Could a fixed wing entomopter with a wingspan of 2 meters actually fly in the Martian atmosphere?
If so, could it reach a flight speed of over 250 mph in the thin atmosphere of Mars?
From that linked Wikipedia page:
Several NASA Research Centers have noted its unique ability to fly on the planet Mars. Fixed wing aerial Mars rovers would have to fly at over 250 mph just to stay aloft in the rarefied Mars atmosphere.
This is for an entomopter with a 15 to 18cm wingspan.
Anthony Colozza's paper at the Ohio Aerospace Institute, has this:
A Mars aircraft with a 1 meter wingspan, would operate at a similar Reynolds number as terrestrial insects. Using the enormous lift producing mechanism of the entomopter may be an effective way to design vehicles capable of flying in the Martian atmosphere. Another advantage is that the reduced Mars gravitational force enables substantially lighter structures.
Georgia Tech Research Institute has confirmed that this concept, on a preliminary level, appears feasible for a Mars application and may, in fact, be easier to accomplish due to vehicle scaling. It would greatly enhance mission capability allowing the vehicle to take off, fly slowly or hover, and land.
So to answer your question, yes, it should be able to fly, but no, it will not fly at 250mph, but considerably slower, which will be a benefit as it can spend more time over target, observing.