You can't really say how far Canis Major is from Earth because it's not a single object, but a constellation made up of many stars.

Here's why it's tricky:

* Stars are at different distances: Each star in Canis Major is at a different distance from Earth. The constellation's shape is just a projection in our sky.

* Variable distances: Even the closest stars are light-years away, and their distances change slightly over time due to their own movement in space.

Instead of asking "how far is Canis Major?," you could ask:

* How far is Sirius, the brightest star in Canis Major? Sirius is about 8.6 light-years from Earth.

* How far is [insert specific star name] in Canis Major? You can find this information in star catalogs or online databases like the Simbad Astronomical Database.

Remember, constellations are helpful visual tools, but they don't represent actual physical groupings of stars in space.