Were they closer to the sun?

[TransformerRobot]

Was there a time when the planets in our galaxy were closer to the sun than they are now?

[Ophiolite]

I think you mean, was there a time when the planets in our solar system were closer to the sun than now. The galaxy consists of billions of planetary systems, so very likley there have been times when some of them approached our sun more closely than is the case at present.

 

In terms of the solar system, planets did a lot of moving around when the system was forming. Researchers seek to figure this out by running complex simulations. From what I recall it is likely that Jupiter moved in a little closer than it was, while Uranus and neptune may have swapped places. There was not, however, a general condition that all or most of the planets were at one time closer. I don't want to go into the effects of decrease in mass of the sun as a consequence of nuclear fusion.

[dirtyamerica]

IIRC, Earth was closer to the sun about 8 months ago than now during its perihelion.

[ACG52]

Here's a simulation of the evolution of the outer gas giants.

 

http://www.youtube.com/watch?v=6LzQfR-T5_A

[swansont]

IIRC, Earth was closer to the sun about 8 months ago than now during its perihelion.

 

~6.5 months. Perihelion was on January 2, aphelion on July 5 (using UTC).

http://www.usno.navy.mil/USNO/astronomical-applications/data-services/earth-seasons

[TransformerRobot]

But I was wondering if maybe the planets were slowly drifting away from our sun.

[ACG52]

Earth is slowly moving outward, due to the transfer of gravitational energy from the moon via the tides.

[TransformerRobot]

Earth is slowly moving outward, due to the transfer of gravitational energy from the moon via the tides.

 

Is it the same case for Mars, Ceres and Jupiter?

[ACG52]

 

Is it the same case for Mars, Ceres and Jupiter?

No. What makes the earth-moon system unique is the relative size of the moon to the earth.

[swansont]

Earth is slowly moving outward, due to the transfer of gravitational energy from the moon via the tides.

 

That is slowing our rotation, but not robbing us of orbital KE; for that to happen the interaction must come from outside the earth-moon system. Tidal braking with the sun should be occurring, as well as a tiny reduction in gravity from the sun from the conversion of mass into energy emitted in photons, and also a reduction in KE from our continued collection of dust and other particles. All small effects, AFAIK.

No. What makes the earth-moon system unique is the relative size of the moon to the earth.

 

Also the water, even though there are solid earth tides. The configuration of land vs ocean affects the efficiency of our tidal braking.