Earth’s neighbours will appear to swing by each other in the evening sky this July — and we’ll be able to witness this special hangout with the unaided eye.

“Mars and Venus are passing close to each other in the sky and will be only 0.5 deg (as wide as the size of the Moon) on 13 July. The Moon will also be close to them on 12 July,” Bengaluru-based Indian Institute of Astrophysics (IIA) tweeted today.

This ‘conjunction’, as it is called, can be witnessed by anyone — without the need for binoculars or telescopes — starting today (8 July) just after sunset.

On 12 July, the Moon will be seen close to Mars and Venus, coming within 4 degrees of the two celestial bodies. And the very next day, the Red Planet and the Earth’s twin will be closest to each other.

Just after 7 pm on 13 July, Mars and Venus will be separated by about half a degree or roughly one Moon diameter. Venus and Mars will appear at magnitude -3.9 and 1.8 respectively.

Venus will appear brighter than Mars by about 200 times.

In astronomy, magnitude is a measure of the brightness of an astronomical object as seen from Earth. This is the apparent brightness, different from the intrinsic brightness of the object in space.

For us Earthlings, the brighter the object, the lower is its ‘magnitude’. For reference, the apparent magnitude of the Sun is -26.7, and that of the full moon is -11. The dwarf planet Pluto registers 13.6 magnitude.

As for conjunction, it refers to the apparent passing by of celestial objects in the sky — as in the case of Mars, Venus, and Moon over the next six days. They will only appear to us to be passing each other close; the actual distances between the objects will remain mind-boggling.

Last year, Earth was witness to the great conjunction of Saturn and Jupiter. It was a year-end treat as the two biggest worlds in our solar system, Jupiter and Saturn, came close in the sky and were visible to the naked eye. From our vantage point, Jupiter was seen catching up to Saturn and overtaking it.

According to NASA, it had been nearly 400 years since the planets passed this close to each other in the sky. The last similar close encounter was 1623 — thirteen years after a certain Italian astronomer published his findings that the tiny points of light around the planet Jupiter he observed were, in fact, its satellites.

Now, in July, we will get to see Mars, Venus, and the Moon get up close.

Conjunctions don’t carry significance from a purely astronomy point of view, but they offer a wonderful opportunity to look up and take in the sight — in the process, they serve us a reminder and provide perspective on our place in the cosmos.

IIA has shared posters about the Mars-Venus-Moon conjunctions in 12 languages — English, Kannada, Tamil, Malayalam, Telugu, Hindi, Marathi, Gujarati, Punjabi, Bengali, Urdu and Odia.

Later in the month, both Mars and Venus will also have their rendezvous with Regulus, a bright star in the constellation Leo.

These upcoming conjunctions with Regulus — 22 July for Venus and 30 July for Mars — will take place early in the morning.