Terraformed Mars in the 19th Century

[Cray]

Given that the setting is steam punk and, more importantly, the evidence that Mars was earth like should be more apparent you could postulate that spectroscopy and telescope technology is more advanced in this timeline. Chalk it up to a series of sponsorships to the Astronomical and Spectrographic Societies from aristocrats with extemely ambitious expansion plans.

I could do that (or utilize many other advanced technologies), but my original question was "what would historical 19th Century astronomy spot?"

Handwaving can come later when I know what I need to handwave and alter.