Two galaxies merging

Merging galaxies
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a survey project to photograph the entire Arp catalog of 338 “peculiar galaxies,” put together by astronomer Halton Arp in 1966. From the caption:

The larger galaxy (in the left of this image) is an extremely energetic galaxy type known as a Seyfert galaxy, which house active galactic nuclei at their cores. Seyfert galaxies are notable because despite the immense brightness of the active core, radiation from the entire galaxy can be observed. This is evident in this image, where the spiraling whorls of the whole galaxy are readily visible. The smaller companion is connected to the larger by a tenuous-seeming ‘bridge’, composed of dust and gas. The colliding galactic duo lie about 465 million light-years from Earth.

Note that if you ignore the blue whorls of the left galaxy, the two bright cores of these merging galaxies are about the same size. As it is unclear how long this merger has been on-going, it is possible that the galaxy on the right, in circling the left galaxy, drew out those whorls and that tenuous bridge. Other scenarios are also possible, however, such as the galaxy on the left stripping and scattering the arms of the galaxy on the right.

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A triangular Martian hill

A triangular Martian hill
Click for full image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 29, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels an “unusual shaped hill” that is estimated to be about 20 to 40 feet high.

What makes it unusual? First, it sticks up out of the endless northern lowland plains for no obvious reason, though its shape suggests the existence of bedrock topography that is now buried by the dust and debris that coats the surface of those plains.

Second, the hill itself suggests that it formed after it was covered with debris. Note the crater near its northeast cliff. It appears that the cliff chopped off part of the crater, suggesting that the hill was once level with the surrounding terrain. Some later underground pressure pushed it upward, with its angled sides determined by existing faults.

Why those forces tilted the hill upward as it did, with only its eastern fringes raised, is a question a wide view might answer.
» Read more

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New analysis of Chandrayaan-1’s lunar orbital data might explain its detection of widespread surface hydrogen on the Moon

The Earth's magnetic field, shaped by the solar wind
The Earth’s magnetic field, shaped by the solar wind

One of the significant finds coming from India’s first lunar orbiter, Chandrayaan-1, was the detection of hydrogen in many places across the entire lunar surface, in places where it seemed impossible for hydrogen to be there, even if it was locked in a molecule like water.

Researchers in Hawaii now think they have found an explanation by linking that data to the Earth’s long magnetotail, formed by the solar wind pushing against the Earth’s magnetic field. The graphic to the right illustrates that process. The scientists focused on the kind of weathering processes that occurred both when the Moon was inside that tail, and when it was not.

Li and co-authors analyzed the remote sensing data that were collected by the Moon Mineralogy Mapper instrument onboard India’s Chandrayaan 1 mission between 2008 and 2009. Specifically, they assessed the changes in water formation as the Moon traversed through Earth’s magnetotail, which includes the plasma sheet.

“To my surprise, the remote sensing observations showed that the water formation in Earth’s magnetotail is almost identical to the time when the Moon was outside of the Earth’s magnetotail,” said Li. “This indicates that, in the magnetotail, there may be additional formation processes or new sources of water not directly associated with the implantation of solar wind protons. In particular, radiation by high energy electrons exhibits similar effects as the solar wind protons.”

In other words, the evidence suggests that the hydrogen signal seen by Chandrayaan-1 might have been a very temporary implacement of that hydrogen by the solar wind, which ceases during the Moon’s periodic passages through the magnetotail. The Moon’s harsh environment then causes that hydrogen to vanish, only to reappear when it is once again exposed to the solar wind.

None of this is confirmed, so some skepticism is required. If true, however, it would provide further evidence that the hydrogen signal seen at the lunar poles that scientists hope is evidence of ice in the permanently shadowed craters might be nothing of the sort, and we shall find little ice there.

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Polygons and scallops in the high mid-latitudes of the Martian lowland plains

Polygons and scallops in the high mid-latitudes of Mars
Click for original image.

Cool image time! Only yesterday I posted an image of polygons in the dry equatorial regions of Mars, where little evidence of near-surface ice is found and are thought to be the remnants from a long-dried lakebed.

