So, we are mere percentage points closer to the Angry Red Planet™ than we have been or will be for an impressive number of years.
But, it IS only MAR(s)ginally closer to the Earth.
Have there been oppositions where Mars was brighter, perhaps because that particular opposition had Mars closer to the Sun (or for other reasons)?
I guess posting this right before a 3 day weekend killed it.
Or, no one in GQ knows.
Hmmmm…
Which is it? 
I’d say it’s your boyish charm, but what do I know.
Each orbit has an apogee (furthest) and perigee (closets) approach to the sun. Orbits also rotate. I suppose precess would be the right word. So the apogee and perigee would slowly change over the eons.
We’ve just experience our apogee and so has Mars. It also seems that both apogees are lined up so that the minimal distance is the absolute minimum possible during an apogee lineup.
I would think that a perigee lineup would be more impressive simply due to Mars being closer to the sun and therefore brighter.
Maybe Aldebaran will drop by with better info.
Interesting question, and I’m going to hazard a “yes” answer, but the explanation will probably not satisfy you. Opposition occurred on Aug. 30 this year. However, it looks like Mars was closer (100,000km) to the Earth (and only 10,000km farther from the Sun) three days before that–and so probably brighter. Not by much, of course.
Just looking at the past hundred years, perihelion of Mars was at a farther distance than this years opposition–farther even than on Aug. 27–so there’s not much chance that Mars appeared brighter.
I guess what you mean by opposition also makes a difference.
a) FYI, the terms “perigee” and “apogee” is commonly applied to a moon’s orbit in relation to its orbit about a planet. The terms you are thinking of, more correctly, are “perihelion” (closest point to the sun) and “aphelion” (furthest point). The earth reaches aphelion in early July.
b) Yes, Mars’ perihelion can make it appear to be at its brightest, as viewed from Earth. Also, as you might guess, it requires Earth to be in a good position, too. This happened just a few years ago.
“There is no dark side of the moon…matter of fact it’s all dark!”
Probably, though not much brighter, just a tiny fraction of a percent. Roughly speaking the closest possible approach between the Earth and Mars will occur when the Earth is at aphelion and when Mars is at perihelion during an opposition (the Earth falls in a straight line between the Sun and Mars). Because Mars and the Earth don’t lie in the same orbital plane, the actual closest approach comes a little bit before the opposition occurs. In this case the closest approach was August 27, when the opposition itself occurred on August 28, to correct the post above.
Though this year’s opposition didn’t occur when the Earth and Mars were in the exact spots to achieve their closest approach, they were pretty dang close to it. Even closer approaches are expected in 2287 and 2729, as the precession of the orbits of the two planets align for more favorable (mathematically, anyway) approaches (see Space.com article here)
Since these next approaches will only be a few hundred thousand miles closer at best (tiny, astronomically speaking), Mars won’t be much brighter than it is right now.
Thanks!
Ah, but wait a minute, Triton. You’re only discussing how close Mars is to Earth, which determines its apparent diameter. The brightness of Mars depends on the combined length of the Sun-Mars-Earth vector.
The computer programs which determine how far Mars is from Earth at each opposition presumably also calculate how far it is from the Sun. But I haven’t seen any news articles which discuss that aspect of the situation. And unless a member of this Board has access to such a program, we won’t get a definitive answer.
Ah, but wait a minute, jklann. Shouldn’t we also take into account the mars-sun-earth angle. Close to zero offers maximum reflectance (zero would be earth eclipsing mars), whereas moving up to ninety degrees we would gimpse more shadow.
Maybe this is insignificant.
Hard to say, antechinus. Mars is close enough to Earth that it presents a noticeably gibbous shape when it’s near quadrature, and this obviously lowers its brightness. When it’s near opposition, the angle is always close to zero–but not usually exactly zero. Do the small disparities make a difference? Maybe, in comparison to small Sun-Mars-Earth differences we’re talking about when comparing close passes. I don’t know.
Yet another factor would be variation in albedo. There are seasonal and weather-related factors–melting and shrinking of the polar caps, tilt of the caps toward Earth, and dust storms covering and uncovering darker surface areas. Obviously there is no reliable way to model this.
I’m beginning to see why the news media didn’t address this.