Does the expansion of space apply in the solar system?

The prevailing cosmological model for the universe accounts for the fact that the universe expanded from a very high density and high temperature state, and that nowadays the expansion is even accelerating. This is an expansion of space, that is, the increase of the distance between two distant parts of the universe with time. It is an intrinsic expansion whereby the scale of space itself changes. This is different from other examples of expansions and explosions in that, as far as observations can ascertain, it is a property of the entirety of the universe rather than a phenomenon that can be contained and observed from the outside.

By NASA/WMAP Science Team - Original version: NASA; modified by Ryan Kaldari, Public Domain,

Since it is an intrinsic expansion, it is natural to think that the planets in our solar system are expanding with time, as universe is. Moreover, our measurement devices should be expanding too. But, taking into account that a measurement is the assignment of a number to a characteristic of an object by comparing with other objects, why were we able to measure the expansion of the universe if our devices are expanding too?

Does the expansion of space apply to the objects inside our solar system?

Please, explain your reasoning. You can post your attempted answers in the comment box below. Please, do not use Facebook or Twitter to give your answers.


  1. This comment has been removed by the author.

  2. There is no expansion in our Solar system because there is gravity. Th Sun pulls the Earth and the other planets together. In fact our galaxy will collide with Andromeda in the future. This is beacuse their gravitational pull is greater than that of the expansion. These, as far as I´m concerned, are called peculiar velocities.
    Please correct any mistakes

    1. Very good!
      At smaller scales matter is bound together under the influence of gravitational attraction, so galaxies do not expand at the metric expansion rate as the universe ages.
      See this link for more information.
      This cognitive conflict is suitable in order to give a basic introduction to cosmology to undergraduates and even in high school senior year (12th grade).