The Sky Tonight Update: Mars at Opposition
This July 27th, the red planet will be at its closest approach to Earth and its face will be fully illuminated by the Sun. It will be brighter than any other time of the year and will be visible all night long. This is the best time to view and photograph Mars. A medium-sized telescope will allow you to see some of the dark details on the planet’s orange surface.
You may have heard an internet rumor that, on a particular date, Mars will appear as large as the moon. This is physically impossible, because Mars is always much farther away than the moon, and never appears larger than 1/70 of the diameter of the moon. On opposition night, Mars will be only 1/100 of the diameter of the moon. In other words, it will take a telescope magnifying 100 times to make Mars look as big as the moon as seen with the naked eye.