How do they predict when Mars will go retrograde and in which constellation will it this autumn?

and how many times will it move back and forth?



also, if anyone can explain . i dont understand if the planet is "seeming to move backwards" due to our planet passing it in the sky, how does it then seem to move forward again?





i dont understand the second part.



please explain.



Thanks for your answers!How do they predict when Mars will go retrograde and in which constellation will it this autumn?It's not that difficult when you think about it.... a mixture of a couple hundred years of research learning about each planet's orbit in relation to each other, coupled with some maths to work it all out....... but these days it's LOADS easier with Astronomy software such as:

STARRY NIGHT

http://www.starrynight.com/

http://astore.amazon.co.uk/jdcouk-astro-鈥?/a>



DISTANT SUNS

http://www.distantsuns.com/



STELLARIUM

http://www.stellarium.org/



DeepSky

http://www.deepsky2000.com/



SkyMap

http://www.skymap.com/



The observing tools on the SKY %26amp; TELESCOPE website

http://www.skyandtelescope.com/observing鈥?/a>



Playing around with one of these softwares may give you a better idea, but basically an Earth year lasts (as you should know) 365days... while a Mars year (1 orbit round the sun) takes 687 Earth days......... and just like 2 race cars going round a track, the faster one round the track (Earth) will eventually come round to put a lap on the slower moving one (Mars). As Earth catches it up to overtake, Mars appears to be going in one direction (made more confusing while stood watching on earth 'cos it's spinning round at several thousand MPH)...... then Earth overtakes, and Mars gets left behind (and appears elsewhere in the sky).



Not familiar with which constellation it's going to be in, as I mainly just rely on the Astronomy software I use (Starry Night Backyard SE) to show me which direction (North, East, South or West) to look for stuff at any given time / date.How do they predict when Mars will go retrograde and in which constellation will it this autumn?they know because they know when mars will fall behind the earth when it is going around the sun.



not sure about the rest.



Leo maybe?