MarsNews.com
April 10th, 2019

Largest dust storm on Mars ever recorded may reveal why it’s so dry

A dust storm on Mars photographed by the European Space Agency’s Mars Express
SA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO

Dust storms on Mars aren’t all about dust — they’re also full of water. A satellite orbiting Mars has taken the most detailed measurements yet of how these rare events trap water at lower altitudes, which may help reveal what happened to the water that used to be abundant on the Red Planet.

In 2018, the largest recorded dust storm circled the entire Martian globe, so thick that it hid the surface from the sun and killed the Opportunity rover. The ExoMars Trace Gas Orbiter watched this cataclysmic storm from orbit. Just before sunset and just after sunrise on Mars, it examined the atmosphere to determine how the dust storm absorbed sunlight.

Ann Carine Vandaele at the Royal Belgian Institute for Space Aeronomy and her colleagues used this data to determine how water was behaving in the storm. They found that just before the storm, there were water ice clouds in the atmosphere, but no water vapour more than 40 kilometres above the surface. This changed a few days later when water vapour appeared at altitudes of 40 and 80 kilometres, seemingly replacing the water ice clouds.

April 1st, 2019

Mars Express matches methane spike measured by Curiosity

Mars Express results ESA/Giuranna et al (2019)

A reanalysis of data collected by ESA’s Mars Express during the first 20 months of NASA’s Curiosity mission found one case of correlated methane detection, the first time an in-situ measurement has been independently confirmed from orbit.

Reports of methane in the martian atmosphere have been intensely debated, with Mars Express contributing one of the first measurements from orbit in 2004, shortly after its arrival at the Red Planet.

The molecule attracts such attention because on Earth methane is generated by living organisms, as well as geological processes. Because it can be destroyed quickly by atmospheric processes, any detection of the molecule in the martian atmosphere means it must have been released relatively recently – even if the methane itself was produced millions or billions of years ago and lay trapped in underground reservoirs until now.

While spacecraft and telescopic observations from Earth have in general reported no or very low detections of methane, or measurements right at the limit of the instruments’ capabilities, a handful of spurious spikes, along with Curiosity’s reported seasonal variation at its location in Gale Crater, raise the exciting question of how it is being generated and destroyed in present times.

Now, for the first time, a strong signal measured by the Curiosity rover on 15 June 2013 is backed up by an independent observation by the Planetary Fourier Spectrometer (PFS) onboard Mars Express the next day, as the spacecraft flew over Gale Crater.

February 28th, 2019

First Evidence of Planet-Wide Groundwater System On Mars

Evolution of water-filled basins over time

Mars Express has revealed the first geological evidence of a system of ancient interconnected lakes that once lay deep beneath the Red Planet’s surface, five of which may contain minerals crucial to life.

Mars appears to be an arid world, but its surface shows compelling signs that large amounts of water once existed across the planet. We see features that would have needed water to form – branching flow channels and valleys, for example – and just last year Mars Express detected a pool of liquid water beneath the planet’s south pole.

A new study now reveals the extent of underground water on ancient Mars that was previously only predicted by models.

“Early Mars was a watery world, but as the planet’s climate changed this water retreated below the surface to form pools and ‘groundwater’,” says lead author Francesco Salese of Utrecht University, the Netherlands.

“We traced this water in our study, as its scale and role is a matter of debate, and we found the first geological evidence of a planet-wide groundwater system on Mars.”

December 21st, 2018

Mars Express gets festive: A winter wonderland on Mars

Perspective view of Korolev crater. ESA/DLR/FU Berlin

This image shows what appears to be a large patch of fresh, untrodden snow – a dream for any lover of the holiday season. However, it’s a little too distant for a last-minute winter getaway: this feature, known as Korolev crater, is found on Mars, and is shown here in beautiful detail as seen by Mars Express.

ESA’s Mars Express mission launched on 2 June 2003, and reached Mars six months later. The satellite fired its main engine and entered orbit around the Red Planet on 25 December, making this month the 15-year anniversary of the spacecraft’s orbit insertion and the beginning of its science programme.

