What mind you expect to find if you were to come back to our solar system in 1 billion year?

The Sun would be largely unchanged, though it would be only four billion years from its red giant stage.

If humanity managed to avoid killing itself and explored space, the planet Mercury would probably be gone as we would have mined it into nonexistence.

Venus might have been terraformed and would then be enjoying some primitive life.

Earth? Hard to say. We might have polluted it back to an azoic condition or left it altogether.

Earth's Moon would be much farther away. No more solar eclipses visible from the planet.

Mars would be pretty much as it is today; even if we managed to terraform it, its low mass would have let its atmosphere escape again.

Jupiter might have moved in closer to the Sun.

Saturn's rings would be gone.

The Ice worlds would be unchanged.

Of course, Nemesis/Shiva, the Sun's putative dwarf companion, might have made about forty passes, any one of which could have provoked a catastrophe.

We would in all probability have drifted out of the Origin Spur and into a region of either more or less interstellar matter.

All the constellations would be changed beyond recognition and all the bright stars of the Earth's sky would be burned out.