Scientists: Ice layers in Burroughs Crater confirm Martian orbital climate cycles

Layering in the west side of Burroughs Crater
Click for full image.

According to a new paper published today, scientists have used the ice layers inside Burroughs Crater on Mars to confirm the theory that the Red Planet has undergone numerous climate cycles during the past four million years, caused by the swings in the planet’s rotational tilt and eccentric orbit. From the press release:

Previously, Martian climate scientists have focused on polar ice caps, which span hundreds of kilometers. But these deposits are old and may have lost ice over time, losing fine details that are necessary to confidently establish connections between the planet’s orientation and motion and its climate.

Sori and his colleagues turned to ice mounds in craters, just tens of kilometers wide but much fresher and potentially less complicated. After scouring much of the southern hemisphere, they pinpointed Burroughs crater, 74 kilometers wide, that has “exceptionally well-preserved” layers visible from NASA HiRISE [Mars Reconnaissance Orbiter’s high resolution camera] imagery, Sori said.

The researchers analyzed the layers’ thicknesses and shapes and found they had strikingly similar patterns to two important Martian orbital dynamics, the tilt of Mars’ axis and orbital precession, over the last 4 to 5 million years.

The photo above of those layers was taken by Europe’s Trace Gas Orbiter on March 13, 2019, cropped and reduced to post here.

This research greatly strengthens the theory that the ice on Mars gets distributed to different latitudes in cycles, depending on the cyclical fluctuations in the planet’s orbit and tilt. However, it does not yet confirm these cycles apply to the glaciers found in craters in lower latitudes. Burroughs Crater is at 72 degrees south latitude, near the southern polar ice cap, well south of the band of glaciers scientists have discovered in the mid-latitudes down to 30 degrees latitude. Nonetheless, this research strongly suggest the same cycles apply in those lower latitudes.

Scientists discover underground reservoir of hydrogen, likely ice, near Martian equator

Detection of underground hydrogen in Valles Marineris
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In what could be a very significant discovery, scientists using Europe’s Trace Gas Orbiter (TGO) have discovered a surprisingly large underground reservoir of hydrogen, likely ice, near Martian equator and inside the solar system’s largest known canyon, Valles Marineris.

The map to the right, reduced to post here, provides all the important data. From its caption:

The coloured scale at the bottom of the frame shows the amount of ‘water-equivalent hydrogen’ (WEH) by weight (wt%). As reflected on these scales, the purple contours in the centre of this figure show the most water-rich region. In the area marked with a ‘C’, up to 40% of the near-surface material appears to be composed of water (by weight). The area marked ‘C’ is about the size of the Netherlands and overlaps with the deep valleys of Candor Chaos, part of the canyon system considered promising in our hunt for water on Mars.

What the caption does not note is the latitude of this hydrogen, about 3 to 10 degrees south latitude. Assuming the hydrogen represents underground ice, this would be the first detection on Mars below 30 degrees latitude, and the very first in the equatorial regions. Data from orbit has suggested that Mars has a lot of water ice, found near the surface more and more as you move into higher latitudes above 30 degrees and making Mars much like Antarctica. Almost no ice however had until now been detected below 30 degrees latitude. As the European Space Agency’s press release noted,
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Both methane and oxygen fluctuate in unison seasonally in Gale Crater

The uncertainty of science: According to a new science paper, data from Curiosity on Mars has now found that both methane and oxygen fluctuate in unison seasonally in Gale Crater.

From the paper’s abstract:

[T]he annual average composition in Gale Crater was measured as 95.1% carbon dioxide, 2.59% nitrogen, 1.94% argon, 0.161% oxygen, and 0.058% carbon monoxide. However, the abundances of some of these gases were observed to vary up to 40% throughout the year due to the seasonal cycle. Nitrogen and argon follow the pressure changes, but with a delay, indicating that transport of the atmosphere from pole to pole occurs on faster timescales than mixing of the components. Oxygen has been observed to show significant seasonal and year‐to‐year variability, suggesting an unknown atmospheric or surface process at work. These data can be used to better understand how the surface and atmosphere interact as we search for signs of habitability.

The data shows that the unexpected and so far unexplained seasonal oxygen fluctuation appears to track the same seasonal methane fluctuations. While biology could cause this signature, so could geological processes, though neither can produce these fluctuations easily.

