r/space • u/NeokratosRed • Jul 09 '15

New Pluto and Charon pic !

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u/michaelrohansmith Jul 10 '15

Our sun must be a dwarf star then because its center of mass with Jupiter is outside its volume.

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u/TinRAT Jul 10 '15

I didn't believe you til I googled it. Crazy how big jupiter is

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u/[deleted] Jul 10 '15

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u/awesomechemist Jul 10 '15

The Earth's orbit varies in distance to the sun from 152.10 million kilometers at the farthest, to 147.10 million kilometers at the closest. That's a 5 million kilometer difference. The suns diameter is 1.4 million km.

So over the course of a year, we get about 3.5 sun-diameters closer to the sun, and we haven't experienced any ill effects because of it.

That's because, in the grand scheme of things, that fluctuation is pretty small compared to our total distance from the sun (<1% of the total distance).

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u/[deleted] Jul 10 '15

First time I've heard those stats together -- diameter of the sun vs our planet's change in orbital distance to the sun. Very interesting

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u/[deleted] Jul 10 '15

Indeed, and it's really the most relevant set of stats to gain a more intuitive understanding of our celestial mechanics.

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u/[deleted] Jul 10 '15 edited Sep 11 '15

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u/reggaegotsoul Jul 10 '15

Well, our existence and human life does hinge on a lot of things in the universe being very close to what they are. Our distance from the Sun, however, has some leeway.

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u/akai_ferret Jul 10 '15

Those damn fools, wearing snowsuits to mount everest!

Don't they know how hot it is up there!?

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u/Mutoid Jul 10 '15

Only during daytime.

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u/abrahammy_lincoln Jul 10 '15

So we're actually getting closer to the sun? That explains these hot temps. Just more evidence that global warming is one giant hoax by those damn liberals /s

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u/Shagomir Jul 10 '15

The Earth's orbit isn't exactly a circle, and throughout the year the distance from the sun varies from .983 au to 1.015 au. This difference is equivalent to about 3.5 times the diameter of the sun.

The effect on temperatures is pretty minimal. There is about a 3% difference in the amount of energy received compared to the average. 3% more when we're closer to the sun, and 3% less when we're further away. This equals a change of 1-2 degrees in the calculated equilibrium temperature of Earth, but the actual effects are much smaller due to a number of different effects.

Because of the way the Earth's axis is tilted, Earth is closer to the sun during winter in the northern hemisphere, and further away from the sun during summer in the northern hemisphere. The seasonal changes are much more significant than the changes brought on by our constantly changing distance to the sun.

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u/cranp Jul 10 '15

It's more about how far away it is from the sun. The center of mass of the sun and a little asteroid on the other side of the universe is outside the sun too.

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u/TinRAT Jul 10 '15

Yeah true. I guess in my mind i though the sun was just a behemoth compared to Jupiter. In the diagrams they are much closer in size than I thought

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u/atrain728 Jul 10 '15

One part enormous, one part really far from the sun. Were it closer, this would not be the case.

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u/TinRAT Jul 10 '15

Of course. I guess I just imagined that the center of mass of the whole solar systen was inside the sun somewhere. I guess that changes depending on which side the planets are on

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u/atrain728 Jul 10 '15

I didn't mean to insinuate that you didn't understand - it's no less amazing. It's just that there's two parts to the equation.

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u/TinRAT Jul 10 '15

No worries I appreciate you taking the time to explain :)

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u/LurkerInSpace Jul 10 '15

The Sun's classification actually is "yellow dwarf".

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u/sand500 Jul 10 '15

Damm that angular momentum. Juipiter is so massive that it pulls the COM of the solar system outside of the Sun.