Atheism is as scientific as it gets.
Actually, if we take atheism as the rejection of the belief in any deities, I'd say atheism is as unscientific as religion is.
There is a basic rule of science: "Absence of evidence is not evidence of absence".
At that, atheism is just the (wrong) belief that, because science has been unable to prove the existence of any such deities, they just don't exist.
I'm not inclined to believe that without religion, the world would be a hellish landscape with no true "moral philosophy."
Why, is it any better now, with religion?
That is to say, can objective morality ever be reached, and can it be reached without religion? I think so. And it can be reached through science because atheism is a science based approach to reality, not one of hearsay books or writing, outlandish stories, many of which are physically improbable (or downright impossible). It sounds like you're describing agnosticism, that we cannot prove or disprove God.
Well, it could be argued that objective morality can
ONLY be reached without religion, since a religious person will only be moral for fear of being punished, or because they're expecting to be rewarded.
In any case, the fact that a claim may be "outlandish" doesn't necessarily disprove it.
"If God wanted men to fly, he would've given him wings", was the belief in the early 1900s, against the Wright brothers' "outlandish" claims. Mel Brooks said "He would've given him tickets".
But really, the burden of proof lies on the religion fanatics. Considering they impose their religion on so much of their life, you think they'd have some reasoning to believe what they believe. Not just a belief because someone told them so, but actual evidence. Most just use religion as a moral guide or to have a sense of belonging. Not that it would effect anyone, but religion has led to the most pain and suffering in human history. It's possible that all this pain and suffering would have happened anyway, even if it wasn't in the name of god, because let's face it, humans were pretty animalistic before modern moral philosophy.
The burden of proof lies on everybody making a claim. Not being able to prove the existence of something doesn't necessarily disprove it.
Personally, I don't know if deities (or any specific deity) exist, so I believe (without any proof whatsoever) they don't. So I act as if they don't, and follow my own moral compass, without fear of retaliation or expectation of reward.