NASA’s New Mars InSight Weather Station Detects Bizarre Infrasound


NASA’s first 24 hour Mars weather station has detected an unexplained, low-frequency infrasound. The infrasound was detected some 72 hours ago as it swept past a suite of detectors atop the InSight Mission lander, Cornell University planetary scientist Don Banfield told me.

Because infrasound waves have such low-frequency, they lie at least several octaves below the human range of hearing. But this particular infrasound’s amplitude was pretty big, Banfield, InSight’s science lead for its auxiliary payload sensor subsystem, says. And if equipped, one might have heard it as it rolled through at a period of one-hundredth of a hertz, over a period of 100 seconds, he says.

As for its source?

Banfield speculates that the infrasound could have been caused by a meteor crashing into Mars’ atmosphere; some sort of airflow over an underlying stable local atmosphere; or maybe even a landslide. He has no idea about how the distance to the source of this infrasound, but he says the insight team may be able to determine that once they have done further analysis.

Even so, the weather station’s real purpose is to measure wind speed, temperature changes and barometric pressure that could all interfere with the lander’s unique measurements of Mars’ deep interior.

Thus far, the InSight lander, which took up residence just north of the Martian equator on the plains of Elysium Planitia, has gone swimmingly. But InSight only arrived in late November and has a nominal two-year mission to probe Mars’ deep interior and measure the planet’s interior heat flow.

As for the station’s wind measurements?

The seismometer is tremendously sensitive, so we want to measure the wind to know when to take the best seismic data , says Banfield. That’s because when it’s really windy, the lander and rocks nearby are actually shaking.

“So there’s a lot of seismic noise,” said Banfield.

There are also effects from pressure changes when dust devils pass, says Banfield. Although Mars’ atmosphere is equal to only one percent that of earth, he says, you can still feel the wind on Mars; it definitely moves sand and dust.

Such low-pressure whirlwinds of Martian soil can spin at nearly 60 miles an hour and reach heights of 10 kilometers and span a hundred meters in diameter.

Because the lander’s air pressure sensor is ten times more sensitive than such sensors on previous Mars landers, the insight team can spot detect dust devils from hundreds of feet (dozens of meters) away.

There have already been other surprises.

Thus far, Cornell reports that the coldest temperatures the weather monitoring equipment on insight has thus far detected, ranging from minus 139 degrees Fahrenheit (F) which occur around 5 A.M. Martian time. The warmest temperature that insight has thus far recorded, has been 23 F.

NASA has set up a webpage for the public to check on Mars surface conditions here. The page updates twice a day in order to give Mars’ buffs a sense of being there in real time.

What spot on Earth is most Mars-like?

The barren Canadian Arctic which is dry, with no life except a few polar bears, says Banfield.

“Haughton Crater on Devon Island in the Canadian Far Arctic looks very Mars-like as it’s quite cold and dry,” said Banfield. “But Mars is more extreme than anything you could find on Earth.”


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