Kolkatans set for Celestial treat: Mars to come closest to Earth since 2003 on Tuesday

Kolkata: A spectacular celestial event will enthrall the city residents and astronomers on July 31, when Mars will be closest to Earth since 2003.

The red planet will be at its brightest since 2003, when Mars made its closest approach to Earth in almost 60,000 years (since September 24, 57,617 BC).

According to Dr. Debiprosad Duari, director, research & academic, M P Birla Planetarium, Mars, the fourth planet from the Sun, orbits the Earth at a greater distance than our planet. As the distance from the Sun increases the orbital period also increases.

While Earth takes a little more than 365 days to go round the Sun, Mars takes 687 days. Due to the difference of the orbital speed and orbital period, every 26 months or so, Earth passes between Mars and the Sun, bringing Mars and Sun on exactly opposite sides of Earth. This is called Mars at opposition.

This year, Mars was at its opposition on July 27, only 51 days before it passes through its perihelion — its closest point relative to the sun in its orbit. Since it will be quite close to Earth by that time, it will appear very bright and will be visible roughly after sunset and will remain in the sky till sunrise.

The red planet will shine very prominently in our night sky. At this time, it will be easier to see the red planet clearly with telescopes or even with the naked eye.

Mars comes close enough for these exceptional viewing occasions only once or twice every 15 or 17 years.

Because of the elliptical orbits of the planets, Earth and Mars come close to each other around the time of opposition.

"The closest approach of Mars this time will be on July 31, and it will look brighter and bigger than it did in 2003. The red planet's next closest approach, though not as close as on 2003, will not occur until 2035. Mars will come closer to Earth than it was on 2003 only in 2287 (August 29), when nobody present on Earth now will remain alive," said Dr. Duari.

The next opposition of Mars, when it will look relatively brighter and bigger than the average, will be on October 6, 2020, but it will be a little further away and will be relatively looking smaller and less bright than on July 31, 2018.

Mars will be visible in the night sky after sunset till sunrise from everywhere in India, provided the monsoon clouds do not play spoilsport.

It is perfectly safe to observe Mars through the naked unaided eye, but if enthusiasts are eager to see a little more in detail, they can use telescopes with 4 inch diameter and above to see some of the surface features on the planet.