A little over a week ago (February 18th, 2021), NASA’s Perseverance rover landed in the Jezero crater on the surface of Mars. In what was truly a media circus, people from all over the world tuned to watch the live coverage of the rover landing. When Perseverance touched down, it wasn’t just the mission controllers at NASA who triumphantly jumped to their feet to cheer and applaud.
In the days that followed, the world was treated to all kinds of media that showed the surface of Mars and the descent. The most recent comes from the Trace Gas Orbiter (TGO), which is part of the ESA-Roscosmos ExoMars program. From its vantage point, high above the Martian skies, the TGO caught sight of Perseverance in the Jezero crater and acquired images that show the rover and other elements of its landing vehicle.
Remote sensing is only useful if scientists have an idea of what they are looking at. That knowledge is especially important for remote sensing applications on other planets, such as Mars, where it is extraordinarily difficult to collect information about an observed object in any other way. To make up for the lack of ability to perform other tests in situ, scientists set up laboratory experiments with different environments and materials and compare the remote sensing data with the observed remote objects.
That is exactly what Jiacheng Liu, a doctoral student at the University of Hong Kong, did with remote sensing data from the surface of Mars. What he found gave new weight to a novel theory – that Mars didn’t used to have a significant amount of oxygen in its atmosphere. The fact that it does now prompts the question of where all the oxygen that exists in the atmosphere today came from. One possible answer is the same place it came from on Earth – photosynthetic life.
Even though Earthling scientists are studying Mars intently, it’s still a mysterious place.
One of the striking things about Mars is all of the evidence, clearly visible on its surface, that it harbored liquid water. Now, all that water is gone, and in fact, liquid water couldn’t survive on the surface of the Red Planet. Not as the planet is now, anyway.
But it could harbour water in the past. What happened?
The InSight lander has been on the surface of Mars for about a year, and a half dozen papers were just published outlining some results from the mission. Though InSight’s primary mission is to gather evidence on the interior of Mars—InSight stands for Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport—the lander also keeps track of Martian Meteorology. A new paper reports that InSight has found gravity waves, swirling dust devils, and a steady background rumble of infrasound.
An atmospheric drama has been playing out on Mars lately. Up until now, the main actor has been methane, and its unusual, spiking behaviour. But now Oxygen is taking the stage, and performing some theatrics of its own.
Springtime on Earth can be a riotous affair, as plants come back to life and creatures large and small get ready to mate. Nothing like that happens on Mars, of course. But even on a cold world like Mars, springtime brings changes, though you have to look a little more closely to see them.
Lucky for us, there are spacecraft orbiting Mars with high-resolution cameras, and we can track the onset of Martian springtime through images.
It’s easy to take for granted the detailed, almost real-time knowledge of Mars that we have at our fingertips. After all, in the not-too-distant past, Mars was largely mysterious. All we had were ground-based images of the planet. Now? Now we have daily weather reports and images of dust storms.
For centuries, scientists have speculated about the existence of life on Mars. But it was only within the past 15 years that the search for life (past and present) really began to heat up. It was at this time that methane, an organic molecule that is associated with many forms of life here on Earth (i.e. a “biosignature”) was detected in Mars’ atmosphere.
Since that time, attempts to study Mars’ atmospheric methane have produced varying results. In some cases, methane has been found that was several times its normal concentrations; in others, it was absent. Seeking to answer this mystery, an interdisciplinary team from Aarhus Universityrecently conducted a study where they investigated a possible mechanism for the removal of methane from Mars’ atmosphere.
On Earth, clouds form when enough droplets of water condense out of the air. And those droplets require a tiny speck of dust or sea salt, called a condensation nuclei, to form. In Earth’s atmosphere, those tiny specks of dust are lofted high into the atmosphere where they trigger cloud formation. But on Mars?
To say there are some myths circulating about Martian dust storms would be an understatement. Mars is known for its globe-encircling dust storms, the likes of which are seen nowhere else. Science fiction writers and Hollywood movies often make the dust storms out to be more dangerous than they really are. In “The Martian,” a powerful dust storm destroys equipment, strands Matt Damon on Mars, and forces him into a brutal struggle for survival.