Question: Contour plot of potential

Hello everyone! I'm currently trying to plot the effective potential for Sun-Jupiter system, to show the lagrangian points in this system. I've converted to a system of units where G=1, m_sun+m_jupiter=1 and R=1, whereby I get the following equation describing the effective potential of a third mass m in the system:

U(x,y)=-1 * 0.999047/abs(sqrt((x-(-0.000953))^2 +y^2 ))-1 * 0.000953/abs(sqrt((x-0.999047)^2 +y^2 ))

However, when I plot this in Maple, I don't get a contour plot that matches up with what I would [expect](https://upload.wikimedia.org/wikipedia/commons/thumb/e/ee/Lagrange_points2.svg/2000px-Lagrange_points2.svg.png), but [this](http://imgur.com/oZLE3gV). Is there possibly anyone here who could point out a mistake I've done, or give me some advice? Thanks in advance!