8. Given that the line $x+3 y=m$ intersects the ellipse $\frac{x^{2}}{9}+y^{2}=1$ at two points $A$ and $B$, and makes $\angle A O B \leqslant 90^{\circ}$, then the range of values for $m$ is $\qquad$ _.
8. $(-3 \sqrt{2},-3] \cup[3,3 \sqrt{2})$

It is easy to observe (by drawing a graph) that when $m= \pm 3$, 
$\angle A O B=90^{\circ}\left(A, B\right.$ are exactly the vertices of the major axis of the ellipse), and the line $l$ intersects the ellipse at two points. Substituting $x=m-3 y$ into $\frac{x^{2}}{9}+y^{2}=1$, we get $18 y^{2}-6 m y+\left(m^{2}-9\right)=0$.
$$
\begin{aligned}
0<\Delta & =36 m^{2}-4 \cdot 18 \cdot\left(m^{2}-9\right) \\
& =648-36 m^{2} \\
& \Rightarrow|m|<3 \sqrt{2}
\end{aligned}
$$

Combining with the graph, the range of $2 m$ is $(-3 \sqrt{2},-3] \cup[3,3 \sqrt{2})$.