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Mars Swings Unusually Close to Earth
Posted by
CowboyNeal
on Fri Oct 28, 2005 02:36 AM
from the violating-personal-space dept.
from the violating-personal-space dept.
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.
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Unusual? (Score:2, Interesting)
Re:Unusual? (Score:4, Informative)
"Unusual" can also mean "rare"-I think that's the context it's used in here.
Parent
In galactic scales... (Score:3, Insightful)
Re:In galactic scales... (Score:5, Insightful)
Parent
Re:In galactic scales... (Score:5, Informative)
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!
Parent
Re:In galactic scales... (Score:5, Funny)
Haven't you noticed? 5 years ago, it would have been rare to meet 2 dense induhviduals in a week! Now, I usually encounter at least 1 a day. This accumulating density is subtly increasing the Earth's gravitational field. (Yes, yhat's also why your scale keeps going up.)
I believe reality television is to blame. I eagerly tuned in to the first season of Survivor, thinking "Oh boy! Televised Darwin Awards!" But, wha?? They *vote* people off? The smart people? This isn't "survival of the fittest", it's survival of the weaseliest. (It is so a word, Dilbert [dilbert.com] says so and that's good enough for me!)
And weaselness is closly related to denseness. Don't believe me? Take a minute to talk to your upper management. Then another minute to see what they get away with. See!?
Parent
Re:In galactic scales... (Score:4, Informative)
Parent
Re:In galactic scales... (Score:5, Informative)
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.
Parent
Re:In galactic scales... (Score:3, Informative)
The reporting last time was ridiculous; some even stated that Mars would look as big as the moon; this again was sloppy misquoting; S&T had said that Mars IN A 75X TELESCOPE would appear as big as the Moon does TO THE
Re:In galactic scales... (Score:4, Funny)
Parent
Time zone? (Score:5, Insightful)
Re:Time zone? (Score:5, Informative)
EDT is 4 hours behind of Coordinated Universal Time (UTC), ergo closest orbit will be at 03:25 a.m. UTC.
I think.
Parent
Re:Time zone? (Score:5, Funny)
Great - The UK (and many other countries) flip back to GMT\UTC Sunday morning, so now my head hurts trying to work out when I have to set my alarm so I can get up, get get dressed, go outside, and stand disapointedly staring at a cloud covered sky
-Jar.
Parent
Re:Time zone? (Score:3, Insightful)
Re:Time zone? (Score:4, Informative)
Parent
Re:Time zone? (Score:3, Informative)
Re:Time zone? (Score:3, Interesting)
No.
A true geek would know all the different ways employed to measure time, included, but not limited to, the various different variations of Universal Time, Atomic Time, Solar Time, Sidereal Time, Ephermis Time and Terrestrial Time, not to mention time according to the day/night cycle of an extra-terrestrial body. He would also be able to tell you in minute detail the differences between GMT and UTC.
Time zones are easy, they're all just simple offset
Re:Time zone? (Score:3, Informative)
Re:Time zone? (Score:4, Informative)
GMT and UTC are two very different time scales.
GMT is simply the mean solar time at Greenwich Observatory.
UTC is measured using atomic clocks, based on TAI (International Atomic Time) which is a weighted average of a few hundred atomic clocks around the world. Now, to keep it within one second of mean solar time at Greenwich Observatory, they occasionally add in a leap second here and there to make it work. The result being that UTC is offset an integral number of seconds from TAI.
The particular dispute with the French that I've heard of is that the French wanted to call UTC TUC (for Temps Universel Coordonné, or something like that) while others wanted to call it CUT (Coordinated Universal Time). So to ensure nobody got what they wanted, they agreed to call it UTC out of spite for one another.
Now, there may be another conflict with the French (the French are always making a fuss about something
Interesting, however, how the Proud French People values communications and interoperability with the Benelux, Germany and Italy more than being in a time zone corresponding to solar time at their latitude. They'd be a much closer match having the same time as the UK, Paris being just at about 2 E. Then again, the only thing the French like more than to be different than anyone else is to spite the English.
Parent
Re:Time zone? (Score:5, Informative)
When it's 11:25 PM wherever you are, that's the time to look.
Parent
Maybe... (Score:3, Informative)
Use as directed. Comment not valid in Canada or either of the two poles. Author not responsible for alien abductions due to stargazing.
Time Zone (Score:4, Informative)
On Saturday, Mars' orbit will bring it 43.1 million miles away from Earth, with its closest pass scheduled for 11:25 p.m. EDT.
Re:Time Zone (Score:3, Informative)
And just to further confuse the crap out of people, at 11:25pm Eastern Daylight Time, Europe will be in Winter time, having changed its clocks just a few hours before. So 23:25 EDT will be 03:25 GMT, not the typical 04:25 GMT.
