One of the most asked questions this week is Will Mars Be The Same Size As The Moon on August 27? The answer is no, not really. This story has been spreading since 2003.
Will Mars Be The Same Size As The Moon on August 27, 2020? Is Mars really going to be as large as the moon, visible from Earth? No to all of these stories. This joke is rooted in a 15-year Mars cycle that really happened, which is peaking – allowing us a fantastic year to observe Mars – in 2020.
While this is not valid, you are probably going to see the statement in an email – or social networks; that Mars will be as big as a full moon in Earth’s sky on a specific day, usually August 27 in any given year. Often there is a belief that the moon of Mars and Earth would appear as a double moon. And that’s just not the facts. It’s not the case in 2020. And therefore, it never was. It’s never going to be true.
The hoax usually looks like this:
“NOW YOU HAVE A CHANCE TO WATCH MARS – IT IS GOING TO BE AS LARGE AS THE FULL MOON. YOU TRULY DON’T WANT TO MISS THIS!”
It definitely sounds awesome. But, could it really be true?
The answer is no.
Mars will never be as big as the full moon as viewed from Earth. As seen from Earth, in the periods when Mars appears side by side with the full moon, Mars’ diameter is, on average, around 1/140th of the full moon’s diameter.
Therefore, you’d have to line up 140 Mars planets – beside each other – to match the diameter of the moon.
On July 27, 2018, Earth and Mars had an extremely close opposition. Starting from July 7, 2018, Mars knocked Jupiter out of the second-brightest planet spot; Mars became the second-brightest planet (after Venus) and stayed so until about September 7, 2018.
The opposition of Mars occurs every time we pass between it and the sun in our smaller, faster orbit. Mars was nearest to us on July 31, 2018, closer than it had been in 2003. It was very light and with red shades! Much like a spot of fire.
Consequently, the claims of Mars being the same size as the moon are going off!
Oh, Mars. A world of dreams and fantasies. Mars is a planet that orbits one step out of Earth’s orbit. This planet is significantly smaller than the Earth but somewhat bigger than the Earth’s moon. Mars is a lot farther away than the Earth’s moon, too. It’s difficult to grasp what little specks the planets and moons are in comparison to the immensity of space, so it can be put this way. The Earth’s Moon is a light-second ahead. Traveling 186,000 miles per second (300,000 km/sec), light emanating off the surface of the moon takes just a second to come here on Earth. Furthermore, the light from Mars takes a long time to reach Earth – from a few minutes to about 20 minutes.
Here, the difference is the outcome of Earth’s and Mars’ movements around the sun. Simply put, when Mars and Earth are on the same side of the sun, Mars’ distance from us is smaller than when it is on the other side of the sun from us.
The moon is a lot closer than Mars, and that is the reason why we see it as a light dot in the sky. Additionally, we see Mars as only a reddish point in the shape of a star.
The question is, how did the story start spreading? It began with a true (however much more subtle) occurrence in 2003. On August 27 of that year, Earth and Mars were a bit closer than they had been in almost 60,000 years. Center-to-center, Earth, and Mars were less than 35 million miles away from each other (approximately 56 million km) – just over three light minutes away. Astronomy authors had a great day that year, writing about Mars at its nearest point. Was it a wonderful moment? Sure!
But, was Mars as large and light as the moon, even at its closest point in 2003? Never. Yet the story lives on…
The 2003 occurrence was part of the 15-year Mars cycle described above.
To sum up, Mars will never be as large as a full moon in Earth’s atmosphere. The claims you see on social media are a hoax. Nonetheless, 2020 is a great year for Mars. The once-in-two-years opposition – middle of this year’s greatest time to see it – will arrive in October.