Mars still at its BRIGHTEST, but beware this persistent hoax
Thursday, August 23, 2018, 4:07 PM - Have you noticed that bright little orange light in the night sky? That's the planet Mars, and right now, it's at its closest distance to Earth in years!
This article has been updated.
In the early morning hours of Tuesday, July 31, Earth and Mars came very close to one another in their voyages around the Sun.
This close pass for the two planets meant that Mars was one of the brightest objects in our night sky, and would continue to be so in the weeks to come!
This simulated view of the night sky, at 1 a.m. local time, on July 31, 2018, shows Mars to the south, accompanied by the Moon to the east, and Saturn to the west. The labels will, of course, not be seen in the sky. They're just here for convenient reference. Credit: Stellarium/Scott Sutherland
Keep watching in the nights and weeks ahead, though. For all of August, and even into the first week of September, Mars will still be brighter than we'll see it at any point after, until the year 2020!
WHY IS MARS SO BRIGHT?
Back on Friday, July 27, 2018, Mars aligned for an event known as Opposition - when the Sun, Earth and Mars lined up perfectly, with Mars on the opposite side of Earth from the Sun.
On that night, Mars was up from dusk until dawn, crossing the sky with the Full Thunder Moon - the smallest, most distant 'apogee' Full Moon of 2018. Coincidentally, depending on where you were, it was also be the night of a Total Lunar Eclipse, which was the longest total lunar eclipse for the next century!
Due to the shapes of the orbits of Earth and Mars, though, it wasn't until four days after opposition that the two planets reached their closest distance to one another.
Mars at closest approach, just a few days after its Opposition. Credit: NASA GSVS
The July 31 close approach of Earth and Mars was the closest since 2003, when Mars was 55.7 million km away, and was also the closest until 2035, when Mars will be 56.9 million km away
Mars reaches opposition roughly every 26 months, so this is the 7th opposition since 2003 and there are another 7 oppositions before 2035, each having its own closest approach to Earth, in the days before or after the alignment.
Since these oppositions occurred, or will occur, at different points along Mars' more highly-elliptical orbit, however, none of the other 13 oppositions in that time span - 2003 to 2035 - are as close as in 2018.
The 2020 opposition will be the next closest - both chronologically and distance-wise - as Mars comes to within 62.1 million kilometres of Earth.
These two simulated telescopic views of Mars show the planet at its brightest in 2018, at 35.8 million miles (57.6 million km) and in 2020, at 38.6 million miles (62.1 million km). Credit: NASA/JPL-Caltech
The above image shows what Mars looks like through a telescope. The planet would never look that large and that clear to the naked eye, from Earth. Also, currently, the surface features appear more 'washed out', due to the global dust storm the planet is experiencing right now.
If you were under cloudy skies at the time, or couldn't get out to see Mars during the close pass, NASA's Jet Propulsion Laboratory hosted a livestream, which aired from Los Angeles' Griffith Observatory, early in the morning on Tuesday, July 31.
Watch a replay of it, below:
BEWARE THE MARS HOAX!
While watching Mars right now is great, due the planet's brightness in our night sky, also watch out for a persistent hoax that is going to try to blow this fact WAY out of proportion.
Every year, it seems, a message makes the rounds over email, Facebook or other social media, with a wild, and completely false claim that the planet Mars is going to look as big as the Moon in our sky.
Normally, this message targets the date of August 27, but with the close pass on July 31, it's the perfect opportunity for the hoaxers to revive their story, and just change the date. So, keep an eye out to see if it shows up in your social media feed (and maybe send the perpetrators here, in response).
The plain and simple truth us, the planet Mars has never come even close to appearing as big as the Moon in Earth's skies, and it never will.
The problem with the hoax meme is that it leaves out a very important detail:
The only way the Moon and Mars will ever look to be the same size, is if - on the night of a particularly close approach between Earth and Mars - you look at the Moon with the naked eye, and you look at Mars through a telescope.
This detail was included in the original 2003 notice to the public, which told of the closest approach of Mars in some 60,000 years, and which won't be repeated until 2287. The hoaxers subsequently left that out as they repeated in, in the years after, trying to fool people into heading out to see such an incredible event.
How can we be sure it won't happen?
Well, let's look at the two ways that it could happen:
1) The closest Earth and Mars ever come to each other is 54.6 million kilometers. That's roughly 142 times farther away than the Moon. So, if Mars was to appear as big as the Moon, from that distance, the planet would need to be 142 times larger than it is, or over three and a half times bigger than Jupiter! In reality, Mars is smaller than Earth. So, it's impossible for Mars to appear as large as the Moon, from over 54 million kilometres away.
2) With a diameter of 6,779 km, Mars is just under twice as big as the Moon (diameter 3,474 km). So, if you kept Mars the same size, you would have to move Mars up to being just under twice as far away as the Moon, or around 750,000 km away from Earth. Mars getting that close to Earth, though, is just as impossible as the planet suddenly inflating to 3.5x the size of Jupiter. Earth and Mars are locked in their respective orbits, only coming as close as 54.6 million km, due to the persistent gravitational influence of the big players in the solar system - the Sun and Jupiter. Something utterly cataclysmic would need to happen to our solar system for that to change, and since nothing like that will happen (at least not for billions of years), Mars will continue to keep its distance from us.
That's it. Either you inflate the size of Mars by an impossible amount, or you move it impossibly close to Earth, and neither of those things are going to happen. Ever.
Of course, given its persistence now, this hoax meme will probably still show up, and may even keep showing up until the next time Mars reaches its absolute closest, in 2287 (depending on the fate of the internet and civilization).
Also, take note: Some of the newest additions to this hoax, notably in 2016, tried to add a measure of 'doomsday' to the meme, since apparently non-doomsday memes no longer pack the same punch. Mainly stemming from Russian news sites, these claims stated that the close-encounter with Mars had "caused panic in the scientific community," due to a previous closest encounter - back in the year 57,617 B.C. - supposedly caused "changes in the earth's crust and climatic disasters."
This is also untrue, because Mars cannot have that kind of affect on Earth from over 50 million km away. While Earth and Mars do exert gravitational forces on each other, these forces become very tiny, very quickly as you move farther away. They are so tiny at the distance of 56 million km that they have no notable impact on Earth's tectonics or climate. Quite simply, if Earth's crust and atmosphere could be influenced in any major way by such minuscule forces, the Universe itself would never have been able to sustain itself. It would be so fragile that it simply couldn't exist. Since the universe does exist, and we exist to experience it, there's no way for the meme, or any of its doomsday additions, to be true.
The best things to do for the approach of Mars Opposition, and the Mars close approach shortly after, is to keep an eye on the weather, to ensure you have clear skies, arrange to acquire some binoculars or a telescope, or see what kind of star parties may be happening in your area on or around that night, so that you can not only experience this close pass, but also share the experience with other skywatching enthusiasts. Even if no opportunities are available, still get out and see Mars. It will be visible, bright in the night sky, even from the most heavily light-polluted urban areas.
Author's note: A previous version of this article stated that Mars Opposition is an annual event. This is incorrect. While Earth does go around the Sun once every 12 months, since Mars has moved along its orbit in that same time, it takes another 14 months for Earth to catch up to Mars for another opposition. For a cool demonstration, check out this Windows to the Universe animation. Apologies for any confusion this caused, and also a shout-out to James Dubano (@astronomer4hire) for pointing out the error.