Voyager-2 discovered Neptune to be a planet of quickly changing weather

Neptune's fast changing weather
Click for source.

Cool image time! When Voyager-2 flew past Uranus in 1986, the data showed the gas giant’s weather to be relatively sedate and quiet, with little changing during the fly-by. Scientists expected this: Uranus’s distance from the Sun meant it got little energy to fuel an active climate, with any activity produced by internal heating due to the gravitational pressure of its mass. And Uranus did not produce that much heat internally.

When Voyager-2 passed Neptune three year later, the scientists expected something similar, or even less, due to Neptune’s greater distance from the Sun. Instead, Voyager-2’s data showed Neptune’s weather patterns to be changing constantly and quickly, as illustrated by the three images of the Great Dark Spot to the right, the biggest storm on Neptune at that time and located in the planet’s southern mid-latitudes.

The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipating over periods of several to tens of hours. In this sequence spanning two rotations of Neptune (about 36 hours) Voyager 2 observed cloud evolution in the region around the Great Dark Spot at an effective resolution of about 60 miles per pixel. The surprisingly rapid changes which occur over the 18 hours separating each panel shows that in this region Neptune’s weather is perhaps as dynamic and variable as that of the Earth. However, the scale is immense by our standards — the Earth and the [Great Dark Spot] are of similar size.

In Neptune’s frigid atmosphere, where temperatures are as low as 55 degrees Kelvin (-360 F), the cirrus clouds are composed of frozen methane rather than Earth’s crystals of water ice.

Subsequent observations by the Hubble Space Telescope in 1994 found this Great Dark Spot was gone, replaced by a comparable storm in the northern hemisphere. Further Hubble observations found Neptune’s storms tend to last about two years, fading as they drifted towards the equator. Those observations however also detected storms drifting away from the equator. Other research suggested the storms might be influenced by the Sun’s sunspot cycle.

All of the data post-Voyager-2 remains very coarse and uncertain, as we are looking at Neptune at a great distance. Thus, no theory about what is happening carries much weight, especially because we do not know why Neptune produces so much more internal heat than Uranus, fueling this fast-changing weather. For example, Neptune gets 1/20th of the energy received by Jupiter, yet its atmosphere appears even more active and variable.

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Voyager-2’s view of clouds on top of clouds on Neptune

Neptune's upper clouds
Click for original image.

Time to continue our cool image tour this week of the Voyager-2 archive of Neptune, taken during the spacecraft’s August 25, 1989 close fly-by of the gas giant, zipping only 2,700 miles above the cloud-tops. This remains the only mission to visit Neptune so far.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken two hours before Voyager-2’s closest approach. From the caption:

These clouds were observed at a latitude of 29 degrees north near Neptune’s east terminator. The linear cloud forms are stretched approximately along lines of constant latitude and the sun is toward the lower [right]. The bright sides of the clouds which face the sun are brighter than the surrounding cloud deck because they are more directly exposed to the sun. Shadows can be seen on the side opposite the sun.

These shadows are less distinct at short wavelengths (violet filter) and more distinct at long wavelengths (orange filter). This can be understood if the underlying cloud deck on which the shadow is cast is at a relatively great depth, in which case scattering by molecules in the overlying atmosphere will diffuse light into the shadow. Because molecules scatter blue light much more efficiently than red light, the shadows will be darkest at the longest (reddest) wavelengths, and will appear blue under white light illumination.

The resolution of this image is 6.8 miles per pixel and the range is only 98,000 miles. The width of the cloud streaks range from 30 to 125 miles, and their shadow widths range from 18 to 30 miles. Cloud heights appear to be of the order of 31 miles.

Of all the high resolution images taken of Neptune by Voyager-2, this is the only one that clearly shows some dimensionality. Later photographs taken by Hubble and other ground- and space-based telescopes can only show global views that are far less sharp than the global views produced by Voyager-2.

This picture hints at Neptune’s very complex weather patterns, which has no well-defined surface and is made up mostly of gas and liquid. Though scientists have used Hubble to roughly track those weather patterns, they can only glean the most basic facts. For example, its fast-changing weather appears to be driven by high winds, thought to move as fast as 1,300 miles per hour. This fact however is woefully incomplete and very uncertain, as we have no way to track detailed weather patterns at multiple depths.

