Tag: science

Big Martian gullies partly filled with glacial material

1:15 pm

Overview map

Big Martian gullies partly filled with glacial material

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on August 18, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists dub as “large gullies with infilled alcoves.”

Gullies on Mars were one of the first discoveries by orbiters of small-scalle potential water-caused features on the Red Planet. The favorite explanation for their formation today involves the seasonal freeze-thaw cycle, combined with the deposition of ice and dry ice frost in the winter. When that ice and dry ice sublimates away in the spring it causes collapse and erosion, widening the gullies.

These gullies also exhibit evidence that underground and glacial ice might contribute as well. The material in the largest gullies looks like a mixture of glacial material and dust and debris. It could also be that there is ice impregnated in the ground, which can cause large collapses when it sublimates away.

The white rectangle on the overview map and inset above marks the location of this picture, on the western rim of a 13-mile-wide unnamed crater inside the western portion of the 2,000-mile-long mid-latitude strip on Mars I dub glacier country, since every image from orbit shows evidence of glaciers.

This picture is no different, as the horizontal cracks at the base of the crater rim suggests the glacier that fills the crater floor is being pulled apart by gravity at its edges. The elevation drop from the top of the rim to the floor is about 3,200 feet, so any ice on that slope will definitely be stressed by gravity. Such cracks are therefore not surprising.

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Psyche takes its first pictures

9:49 am

The spacecraft Psyche — going to the metal asteroid Psyche — has successfully taken its first pictures, proving its camera and pointing system work as planned.

The pictures, taken on December 4, 2023 from about 16 million miles from Earth, are actually quite boring, merely showing a field of stars. However,

The imager instrument, which consists of a pair of identical cameras, captured a total of 68 images, all within a star field in the constellation Pisces. The imager team is using the data to verify proper commanding, telemetry analysis, and calibration of the images. …The imager takes pictures through multiple color filters, all of which were tested in these initial observations.

At this moment all looks good for Psyche’s eventual arrival at Psyche in 2029.

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Mars Reconnaissance Orbiter takes another look at the non-face on Mars

12:51 pm

The non-face on Mars
Click for original image

In 2007, shortly after it began science operations in Mars orbit, the science team for Mars Reconnaissance Orbiter (MRO) pointed its high resolution camera at the so-called “Face on Mars”, taking a picture that confirmed (as had Mars Global Surveyor several years earlier) that this “face” was a non-face, simply a mesa whose features made it appear roughly facelike in low resolution imagery.

Now, more than sixteen years later, scientists have used MRO to take a new picture of the non-face mesa. That picture is to the right, cropped, reduced, and sharpened to post here. Compared to the 2007 photo the new photo has far better lighting conditions, revealing many details on the mesa’s eastern half that were mostly obscured by shadows previously.

In fact, these new details strongly suggest that the depression on the mesa’s eastern slopes harbors a decaying glacier. At least, that is what the features there resemble.
» Read more

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China launches Egyptian Earth observation satellite

12:03 am

China successfully launched an Egyptian Earth observation satellite on December 4, 2023, its Long March 2C rocket lifting off from its Jiquan spaceport in northwestern China.

The satellite was built in Egypt with Chinese assistence, and is designed to study water and land resources for Egypt.

No word on where the rocket’s lower stages, which use toxic hypergolic fuels, crashed within China.

The leaders in the 2023 launch race:

89 SpaceX
54 China
16 Russia
7 Rocket Lab
7 India

American private enterprise still leads China in successful launches, 101 to 54, and the entire world combined 101 to 86. SpaceX by itself now leads the entire world (excluding other American companies) 89 to 86.

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Sunspot update: The Sun continues to prove that solar scientists understand nothing

3:49 pm

With today’s monthly update from NOAA of its graph tracking the number of sunspots on the Sun’s Earth-facing hemisphere, we find that the Sun continues to confound the experts. As I do every month, I have posted this graph below, with additional details to provide the larger context.

In November the sunspot count rose slightly, but remained well below the highs that had occurred through most of the first half of 2023. Yet, despite that continuing reduction in the number of sunspots, the overall amount of activity remains above the prediction of some scientists, and below the prediction of other scientists.
» Read more

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Lava-filled Martian crater

12:56 pm

Lava-filled Martian crater
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 10, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the northeast corner of an unnamed 7-mile-wide crater, located near the equator in the dry Martian tropics.

