まだ肉眼じゃ無理だよ。双眼鏡だと、ちょびっとだけ見えるかも・・・。

。、・・・。

It's still too small for the naked eye. With binoculars, you might be able to make out a tiny bit...

Literal

Still naked-eye [with-じゃ] impossible [emph-よ]. Binoculars [if-だと], a-tiny-bit [only-だけ] can-see [maybe-かも]...

じゃ is the casual contraction of では (here the contrastive/instrumental 'with / by means of'); 無理 used predicatively means 'impossible / no way.' The conditional だと (copula + と) frames a hypothetical: 'in the case of binoculars, then...'. ちょびっと is a casual diminutive of ちょっと, stacking with だけ 'only' to play up just how little. 見えるかも is clipped from 見えるかもしれない, an extremely common spoken truncation.