Phoenix Lander Sees, Feels Martian Whirlwinds in Action

Sep 12, 2008
The Surface Stereo Imager on NASA's Phoenix Mars Lander caught this dust devil in action west of the lander in four frames shot about 50 seconds apart from each other. Image Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University

(PhysOrg.com) -- NASA's Phoenix Mars Lander has photographed several dust devils dancing across the arctic plain this week and sensed a dip in air pressure as one passed near the lander.

These dust-lofting whirlwinds had been expected in the area, but none had been detected in earlier Phoenix images.

The Surface Stereo Imager camera on Phoenix took 29 images of the western and southwestern horizon on Sept. 8, during mid-day hours of the lander's 104th Martian day. The next day, after the images had been transmitted to Earth, the Phoenix science team noticed a dust devil right away.

"It was a surprise to have a dust devil so visible that it stood with just the normal processing we do," said Mark Lemmon of Texas A&M University, College Station, lead scientist for the stereo camera. "Once we saw a couple that way, we did some additional processing and found there are dust devils in 12 of the images."

At least six different dust devils appear in the images, some of them in more than one image. They range in diameter from about 2 meters (7 feet) to about 5 meters (16 feet).

"It will be very interesting to watch over the next days and weeks to see if there are lots of dust devils or if this was an isolated event," Lemmon said.

The Phoenix team is not worried about any damage to the spacecraft from these swirling winds. "With the thin atmosphere on Mars, the wind loads we might experience from dust devil winds are well within the design of the vehicle," said Ed Sedivy, Phoenix program manager at Lockheed Martin Space Systems Company, Denver, which made the spacecraft. "The lander is very rigid with the exception of the solar arrays, which once deployed, latched into position and became a tension structure."

Phoenix monitors air pressure every day, and on the same day the camera saw dust devils, the pressure meter recorded a sharper dip than ever before. The change was still less than the daily change in air pressure from daytime to nighttime, but over a much shorter time.

"Throughout the mission, we have been detecting vortex structures that lower the pressure for 20 to 30 seconds during the middle part of the day," said Peter Taylor of York University, Toronto, Canada, a member of the Phoenix science team. "In the last few weeks, we've seen the intensity increasing, and now these vortices appear to have become strong enough to pick up dust."

A key factor in the whirlwinds getting stronger is an increase in the difference between daytime and nighttime temperatures. Daytime highs at the Phoenix site are still about minus 30 Celsius (minus 22 Fahrenheit), but nighttime lows have been dropping a few degrees, getting close to minus 90 Celsius (minus 130 Fahrenheit).

The same day as the dust devils were seen, the photographed swinging of Phoenix's telltale wind gauge indicated wind speeds exceeding 5 meters per second (11 miles per hour).

Images from spacecraft orbiting Mars had previously indicated that dust devils exist in the region where Phoenix landed.

"We expected dust devils, but we are not sure how frequently," said Phoenix Project Scientist Leslie Tamppari of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It could be they are rare and Phoenix got lucky. We'll keep looking for dust devils at the Phoenix site to see if they are common or not."

The dust devils that Phoenix has observed so far are much smaller than dust devils that NASA's Mars Exploration Rover Spirit has photographed much closer to the equator.

Provided by NASA

Explore further: Student to live in simulated space habitat

add to favorites email to friend print save as pdf

Related Stories

Telltale tells story of winds at Phoenix landing site

Sep 16, 2009

Wind speeds and directions were measured for the first time in the Mars polar region using the Phoenix lander’s Telltale instrument. Astronomers recorded Easterly winds of approximately 15-20 kilometres ...

Electric sand findings could lead to better climate models

Jan 07, 2008

Wind isn't acting alone in the geological process behind erosion, sand dunes and airborne dust particles called aerosols. The other culprit is electricity. By taking both factors into account, researchers at the University ...

Recommended for you

Student to live in simulated space habitat

2 hours ago

A Purdue University industrial engineering doctoral student is among six "crew members" spending the next eight months in a domed habitat on a volcanic landscape mimicking life on a Martian outpost.

The wake-up call that sent hearts racing

5 hours ago

"But as the minutes ticked by, the relaxed attitude of many of us began to dissolve into apprehension. Our levels of adrenaline and worry began to rise."

US-India to collaborate on Mars exploration

15 hours ago

The United States and India, fresh from sending their own respective spacecraft into Mars' orbit earlier this month, on Tuesday agreed to cooperate on future exploration of the Red Planet.

Swift mission observes mega flares from a mini star

15 hours ago

On April 23, NASA's Swift satellite detected the strongest, hottest, and longest-lasting sequence of stellar flares ever seen from a nearby red dwarf star. The initial blast from this record-setting series ...

Sandblasting winds shift Mars' landscape

20 hours ago

High winds are a near-daily force on the surface of Mars, carving out a landscape of shifting dunes and posing a challenge to exploration, scientists said Tuesday.

PanSTARRS K1, the comet that keeps going

22 hours ago

Thank you K1 PanSTARRS for hanging in there! Some comets crumble and fade away. Others linger a few months and move on. But after looping across the night sky for more than a year, this one is nowhere near ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

Modernmystic
1 / 5 (2) Sep 12, 2008
DUST DEVILS YAY!!! Oh wait wasn't this the probe that was supposed to tell us wether or not there was LIFE on the planet....
Sirussinder
1 / 5 (1) Sep 12, 2008
Well when they make an oven as tiny as a few millimeters big and a screen size opening a little bigger than a human hair what else would you expect from this hunk of junk.
warmer
5 / 5 (1) Sep 13, 2008
There is no pleasing some people...

The openings are considerably larger than a human hair. Check out Nasa's page on The lander if you'd like some good info

here is a couple good link

http://www.nasa.g...dex.html
deatopmg
1 / 5 (1) Sep 13, 2008
Anyone know where we can find pictures from NASA/ESA orbiters w/ resolutions of less than 1 meter, as claimed before launch, or have these been "airbrushed" too?