Tag: science

First Webb infrared image of Cartwheel Galaxy

9:13 am

Webb's view of the Cartwheel Galaxy
Click for full image.

Scientists today have released a new infrared image of the Cartwheel Galaxy, taken by two instruments on the James Webb Space Telescope. That image is to the right, reduced to post here. From the caption:

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The galaxy, located about a half billion light years away, is one of the more well known astronomical objects due to its unusual shape, believed caused by a collision with a smaller galaxy sometime in the past. Earlier this year for example astronomers discovered a supernovae had exploded in the galaxy sometime in 2021. To see a 1995 Hubble optical image, go here.

This Webb image reveals many new details previously obscured by dust.

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Sunspot update: Activity recovers mostly from last month’s decline

9:04 pm

It is the start of the month, and thus time to post NOAA’s monthly update of its graph tracking the number of sunspots on the Sun’s Earth-facing hemisphere. That graph is below, with some additional details added by me to provide a larger context.

After the first real decline in sunspot activity in June, the Sun recovered that decline almost completely in July. Though the ramp up to solar maximum has stalled somewhat in the last two months, the trend continues to point to a very active maximum, much higher than predicted as well as much stronger than the last very weak maximum in 2020.

» Read more

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Ice in the Martian equatorial region?

1:55 pm

Global overview of ice on Mars

Glacial features in low latitude Martian crater

Today’s cool image to the right, rotated, cropped, and reduced to post here, is actually an older captioned image, published in 2017 by the science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO). I missed its significance when it was first released. From the caption by Alfred McEwen of the Lunar & Planetary Laboratory in Arizona:

The material on the floor of this crater appears to have flowed like ice, and contains pits that might result from sublimation of subsurface ice. The surface is entirely dust-covered today. There probably was ice here sometime in the past, but could it persist at some depth?

This crater is at latitude 26 degrees north, and near-surface ice at this latitude (rather than further toward one of the poles) could be a valuable resource for future human exploration.

As shown in the global map of Mars above, this 26-mile-wide unnamed crater, marked by the black cross, is well inside the equatorial region 30 degrees north and south from the equator where almost no evidence of near surface ice has been found. Whenever I look at an image from MRO, if the picture appears to show ice or glacial features, its latitude is always 30 degrees or higher. If it does not, it is almost always in this equatorial region.

This crater however shows evidence of glacial features in its interior, but is far closer to the equator than normal. How could this be? It is possible that its high altitude, sitting in the southern cratered highlands, might have helped preserve its buried but near surface glacial features.

Regardless, as McEwen notes, its location closer to the equator is tantalizing, because it suggests that such ice could exist even in the equatorial regions, though buried and thus not detected by the instruments presently available in Mars orbit.

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Inverted Martian tadpole

2:17 pm

Inverted Martian tadpole
Click for full image.

Cool image time! On Mars it is not unusual to see what scientists call tadpole features, craters with meandering canyons or channels either flowing into or out from the crater’s rim. The photo to the right, rotated, cropped, and reduced to post here, is another example, though with one major difference. The channel and crater are inverted, with the channel instead a ridge and the crater a circular plateau. The picture itself was taken on April 16, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

Orbital images have found on Mars a lot of what scientists call pedestal craters, where the impact packed and hardened the ground under the crater so that when the surrounding terrain eroded away the crater remained, as a plateau.

Scientists have also found on Mars a lot of what they call “inverted channels,” places where the channels of a drainage pattern followed the same geological process, becoming more resistant to erosion so that over time it turned from a channel to a ridge.

Here we have a combination of both. The overview map below provides us the larger picture.
» Read more

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Study: The Moon’s poles might not be the only places to find lunar water

1:03 pm

Global map of hydrogen abundances on Moon
Click for full image.

According to a new study published in June in the Journal of Geophysical Research: Planets, while the lunar poles might contain water ice in permanently shadowed craters — based on detected hydrogen abundances — there is an even higher concentration of hydrogen found in the Aristarchus Plateau region in the lower mid-latitudes.

The map to the right is figure 9 from the paper, annotated to post here, showing the Moon’s hydrogen abundances globally, with lighter areas having higher concentrations. The boxes indicate five lunar regions that appear to hold higher levels of hydrogen and thus might contain higher amounts of water. From the paper’s conclusions:

The bulk hydrogen map also led to the first identification of bulk hydrogen enhancements within a pyroclastic deposit (Aristarchus Plateau), an identification that corroborates previous suggestions that hydrogen was among the volatiles involved in the eruption and emplacement of pyroclastic deposits. Further, with the understanding that there are enhanced bulk hydrogen abundances within at least one pyroclastic deposit and not just a surface enhancement, this leads to the implication that the hydrogen contained within just the Aristarchus Plateau may represent a significant fraction of the hydrogen that exists in the Moon’s near-subsurface, including that at both lunar poles. [emphasis mine]

It is important to note that finding high hydrogen abundances does not automatically mean you have found water. For hydrogen to exist on the Moon the atom must be bound in a molecule, and usually water is chosen as the most likely candidate. In the case of Aristarchus, however, the paper instead suggests that hydrogen was placed there as pyroclastic deposits, when active volcanism was occurring a long time ago. While water ice might not be present now in these regions, the data also suggests that water played a major role in its formation.

