Doctoral dissertation questions a prevailing perception related to dust devils on Mars

Mars, the fourth planet from the sun, fascinates folks in some ways. For atmospheric researchers it’s an attention-grabbing topic as Mars is essentially the most Earth-like planet of our solar system. Since 1976, probes landed on Mars have collected info on its dynamic climate phenomena.

In his doctoral dissertation at Aalto College, Henrik Kahanpää studied measurements of the atmospheric strain on Mars, necessary not just for modeling the ambiance of Mars but in addition for understanding the circumstances of different planets.

“The climate change has elevated the necessity for modeling the ambiance of the Earth. The final word check for verifying the validity of Earth’s climate models is evaluating them to fashions of one other planet. Fashions of planetary atmospheres are additionally helpful in assessing the circumstances of exoplanets discovered outdoors our solar system,” says Kahanpää and admits that pure curiosity impressed him to review Mars.

“It’s no coincidence that the rover despatched to Mars by NASA in 2011 and nonetheless performing measurements there’s known as Curiosity.”

Finnish know-how for Mars measurements

Kahanpää’s doctoral research started whereas he was working on the Finnish Meteorological Institute. There he was concerned within the improvement of the strain instrument of the Curiosity rover.

The Finnish Meteorological Institute additionally supplied a strain instrument for NASA’s Phoenix probe which landed on Mars in 2008. These devices are primarily based on Barocap sensor heads developed by the Finnish firm Vaisala Oyj. Though these are essentially the most correct meteorological devices despatched outdoors the Earth, all measurements are affected by uncertainties, particularly below harsh and sudden circumstances akin to on Mars.

Kahanpää investigated uncertainty sources affecting these strain measurements and developed correction algorithms to compensate for them. The outcomes have been utilized within the improvement of the strain instrument of NASA’s Perseverance rover working at the moment on Mars. The dissertation confirmed that the floor atmospheric strain of one other celestial physique could be measured with an accuracy of roughly 0.5% by these devices.

“Comparability of the corrected strain measurements of the Phoenix probe to the measurements of NASA’s Viking landers revealed that no measureable adjustments have taken place within the Martian local weather between the Nineteen Seventies and 2008.”

Mud devils

Lifting dust into the ambiance, dust devils are necessary for the analysis of the Martian local weather. They’ll have diameters exceeding one kilometer and be over ten kilometers excessive, though normally they’re much smaller.

“On Earth, weak dust devils spin autumn leaves on parking lots, whereas sturdy dust devils resemble tornados. Within the skinny air of Mars, dust devils are a extra vital phenomenon as dust lifted from the planet’s floor has a big impact on the atmospheric flows of Mars.”

Mud storms elevate dust into the Martian ambiance when the planet is closest to the sun. Nonetheless, the ambiance is dusty additionally when Mars is farthest away from the sun. Mud devils have been suspected to be the reason. Kahanpää’s analysis questions this prevailing notion.

“I searched for indicators of vortices within the climate measurements of Curiosity and discovered that only some of the vortices had been sturdy sufficient to lift dust. Certainly, based on latest research evidently additionally different small-scale phenomena, akin to slope winds, are capable of elevate numerous dust into the Martian ambiance.”

Details about the dust devils is necessary for the planning of future Mars touchdown websites as they considerably influence tools on the planet’s floor. The dust devils can be useful for Mars landers as they could clear up solar panels of probes. Due to this, NASA’s rover Spirit survived on the floor for for much longer than deliberate.