Lunar Occultation of Mars

~2 min

On September 6, 2020, observers from South America and several other regions will have a chance to see a lunar occultation of Mars. Read on to learn more about this astronomical event.

What is a lunar occultation?

Moving along its orbit, the Moon sometimes passes in front of other celestial bodies and hides them from our view. This phenomenon is called a lunar occultation. As the Moon is very close to the Earth, it can occult all sorts of distant space objects that seem much smaller to us – stars, planets, and asteroids. Spectacular solar eclipses that everybody loves are, in fact, lunar occultations of the Sun.

An occultation is not only an interesting visual phenomenon, but it can also provide scientific knowledge. For example, observing a star’s lunar occultations can help calculate its angular diameter and even study its surface structure.

Mars slips behind the Moon

On September 6, at 12:46 a.m. EDT (04:46 a.m. GMT), the Moon will pass in front of Mars and block it from the view of the terrestrial observer. It will be the fourth lunar occultation of Mars in 2020; the next and last one will occur on October 3. Unfortunately, only observers from South America, Southern Europe, and Western Africa will be able to see this month’s lunar occultation.

If you’re lucky enough to live in one of the regions where the occultation will occur, you’ll need to know where to look. The Moon is, of course, one of the easiest objects to find in the sky. To be able to locate Mars at any time and even during the occultation, use Star Walk 2. Note that the Moon’s proportions in the app are a bit exaggerated. Thus, on your screen, the Moon will cover Mars earlier than in real life. To get rid of this effect, you’ll need to zoom in on the Moon using your fingers.

The Moon reaches its apogee

On the same night of September 6, the Moon will also reach its apogee. As the Moon’s orbit is not circular but elliptical, our natural satellite sometimes moves closer to the Earth and other times gets farther away from it. The Moon's most distant point from the Earth is called the apogee. At apogee on September 6, the Moon will be 405,607 km away from us and will appear a bit smaller than usual.

To learn more about the Moon, use the Star Walk 2 app. Tap the “Sky Live” option to get information about the Moon’s phases and its rise and set times for your location.

We wish you clear skies and happy stargazing!