Today we take a look at some polygons in the mid-latitudes of the icy northern lowland plains, where near-surface ice appears ubiquitous and as it sublimates away with the changing seasons causes all kinds of strange formations, including polygons.

The picture to the right, cropped, reduced, and sharpened to post here, is a good example, centered on a 0.6-mile-wide bright crater that appears to be filled with glacial ice. The image was taken on June 22, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and is located at 44 degrees north latitude on the western edge of Utopia Basin. As noted by the MRO science team in 2006 for a different MRO picture with similar features:
» Read more

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The drying out of Mars’ tropics

The drying out of Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on June 26, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team calls the features surrounding these small 20 to 60 foot high hills “polygon features,” an apt description and a geological feature that is seen in many places on Mars.

When these features are found in the icy higher latitudes, it is believed they are formed in connection to the freeze-thaw cycle that causes cracks in the near surface ice. When found in the dry equatorial regions, where these polygons are located, they are usually thought to be ancient evidence of past standing water that left behind these cracks, much like the cracks seen in mud after the water has evaporated away on Earth.

The formation of these tiny hills is a bit more complex.
» Read more

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Chandra: New X-ray composite images of galaxies and supernovae remnants

Chandra image
Click for original image.

The science team for the Chandra X-Ray observatory today released five new composite images of two galaxies, two supernovae remnants, and the center of the Milky Way, combining data from multiple telescopes looking in radio, infrared, optical, and X-ray wavelengths.

The image to the right, reduced and sharpened to post here, is one of those pictures. From the press release:

As the galaxy moves through space at 1.5 million miles per hour, it leaves not one — but two — tails behind it. These tails trailing after ESO 137-001 are made of superheated gas that Chandra detects in X-rays (blue). ESO’s Very Large Telescope shows light from hydrogen atoms (red), which have been added to the image along with optical and infrared data from Hubble (orange and cyan).

The inset shows just the Hubble optical image, reduced by about 50%, to get a clearer sense of the galaxy itself. It appears to be a jelly-fish galaxy, flying through space at right angles to its plane and with tendrils of stars trailing off below.

The other four images are as interesting. The full set, including separate images in the individual wavelengths prior to combination, can be found here.

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Weird rocks on Mars

Weird rocks seen by Curiosity and Perseverance
For original images, go here and here.

Time for two cool images, this time from both of the American rovers on Mars.

The left picture above was taken on September 9, 2023 by the high resolution mast camera on Curiosity. It shows what appears to be a many-layered but rounded rock which appears typical of the many boulders that cover the terrain through which Curiosity is presently traveling. In the past the layered rocks that Curiosity has observed lower on the flanks of Mount Sharp have not been rounded. Instead, the delicate layers have often extended outward at the rock’s edges, almost like paper or threads. For some reason, the layers in the rocks here have been eroded smooth, suggesting they were once covered by flowing water or ice, able to round the rough edges in a way that Mars’ thin atmosphere can’t.

What is puzzling is the location, higher on Mount Sharp. One would expect the reverse, with such erosion more typical lower on the mountain and uneroded delicate layers more common higher on the mountain.

The right picture above was taken on September 8, 2023 by one of the high resolution mast cameras on the rover Perseverance in Jezero Crater, about 5,000 miles to west of Curiosity. It shows a rock whose shape is so strange it is hard to fathom a geological process that would result in this form. Possibly the rock was a surface layer on a larger round boulder, and the normal freeze-thaw cycle of Mars caused it crack off as one piece. The lump in the middle however makes this explanation questionable.

Also puzzling is the curved shape. On Mars almost no geological layers have been found that are curved. They are generally flat and horizontal, reflecting the lack of tectonic processes that on Earth often twist and squash layers.

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Ingenuity completes 58th flight on Mars

Overview map
Click for interactive map.

Ingenuity yesterday successfully completed its 58th flight on Mars, flying 571 feet to the northwest for 107 seconds at a height of 33 feet.

The overview map above shows with the green line the approximate route of the helicopter. Though the Ingenuity engineering team has updated the flight log (at the link above), the route has not yet been added to the Perseverance interactive map. I am guessing at that route based upon the flight plan posted on September 7, 2023, which stated the rover would head northwest as well as image science targets. That suggests it was flown above Perseverance’s planned route, as indicated by the red dotted line.

