Thursday, April 2, 2009

4-01-09 Luna and Saturn Street Astro

Another family outing to the Marina turned into an educational experience! The Scott entourage get engaged with some serious astronomy with the astro guy. After gleeful views of Luna and Saturn on to questions and presentations. Stephen in the blue t-shirt popped out a question that was so incredible and totally in tune with the evenings observations; " Why does the inner Solar System lack Moons?" This was a incredible question, with a complex answer that involves the whole realm of solar system formation and dynamics of planets and stars. But the Scott clan were up to the task and we tackled this issue with Atlas and Poster presentations which helped to cover this complex issue in easy to understand terms. Then daughter Jesse? asked about life on solar system moons, and Kevin asked about Jupiter's super hot, weird interior we go again! Scott people you made this session too much fun!


NiteSkyGirl said...

Hay there sidewalk dude
Since you reach out to the public .. For this post of yours I reached out to my public and asked "Why does the inner Solar System lack Moons?" Here are their answers ..

~ 1. they have no magnetic field
2. they move really slow.
3. they are really small planets.
They all went to the asteroid belt.

~ the eliptical paths of all objects big enough to be a moon probably got sucked into the sun, going right by mercury. Also mercury is small, so doesn't have enough gravity to pull in anything of size.

~ It may be possible that Mercury is in fact a lost moon - it is rocky and small enough with no atmosphere.

~ One young guy said ..
in general moon infoThere are 3 current theories for Moons:

1. Collisional. (Earth and Pluto) A massive object collided with the parent body resulting in mass being ejected into orbit around the parent whcih accreted over time to form the moon. Luna and Charon are believed to have formed in this way.

2. Captured. Mars and the Gas/Ice giants of the outer solar system. Note also that ~15% of asteroids also have moons. Many are expected to have captured through low speed encounters as their gravity (like Mars) is too small to capture passing objects.

3. Fission. For Asteroids, particularly fast spinners, Fission is the expected mechanism. Angular momenum causes 'landslides' on these rubble piles throwing off mass into orbit that then acrete to form moons.

Note that therory states that Mercury is not a lost moon but the remnant core of a planet after a collision removed most of its crust and mantle

Sidewalk Universe said...

Wow - it is nice to know that I helped to create such a stir out there! YOU HAVE GOT TO BE LOVING THIS.Thanks for letting me know whats going on in NSG land!

Sidewalk Universe said...

I am enjoying all these responses you received. These answers are a reflection of folks with an interest and a SPACE SCIENCE FOUNDATION IN THEIR LIVES! It is important that we examine why we see the universe the way that we do - test our "theories" and dig into some science study. It is a complex question, and it's answer is multifaceted and complex but that does not mean we cannot as non-scientist enjoy the process of discovery and learn what modern science is telling us.

I am not a know it all-and I NEVER WANT TO BE! I want to have that constant awe about this universe and spread it to others. That is one thing I appreciate about what you are doing NSG.