Either way, it's on Saturday night. I'll have trouble seeing my feet, let alone Mars.
Re:Time Zone (Score:3, Insightful)
At 3AM BST Sunday morning, it will become 2AM GMT. It will then be GMT through to the last Sunday in March.
This is even more annoying than usual, because we are using Windoze laptops on a ghost hunt overnight Saturday night / Sunday morning. We are expecting very annoying data logging problems at 2AM BST/3AM GMT as Windoze automatically switches timezone. Which is w
Re:Time Zone (Score:3, Interesting)
The "G" in GMT stands for Greenwich, a town in England that houses the royal observatory. The French disputed the position of the GMT line for a couple of hundred years. They said it was ~1km to the left, they even went to the trouble of marking it on the countryside with a line of poles. Given the history of the two countries it's remarkable they settled the matter without going to war.
Re:Time Zone (Score:5, Funny)
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!
Parent
The Distance... (Score:3, Informative)
Re:The Distance... (Score:5, Funny)
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Getting closer! (Score:3, Insightful)
Re:Getting closer! (Score:5, Informative)
Planetary orbits are pretty stable (especially considering the short time frame), so it is fairly simple to calculate where Earth and Mars have been during the last 60,000 years.
Parent
From article (Score:5, Informative)
once per 60'000? (Score:3, Interesting)
So the event that happens once per 60,000 years - happens now a SECOND time, just after two years?
No (the summary is of course poorly written), in 2003 it was 35 million miles (56 000 000 km), and then it was an event once per 60,000 years. Now it is 43.1 million miles (69 000 000 km) and it is an event once per
Re:once per 60'000? (Score:4, Informative)
Parent
For those who aren't in the 19th century anymore (Score:5, Informative)
> 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.
Re:For those who aren't in the 19th century anymor (Score:3, Interesting)
I.e., a good thing for some chill-out at our party tomorrow. :-)
Hunker Down (Score:4, Funny)
The early Catholic church rang... (Score:5, Insightful)
...and they want their geocentric theory back...
From TFA: The two planets -- normally separated by about 140 million miles -- will not be this close again until 2018.
Normally separated by 140 million miles? On average, Earth orbits at 93m miles, Mars at 140m miles, both roughly on the same plane. That means the distance will vary periodically from around 230m miles to 47m miles. This current phenomenon is a "minimum minimum" which is why it is notable.
It sounds like CNN looked up the orbital distance from Mars and assumed that it orbits the Earth...
Re:The early Catholic church rang... (Score:3, Insightful)
people please (Score:5, Informative)
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
Doom (Score:5, Funny)
Re:Doom (Score:3, Funny)
But what about the Leather Goddesses?
junk science (Score:4, Funny)
Think about this: all of these people are voters. Now extrapolate to environemental policies, energy issues, stem cell research
Freedom is on the march!
Re:again? (Score:5, Insightful)
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.
Parent
Re:Wow. (Score:4, Funny)
How long will we have to wait intil we're advanced enough to put women there as well?
Parent
Re:Wow. (Score:4, Funny)
We can't very well send both men and women since they wouldn't be able to control themselves [slashdot.org]. :)
Parent
Re:Wow. (Score:3, Insightful)
This makes virtually no difference to the effort required to transfer an object to Mars from Earth. The orbit would be an elliptical transfer orbit (the most efficient), and is far more dependent on the position of Mars relative to Earth (hence "launch windows" for probes).
The 7ish million miles will make naff all difference - the point is actually when someone will stump up the cash, and when we figure out how
Re:Wow. (Score:5, Informative)
Peppe
Parent
Re:But what about getting them back? (Score:4, Insightful)
Who says it has to be a return mission? Come on, don't you think there would be plenty of qualified volunteers for a one way mission? This is why I think China will be space pioneers (well, 2nd generation pioneers) - because they will be able to launch one way missions without too many naysayers complaining about it.
Parent
doesn't work that way (Score:3, Insightful)
In any case, what would the motivation be? The only reason for manned travel to Mars in the near future is as a publicity stunt and to make people believe that the universe works like it does in Star Trek. That illusion is going to be destroyed if you
Re:Next swing-by (Score:3, Informative)
I don't know what speeds exactly rockets travel at, but at Mach 2 (earth relativistic since there's not air in space, but about 1200-1400MPH give or take depending on altitude)
Even a relative slow moving spacecraft travels far, far faster than the speed of sound. The average interstellar spacecraft generally cruises at somewhere around the neighborhood of 50,000 mph - roughly Mach 66. Some have been known to hit much higher speeds, but usually that's a result of a nearby planet's gravitational pull.