This particular flight was different than recent flights, which have generally lasted slightly longer and covered a slightly longer distance, probably so the helicopter could find a safe landing spot. This time Ingenuity landed about 23 seconds early, though the distance traveled was still slightly longer. The difference once again was almost certainly caused by the helicopter’s software picking a good landing spot. It just got above its planned landing spot sooner than expected, found a good pad, and then landed.

The blue dot marks Perseverance’s present location. It is presently moving west to reach what the scientists consider an important geological contact between two layers.

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Repeating moonquakes on Moon found to be caused by remaining sections of Apollo 17’s LM

Scientists reviewing the archive seismic data produced by the seismometers placed on the Moon by the Apollo missions have discovered that repeating small moonquakes in that data were actually caused by base of Apollo 17’s Lunar Module (LM) that provided a launchpad for the part of the LM that lifted the astronauts off the Moon.

Triangulating the origin of the mystery quakes, researchers surprisingly realized they came from the Apollo 17 lunar lander base, which expands and vibrates each morning as it becomes heated by the sun.

“Every lunar morning when the sun hits the lander, it starts popping off,” Allen Husker, a Caltech research professor of geophysics who worked on the project, said in a statement. “Every five to six minutes another one, over a period of five to seven Earth hours. They were incredibly regular and repeating.”

That the extreme range of temperatures experienced by the LM could cause detectable quakes as the LM base expanded suggests strongly how difficult it is for a spacecraft to survive the lunar night lasting 14 Earth days. For all we know, that base has now literally fallen apart due to these stresses. This in turn suggests it is highly unlikely that India’s Pragyan rover will come back to life when the sun rises on September 22, 2023.

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Lucy gets first images of its first target asteroid, Dinkinesh

The asteroid Dinkinesh as seen by Lucy

The asteroid probe Lucy has obtained its first images of Dinkinesh, the first of the ten asteroids the spacecraft is hoping to visit during its twelve year voyage to the Trojan asteroids.

The image to the left shows the motion of that asteroid over a two day period when Lucy was getting the pictures.

Lucy took these images while it was 14 million miles (23 million km) away from the asteroid, which is only about a half-mile wide (1 km). Over the next two months, Lucy will continue toward Dinkinesh until its closest approach of 265 miles (425 km) on Nov. 1, 2023. The Lucy team will use this encounter as an opportunity to test out spacecraft systems and procedures, focusing on the spacecraft’s terminal tracking system, designed to keep the asteroid within the instruments’ fields of view as the spacecraft flies by at 10,000 mph (4.5 km/s). Lucy will continue to image the asteroid over the next months as part of its optical navigation program, which uses the asteroid’s apparent position against the star background to determine the relative position of Lucy and Dinkinesh to ensure an accurate flyby. Dinkinesh will remain an unresolved point of light during the long approach and won’t start to show surface detail until the day of the encounter.

Lucy’s primary targets are asteroids in the two Trojan groups that orbit the Sun in the two Lagrange points in same orbit as Jupiter, fore and aft of the gas giant by 60 degrees. For a map of Lucy’s full mission profile, go here.

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Frank Rubio on ISS sets new record for an American in space

Though Frank Rubio was only supposed to do a six month mission, a leak on the Soyuz capsule that brought him and his two crewmates into space has resulted in all three doing a mission exceeding one year, and setting a new record for an American in space.

Today Rubio broke the old American record of 355 days, set by Mark Vande Hei in 2022. When they return on September 27, 2023, all three will have spent 371 days in space, the third longest manned mission in history, exceeded only by Sergei Avdeyev’s 381 in 1999 and Valeri Polyakov’s 437 in 1994-1995, both on Russia’s Mir space station.

Based on my interviews with Polyakov and Musa Manarov (who was on the first mission with Vladimir Titov to spend one year in space — 366 days total — in 1988) for my book Leaving Earth, it will take Rubio about one year to fully recover from this mission, though he will likely be able to function almost normally within a month or so.

