When is Mars closest to Earth?

Mars comes closest to Earth around each opposition, the moment when our planet lies between the Sun and Mars. That alignment repeats roughly every 26 months, and that's when the planet appears brightest and largest through a telescope. Not all oppositions are equal: so-called perihelic oppositions, with Mars near its closest point to the Sun, happen only every 15 to 17 years and are the ones that offer a truly generous disk.

The next opposition occurs on February 19, 2027, at 15:45 UT. Closest approach follows the very next day, at 00:14 UT on February 20, with Mars at 101,415,244 km (63,016,511 miles) and an apparent disk of 13.8 arcseconds. This is a modest approach: to the naked eye Mars will be a very bright orange point, but telling apart the polar cap and dark markings will require a decent telescope and a night of steady air.

Mars's orbit is noticeably elliptical, and gravitational tugs from the other planets perturb it further, so the moment of minimum distance doesn't exactly coincide with geometric opposition: it can come earlier or later. That's why almanacs publish two dates instead of one. For observing, the distinction barely matters: what counts is the span of weeks around opposition, when the planet rises early, climbs high, and stays for hours above the turbulence near the horizon.