A constellation on the eastern horizon at sunset will be roughly higher in the sky and further west one month later.

Here's why:

* Earth's Rotation: The Earth rotates on its axis, causing the apparent movement of celestial objects across the sky.

* Earth's Orbit: The Earth also orbits the sun, completing a full orbit in about 365 days. This means our perspective of the stars changes slightly each night.

* Constellation Movement: As the Earth moves in its orbit, constellations appear to shift slightly eastward each night. This is similar to how, from a moving car, nearby objects seem to move faster than distant ones.

Therefore, over a month, the constellation will have:

* Moved eastward: It will be higher in the sky at sunset.

* Appeared to move westward: This is due to the Earth's rotation.

Important Note: This movement is gradual, and the constellation will not be dramatically different in its position.