It remains interesting that these American records set by Rubio and Vande Hei occurred because of decisions by the Russians, not the American space agency NASA. NASA has consistently resisted doing long missions on ISS, even though this is exactly the kind of medical research required if we are to send humans on multi-year missions to Mars and beyond. Even more embarrassing, the longest NASA planned mission, flying Scott Kelly for 340 days, was touted by NASA as a year-long mission, even though it was never going to and did not achieve that distinction.

In doing this research the Russians have always led, and appear to continue to do so on ISS.

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Ridge in Martian lowland plains

Tiny ridge in Martian lowlands
Click for original image.

Today’s cool image is interesting not because it shows us some spectacular Martian terrain, but because the most distinct feature is a thin ridge only a few feet high that pokes up out of the northern lowland plains for apparently no reason.

The picture to the right, cropped, reduced, and sharpened to post here, was taken on July 1, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The ridge is about 1.8 miles long, and is only about five feet high on its western end, rising to about 25 feet on its eastern end.

The colors differences indicate that the ridge’s peak is likely bedrock, and the surrounding greenish/blue hue suggesting sand and rocks covered with dust. The ridge might be the top of a deeper buried topological feature but that is only a guess.
» Read more

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Layered glaciers in two small Martian craters

Layered glaciers in two small Martian craters
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 7, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what planetary scientists label somewhat vaguely as “layered deposits,” because though the features inside both of these craters strongly resemble glacial ice features, until this is confirmed a good scientist remains skeptical.

I can be more bold, and call the layers glacial in both of these small and very shallow craters (less than a 100 feet deep). To explain this it is important to understand that the lighting and shadows make it hard to distinguish the high points of these layers. Based on the elevation data from MRO, the ground descends to the south, and the mesa in the southern half of each crater’s floor is actually far below the layers and material to the north.

This elevation data suggests that the layered material is surviving best against the crater’s northern interior wall, which at this latitude, about 36 degrees south, will be in shadow the most.
» Read more

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Ingenuity flies on, completing its 57th flight

Overview map
Click for interactive map

On September 3, 2023 Ingenuity successfully completed its 57th flight on Mars, traveling 713 feet for two minutes and nine seconds. As noted at the tweet at the link, the helicopter has now accumulated more than 100 minutes of flight time.

As it has on almost all its recent flights, the helicopter flew a slightly longer distance for slightly longer that its flight plan, probably because it was taking time to find a safe landing spot.

The green dot on the overview map above shows Ingenuity’s new location. It has moved west and north of Perseverance, following the rover’s planned route as indicated by the red dotted line. The blue dot marks Perseverance’s present location. The yellow lines indicate the approximate area of the mosaic below, just released by the Perseverance science team, taken on July 8, 2023 by the rover’s high resolution camera and cropped and reduced to post here. It shows us the rover’s eventual path forward, into that mountain gap.

Mosaic looking west at the rim of Jezero Crater
Click for original, full resolution image (a large file).

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Japan successfully launches XRISM X-ray space telescope and SLIM lunar lander

SLIM's landing zone
Map showing SLIM landing zone on the Moon.
Click for interactive map.

Japan today (September 7th in Japan) successfully used its H-2A rocket to place both the XRISM X-ray space telescope and SLIM lunar lander into orbit.

As of posting XRISM has been successfully deployed. SLIM has not, as it needs to wait until after a second burn of the rocket’s upper stage about 40 minutes later. The map to the right shows SLIM’s landing target on the Moon, where it will attempt a precision landing within a zone about 300 feet across.

This was Japan’s second launch this year, so it does not get included in the leader board for the 2023 launch race:

62 SpaceX
39 China
12 Russia
7 Rocket Lab
7 India

In the national rankings, American private enterprise still leads China in successful launches 71 to 39. It also still leads the entire world combined, 71 to 64, while SpaceX by itself now trails the rest of the world (excluding American companies) only 62 to 64.

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Martian ice islands amidst a Martian ice ocean

Glacier country on Mars
Glacier country on Mars

Martian ice islands in a Martian sea of ice
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on June 19, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists simply labeled this “Deposit Layers,” but that description hardly covers the incredibly diverse and puzzling features within the picture. We see layers, swirls, and radiating groves, all suggesting glacial features. We see mesas apparently covered with ice, and a flat surrounding lower plain that appears to be also ice but acting more like an ocean or sea. If there is any visible bedrock at this location it is difficult to determine.

