Is cancer in the solar system?

Cancer is in the solar system, at infinity.

Cancer is a constellation of the zodiac, with an area of 505.87 square degrees, in which there is no star brighter than 3.

Seen from the earth, the constellation is an area in the sky. As long as the celestial bodies in this area, no matter far or near, are members of this constellation. These celestial bodies may be very close. For example, if a planet moves into this region, then a member of this constellation is in this constellation and this constellation is also in the solar system.

But these celestial bodies can also be very far away. For example, M67 in Cancer is a big black open cluster. It is one of the oldest clusters in the galaxy, with an age of over one billion years and a distance of 2,700 light years. This distance is far beyond the solar system.

NGC2775 galaxy is even farther away. It is a huge spiral galaxy with a distance of 55.5 million light years. It is not only outside the solar system, but also a member of another galaxy group that belongs to virgo supercluster instead of the Milky Way. Of course, in the vast universe, tens of millions of light-years are not far away, and they still belong to local supercluster.

Remember, constellations have no distance. In principle, as long as it is within the scope of this constellation, all celestial bodies that leave the earth and reach infinity are members of this constellation.