that mean they have gravity?

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  4. Hi Stephen .. I hadn't heard about Ida before ... now I've seen two blog posts on her .. here's the other it's one of our bloggers;
    http://idachiavaro.blogspot.co.uk/2014/04/26-greatest-loves-of-my-life-lets-call_10.html enjoy meeting the other Ida ..

    Space is just one huge fascinating subject .. cheers Hilary

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  5. no. no . NOOOOOOOOOOOOOOOOOO. You're a "Pluto isn't a planet" acolyte?!? *shakes fist*

    (there, there, Pluto. Don't listen to him. I believe in you)

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    Replies
    1. OH, and thanks for hosting A to Z

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    2. Huntress, actually I am very much a Pluto is a planet kinda guy. Stop back for P is for Pluto.

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  6. I knew that planets had moons but not that asteroids too had moons.

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  7. I did not know that some asteroids had their own mini-me. :-)

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  8. This is the first time I ever heard that asteroids had moons.

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  9. I never knew asteroids could have moons, that's interesting.

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  10. Glad to see some love for Ida today. :)

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  11. I'm glad to see some more love for Ida too:) - Hilary Melton-Butcher from Positive Letters...Inspirational stories' directed me her because I showed Ida some love too... but now I have to go back and change my post to 'first asteroid discovered with a moon.' Thanks for the new information

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  12. I never even thought such a thing was possible. Very cool thing to know.

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  13. Wow. Asteroid moons - super cool. I'm learning sooooo much from your posts.

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  14. I did not know that asteroids had moons, but then again, with all the asteroids in "close" proximity in the asteroid belt, it makes sense. Of course things would orbit each other. Gravity is a crazy thing.

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  15. I had no idea. I.m glad I stopped by. Nice post!

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  16. So fascinating! I wish Galileo were here. Wonder what he'd have to say about all of this? Of course, he might be condemned as he was in the past for coming up with all kinds of new fangled ideas.

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  17. I'm trying to visualize a moon orbiting an asteroid zipping through space. But then, we're all zipping through space, aren't we?

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  18. I love learning new stuff. I've shaken away my stereotype of an asteroid, thank you very much. You've got me wondering if somewhere out there is a comet with a moon revolving around it.
    The View from the Top of the Ladder

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  19. I had no idea asteroids could have moons. I learned something today. =)

    ~Patricia Lynne~
    Story Dam
    Patricia Lynne, YA Author

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  20. I had no idea. I love learning new things and I just did! Thanks for that...

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