Enjoying EarthSky? Subscribe.

221,386 subscribers and counting ...

Mystery plumes on Mars puzzle scientists

Amateur astronomers spotted them first, but they show up in Hubble images, too. Astronomers are scratching their heads, wondering these mystery plumes are.

Observations of a mysterious plume-like feature (marked with yellow arrow) at the limb of the Red Planet on 20 March 2012. The observation was made by astronomer W. Jaeschke. The image is shown with the north pole towards the bottom and the south pole to the top.

Observations of a mysterious plume-like feature (marked with yellow arrow) at the limb of Mars on March, 20 2012. Amateur astronomer W. Jaeschke made the observation. This image is shown with the north pole towards the bottom and the south pole to the top. Image via ESA

The European Space Agency said this week (February 16, 2015) that scientists are scratching their heads over mystery plumes seen reaching high above the surface of the Red Planet, Mars. Amateur astronomers were the first to report plume-like features developing on Mars, on two separate occasions in March and April 2012. A check of Hubble images also revealed an abnormally high plume in May, 1997, similar to those spotted by the amateurs. Scientists are now working on determining the nature and cause of the plumes by using the Hubble data in combination with the images taken by amateurs.

The plumes have been seen rising to altitudes of over 150 miles (250 km) above the same region of Mars on both occasions. By comparison, similar features seen in the past have not exceeded about 60 miles (100 km). Agustin Sanchez-Lavega of the Universidad del País Vasco in Spain, lead author of a paper reporting the results in the journal Nature, said:

At about 250 km, the division between the atmosphere and outer space is very thin, so the reported plumes are extremely unexpected.

The features were seen to develop in less than 10 hours. They cover an area of about 600 x 300 miles (1000 x 500 km) have been seen to remain visible for around 10 days. Day by day, the strange plumes change shape.

Why didn’t our spacecraft see them? ESA says none of the spacecraft orbiting Mars saw the features because of their viewing geometries and illumination conditions at the time.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

A curious plume-like feature was observed on Mars on 17 May 1997 by the Hubble Space Telescope. It is similar to the features detected by amateur astronomers in 2012, although appeared in a different location.

The Hubble Space Telescope also saw a curious plume-like feature on Mars on May 17, 1997. It is similar to the features detected by amateur astronomers in 2012, although appeared in a different location.

At this point, scientists studying the atmosphere of Mars are unsure what they are. Agustin said:

One idea we’ve discussed is that the features are caused by a reflective cloud of water-ice, carbon dioxide-ice or dust particles, but this would require exceptional deviations from standard atmospheric circulation models to explain cloud formations at such high altitudes.

Antonio Garcia Munoz, a research fellow at ESA’s ESTEC and co-author of the study, added:

Another idea is that they are related to an auroral emission, and indeed auroras have been previously observed at these locations, linked to a known region on the surface where there is a large anomaly in the crustal magnetic field.

ESA says further insights into the mysterious Martian plumes should become possible following the arrival of ESA’s ExoMars Trace Gas Orbiter at the Red Planet, scheduled for launch in 2016.

The top image shows the location of the mysterious plume on Mars, identified within the yellow circle (top image, south is up), along with different views of the changing plume morphology taken by W. Jaeschke and D. Parker on 21 March 21 2012.

The top image shows the location of the mysterious plume on Mars, identified within the yellow circle (top image, south is up), along with different views of the changing plume morphology observed by astronomers W. Jaeschke and D. Parker on March 21, 2012.

Via European Space Agency

Deborah Byrd

MORE ARTICLES