Our tour will continue tomorrow.

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A soft barred galaxy with an active nucleus

A barred galaxy with an active galactic nucleus
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 two different surveys aimed at studying galaxies with what scientists call active galactic nuclei.

IC 486 lies right on the edge of the constellation Gemini (the Twins), around 380 million light-years from Earth. Classified as a barred spiral galaxy, it features a bright central bar-shaped structure from which its spiral arms unfurl, wrapping around the core in a smooth, almost ring-like pattern.

…At the galaxy’s center a noticeable white glow outshines the starlight around it. This is light given off by IC 486’s active galactic nucleus (AGN), powered by a supermassive black hole more than 100 million times the mass of the Sun. Every sufficiently large galaxy hosts a supermassive black hole at its center, but some of these black holes are particularly ravenous, marshaling vast amounts of gas and dust into swirling accretion discs from which they feed. The intense heat generated by the orbiting disc of material generates intense radiation up to and including X-rays, which can outshine the entire rest of the galaxy. In these cases, the galaxy is known as an active galaxy, with an AGN at its center.

For comparison, the relatively inactive supermassive black hole at the center of the Milky Way has a mass of about four million Suns, considerably smaller than IC 486’s. Why one is active and the other not however is not yet truly understood, though their different masses might provide part of the explanation.

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A luminous swirl set against the deep black of space, the barred spiral galaxy IC 486 glows with a soft, ethereal light in this new ESA/Hubble Picture of the Month image. IC 486 lies right on the edge of the constellation Gemini (the Twins), around 380 million light-years from Earth. Classified as a barred spiral galaxy, it features a bright central bar-shaped structure from which its spiral arms unfurl, wrapping around the core in a smooth, almost ring-like pattern. Hubble’s keen eye reveals subtle variations in colour across the galaxy. The pale, luminous centre is dominated by older stars, while faint bluish regions in the surrounding disc trace pockets of more recent star formation. Wisps of dust thread through the galaxy’s structure, gently obscuring light and tracing regions of increased molecular gas where new stars are likely to form. At the galaxy’s centre a noticeable white glow outshines the starlight around it. This is light given off by IC 486’s active galactic nucleus (AGN), powered by a supermassive black hole more than 100 million times the mass of the Sun. Every sufficiently large galaxy hosts a supermassive black hole at its centre, but some of these black holes are particularly ravenous, marshalling vast amounts of gas and dust into swirling accretion discs from which they feed. The intense heat generated by the orbiting disc of material generates intense radiation up to and including X-rays, which can outshine the entire rest of the galaxy. In these cases, the galaxy is known as an active galaxy, with an AGN at its centre.  The data used to make this image comes from two separate observing programmes — #17310 (PI: M. J. Koss) and #15444 (PI: A. J. Barth) — with similar aims: to survey nearby active galaxies like IC 486 and record detailed, high-quality images of their central black holes and the stars near the core of the galaxy. By combining Hubble’s sharp imaging with large comprehensive samples, these programmes are enabling detailed comparisons of how stars, gas, dust, and black holes interact in galaxy centres. A key goal of this work is to understand how galaxies grow by linking their large-scale structures, such as bars and spiral arms, to activity in their nuclei. To achieve this, the research teams are leveraging both expert classifications and citizen science through Galaxy Zoo, with datasets that will ultimately be released to the public. In parallel, the same images are being used to test how well large language models and other machine learning techniques can reproduce or extend human classifications, offering a new way to scale galaxy morphology studies to the largest surveys that are currently being performed with the Euclid telescope. Beyond IC 486 itself, the image is peppered with distant background galaxies and foreground stars. Some stars appear with characteristic diffraction spikes, while the more diffuse, reddish smudges are far more distant galaxies scattered across the cosmos. Though it may appear calm and orderly, IC 486 is a dynamic system shaped by gravity and stellar evolution. Over millions of years, its structure will continue to evolve as stars are born, age, and fade, contributing to the ongoing story of galactic life in the Universe. [Image Description: A face-on view of the barred spiral galaxy IC 486, showing a bright, elongated central bar and softly curving, ring-like spiral arms with subtle blue star-forming regions and dark dust lanes, set against a black background dotted with distant galaxies and a few foreground stars.] Links IC 486 (wide-field view) Image on ESA website Pan video: IC 486 Pan video: IC 486 (wide-field view)

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Neptune as seen by Voyager-2 in 1989, four days before closest approach

Neptune as seen by Voyager-2 on approach
Click for original image.