These images are an excellent celebration of such a milestone. Taken by the Mars Express High Resolution Stereo Camera (HRSC), this view of Korolev crater comprises five different ‘strips’ that have been combined to form a single image, with each strip gathered over a different orbit. The crater is also shown in perspective, context, and topographic views, all of which offer a more complete view of the terrain in and around the crater.

October 25th, 2018

Mars Express keeps an eye on curious cloud

Elongated cloud on Mars – ESA

Since 13 September, ESA’s Mars Express has been observing the evolution of an elongated cloud formation hovering in the vicinity of the 20 km-high Arsia Mons volcano, close to the planet’s equator.

In spite of its location, this atmospheric feature is not linked to volcanic activity but is rather a water ice cloud driven by the influence of the volcano’s leeward slope on the air flow – something that scientists call an orographic or lee cloud – and a regular phenomenon in this region.

The cloud can be seen in this view taken on 10 October by the Visual Monitoring Camera (VMC) on Mars Express – which has imaged it hundreds of times over the past few weeks – as the white, elongated feature extending 1500 km westward of Arsia Mons. As a comparison, the cone-shaped volcano has a diameter of about 250 km; a view of the region with labels is provided here.

Mars just experienced its northern hemisphere winter solstice on 16 October. In the months leading up to the solstice, most cloud activity disappears over big volcanoes like Arsia Mons; its summit is covered with clouds throughout the rest of the martian year.

However, a seasonally recurrent water ice cloud, like the one shown in this image, is known to form along the southwest flank of this volcano – it was previously observed by Mars Express and other missions in 2009, 2012 and 2015.

October 23rd, 2018

Mars could have enough molecular oxygen to support life, and scientists figured out where to find it

Mars as seen by NASA’s Hubble Space Telescope on July 18, near its closest approach to Earth since 2003. (NASA / ESA / STScI)

Modern-day Mars may be more hospitable to oxygen-breathing life than previously thought.

A new study suggests that salty water at or near the surface of the red planet could contain enough dissolved O2 to support oxygen-breathing microbes, and even more complex organisms such as sponges.

“Nobody thought of Mars as a place where aerobic respiration would work because there is so little oxygen in the atmosphere,” said Vlada Stamenković, an Earth and planetary scientist at the Jet Propulsion Laboratory who led the work. “What we’re saying is it is possible that this planet that is so different from Earth could have given aerobic life a chance.”

As part of the report, Stamenković and his coauthors also identified which regions of Mars are most likely to contain brines with the greatest amounts of dissolved oxygen. This could help NASA and other space agencies plan where to send landers on future missions, they said.

The work was published Monday in Nature Geoscience.

July 25th, 2018

Mars Express Detects Liquid Water Hidden Under Planet’s South Pole

The European Space Agency (ESA)

Radar data collected by ESA’s Mars Express point to a pond of liquid water buried under layers of ice and dust in the south polar region of Mars.

Evidence for the Red Planet’s watery past is prevalent across its surface in the form of vast dried-out river valley networks and gigantic outflow channels clearly imaged by orbiting spacecraft. Orbiters, together with landers and rovers exploring the martian surface, also discovered minerals that can only form in the presence of liquid water.

But the climate has changed significantly over the course of the planet’s 4.6 billion year history and liquid water cannot exist on the surface today, so scientists are looking underground. Early results from the 15-year old Mars Express spacecraft already found that water-ice exists at the planet’s poles and is also buried in layers interspersed with dust.

The presence of liquid water at the base of the polar ice caps has long been suspected; after all, from studies on Earth, it is well known that the melting point of water decreases under the pressure of an overlying glacier. Moreover, the presence of salts on Mars could further reduce the melting point of water and keep the water liquid even at below-freezing temperatures.

But until now evidence from the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, MARSIS, the first radar sounder ever to orbit another planet, remained inconclusive.

It has taken the persistence of scientists working with this subsurface-probing instrument to develop new techniques in order to collect as much high-resolution data as possible to confirm their exciting conclusion.

