Opposition on 22 May
SInce the start of the month of May the earth and mars are approaching opposition each day, making its closest aproach nearer and nearer. On 22 May, mars Earth and the sun will align in a straight line, with Mars at the opposite side of the sun and earth in between; however, the actual day of closest approach will be a week later, on 30 May.
At the closest approach the two planets will be 75 million km (47 million miles) apart. The angular size of the red planet in the sky will be 18.6 arcsecs, which will be easily resolved with a 6” aperture telescope.
With a more powerful telescope; lets say, a 100x magnification power, one will be able to see Mars the same size as the Moon.
The red planet
Mars is the fourth planet in the solar system.It is 230 million km from the sun and it orbits the sun in 687 days The reddish look of this planet is due to iron oxide content n its surface. In the same way as the Moon, Mars shows surface features, including deserts, craters, valleys, canyons, mountains and polar ice caps.
Mars at closest approach to earth
Mars and Earth´s closest approach will be on 30 May around midnight. The planet will reach 30° above the southern horizon as seen from the northern hemisphere. It will be seen for almost much of the night.
The planet will be gaining size over the course of the days, reaching an apparent diameter of 11.9 arsecs during the first days of April. At the beginning of May, it will grow to about 16 arcsecs and on the day of closest approach, it will be seen at 18.6 arcsecs in the sky.
Mars´ orbit
Due to their orbits, while earth circles the sun in 365 days, mars takes almost two years to circle the sun twice.
If their orbits were circular, the time of opposition would be their closest approach; however, because the planets have elliptical orbits, their closest approach does not match the time of opposition.
Mars´ opposition occurs approximately every 26 months at aphelion of perihelion; however, exact opposition at perihelion does not occur often.
Every 15 or 17 years mars opposition may occur one week apart from the time ofperihelion. A future Mars close approach is expected to occur in 31 July, 2018. This may allow scientists to conductMars´explorationwith minimum budgets.
