In order to see objects that humans left on the moon, you'd need a telescope 50x larger than The Hubble!

The Hubble Space Telescope (HST) is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4-meter (7.9 ft) aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared.

Hubble's orbit outside the distortion of Earth's atmosphere allows it to take extremely high-resolution images with almost no backgroundlight. Hubble's Deep Field has recorded some of the most detailed visible-light images ever, allowing a deep view into space and time.

You will need a telescope 50 times the size of the Hubble to see objects left by humans on the moon. Even if we use the Hubble Space Telescope to look at the moon, a football stadium sized object would appear as only one pixel.

(Source)