These hydrogen abundances however also signal the faint possibility of that water ice might be buried here, below the surface, left over from those early volcanic processes. The data also suggests even if the hydrogen is bound in other materials, mining and processing might be able to extract water from it.

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The big storms at Jupiter’s poles are coherent and stable

1:46 pm

Storms on Jupiter
Click for full image.

After four years of observations by Juno in orbit around Jupiter, scientists studying the storms at the gas giant’s poles have found that those storms are stable, long-lasting features. From the abstract of their paper:

These data have shown cyclones organized in snowflake-like structures. The Jupiter’s polar cyclones are long-lasting features, which did not disappear or merge during four years of observations.

The image to the right, posted by me earlier this week, shows several of these storms, or vortices, at Jupiter’s north pole. Previous work had documented the overall pattern, as described in the paper:

The observed vortices display geometrical symmetries around both poles: circumpolar cyclones (CPCs), organized in a regular pattern, surround a central one. At the north pole, eight circumpolar vortices form an octagonal structure, while at the south pole, five circumpolar vortices are arranged in a pentagonal pattern; both central polar vortices show some degree of displacements to the geometrical pole, about 0.5° for the Northern Polar Cyclone (NPC) and 1°-2° for the Southern Polar Cyclone (SPC).

While this research has found little change in these storms over four years, it is unknown what their long term evolution will be for an entire Jupiter year, twelve Earth years long.

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New paper: Glaciers on Mars could have been extensive, despite the lack of expected subsequent landforms

12:18 pm

glacial drainage patterns as expected on Mars
Click for full figure.

According to a new paper published this week, scientists now posit that glaciation could have been much more extensive in the geological history of Mars than presently believed, despite the lack of the expected subsequent landforms as seen on Earth.

From the abstract:

The lack of evidence for large-scale glacial landscapes on Mars has led to the belief that ancient glaciations had to be frozen to the ground. Here we propose that the fingerprints of Martian wet-based glaciation should be the remnants of the ice sheet drainage system instead of landforms generally associated with terrestrial ice sheets. We use the terrestrial glacial hydrology framework to interrogate how the Martian surface gravity affects glacial hydrology, ice sliding, and glacial erosion. …[W]e compare the theoretical behavior of identical ice sheets on Mars and Earth and show that, whereas on Earth glacial drainage is predominantly inefficient, enhancing ice sliding and erosion, on Mars the lower gravity favors the formation of efficient subglacial drainage. The apparent lack of large-scale glacial fingerprints on Mars, such as drumlins or lineations, is to be expected. [emphasis mine]

In other words, on Earth the higher gravity causes glaciers and ice sheets to slide, with the liquid water at the base acting as a lubricant. On Mars, the lower gravity slows that slide, so that the water at the glacier’s base drains away instead, causing erosion and the formation of a drainage pattern in the ground beneath the glacier or ice sheet.

The image above, from figure 1 of the paper, shows on the left a graphic of the two types of drainage patterns expected, and on the right two examples found on Earth (D1: Devon Island; D2: Northwest Territories). Orbiter images of Mars have found variations of these types of drainage patterns in numerous places in Mars’ mid-latitude glacial bands, as shown below.
» Read more

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NASA/ESA revise plan to recover Perseverance core samples from Mars

8:52 am

NASA and ESA yesterday announced that the agencies have revised their plan to recover Perseverance core samples from Mars, dropping the launch of a rover to pick up the samples.

Instead, they have decided to use Perseverance to bring the samples to the return vehicle, which will also carry two small helicopters.

In 2030, if all goes as planned, the NASA lander will touch down near where Perseverance is working. The rover will drive over to the lander, and an ESA-built robot arm will extract the tubes one by one and place them inside a spherical container the size of a basketball. In early 2031, a rocket on the lander will loft the container into Mars orbit, where a return craft built by ESA will snare it, enclose it in several layers of shielding for safety, and then head for home. In 2033, a saucer-shaped descent pod will carry the samples down to the Utah desert.

If Perseverance gets into difficulties during its 9-year wait for company, controllers can instruct it to drop its cargo of sample tubes onto the ground, creating a second depot. If that happens, the helicopters come into play: they can fly up to 700 meters, land next to a sample tube—each weighs up to 150 grams—and, with wheels on the bottom their feet, roll over the tube and pick it up with a grabber. On returning to the lander, they will drop the tubes on the ground for the arm to pick up.

The change means that the rover the United Kingdom was planning to build will either be abandoned, or repurposed as a lunar rover.

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A Martian slot canyon!