The MRO science team labels this “crater and lava fill”, suggesting that the crater interior is filled with lava material. The nature of that crater floor reinforces this conclusion, as it is relatively smooth and does not have rough aspects of glacial material found in craters in the mid-latitudes. Instead, it looks like a frozen lake of lava that has the peaks of mostly buried features poking up at various spots.

What makes this crater interesting however are the gullies on the northern interior rim. Gullies on Mars are normally thought to be associated with some water-frost-ice process, probably seasonal, where the thaw-freeze cycle causes small collapses and avalanches. Yet, this crater is almost at the equator, in a very dry region where no evidence of near-surface ice is found. Gullies here suggest the hypothesis for explaining the gullies on Mars have not quite solved the mystery.
» Read more

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Astronomers: A solar system with six Earth-sized planets orbiting in perfect resonance

9:38 am

The resonances of this exo-solar system
Click for original image.

Astronomers today announced the discovery of a solar system with six Earth-sized exoplanets that orbit their Sun-like star in a synchronized manner, their orbits in a gravitational lock-step called resonance.

The graphic to the right illustrates that pattern. From the press release:

While multi-planet systems are common in our galaxy, those in a tight gravitational formation known as “resonance” are observed by astronomers far less often. In this case, the planet closest to the star makes three orbits for every two of the next planet out – called a 3/2 resonance – a pattern that is repeated among the four closest planets.

Among the outermost planets, a pattern of four orbits for every three of the next planet out (a 4/3 resonance) is repeated twice. And these resonant orbits are rock-solid: The planets likely have been performing this same rhythmic dance since the system formed billions of years ago. Such reliable stability means this system has not suffered the shocks and shakeups scientists might typically expect in the early days of planet formation – smash-ups and collisions, mergers and breakups as planets jockey for position. And that, in turn, could say something important about how this system formed. Its rigid stability was locked in early; the planets’ 3/2 and 4/3 resonances are almost exactly as they were at the time of formation. More precise measurements of these planets’ masses and orbits will be needed to further sharpen the picture of how the system formed.

All the planets have orbits less than 55 days long, and though all have masses less than six Earth-masses, data suggests they more resemble Neptune because of their expanded gaseous make-up caused by the close orbits to the star.

Future observations are planned, most especially with Webb because its infrared capability will detect much of the chemistry of this system.

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Communications resume with Mars orbiters and rovers

9:06 am

It now appears that communications have resumed between Mars and the Earth, the planets having moved do that the Sun is no longer in between. From an update by the Curiosity science team today:

Mars has just emerged from its solar conjunction period, when sending commands to all Mars spacecraft was not safe for three weeks since the Red Planet was behind the Sun as seen from Earth. During that time, Curiosity followed a long plan of instructions covering Sols 4004-4022 which were uploaded to the rover during the week of October 30. The early word on is that the rover weathered the long blackout period just fine.

During the black-out the rovers had continued to upload data to the orbiters above, and some of that data was relayed back to Earth this past weekend, though the relay was “spotty” with some data packages lost.

Communications have now cleared up, and so we should expect both Curiosity and Perseverance to resume full operations again.

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Hubble in safe mode due to gyroscope problem

8:58 am

One of the three working gyroscopes (three have already failed0 on the Hubble Space Telescope experienced repeated problems in mid-November, and has now put the telescope in safe mode while engineers trouble-shoot the problem.

Hubble first went into safe mode Nov. 19. Although the operations team successfully recovered the spacecraft to resume observations the following day, the unstable gyro caused the observatory to suspend science operations once again Nov. 21. Following a successful recovery, Hubble entered safe mode again Nov. 23.

The team is now running tests to characterize the issue and develop solutions. If necessary, the spacecraft can be re-configured to operate with only one gyro. The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009. To date, three of those gyros remain operational, including the gyro currently experiencing fluctuations. Hubble uses three gyros to maximize efficiency, but could continue to make science observations with only one gyro if required.

The long term plan when the telescope only has two working gyros, assuming no improvised maintenance mission is flown to Hubble to give it new gyroscopes, is to work with only one (treating the second as a back-up) in order to extend the telescope’s life as long as possible.

