Context

• An event referred to as “opposition”, which takes place every two years and two months, Mars will outshine Jupiter, becoming the third brightest object in the night sky during the month of October.

Background

• The opposition took place, on October 13, which gave the planet its “biggest, apparent size of the 2020s.
• An opposition can occur anywhere along Mars' orbit, but when it happens when the planet is closest to the sun, it is also particularly close to the Earth.
• Opposition is the best time to view Mars.

Analysis

When does Mars Oppositions take place?

• Mars oppositions happen about every 26 months. Every 15 or 17 years, opposition occurs within a few weeks of Mars' perihelion (the point in its orbit when it is closest to the sun). This year, Mars opposition occurs on Oct. 13, 2020.
  
• Mars’s next close approach will happen on December 8, 2022, when the planet will be 62.07 km away from the Earth. Even so, the closest approach does not mean that Mars will appear to be the same size as that of the moon.

What is opposition?

• Opposition is the event when the sun, Earth and an outer planet are lined up, with the Earth in the middle.
• The time of opposition is the point when the outer planet is typically at its closest distance to the Earth for a given year, and the planet appears brighter in the sky.
• An opposition can occur anywhere along Mars’ orbit, but when it happens when the planet is also closest to the sun, it is also particularly close to the Earth.
• Like all the planets in our solar system, Earth and Mars orbit the sun. But Earth is closer to the sun, and therefore races along its orbit more quickly.
• Earth makes two trips around the sun in about the same amount of time that Mars takes to make one trip. So sometimes the two planets are on opposite sides of the sun, very far apart, and other times, Earth catches up with its neighbor and passes relatively close to it.

Why it is called as opposition?

• Because from the perspective on Earth, the sun and Mars appear to be on the opposite sides of the sky, Mars is said to be in “opposition”. Essentially, opposition is a reference to “opposing the sun” in the sky.

Conditions for its occurrence

• The Earth and Mars orbit the sun, there comes a point when they are on the opposite sides of it, and hence very far apart. At its farthest, Mars is about 400 million km from the Earth.
• In case of opposition, however, Mars and sun are on directly opposite sides of the Earth. In other words, the Earth, sun and Mars all lie in a straight line, with the Earth in the middle.
• According to NASA, from an individual’s perspective on the Earth, Mars rises in the east and after staying up all night, it sets in the west just as the sun rises in the east and sets in the west.