Science & Tech · Space · 12 hrs ago
A 1,000-mile cloud on Mars may form through unusual ice-making physics
A cloud stretching more than 1,000 miles appears near Mars’s Arsia Mons volcano during spring and summer, then fades each day.
First recorded in 2018, it forms in the morning and repeats this cycle for several months.
Researchers have now modeled how it might form, suggesting water vapor turns directly into ice without particles such as dust.
Their model says winds hitting the 65,000-foot volcano can drive moist air high into the atmosphere, where a sharp temperature drop and very high humidity could trigger the process.
This kind of ice formation has never been directly observed in any planet’s atmosphere, and the humidity needed is more than 100,000 times any level measured on Earth.
The model’s success offers a possible explanation for the cloud, though the proposed process has not been directly seen.
A new model suggests the Arsia Mons Elongated Cloud on Mars may form through a type of ice-making physics never directly observed in a planetary atmosphere.
The thin cloud appears near Arsia Mons during Martian spring and summer, grows to more than 1,000 miles long and then dissipates.
Researchers propose that water vapor forms ice crystals directly, without dust or other particles, through a process called homogeneous nucleation.
The process would require high humidity and a sharp temperature drop, while winds interacting with Arsia Mons lift moist air high into the atmosphere.
The cloud was first recorded in 2018, but its formation had not previously been explained.
- Who
- Researchers modeled the Arsia Mons Elongated Cloud. The study’s lead author is planetary scientist Jorge Hernández-Bernal of Sorbonne Université.
- What
- A new model suggests the cloud may form through homogeneous nucleation, in which vapor turns directly into ice crystals without particles.
- When
- It appears each morning during Martian spring and summer and repeats for several months. The cloud was first recorded in 2018.
- Where
- Near the Martian volcano Arsia Mons.
- Why
- The model suggests a sharp temperature drop and high humidity enable ice formation, while winds interacting with the volcano lift moist air.
This story does not have two clearly opposing sides.
A probe first recorded the Arsia Mons Elongated Cloud.
Researchers modeled the cloud’s formation for the first time.
- Cloud length
- More than 1,000 miles
- Location
- Near Arsia Mons, Mars
- First recorded
- 2018
- Temperature drop
- 30 degrees Celsius within 10 minutes
- Humidity
- More than 100,000 times greater than any value measured on Earth
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What people are saying
We found that we needed to include some exotic physics … physics that, while included in textbooks, is treated as theoretical and usually thought not to happen in nature. It certainly hasn’t been seen in action before
Once we included this physics in our simulations, the AMEC emerged just as we hoped.
It’s wholly unexpected.