I like the rocket idea.
However, if it's Venus, why has it been on the exact same orbit and the same place in the sky for at least 6 weeks? Hmmmm?
(PS Jem is bent)xx
Well, if you look carefully, it hasn't: it has been moving relative to the background stars fairly quickly. It's just that at this particular point in its orbit around the Sun, as viewed from the Earth (it's a slightly complicated perspective problem, because the Earth and Venus are both orbiting the Sun with different orbital periods, with Venus catching the Earth up and passing us as it whizzes around closer to the Sun), it's not moving very quickly with respect to the Sun.
What you're saying then is right in a sense: relative to the Sun or relative to the time of evening as judged by time after sunset, Venus has been more or less stationary. That is, if you have been looking just after the Sun had set each evening, Venus would have appeared to be pretty much at the same place in the sky or relative to your greenhouse (or Tardis if you're Jem) for the last few weeks: in this guise, Venus is known as the Evening Star (or Hesperus). However, if you'd looked at the stars closely, Venus and the Sun have been moving along together relative to them.
Indeed, this will continue to be roughly true until the end of February or so, at which point the interplay of the orbits of Venus and the Earth will result in Venus apparently moving back towards the Sun, i.e. visible lower in the sky and closer to the Sun at sunset until, around mid-March or so, when they'll be so close that Venus won't be visible.
By the beginning of May, Venus will be at at roughly the same large distance on the side of the Sun. It should be easy to figure out, after a little head-scratching, that Venus will then adopt its other guise, the Morning Star (Eosphorus, or Phosphorus, or Lucifer), which fewer people see, particularly astronomers like me, 'cos we're night-owls
A particularly nice tool for visualising all this is Google Earth, which can be turned inside out to look at the sky. It allows you to run the clock backwards and forwards on a slider, and thus see how the planets are moving relative to the Sun and each other.
I used it quite a lot a few weeks ago when we had several clear nights in a row. I took my binoculars out each night and spotted Jupiter, Venus, Uranus, and Neptune: the latter two are quite faint and very hard to distinguish from stars, but by watching how they moved against nearby fixed stars each night, I could confirm that it was definitely them I was seeing.
Lecture mode off
(p.s. How do you know Jem is bent? Pictures please ... or then again ...)
