Context: As a result of an event referred to as “opposition”, Mars will outshine Jupiter, becoming the third brightest object (after moon and Venus) in the night sky.
More on the news:
- According to NASA, the opposition, which takes place every two years and two months will happen on October 13, which will give the planet its biggest, apparent size of the 2020s.
- Mars’s next close approach will happen on December 8, 2022. The closest approach does not mean that Mars will appear to be the same size as that of the moon.
About opposition phenomena:
- Lining up of Sun-Earth-Mars: In case of opposition, 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.
- Closest to the Earth:
- The time of opposition is the point when the outer planet is typically also at its closest distance to the Earth for a given year. Because it is close, the planet appears brighter in the sky.
- However, the closest distance is relative and hence can vary. This is because the orbits of Earth and Mars are not perfectly circular and their shapes can change slightly because of gravitational tugging by other planets. For instance, Jupiter influences the orbit of Mars
- 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.
- When does opposition happen?: Mars is farther apart from the sun than Earth and therefore takes longer to complete one lap around the sun. Hence, opposition can happen only for planets that are farther away from the sun than the Earth.
- Opposition: Why called so? - Because from the perspective on Earth, the sun and Mars appear to be on opposite sides of the sky. Essentially, opposition is a reference to “opposing the sun” in the sky.
- Opposition is the best time to view Mars: During this time, Mars will appear as a bright star to the unaided eye and when viewed from a telescope, it will grow dramatically in size.
Image Source: IE