There's a lot of information that we don't know about this, but I bet that there are a couple of pieces of information that you are overlooking here.

My guess is that someone who believes that another person is a trapped astronaut is probably not just "stupid," as in it's not just that they didn't go to enough schooling or they weren't paying attention to their surroundings, but they are more likely to be someone with an intellectual or cognitive impairment.

Cognitive decline and dementia are common parts of aging, and frequently affect people in their 80's, as this woman is reported to be.

Scams also frequently target people who are vulnerable, with one theory being that misspellings and grammar mistakes in written correspondence may be deliberate ways of screening out more savvy individuals.

Vulnerable people are often targeted, not just through romance scams which prey on our desires for connection and understanding, but also towards people with intellectual disabilities and impairments, or more pronounced mental health conditions.

Adding to this, many of these vulnerable people also have extremely limited financial resources; as individuals with cognitive decline, intellectual disabilities, and mental health conditions often live in poverty or are reliant on meager social service programs.

I can only imagine what portion of this woman's savings $6700 was, and what she may have been sacrificing to try to help someone who she believed was in danger.

As magnetosphere mentions above, it is possible to laugh at the absurdity of the situation, while still holding empathy and compassion for the real person who was hurt here.