Should scientific writing all be in the passive voice?
Your English department will most likely tell you that third person and passive voice is the way to go. It's a popular misconception that *all* scientific literature must be like that. But that kind of writing tends to be boring. You can be formal and not boring.
Different fields may have different conventions, but for all fields, refereed journal articles are the final product, as formal as it gets. The four refereed education journal articles I have written are all mostly passive voice. But out of the 147 (and counting) refereed astronomy journal articles I have authored or co-authored, all include the use of the first person singular or plural.
Let's approach this scientifically. All the abstracts for everything (including journal articles) are public, so you don't need any special access to get the abstracts. Sit with an AJ, ApJ, A&A, or any other astronomy journal table of contents and count how many use the first person in their abstract. I did about 2/3rds of http://iopscience.iop.org/issue/1538-3881/154/3 -- I quit at 24 first person (where "we" is often the first word of the abstract) to 6 passive voice/3rd person; admittedly many were mixtures. Another important variable may be the country from which it originates. In the 30 I looked at, there seemed like there might be a correlation between the country of origin of the author list and the voice the article is written in; one that had all Chinese authors was entirely, strictly passive voice/3rd person.
You could also sit with the most recent astro-ph mailing - since all the abstracts are included in a mailing, there's less clicking required; the diversity of articles is greater here, because the articles need not be refereed to appear here: https://arxiv.org/archive/astro-ph