Marching Sand Dunes Create Mars Mystery

[mickw]

Marching Sand Dunes Create Mars Mystery

Sand grains stirred up by the winds of Mars are tossed higher and farther than those kicked up by winds on Earth, a new study finds. The results could help explain how dunes migrate across the Martian surface as well as what whips up dust storms that blow across the red planet.
Scientists first noticed dunes on the Martian surface in pictures taken by NASA's Mariner missions in the 1970s and have seen dust storms of all sizes spread across the planet — one major storm in 2005 was even visible through a simple backyard telescope. But these features have puzzled astronomers because Mars has almost no atmosphere and very weak winds that seem unlikely to be able to sculpt dunes or whip up storms

More:  http://www.space.com/scienceastronomy/080429-st-mars-sands.html

[Rick]

one major storm in 2005 was even visible through a simple backyard telescope.

They make it sound as if amateur observations of Martian dust storms were rare... 

[mickw]

The Americans lead sheltered lives 

[Rick]

I'd have expected a Space.com journalist to know better, and do a little research, or at least spend a few minutes browsing other articles on Space.com...

One of the links in the story points to an article which says "Dust storms are fairly common on Mars", and that one links to yet another story about a dust storm on Mars.

There's also an article elsewhere on Space.com about observing Mars. It has a section which begins thus: "Yellow dust storms tend to begin every Martian year soon after the summer solstice...".

[Rick]

The puzzle of why the northern and southern hemispheres of Mars look so different may now have been solved.

Mars' crust is thicker in the southern hemisphere, and magnetic anomalies are found in the south but not the north.

New studies in Nature magazine suggest that a massive space rock smashing into the planet could have created an abrupt disparity between the two halves.

This asteroid would have been close to the size of Earth's moon and hit Mars' northern regions, scientists say.

More: http://news.bbc.co.uk/2/hi/science/nature/7473128.stm

...and also: http://news.bbc.co.uk/2/hi/science/nature/7408033.stm

[Rick]

New data from NASA's Mars Reconnaissance Orbiter and Mars Global Surveyor backs a theory that the Red Planet's huge northern hemisphere Borealis basin was created by an impact 3.9bn years ago by a body some 1,900km (1,200 miles) in diameter, or larger than Pluto.

More: http://www.theregister.co.uk/2008/06/26/mars_impact_crater/

[mickw]

Planetary scientists have discovered new details to explain a mysterious seasonal asymmetry of a Martian polar ice cap.

Like Earth, Mars has frozen polar caps, but unlike Earth, these caps are made of carbon dioxide ice as well as water ice. During the southern hemisphere's summer at Mars, much of the ice cap sublimates, a process in which the water ice turns straight back into gas, leaving behind what is known as the residual polar cap of mostly carbon dioxide ice

More:   http://www.space.com/scienceastronomy/080929-mm-mars-ice.html

[mickw]

A group of seventh-graders in California has discovered a mysterious cave on Mars as part of a research project to study images taken by a NASA spacecraft orbiting the red planet.

The 16 students from teacher Dennis Mitchell's 7th-grade science class at Evergreen Middle School in Cottonwood, Calif., found what looks to be a Martian skylight — a hole in the roof of a cave on Mars.

The intrepid students were participating in the Mars Student Imaging Program at the Mars Space Flight Facility at Arizona State University. The program allows students to frame a research question and then commission a Mars-orbiting camera to take an image to answer their question.

More:   Holes

[Mike]

Plumes seen reaching high above the surface of Mars are causing a stir among scientists studying the atmosphere on the Red Planet.

On two separate occasions in March and April 2012, amateur astronomers reported definite plume-like features developing on the planet.

The plumes were seen rising to altitudes of over 250 km above the same region of Mars on both occasions. By comparison, similar features seen in the past have not exceeded 100 km.

MORE...

via Phys.org

[doug]

It`s Curiosity rover getting a move on . whoosh ....... or the Martians sending up smoke signals..

[Rick]

Mystery Mars haze baffles scientists

Around the world, a network of amateur astronomers keep their telescopes trained on the Red Planet.

They first spotted the strange plume in March 2012 above Mars' southern hemisphere.

Damian Peach was one of the first stargazers to capture images of the phenomenon.

He told BBC News: "I noticed this projection sticking out of the side of the planet. To begin with, I thought there was a problem with the telescope or camera.

"But as I checked more of the images, I realised it was a real feature - and it was quite a surprise."

More: http://www.bbc.co.uk/news/science-environment-31491805

[Rick]

Mystery Mars Plume Baffles Scientists

Plumes seen reaching high above the surface of Mars are causing a stir among scientists studying the atmosphere on the Red Planet.

On two separate occasions in March and April 2012, amateur astronomers reported definite plume-like features developing on the planet.

The plumes were seen rising to altitudes of over 250 km above the same region of Mars on both occasions. By comparison, similar features seen in the past have not exceeded 100 km.

"At about 250 km, the division between the atmosphere and outer space is very thin, so the reported plumes are extremely unexpected," says Agustin Sanchez-Lavega of the Universidad del País Vasco in Spain, lead author of the paper reporting the results in the journal Nature.

More: http://www.esa.int/Our_Activities/Space_Science/Mystery_Mars_plume_baffles_scientists

[Rick]

Study Predicts Next Global Dust Storm on Mars

Global dust storms on Mars could soon become more predictable -- which would be a boon for future astronauts there -- if the next one follows a pattern suggested by those in the past.

A published prediction, based on this pattern, points to Mars experiencing a global dust storm in the next few months. "Mars will reach the midpoint of its current dust storm season on October 29th of this year. Based on the historical pattern we found, we believe it is very likely that a global dust storm will begin within a few weeks or months of this date," James Shirley, a planetary scientist at NASA's Jet Propulsion Laboratory, Pasadena, California.

Local dust storms occur frequently on Mars. These localized storms occasionally grow or coalesce to form regional systems, particularly during the southern spring and summer, when Mars is closest to the sun. On rare occasions, regional storms produce a dust haze that encircles the planet and obscures surface features beneath. A few of these events may become truly global storms, such as one in 1971 that greeted the first spacecraft to orbit Mars, NASA's Mariner 9. Discerning a predictable pattern for which Martian years will have planet-encircling or global storms has been a challenge.

More: http://www.jpl.nasa.gov/news/news.php?feature=6638

[Rick]

NASA Mars Orbiter Tracks Back-to-Back Regional Storms (MRO)

A regional dust storm currently swelling on Mars follows unusually closely on one that blossomed less than two weeks earlier and is now dissipating, as seen in daily global weather monitoring by NASA's Mars Reconnaissance Orbiter.

Images from the orbiter's wide-angle Mars Color Imager (MARCI) show each storm growing in the Acidalia area of northern Mars, then blowing southward and exploding to sizes bigger than the United States after reaching the southern hemisphere.

That development path is a common pattern for generating regional dust storms during spring and summer in Mars' southern hemisphere, where it is now mid-summer.

More: https://www.jpl.nasa.gov/news/news.php?feature=6771