And though it is true that Hubble could continue to do science with only one gyro, images from that point will likely not be as sharp, and thus will end more than three decades of imagery that changed our perception of the universe.

The Chinese 2-meter Xuntian optical space telescope, now scheduled for launch in 2025, will likely then replace Hubble as the world’s top optical telescope. American astronomers better start learning Chinese, assuming China even allows them access. They will not have a right to complain, however, as it was their decision to not build a Hubble replacement, in their 2000, 2010, and 2020 decadal reports.

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Thick windblown ash in Mars’ largest mountain region

12:35 pm

Thick windblown ash near Mars' largest volcano
Click for original picture.

The cool image to the right, rotated, cropped, reduced, and sharpened to post here, was taken on September 1, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the scientists label as “Erosional Features on Olympus Mons.”

What is eroding? Based on the picture itself the first guess is volcanic ash, as these features strongly resemble the many features seen in the Medusae Fossae Formation, the largest volcanic ash field on Mars — about the size of the subcontinent of India.

Medusae however is many thousand miles away, and is not apparently related to any specific volcano. These features are instead directly linked to Olympus Mons, the largest known volcano in the solar system. However, much of the terrain for many hundreds of miles around Olympus is covered with flood lava, which was deposited and hardened quickly to form smooth featureless plains that have resisted much erosion over the eons. Here the terrain is clearly eroded, which suggests that if the material here is volcanic, it was laid down not by flood lava but by falling ash that got compressed but was easily friable and could be blown away by the winds of Mars’ thin atmosphere.
» Read more

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Close-up of Helene, one of Saturn’s many many moons

2:04 pm

Helene, as seen by Cassini in 2011
Helene, as seen by Cassini in 2011

Cool image time! Though the Saturn orbiter Cassini is long gone, having been sent into Saturn’s atmosphere to burn up in 2017, its image archive of magnificent pictures is still available to peruse. To encourage others to do so, NASA today issued a series of press releases, listing the spacecraft’s top ten pictures from 2011, 2012, 2013, 2014, and 2015.

The picture to the right, cropped, reduced, and sharpened to post here, comes from the 2011 collection and was taken on June 18, 2011. It shows a close-up of 21-mile-wide Helene, one of Saturn’s many many moons and only discovered in 1980. Back in 2010 I featured another Cassini image of Helene, but that picture did not reveal the small surface features seen in the photo to the right.

The light and dark streaks probably indicate dust flowing downhill on the surface. Though the gravity of this object is tiny, it will be enough for dust to act like almost like a liquid, flowing down grade and then pooling in the central pond at the lowest point near the center of the picture. That process is so much like liquid flowing that it appears to have even eroded gullies on slopes near the top and bottom of the picture.

Side note: NASA’s “Science Editorial Team” also issued a press release today that falsely and ignorantly claimed these releases were “to celebrate 10 years since arriving at Saurn,” implying that Cassini arrived in 2013 and is still functioning.

The problem is that Cassini arrived in orbit around Saturn in 2004 and as I noted above ended its mission in 2017. It thus appears that the NASA Science Editorial Team is unable to do even one five-second web search to find out what really happened.

Just another data point indicating the dark age we now live in.

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British scientists get their own Bennu sample to study

9:16 am

The British History Museum has now received a small sample of material from the asteroid Bennu, brought back to Earth by the planetary probe OSIRIS-REx.

The first two years of research at the Natural History Museum will focus on non-destructive tests, such as X-ray diffraction and electron microscopy to learn about Bennu’s mineral composition and structure. The largest grains in the sample are on the order of millimetres wide, while the smallest are mere dust particles. “It doesn’t sound like a lot of material, but it’s plenty to work with,” King said.

The museum is home to one of the world’s leading meteorite collections, and the staff are well-used to handling small amounts of extremely precious materials from outer space. Unlike meteorites that have been baked and battered on their fiery passage through Earth’s atmosphere, the dust and rocky fragments from Bennu were brought to Earth in pristine condition, allowing scientists a rare glimpse of the unaltered asteroid.

The last sentence says it all. Up until recently, researchers have had a distorted view of the overall make-up of asteroids because the oldest kinds, carbonaceous chondrite, are the most delicate and get significantly changed by their passage through the Earth’s atmosphere. The samples from Bennu and Ryugu are changing this, and will eventually revolutionize the understanding scientists have of our present solar system.

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