Meanwhile, adding to the uncertainty were results from the two European orbiters, Mars Express and Trace Gas Orbiter. Both have failed to detect a June 19, 2019 dramatic spike in methane that had been measured by Curiosity.

Results from Europe’s Trace Gas Orbiter at Mars

The European Space Agency today released the results of more than a year of observations from its Trace Gas Orbiter (TGO), among which were two significant findings.

First, the orbiter detected no methane in Mars’s atmosphere, contradicting recent results from both Curiosity and Mars Express.

The new results from TGO provide the most detailed global analysis yet, finding an upper limit of 0.05 ppbv, that is, 10–100 times less methane than all previous reported detections. The most precise detection limit of 0.012 ppbv was achieved at 3 km altitude. As an upper limit, 0.05 ppbv still corresponds to up to 500 tons of methane emitted over a 300 year predicted lifetime of the molecule when considering atmospheric destruction processes alone, but dispersed over the entire atmosphere, this is extremely low.

…“The TGO’s high-precision measurements seem to be at odds with previous detections; to reconcile the various datasets and match the fast transition from previously reported plumes to the apparently very low background levels, we need to find a method that efficiently destroys methane close to the surface of the planet.”

It appears they think the Curiosity and Mars Express detections were very localized and occurred close to the surface, where TGO could not detect it.

The second significant finding is indicated by the map below, showing a global map of subsurface water distribution on Mars. I have also posted below this map a global elevation map from Mars Reconnaissance Orbiter (MRO), as the similarities and differences are important.
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The layering at the Martian poles

Layering in the east side of Burroughs Crater
Click for full image.

Layering in the west side of Burroughs Crater
Click for full image.

In the past month the science teams of both Mars Reconnaissance Orbiter (MRO) and Trace Gas Orbiter (TGO) have released images showing the strange layering found in Burroughs Crater, located near the Martian south pole.

The top image above is the MRO image, rotated and cropped to post here. To the right is a cropped and reduced section of the TGO image.

Though both images look at the inside rim of the crater, they cover sections at opposite ends of the crater. The MRO image of the crater’s east interior rim, with the lowest areas to the right, while the TGO image shows the crater’s northwest interior rim, with the lowest areas on the bottom. As noted at the TGO image site:
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Trace Gas Orbiter finds no methane on Mars

The uncertainty of science: Europe’s Trace Gas Orbiter (TGO) has failed to detect any methane in Mars’ atmosphere, even though data from Mars Express in 2004 had said it should see some.

The Mars Express orbiter first detected hints of methane in the martian atmosphere in 2004. But some scientists said the orbiter’s instruments that found it—at a level of 10 parts per billion (ppb)—weren’t sensitive enough to produce reliable results. Ten years later, NASA’s Curiosity rover detected a methane spike of 7 ppb from its base in Gale crater, which lasted several months. Several years later, Curiosity’s scientists then discovered a minute seasonal cycle, with methane levels peaking at 0.7 ppb in the late northern summer.

To settle this mystery, the European Space Agency’s Trace Gas Orbiter (TGO), which arrived at Mars in 2016, this year began to scan the atmosphere for methane. Two of the TGO’s spectrometers—a Belgian instrument called NOMAD and a Russian one called ACS—were designed to detect methane in such low concentrations that researchers were sure they would. Both instruments, which analyze horizontal slices of the martian atmosphere backlit by the sun, are working well, scientists on the team said today at a semiannual meeting of the American Geophysical Union in Washington, D.C. There’s still some noise to clean up, said Ann Carine Vandaele, NOMAD’s principal investigator and a planetary scientist at the Royal Belgian Institute for Space Aeronomy in Brussels, in her talk. “But we already know we can’t see any methane.”

The team’s initial results show no detection of methane down to a minute level of 50 parts per trillion, with their observations going down nearly all the way to the martian surface.

The data says that any methane seen on the surface (such as by Curiosity) must be coming from below, not from off world, which in itself is a surprise since the scientists expected some methane to be coming from interplanetary dust. TGO has found none..

There are a lot of uncertainties still, so stay tuned.

Europe’s Trace Gas Orbiter detects clouds over Martian volcano

Europe’s Trace Gas Orbiter (TGO) has detected clouds over the western slopes of the giant Martian volcano Arsia Mons.

