Expert: Tom Whiting - 7/31/2005

Question
What planet is suppose pass close to earth this month that will not pass by again for over 100 years? And when will be the best time to see it?

Answer
Hi Debra....
None.  You have been reading a circulating "hoax"  E-mail
announcement stating that Mars will be closest to the
Earth in August, not to happen again until 2287.
Only problem is, it's a hoax, because it's a playoff on the
August 27, 2003 opposition (closest approach) of Mars....
But they try to get you to believe that it is this year, not
2003.  So it's 2 years behind.

BTW, Mars does have another fine opposition this year
(they happen every 26 months as we overtake and pass
Mars up in our orbit.)  But this time the opposition date
occurs the first week in November 2005.  And actually
it's better for us in observational astronomy because Mars
is much higher in the sky in Aries, rather than down low
in Capricornus....although it's going to be slightly smaller
(20 arc-seconds as opposed to 25 arc-seconds)  and
thus a half a magnitude dimmer than the uniquely
"perfect"  August 27,  2003  Mars opposition.

And during the next opposition after that, in late December
2007, Mars will be nearly overhead in Gemini at that
opposition.  

BTW, opposition means....the planet's position in our sky is exactly opposite the position of the sun in our sky,
thus a planet at opposition is rising in the east as the
sun is setting in the west, and it is when we are at the
closest we can get to the planet, as we pass it up (racing
term- lap it) in our orbital race around the sun.   
Thus opposition date, and for a few weeks before and after,
is the very best time to view a planet in our night sky.

BTW, opposition only applies to planets beyond the
Earth...naturally Venus and Mercury can never go through
an "opposition"...that is, can never be opposite the sun
in our sky, because they are inside our orbit, so best times
to see those planets is at their maximum elongation from the
sun...Venus can get as far as 48 degrees from the sun
(Western sky after sunset on Nov. 3 this year) but Mercury
can never get farther than 28 degrees from the sun)....
early morning eastern sky on December 12th this year.

And if you want to see Mars right now, as it's getting quite
bright, it's that bright reddish object in the ESE sky rising
around 1 am local time, and well up in the SE by 2 am.
The moon was close to Mars on July 27 and 28, and will
pass it by again on August 24, so will be fairly close to
the red planet on nights of August 23 (slightly west of
Mars) and August 25 (slightly east of Mars)...just for
a reference for you.



Hope all this helps,
Clear Skies,
Tom Whiting
Erie, PA