Jupiter and Mars opposition

Jupiter opposition, oppositions in general, and media garbage.

A few days ago (on the 11th of June) Jupiter reached "opposition" with the Earth. What this means is that both the Earth and Jupiter were at the same angle from the sun, with the Earth sweeping "under" Jupiter, like the minute hand passing the hour hand on a clock face.

At this point, Jupiter and Earth are (pretty much) as close to each other as they ever get. Which is not to say much, because Jupiter and the Earth are a looooong way apart.

Check out this diagram. The distance between Jupiter and Earth is least when the planets are lined up with the Sun, but at other times that distance isn't hugely different.

Of course, it hadn't stopped some people from losing their minds about this. USA Today has run a story that somewhat breathlessly tells us that "Jupiter will be so close tonight, its moons will be visible with binoculars". Duh, you can ALWAYS see them with binoculars. Decent ones, of course.

It's even worse with Mars, which is much closer to the Earth, so the difference is much bigger (see the next diagram). Mars opposition happens nearly every two years. The last few times it has, a meme has gone around including the quote "Mars will look as large as the full moon to the naked eye".

Seriously, the only way you'll ever get the Moon and Mars to appear the same size is if you've got a big telescope up against ONE eye.

Of course, there's always the backlash, which is almost as unfair at times. Our friends at Celestron recently re-posted the USA Today story, saying it's a good time to watch the planet.

This was followed by a number of comments complaining that Celestron was reporting inaccurately and posting clickbait.

A little bit unfair, I thought.

The fact is, opposition really is the best time to see planets, not because they're closest, but mainly because they're highest in the sky and you're not looking through great chunks of atmosphere.

Oh, finally, have you seen Jupiter?


 

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