Expert: Tom Whiting - 3/17/2009

Question
when can mars be viewed in our nighttime sky

Answer
Hi Dionte,
Anytime it's not within 30 degrees of the sun.  Right now Mars
rises in the east about 40 minutes ahead of the sun which makes
it very difficult to see in the brightening twilight.  (It's just
now re-emerging from behind the sun from our viewpoint).
Conjunction with the sun was on Christmas Day 2008 so it's just
now becoming visible in the eastern dawn morning sky.

By June 1st it will rise in the east right at the crack of dawn
at about 4 am local Daylight savings time, very close to Venus, and on the morning of June 21 will be only 2 degrees to the upper left
of Venus.  By October 1st Mars will rise at about midnight local
time gaining in brightness from 2nd magnitude to first magnitude.
And by the end of 2009 Mars will rise at 9 pm local standard time
at brighter than zero magnitude!

Every other year is good for Mars, and 2009 is not one of them,
having had an opposition on December 27, 2007, the next opposition
is not until January 29, 2010, so 2009 is not a good year.
From now on for the next 10 years or so, the even numbered years
will be good, and the odd numbered years will not be as good, because it takes the Earth nearly 2 years to lap the planet while
we both circle the sun. Oppositions are about every 26 months, (2.13 years) on average.  

All of the other much slower moving outer planets, we lap and pass by in 13 months or less, but Mars, being the closest outer planet, it takes a long time to catch up and pass the planet, thus the 26 elapsed months between oppositions.  Jupiter for instance, we lap every 13 months so each succeeding opposition is about 13 months.  Even less for the slower traveling outer planets of Saturn, Uranus, and Neptune. But Mars goes around the sun in only 687 days, just
barely slower than the Earth, so that's why the long "catch up"
lag time.  That's right, astronauts traveling to Mars are "stuck"
there for over 20 months waiting for the Earth to play 'catch-up'
on the next orbital overtake, before they can launch back to the
Earth!
Hope this helps,
Clear Skies,
Tom Whiting
Erie, PA