November 8th, 2016

Capturing Martian Weather in Motion

Dust stom over Tempe Terra, Mars ESA / DLR / FU Berlin (G. Neukum) / Justin Cowart

Dust stom over Tempe Terra, Mars
ESA / DLR / FU Berlin (G. Neukum) / Justin Cowart

Still images of Mars often give us a false impression that Mars is a dead planet, with nothing going on other than the occasional dust storm. Do a quick image search for Mars and most of the results are mosaics designed to show Martian geography, not meteorology. But these images don’t tell the planet’s full story. Martian weather is dynamic, with water ice cloud streets forming around the polar areas, cold fronts pushing through the midlatitudes and raising dust storms, and thin hazes forming as air flows around topographic obstacles like volcanoes and crater rims.

No space agency has deployed a dedicated weather satellite to Mars, so we can’t watch these systems form and move across the surface like we can with the spectacular images of Earth returned by satellites like Himawari-8. In fact, the only instrument dedicated to monitoring Martian weather, the Mars Color Imager (MARCI) onboard the Mars Reconnaissance Orbiter, can only image a location on the Martian surface once per day (with the exception of some areas near the poles).

Fortunately for Martian weather enthusiasts, there is a way to get a glimpse of weather in action at the Martian surface. The High Resolution Stereo Colour Imager (HRSC) instrument onboard Mars Express was designed to produce stereographic color maps of Mars. To do this, HRSC uses a set of 9 pushbroom sensors. Four of these sensors image the surface in color at blue, green, red, and near-IR wavelengths. The other five collect stereo and photometric data using broadband filters that cover the same roughly the same spectral range. The sensors are mounted at different angles, looking between 20 degrees ahead and behind the spacecraft. Parallax from the five different viewing angles allows mission scientists to create DEMs of the surface with 10 to 15 meter vertical resolution.

That’s the intended purpose, anyway. The offset viewing angles for the sensors onboard the spacecraft allow for something else: time-lapse images. The imaging setup means that the first imaging channel sees the surface about 70 seconds before the last. If the wind is blowing at the surface, the time between sequential images is just long enough that the motion of dust clouds is visible. If clouds are at higher altitude, then the parallax also shows up as motion. The color data can then be overlain to colorize the scene.

September 16th, 2016

Mars had liquid water a billion years longer than we even thought possible

Valleys much younger than well-known ancient valley networks on Mars are evident near the informally named “Heart Lake” on Mars. This map presents color-coded topographical information overlaid onto a photo mosaic. Lower elevations are indicated with white and purple; higher elevations, yellow.
Credits: NASA/JPL-Caltech/ASU

Lakes and snowmelt-fed streams on Mars formed much later than previously thought possible, according to new findings using data primarily from NASA’s Mars Reconnaissance Orbiter.

The recently discovered lakes and streams appeared roughly a billion years after a well-documented, earlier era of wet conditions on ancient Mars. These results provide insight into the climate history of the Red Planet and suggest the surface conditions at this later time may also have been suitable for microbial life.

“We discovered valleys that carried water into lake basins,” said Sharon Wilson of the Smithsonian Institution, Washington, and the University of Virginia, Charlottesville. “Several lake basins filled and overflowed, indicating there was a considerable amount of water on the landscape during this time.”

Wilson and colleagues found evidence of these features in Mars’ northern Arabia Terra region by analyzing images from the Context Camera and High Resolution Imaging Science Experiment camera on the Mars Reconnaissance Orbiter and additional data from NASA’s Mars Global Surveyor and the European Space Agency’s Mars Express.

June 1st, 2015

What’s up with these weird blue patches on Mars? Mashable

A European probe in orbit around Mars just photographed two deep blue patches on the Martian surface, but while they might look like lakes to the untrained eye, don’t be deceived. The spots are actually layers of dark, volcanic rock that appear blue in the photo taken by the European Space Agency’s Mars Express spacecraft. From possible blue auroras to a blue sunset, this photo is just the latest in a series of “blue” images of the red planet.