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Mars Swings Unusually Close to Earth
amazon10x writes "Mars will come unusually close to the Earth on Saturday; the second time in 60,000 years. The last occurrence was in 2003. 'This is the best we're going to see Mars, so we should strike the iron while it is hot,' said Kelly Beatty, executive editor of Sky & Telescope magazine. The Red Planet will be 43.1 million miles from Earth at 11:25pm [Eastern time]." Update by J : Starting a few hours after sunset, look fairly high in the eastern sky.
Well what time zone? 11:25pm here could be 6:25am somewhere else. Bad slashdot!
The information in the article in SI units:
> On Saturday, Mars' orbit will bring it 69.4 million kilometers away from Earth, with its closest pass scheduled for 3:25 p.m. UTC.
*Doesn't something like this happen every year these days?*
If by "every year" you mean "Every other year," and by "every other year" you mean "2003" then yes, it happens every year. Note, please, that every other year (give or take) Mars gets closer to us, then further, then closer, so there are times where it will be closer than others. This one (and the one in 2003) are just extra-close.
*So it came unusually close in 2003... and now again in 2005... and they're expecting it again in 2018?*
They're not "expecting" it so much as "knowing" it, but yes, Mars gets closest to us every couple years, and sometimes it's closer than others, so it will be in 2018 as well (I assume, I haven't actually researched 2018 in particular). It won't be as close as it is this year, or in 2003, which made these two so special.
*And so it's happening 3 times in 15 years... but we're going to blow that up to say "3 times in 60,000 years!!!"*
We're not blowing up anything. 60,000 years ago (or so) Mars was as close to the Earth as it will be this week. Between 60,000 years ago and now, it's only happened once, in 2003, and it will happen again in a couple days.
*Honestly... the New Orleans Saints win playoff games more rarely than this occurs.*
To put this in terms you'll understand, think of it this way. The NOS win a game, after losing, say, 5 in a row. The announcer says "This is their first win in 6 games." Are you going to complain and say "No it's not, it's their first win in ONE GAME!"?
*Other than it's significance to NASA's mars mission and palmists, all this means to john-everyman is that the red dot in the sky is a little brighter.*
Which is why we're having this discussion on a geek website. It's NEWS.
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We all went to school and we all know how this works. Let's just calm down and consider how rare or not rare this event is.
Earth orbits the sun in a nearly circular orbit at a mean distance of 1 astronomical unit (by definition of AU). Mars on the other hand orbits the sun in a less circular orbit that takes it as far as 1.67 and as close as 1.38 astronomical units from the sun. As we all know, it takes earth 1 year to orbit the sun (again, by definition of a year). It takes Mars 687 days (1.88 earth years).
Let's put this into more "human" terms using an analogy. Let's imagine a rock in the middle of a field. And let's put two people walking in circles around the rock. One person at a distance of 10 meters and the other at a distance that varies between 14 and 17 meters from the rock. Very quickly we'll notice that the closest the people can ever come from eachother is 4 meters and the furthest they can come is 27 meters. But we also notice that as they walk around, the person closer to the rock will take 1 minute to walk around the rock and the person on the outside will take 1.88 mintues so the one on the inside will be overtaking the one on the outside roughly every other minute (once per two years in Mars-Earth terms). And whenever they overtake, the distance will be anything from 4 to 7 meters. And quite often, it will be a distance of 4 to 5 meters or so. It's not rare at all. What's rare is that it would be VERY close to the minimum 4 meters.
So.. when we say it's "amazingly close" and "closer than in 60000 years", it's more like getting within 4.1 meters instead of 4.25 in the analogy above. We're not talking about 4 meters vs. 27 meters or anything like that.
Conclusion: this isn't THAT special at all. Mars isn't THAT much closer at all. For example for Mars missions and such, the difference in distance is mostly irrelevant.
Peppe
This is obviously a Martian invasion plan. First they submit a story to /. that doesn't contain the timezone which confuses us a bit. Then they choose a time zone that plenty of people don't know (judging by the other comments). Then, and this is the one that really convinced me it's an invasion, they make sure that the conversion from the given timezone to to the ones used in Europe is as difficult as possible (most of Europe switches from daylight savings time to standard time on that night). This is a cunning ploy to keep us on the back foot while they get their ships of death in place. It should be evidence enough for any one.
To arms, the Martians are coming.
P.S. There are some dubious looking bumps in the sand on Mars. I think they might be hiding WMDs!
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And the worst thing about this whole thing is that it isn't true!
While in 2003 Mars passed us closer then at any other time in the last 60.000 years, it passes us by pretty close every 15 and 17 years. The 2003 passage was a "whopping" 1% closer to us than the 1971 pass, and this year's pass at 43 million miles is not unusual at all, every 15-17 years there's at least one pass that is significantly closer than that, the 1988 pass being at 37 million miles - noticably further than 2003, but much closer than this year's passage.
So as usual, take main stream press accounts of science stuff with a very big grain of salt!
Imagine an egg still in its shell. Looking down at the egg, it's like the shell is the orbit of Mars and the yolk (still inside the shell, of course) is the orbit of the Earth. In 2003, when the two planets got as close as they can get, it was like both were on the wide end of the egg, where the yolk is closest to the shell. Well, Mars' orbit takes about two years and two months to complete, so this year Mars and the Earth meet up near the wide end of the egg again. In two years' time, though, Mars will be a little further along the shell of the egg when it catches up to Earth, which will be a little further from the wide end of the egg.
In 60,000 years or so, the closest approach will have walked all the way around the edge of the egg until it's at the "closest closest approach," the wide end of the egg. There's nothing unusual about it.