mars spectacular

[boann]

> MARS SPECTACULAR!
>
> The Red Planet is about to be spectacular! This
> month and next, Earth is catching up with Mars in an
> encounter that will culminate in the closest
> approach between the two planets in recorded
> history. The next time Mars may come this close is
> in 2287. Due to the way Jupiter's gravity tugs on
> Mars and perturbs its orbit, astronomers can only be
> certain that Mars has not come this close to Earth
> in the Last 5,000 years, but it may be as long as
> 60,000 years before it happens again.
>
> The encounter will culminate on August 27th when
> Mars comes to within 34,649,589 miles of Earth and
> will be (next to the moon) the brightest object in
> the night sky. It will attain a magnitude of -2.9
> and will appear 25.11 arc seconds wide. At a modest
> 75-power magnification
>
> Mars will look as large as the full moon to the
> naked eye. Mars will be easy to spot. At the
> beginning of August it will rise in the east at
> 10p.m. and
> reach its azimuth at about 3 a.m.
>
> By the end of August when the two planets are
> closest, Mars will rise at nightfall and reach its
> highest point in the sky at 12:30a.m. That's pretty
> convenient to see something that no human being has
> seen in recorded history. So, mark your calendar at
> the beginning of August to see Mars grow
> progressively brighter and brighter throughout the
> month.

[Japher]

Mars will look as large as the full moon to the
> naked eye.

I don't believe it

[Kuciwalker]

That would play hell with tides.

[boann]

Originally posted by Japher


I don't believe it

really

[Kuciwalker]

Actually, maybe not. The acceleration due to Mars at that distance would be only about a tenth of that due to the moon...

[Ecthy]

Wait. In 2003, on exactly that day August 27, it was the closest that year. How can it be exactly the same date this year again? Coincidence? OR did boann dig out an old article?

[Jonny]

Originally posted by Ecthelion
Wait. In 2003, on exactly that day August 27, it was the closest that year. How can it be exactly the same date this year again? Coincidence? OR did boann dig out an old article?

Indeed. I believe this is old news.

[boann]

Originally posted by Ecthelion
Wait. In 2003, on exactly that day August 27, it was the closest that year. How can it be exactly the same date this year again? Coincidence? OR did boann dig out an old article?

you're right ecthelion...


Origins: The piece quoted above is another example of an item that was once true but is now being circulated again, long after the events it describes have come to pass. This article was relevant back in 2003, but it is not applicable now, two years later.

Mars did make an extraordinarily close approach to Earth which culminated on 27 August 2003, when the red planet came within 35 million miles (or 56 million kilometers) of Earth, its nearest approach to us in almost 60,000 years. At that time, Mars appeared approximately 6 times larger and 85 times brighter in the sky than it does ordinarily. (The message quoted above was often reproduced with an unfortunate line break in the middle of the second sentence of the second paragraph, leaving some readers with the mistaken impression that Mars would "look as large as the full moon to the naked eye" and not realizing that the statement only applied to those using viewing Mars through a scope with 75-power magnification.)

Although Mars' proximity to Earth in August 2003 (referred to as a perihelic opposition) was a rare occurrence, the red planet comes almost as near to us every 15 to 17 years. To the unaided observer, Mars' appearance in August 2003 wasn't significantly larger or brighter than it is during those much more common intervals of closeness.

Mars will have another close encounter with Earth in in 2005, but that occurrence will take place in October (not August), and the red planet will appear about 20% smaller than it did during similar circumstances in 2003.

[Ecthy]

It's not like I'm an expert on astronomy, but I should remember the day that I met my ex

[DRoseDARs]

Originally posted by Japher
I don't believe it

Boann really ought to have done a better job of posting the article...

How that sentence should have read:

At a modest 75-power magnification Mars will look as large as the full moon to the naked eye.

[boann]

Originally posted by DRoseDARs


Boann really ought to have done a better job of posting the article...

How that sentence should have read:

hehehe... well thats how it came to me in an email.

[KrazyHorse]

Originally posted by Kuciwalker
Actually, maybe not. The acceleration due to Mars at that distance would be only about a tenth of that due to the moon...

wrong.

[DRoseDARs]

Originally posted by boann
hehehe... well thats how it came to me in an email.

Not an acceptable excuse for negligence on your part...

[reds4ever]

It's called 'opposition' and it happens every two years, the actual distance makes a minimal difference to what you can observe through a telescope.

[Kuciwalker]

Originally posted by KrazyHorse
wrong.

You're right, I must've dropped a digit or something. The Moon has half the diameter of Mars, so Mars' gravity would be one-quarter that of the Moon. However, Mars has about 8 times the mass, so it would have twice the acceleration due to gravity all in all. So it would mess with the tides.