Mars is one of the most-visited yet mysterious planets in the solar system.Samantha Lee/Business Insider
- NASA’s InSight Mars lander will try to land around 3 p.m. ET on Monday, November 26.
The robotic probe could be the first Mars mission to measure the “vital signs” of the world and decode its internal structure.
- From skyscrape-size tsunamis to eerie blue sunsets, here are some surprising facts you may not know about the red planet.
NASA is about to land InSight: a new $830-million Mars lander that will probe the red planet’s secrets like never before.
InSight lifted off in May and is expected to land on Monday, but it’s just one of dozens of robotic and satellite missions that humanity has rocketed to Mars over the decades.
Read more: Watch live video coverage of NASA’s InSight probe landing on Mars
These spacecraft have beamed back dazzling photos, inspired sci-fi movies like “The Martian“, and even helped give Elon Musk, the founder of SpaceX, the idea to colonize the red planet with the Big Falcon Rocket.
While scientists readily admit they have much to learn about Mars, including the planet’s internal structure (a mystery InSight will try to solve), what we have found out so far is incredible.
Here are 13 fascinating facts about Mars and our robotic exploration of the red planet.
Volcanoes on Mars dwarf those on Earth.Samantha Lee/Business Insider
Olympus Mons is more than twice as high as Hawaii’s Mauna Loa, the tallest mountain on Earth from top to bottom.
The Grand Canyon has nothing on Valles Marineris.Samantha Lee/Business Insider
Compared to the Grand Canyon on Earth, Valles Marineris on Mars is nearly five times deeper, about four times longer, and 20 times wider.
There are a few ways to rumble the red planet.Samantha Lee/Business Insider
The red planet doesn’t have plate tectonics, which is what causes most quakes on Earth. But rising plumes of magma could trigger Mars quakes, as could meteorite impacts and the contraction of the world due to cooling. InSight will listen for them with its seismometer.
Pools of water could be where life on Mars got its start.Samantha Lee/Business Insider
If aliens existed on Mars, they might have lived in oasis-like pools. These pools would have been habitable for life, just as they are on Earth.
You wouldn’t want to get hit with an ancient Martian tsunami.Samantha Lee/Business Insider
Martian oceans also had tsunamis like those on Earth. The tallest may have reached as high as 400 feet, just slightly shorter than the London Eye.
Melting Mars’ ice caps would help terraform the planet into a cozy world.Samantha Lee/Business Insider
Like Earth, Mars has ice caps at its poles. The northern cap is up to 2 miles deep, is a mix of water and carbon dioxide, and covers an area slightly larger than Texas.
On average, Mars is a frigid planet because it has almost no atmosphere. Samantha Lee/Business Insider
The average surface temperature on Mars is -81˚F, 138 degrees chillier than on Earth. But on a mid-summer day at the red planet’s equator, temperatures can peak at a balmy 95˚F.
Mars is a small planet compared to Earth.Samantha Lee/Business Insider
Mars has almost as much surface as Earth has land — but that doesn’t account for the 71% of Earth that’s covered in water.
Mars’ thin atmosphere is mostly carbon dioxide (CO2), nitrogen (N2), oxygen (O2), and argon (Ar).Samantha Lee/Business Insider
The Martian atmosphere is 61 times thinner than Earth’s, and it consists almost entirely of carbon dioxide, which makes up just 0.04% of Earth’s atmosphere.
Sunsets on Mars are blue.Samantha Lee/Business Insider
On Earth, sunsets are a brilliant mix of reds, pinks, oranges, yellows, and other colors. But on Mars they’re blue. Because air is dozens of times less dense on the surface of Mars than it is on our planet, white sunlight refracts less — leading to fewer colors (primarily blues).
Missions to Mars have waxed and waned over the decades.Samantha Lee/Business Insider
Missions to Mars have become much rarer — after 23 launches in the 1960s and 1970s, we’ve launched just 10 in the new millennium (so far). This count doesn’t include InSight.
This tally doesn’t include InSight, which is an ongoing mission.Samantha Lee/Business Insider
Getting to Mars is hard: About a third of the missions launched have failed.
NASA is hoping to add InSight to the “success” column on November 26.
This story has been updated. It was originally published on June 1, 2017.
Skye Gould and Diana Yukari contributed to this post, and Meghan Bartels wrote a previous version of it.