He was the first to carry out astronomical observations from a stratospheric balloon, in particular to study Mars in a detailed way.

Mars 7 spacecraft carried an array of instruments to study Mars.

The Mars 4 spacecraft carried an array of instruments to study Mars.

They have a point; there's a lot to learn, a lot we can learn about Earth by studying Mars.

The findings were doubly reassuring to scientists studying Mars.

It was also to study Mars from orbit, including its atmosphere and dust storms, plasma and radiation.

When they begin to study Mars and the asteroids in earnest, I would like to go.

Scientists studying Mars hypothesize that if water moves about the planet, it does so as vapor.

I've studied Mars by telescope so often I know it by heart.

For the next fifteen years he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them.