This is not a new discovery, merely a confirmation of many past observations, all of which suggest that water-ice glaciers once flowed down those western slopes, and that some of that ice remains trapped in underground caves and lava tubes there. Undeniably this region appears at present to be the most valuable real estate on Mars. It has caves where the first colonies can be more easily built. Those caves likely have water in them. And the location is near the equator, which is easier to reach and also makes the environment somewhat less hostile.

TGO is presently slowly aerobraking itself down to its planned science orbit, which it is expected to reach in 2018.

ExoMars’ Trace Gas Orbiter images Phobos

As part of its checkout, Europe’s ExoMars’ Trace Gas Orbiter has taken test images of the Martian moon Phobos.

The camera imaged the moon on 26 November from a distance of 7700 km, during the closest part of the spacecraft’s orbit around Mars. TGO’s elliptical orbit currently takes it to within 230–310 km of the surface at its closest point and around 98 000 km at its furthest every 4.2 days. A colour composite has been created from several individual images taken through several filters. The camera’s filters are optimised to reveal differences in mineralogical composition, seen as ‘bluer’ or ‘redder’ colours in the processed image. An anaglyph created from a stereo pair of images captured is also presented, and can be viewed using red–blue 3D glasses.

The images were done to test the spacecraft’s operation, and have apparently shown that it is functioning well.

ExoMars’ Trace Gas Orbiter takes first pictures

The European Trace Gas Orbiter (TGO), part of the ExoMars 2016 mission, has successfully transmitted its first images back to Earth.

I have posted a video they have assembled of the first images below the fold. It is quite spectacular. As for TGO’s future misssion:

In the next months, the team will be starting preparations for the prime mission. “The test was very successful but we have identified a couple of things that need to be improved in the onboard software and in the ground post-processing», says Thomas. “It’s an incredibly exciting time.” Eventually, TGO will use “aerobraking” (skimming into the atmosphere) to slow the spacecraft down and enter a roughly circular orbit 400 km above this surface. This process will start in March 2017 and take around 9-12 months. The primary science phase will start around the end of 2017. CaSSIS will then enter nominal operations acquiring 12-20 high resolution stereo and colour images of selected targets per day.

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Fate of Schiaparelli remains unknown

While Europe’s Trace Gas Orbiter has successfully gone into orbit around Mars, it remains unknown whether the lander Schiaparelli was able today to land successfully on the surface.

The carrier signal from Schiaparelli recorded by Mars Express abruptly ended shortly before landing, just as the beacon tone received by a ground-based radio telescope in India stopped in real-time earlier today.

Paolo Ferri, head of ESA’s mission operations department, just gave an update on the situation. “We saw the signal through the atmospheric phase — the descent phase. At a certain point, it stopped,” Ferri said. “This was unexpected, but we couldn’t conclude anything from that because this very weak signal picked up on the ground was coming from an experimental tool.

“We (waited) for the Mars Express measurement, which was taken in parallel, and it was of the same kind. It was only recording the radio signal. The Mars Express measurement came at 1830 (CEST) and confirmed exactly the same: the signal went through the majority of the descent phase, and it stopped at a certain point that we reckon was before the landing.

“There could be many many reasons for that,” Ferri said. “It’s clear these are not good signs, but we will need more information.”

ExoMars 2016 in detail

This Nature article provides a nice summary of the European/Russian ExoMars 2016 mission that on Wednesday will try to place a lander on Mars as well as put an orbiter in orbit.

Neither probe is going to provide many exciting photos. The orbiter, dubbed boringly the Trace Gas Orbiter, is designed to study Mars’ atmosphere, while the lander, Schiaparelli, is essentially a technology test mission for planning and designing what Europe and Russia hope will be a more ambitious lander/orbiter mission in 2020.

Anyone expecting spectacular pictures from Schiaparelli itself might be disappointed — photos will be limited to 15 black-and-white shots of the Martian surface from the air, intended to help piece together the craft’s trajectory. No photos will be taken on the surface, because the lander lacks a surface camera.

Schiaparelli’s instruments will study the Martian atmosphere, including the possible global dust storm that might happen this month but so far has not yet appeared. The instruments will also be able to detect lightning, should it exist on Mars.