PV Gap

Aaron Said:

What is the mass- to -light ratio of the solar system?

We Answered:

We use the sun as the baseline ratio, it's value is 5133 kg/W.

Melanie Said:

How many light years in diameter is the solar system?

We Answered:

It depends on how you decide where the edge of "the solar system" is. I can think of at least 4 good answers.

#1 Orbit of the farthest planet, Neptune
8.44 light-hours, or 0.000963 light-years

#2 Kuiper belt
approximately 15 light-hours, or 0.0017 light-years

#3 Termination Shock
approximately 22 light-hours or 0.0025 light-years

#4 Oort Cloud
approximately 1 light-year

When NASA talks about the Voyager Spacecraft "leaving the solar system", they usually are referring to #3 the Termination Shock. As a fraction, its diameter is approximately 1/400th of a light-year.

Yvonne Said:

What is the mass-to-light ratio of the solar system?

We Answered:

Undefined.

Light has no mass, so the ratio of mass to zero is undefined.

Willard Said:

how long would it take to get across the solar system @ the speed of light?

We Answered:

from sun to pluto is 5.9x10^12m
times the above by 2 for the whole solar system
speed of light is 3x10^8m/s

t=v/d
39333.33333333333 secs
thats roughly 27 hours

Monica Said:

Does the light of the sun reach and illuminate every planet in our solar system?

We Answered:

The light from our sun reaches even distant solar systems. The stars you see in the sky at night are distant suns.

How illuminated on object in space can be depends on a few things. Two of the most important ones are:

1. Distance from the light source.
2. Reflectivity of the object.
3. The human eye.

The most reflective object in our solar system can't be seen with the human eyes. This is Saturn's moon Enceladus. But if you were approaching it, it'd most definatly appear illuminated.

Saturn's moon Iapetus, however, is a different story. Iapetus, also called the two tone moon, seems to have highly reflective material on one hemisphere and black material on the other. You can see a picture of it here
http://www.planetary.org/explore/topics/…

In the darkness of space, most very large things in the solar system, granted you were close enough, would probably have some degree of illumination.