Tag: science

Voyager-1 has computer issues

9:03 am

According to the Voyager-1 science team, the probe has developed a problem with one of its three onboard computers, called the flight data system (FDS), that is preventing it from sending back useable data.

Among other things, the FDS is designed to collect data from the science instruments as well as engineering data about the health and status of the spacecraft. It then combines that information into a single data “package” to be sent back to Earth by the TMU. The data is in the form of ones and zeros, or binary code. Varying combinations of the two numbers are the basis of all computer language.

Recently, the TMU began transmitting a repeating pattern of ones and zeros as if it were “stuck.” After ruling out other possibilities, the Voyager team determined that the source of the issue is the FDS. This past weekend the team tried to restart the FDS and return it to the state it was in before the issue began, but the spacecraft still isn’t returning useable data.

Engineers are trouble-shooting the problem, and expect it will take several weeks at best to identify and then fix the issue. The 22-hour travel time for communications to reach the spacecraft, now beyond the edge of the solar system more than 15 billion miles away, means that it will at minimum take about two days to find out if a transmitted fix works.

As the spacecraft was launched in 1977, most of the engineers now working on it were not even born then, and must deal with a technology that was designed before personal computers, no less smart phones, even existed. Like the entire 1960s space race, the two Voyager craft now beyond the solar system were built by engineers using slide rules.

Voyager-2 also had problems in August that engineers were able to fix, so the prognosis here is not bad.

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Craters in a row

11:20 am

Craters in a row
Click for original image.

Cool image time from Mars! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 13, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It highlights a string of craters, all lined up in an almost straight line.

Were these craters caused by the impact of an asteroid that broke up as it burned its way through the thin Martian atmosphere? The lack of any raised rims argues instead that these are sinks produced not from impact but from a collapse into a void below, possibly a fault line.

Yet, almost all of the craters in this image, even those not part of this crater string, show no raised rims. If sinks, the voids below don’t seem to follow any pattern, which once again argues in favor of random impacts, with the string produced by a bolide breaking up just prior to hitting the ground.
» Read more

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Galaxies in a row

9:18 am

Galaxies in a row
Click for original image.

Cool image time from Hubble! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a survey of nearby “pecular” galaxies. What makes it unusual is the line of distant galaxies below the largest on the left.

The wonderful quality of this image also reveals several further galaxies, not associated with this system but fortuitously positioned in such a way that they appear to be forming a line that approaches the leftmost (in this image) component of Arp-Madore 2105-332, which is known individually as 2MASX J21080752-3314337. The rightmost galaxy, meanwhile, is known as 2MASX J21080362-3313196. These hefty names do not lend themselves to easy memorisation, but they do actually contain valuable information: they are coordinates in the right ascension and declination system used widely by astronomers to locate astronomical objects.

Both larger galaxies are thought to be about 200 million light years away, with the smaller ones far more distant. If you look at the full resolution image, you will see that there are at least six galaxies in that line, one that appears to be an elliptical galaxy with all the rest a variety of different types of spiral galaxies. The detail provided by Hubble is truly astonishing.

Though they are not linked to the larger galaxies, it is not clear if they are linked to each other.

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Webb takes infrared false-color image of supernova remnant Cassiopeia A

8:54 am

Cass A in infrared
Click for original image.

Using the Webb Space Telescope, astronomers have obtained the first wide full infrared view of the supernova remnant Cassiopeia A, the remains of a supernova that occurred about 11,000 years ago. That image is to the right, reduced to post here.

The most noticeable colors in Webb’s newest image are clumps represented in bright orange and light pink that make up the inner shell of the supernova remnant. Webb’s razor-sharp view can detect the tiniest knots of gas, comprised of sulfur, oxygen, argon, and neon from the star itself. Embedded in this gas is a mixture of dust and molecules, which will eventually become components of new stars and planetary systems. Some filaments of debris are too tiny to be resolved by even Webb, meaning they are comparable to or less than 10 billion miles across (around 100 astronomical units). In comparison, the entirety of Cas A spans 10 light-years across, or 60 trillion miles.

…When comparing Webb’s new near-infrared view of Cas A with the mid-infrared view, its inner cavity and outermost shell are curiously devoid of color. The outskirts of the main inner shell, which appeared as a deep orange and red in the MIRI image, now look like smoke from a campfire. This marks where the supernova blast wave is ramming into surrounding circumstellar material. The dust in the circumstellar material is too cool to be detected directly at near-infrared wavelengths, but lights up in the mid-infrared.

The four rectangles mark specific features of particular interest, with #4, dubbed by the scientists Baby Cas, the most intriguing.

This is a light echo, where light from the star’s long-ago explosion has reached and is warming distant dust, which is glowing as it cools down. The intricacy of the dust pattern, and Baby Cas A’s apparent proximity to Cas A itself, are particularly intriguing to researchers. In actuality, Baby Cas A is located about 170 light-years behind the supernova remnant.

By comparing this infrared view with Hubble’s optical and Chandra’s X-ray views, astronomers will be able to better decipher Cas A’s make-up and geometry.

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The steep mountain slopes inside Valles Marineris

1:28 pm

Overview map

The steep mountain slopes inside Valles Marineris
Click for full image.

Time for another cool image showing the dramatically steep terrain of Valles Marineris on Mars, the largest known canyon in the solar system. The picture to the right, cropped, reduced, and enhanced to post here, was taken on October 31, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists rightly label this picture “Steep Slopes in West Melas Chasma”. The red dot marks the high point on this ridgeline. The green dot at the upper left marks the lowest point in the picture, about 4,800 feet below the peak. The blue dot on the right edge marks the low point on the ridge’s eastern flank, about 4,600 feet below the peak. The cliff to the east of the peak drops quickly about 1,300 feet in less than a mile.

On the overview map above, the white dot marks the location. The inset is an oblique view, created from a global mosaic of MRO’s context camera images, with the white rectangle indicating approximately the area covered by the picture above.

The immense scale of Valles Marineris must once again be noted. The elevations in this picture are comparable to the descent you make hiking down from the South Rim of the Grand Canyon. They pale however when compared to Valles Marineris. In the inset I have indicated the rim and floor of Valles Marineris in this part of the canyon. The elevation distance between the two is 18,000 feet.

In other words, the canyon to the east of this ridge is quite comparable in size to the Earth’s Grand Canyon, and it is hardly noticeable within the larger canyon of Valles Marineris.

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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.
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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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