The dominance of ice features is not surprising however, considering the location. The red dot on the overview map above marks this location, in a large 80-by-56-mile-wide basin inside the 2,000-mile-long northern mid-latitude strip I dub glacier country, because almost every image from MRO shows distinct glacial features. This particular basin is considered part of the segmented and indistinct canyon dubbed Mamers Valles, that winds its way through this glacier country of chaos terrain to eventually drain into the northern lowland plains.

From a geologist’s perspective, however, the layers are the most significant feature in the picture, as those layers mark the innumerable climate cycles that have apparently shaped the Martian surface. Mapping those layers will likely involve decades of work, but when largely completed we shall have a very precise history of the red planet’s geological history, going back several billion years.

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LRO takes image of Vikram on Moon


Click for interactive map. To see the original
image, go here.

The science team for Lunar Reconnaissance Orbiter (LRO) yesterday released an oblique image taken of India’s Vikram lander, on August 27, 2023, four days after the lander touched down about 370 miles from the south pole.

The LROC (short for LRO Camera) acquired an oblique view (42-degree slew angle) of the lander. … The bright halo around the vehicle resulted from the rocket plume interacting with the fine-grained regolith (soil).

That image is shown in the inset to the right. I have cropped it to focus on Vikram itself, which is in the center of the inset, with its shadow to its right, the opposite of all the surrounding craters. Pragyan is in this image, but neither it nor its tracks appear visible. The rover had moved west from the lander, which would be downward to the line of three craters near the bottom of the inset. To get a better sense of Pragyan route, compare this image with the map India’s space agency ISRO released on September 2nd.

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Martian mounds surrounded by moats

Martian mounds with moats
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 1, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the camera team labels “Circular Mounds Surrounded by Moats,” which when all the known data is considered are probably caused by a spray of small meteorites landing on a field of ice.

Why ice? The location is at 37 degrees south latitude, in the cratered southern highlands of Mars, where many images show glacial-type features inside many craters. In fact, all the nearby craters at this location appear to have such features, suggesting the presence of near-surface ice trapped in these craters.

The picture actually looks at the floor of another such crater, with the mounds in the image’s upper left the crater’s indistinct central peaks. Though only 8.5 miles wide, the crater is deep, with interior walls that quickly rise 2,800 feet to the rim. That depth further suggests ice, as any snow that fell here in the far past could easily become trapped, inside what could be thought of a cold trap.
» Read more

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Bubbling but frozen terrain on Mars

Bubbling but frozen terrain on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on June 8, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows some of the more unusual terrain found at the higher latitudes in the Martian northern lowland plains.

How do we explain this strange landscape? Based on what little we presently know about Mars, at 40 degrees north latitude this bubbly-looking surface probably indicates the presence of a lot of near-surface ice that at some time in the past was heated for some reason and thus bubbled upward to form these mounds. Think of tomato soup simmering.

Unlike simmering tomato soup, this terrain is solid and no longer bubbling. We are looking at a soup that has frozen even as it bubbled. The process could have been like an ice volcano, the ice turning to thick slurry that froze quickly, like lava. Or it could have happened fast, and then froze to remain unchanging in the eons since.
» Read more

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JAXA schedules last H-2A rocket launch, carrying X-Ray telescope and lunar lander

SLIM's landing zone
Map showing SLIM landing zone on the Moon.
Click for interactive map.

Japan’s space agency JAXA today announced that it has finally rescheduled the launch of its XRISM X-Ray telescope and its SLIM lunar lander launch for September 7, 2023, lifting off using the last flight of its H-2A rocket.

The previous launch attempt several weeks ago was scrubbed due to high winds. This new launch date has a window of seven days, which means if weather scrubs the September 7th launch they will be able to try again immediately within that window.

The white dot on the map to the right shows the targeted landing site of SLIM, which is testing the ability of an unmanned probe to land precisely within a tiny zone of less than 300 feet across.

Meanwhile, with the retirement of the H-2A rocket and its replacement having not yet flown successfully (its first launch failed in March), Japan after this launch will be in the same boat as Europe, without a large rocket and lacking the ability to put large payloads into orbit.

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