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

Mars, the fourth planet from the Sun, fascinates people in many ways. Mars is an interesting subject for atmospheric researchers because it is the most Earth-like planet in the solar system. Since 1976, rovers landed on Mars have collected information about dynamic weather phenomena.

in him Dissertation At Aalto University, Henrik Kahanpää studied the measurement of Martian atmospheric pressure, which is important not only for modeling the Martian atmosphere, but also for understanding conditions on other planets.

” climate change There is an increasing need to model the Earth’s atmosphere.The Ultimate Test To Validate Earth’s Effectiveness climate model We are comparing them to models of different planets. Models of planetary atmospheres are also valuable in assessing the state of exoplanets outside our solar system,” Kahanpää says, acknowledging that sheer curiosity inspired him to study Mars. .

“It is no coincidence that the rover sent to Mars by NASA in 2011 and still making measurements is called Curiosity.”

Finnish Know-How for Mars Measurements

Kahanpää’s doctoral research began while working at the Finnish Meteorological Institute. There, he worked on the development of Curiosity He Rover’s manometer.

The Meteorological Institute of Finland also supplied pressure gauges to NASA’s Phoenix spacecraft, which landed on Mars in 2008. These instruments are based on the Barocap sensor head developed by the Finnish company Vaisala Oyj. These are the most accurate weather instruments ever sent outside Earth, but all measurements are subject to uncertainty, especially under harsh and unpredictable conditions such as Mars.

Kahanpää has investigated the sources of uncertainty that affect these pressure measurements and developed correction algorithms to compensate for them. This work has been used in the development of pressure gauges for his NASA Perseverance rover, which is currently operating on Mars. The paper showed that these instruments could measure the surface atmospheric pressure of another celestial body with an accuracy of about 0.5%.

“Comparing the corrected pressure measurements from the Phoenix spacecraft with those from NASA’s Viking lander reveals no measurable change in Martian climate between the 1970s and 2008. rice field.”

dust devil

lifting dust in the air, dust devil It is important for the study of Martian climate. They can be over a kilometer in diameter and over ten kilometers in height, but are usually much smaller.

“On Earth, weak dust devils spin autumn leaves. Parking Lot, a strong dust devil resembles a tornado. Dust devils are a more important phenomenon, because in the thin atmosphere of Mars, dust lifted from the planet’s surface has a great influence on the flow of the Martian atmosphere. ”

Dust storms lift dust into the Martian atmosphere when the planet is closest to the Sun. However, even when Mars is furthest from the Sun, its atmosphere is dusty. A dust devil is suspected to be the culprit. Kahanpää’s research challenges this common perception.

“When we looked for signs of eddies in Curiosity’s meteorological measurements, we found that very few eddies were strong enough to stir up dust. Other smaller phenomena also appear to be occurring, which can lift large amounts of dust into the Martian atmosphere.”

Information about dust devils is important for planning future Mars landing sites. Because dust devils have a huge impact on Martian surface instruments. Dust devils are also beneficial for Mars landers, as they may clean the rover’s solar panels. Because of this, NASA’s Spirit rover survived on the surface much longer than planned.