12:02 pm

A Martian slot canyon
For originals go here, here, and here.

Overview map
Click for interactive map.

Cool image time! The mosaic to the right is made up of three images produced by the high resolution camera on the Mars rover Perseverance (found here, here, and here). All three were taken on July 24, 2022 and look north to the nearest cliff face at the head of the large delta that flowed into Jezero Crater some time in the distant past.

The rover was about 80 feet away from the feature when the photo was snapped. Though scale in the photo is not provided, using the scale in the overview map below I would guess this slot canyon is several feet wide, with some spots narrow enough that your body would touch both walls at spots. Its height is likely nor more than 20 feet high, at the very most.

On the overview map, the blue dots mark Perseverance’s location, in both the main map and the inset. The green dot marks where the helicopter Ingenuity presently sits. The red dotted line is my guess as to the future route of the rover up into the delta. The yellow lines indicate the area viewed in the mosaic.

Though hardly as deep as the many slot canyons found in the American southwest, that this slot exists on Mars is quite intriguing. Did it form like those southwestern slots from water flow? Probably not. More likely we are looking at a fracture produced by shifts in the entire delta itself, and then later widened by wind.

That the cliff shows multiple layers suggests the delta was laid down in multiple events, and that the fracture occurred after the delta was emplaced. That the layers on either side of the fracture appear to match up strengthens this conclusion. These layers also suggest that the layering is not simply in a series of small events. The layers are also grouped into larger aggregates, suggesting those larger groupings mark longer epochs, each with its own unique conditions.

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A crowd of Jupiter hurricanes

11:09 am

Storms on Jupiter
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on July 5, 2022 during Juno’s 43rd close fly-by of Jupiter, and was enhanced by citizen scientist Brian Swift. It shows a group of storms, what planetary scientists have labeled “vortices” near Jupiter’s north pole.

These powerful storms can be over 30 miles (50 kilometers) in height and hundreds of miles across. Figuring out how they form is key to understanding Jupiter’s atmosphere, as well as the fluid dynamics and cloud chemistry that create the planet’s other atmospheric features. Scientists are particularly interested in the vortices’ varying shapes, sizes, and colors. For example, cyclones, which spin counter-clockwise in the northern hemisphere and clockwise in the southern, and anti-cyclones, which rotate clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere, exhibit very different colors and shapes.

The image highlights the type of storm Juno scientists are asking the pubic to category in a new citizen scientist project called Jovian Vortex Hunter. You go to its website and go through Juno images, noting and categorizing them. So far more than 2,400 volunteers have marked up more than 375,000 storms.

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The very end of an 800-mile-long Martian canyon

1:39 pm

The very end of an 800-mile-long Martian canyon
Click for full image.

Cool image time! While most geeks interested in Mars are familiar with Valles Marineris, the largest canyon in the solar system, Mars has other large canyons that while not a big are impressive in their own right. The picture to the right, rotated, cropped, and reduced to post here, shows us the very very end of one such canyon. Taken on April 19, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), it shows the easternmost spot where Cerberus Fossae begins. From here, this narrow fracture-caused canyon extends another 800 miles to the west, sometimes splitting into two or three parallel cracks, but always oriented in the same direction, slightly north of due west.

The overview map below provides the context and wider view.
» Read more

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New boss of Roscosmos confirms decision to leave ISS in 2024.

10:36 am

Yuri Borisov, the new head of Roscosmos, today confirmed that Russia will leave its partnership at ISS in 2024.

The decision to leave the station after 2024 has been made,” Yuri Borisov, appointed this month to lead the Russian space agency, Roscosmos, said during a meeting with President Vladimir Putin. He added: “I think that by that time we will start forming a Russian orbiting station.”

This announcement leaves several questions.

1. What will happen to the Russian modules on ISS? They cannot function on their own, so undocking them means they either must be de-orbited or attached to another station. Since it is more likely a snowman could exist on the Moon than the Russians launching a new station by 2024, the future of those modules must be negotiated.

2. What will the Russians do once out of this partnership? As I said, they will not be able to launch a new station by ’24. In fact, it is more likely they won’t be able to launch one at all, considering the pervasive corruption that permeates all levels of their technological society. It took them almost a quarter century to complete and launch the newest module to ISS, Nauka, with many many technical problems along the way.

3. Will Russia and China forge a closer alliance in space? I expect Russia will try to negotiate a partnership with China on its space station, but I doubt China will agree to any agreement that makes Russia an equal. It isn’t, and China has no interest in making believe Russia is.

4. Will this force an acceleration in the launch of the American private space stations now under construction? Hard to say. If we had a competent executive branch run by a clear-minded president, some action could be taken to help make this happen. The present Biden administration is neither competent nor clear-minded, so I do not expect much from it. Managers at NASA however might be able to push for increased funding to speed development, but even if successful that carries risk. It will make the private stations more beholden to the government, thus lessening their independence.

All in all, a most interesting situation.

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