NASA plans to send humans on a scientific round trip to Mars potentially as early as 2035. The trip will take about six to seven months each way and will cover up to 250 million miles (402 million kilometers) each way. The astronauts may spend as many as 500 days on the planet’s surface before returning to Earth.
NASA’s Artemis program plans to return humans to the Moon this decade to practice and prepare for a Mars mission as early as the 2030s. While NASA has several reasons for pursuing such an ambitious mission, the biggest is scientific exploration and discovery.
I’m an atmospheric scientist and former NASA researcher involved in establishing the scientific questions a Mars mission would investigate. There are lots of mysteries to investigate on the red planet, including why Mars looks the way it does today, and whether it has ever hosted life, past or present.
Studying Mars can tell researchers more about the formation of the solar system.
J. Bell/NASA via AP
Mars geology
Mars is an intriguing planet from a geological and atmospheric perspective. It formed with the rest of the solar system about 4.6 billion years ago. Around 3.8 billion years ago, the same time that life formed on Earth, early Mars was very Earth-like. It had abundant liquid water on its surface in the form of oceans, lakes and rivers and possessed a denser atmosphere.
While Mars’ surface is totally devoid of liquid water today, scientists have spotted evidence of those past lakes, rivers and even an ocean coastline on its surface. Its north and south poles are covered in frozen water, with a thin veneer of frozen carbon dioxide. At the south pole during the summer, the carbon dioxide veneer disappears, leaving the frozen water exposed.
Today, Mars’ atmosphere is very thin and about 95% carbon dioxide. It’s filled with atmospheric dust from the surface, which gives the atmosphere of Mars its characteristic reddish color.
Scientists know quite a bit about the planet’s surface from sending robotic missions, but there are still many interesting geologic features to investigate more closely. These features could tell researchers more about the solar system’s formation.
The northern and southern hemispheres of Mars look very different. About one-third of the surface of Mars – mostly in its northern hemisphere – is 2 to 4 miles (3.2-6.4 kilometers) lower in elevation, called the northern lowlands. The northern lowlands have a few large craters but are relatively smooth. The southern two-thirds of the planet, called the southern highlands, has lots of very old craters.
Mars also has the largest volcanoes that scientists have observed in the solar system. Its surface is peppered with deep craters from asteroid and meteor impacts that occurred during the early history of Mars. Sending astronauts to study these features can help researchers understand how and when major events happened during the early…
