Fresh analysis of craters on Mars suggests that asteroids have been smashing into the surface at a consistent rate for at least 600 million years.

In new research, a team of scientists used a new crater detection algorithm to look at 521 impact craters on Mars that are more than 12 miles (20 kilometers) in diameter.

Of that collection, only 49 craters formed in the last 600 million years and these were generated at a consistent rate, according to the new research.

The new work contradicts past research suggesting "spikes" in the number of craters during brief periods in the last 600 million years, study lead author Anthony Lagain, a research fellow and planetary scientist at Australia's Curtin University, said in a statement.

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A particular era on Mars that might require a second look is the so-called "Ordovician spike," which occurred about 470 million years ago.

The new research shows the spike on Mars may instead be "[crater] preservation bias rather than a real increase in the asteroid impact flux," the authors wrote.