Cool image time! In two earlier posts I highlighted the pictures taken by Voyager-2 of Neptune’s two largest moons, Triton and Proteus, when it made its close fly-by of Neptune in 1989. Other than a very distant low resolution picture of 105-mile-wide Nereid, Voyager-2 took no other good images of Neptune’s other known moons.

So today, let’s begin a tour of some of Voyager-2’s imagery of Neptune itself. The picture to the right, reduced slightly to post here, was taken on August 20, 1989 as the spacecraft was beginning its approach to Neptune. It shows the full daylight hemisphere of the gas giant. From the caption:

The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge; on the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds were seen to persist for as long as Voyager’s cameras could resolve them. North of these, a bright cloud band similar to the south polar streak may be seen.

Next week I will post some of the other good shots taken of Neptune, as well as one or two close-ups of Triton that need highlighting. Sadly, at that point we will have more or less reviewed most of the best data now available of this distant world. Astronomers have used the Hubble Space Telescope in subsequent years to attempt to track its weather patterns, but even Hubble really can’t provide enough resolution to really make that research substantive.

But stay tuned. The Voyager-2 images to come are worth viewing.

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Astronomers detect the first comet whose nucleus’ reversed its rotation

Astronomers using data collected by the orbiting Gehrels Swift and Hubble space telescopes now think the nucleus of a small comet reversed its rotation sometime in 2017, caused by the force of the material sublimated off its surface.

From the abstract of their paper [pdf]:

The rotations of cometary nuclei are known to change in response to outgassing torques. The nucleus of the Jupiter-family comet 41P/Tuttle–Giacobini–Kresak exhibited particularly dramatic rotational changes when near perihelion in 2017 April. Here, we use archival Hubble Space Telescope observations from 2017 December to study the postperihelion lightcurve of the nucleus and to assess the nucleus size.

From both Hubble photometry and nongravitational acceleration measurements, we find a diminutive nucleus with effective radius 500 ± 100 meters. Systematic optical variations are consistent with a two-peaked (i.e., rotationally symmetric) lightcurve with period 0.60 ± 0.01 days, substantially different from periods measured earlier in 2017. The spin of the nucleus likely reversed between perihelion in 2017 April and December as a result of the outgassing torque.

In plain English: the thrust of the material being thrown from the surface as the comet made its close approach to the Sun was sufficient to slow and then reverse the nucleus’s rotation. This process was helped by the relatively small size of the nucleus compared to the material being sublimated from it.

The data also suggests the nucleus was once much larger, and has been whittled down to its present small size as it made its multiple close fly-bys of the Sun during the past 1,500 years. Rather than break-up, as most comets do at some point as their nucleus gets smaller, this comet’s nucleus simply kept shrinking, to the point that the thrust of that material could change its rotation.

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Webb and Hubble take a look at Saturn

Saturn seen by Webb and Hubble

Astronomers using both the Hubble Space Telescope and the Webb Space Telescope have produced new complementary views of the ringed planet Saturn.

Those photographs are shown above, with Webb’s false-color infrared image to the left and Hubble’s optical image to the right. From the press release:

In the Webb image, a long-lived jet stream known as the “ribbon wave” meanders across the northern mid-latitudes, influenced by otherwise undetectable atmospheric waves. Just below that, a small spot represents a lingering remnant from the “Great Springtime Storm” of 2010 to 2012. Several other storms dotting the southern hemisphere of Saturn are visible in Webb’s image, as well. All these features are shaped by powerful winds and waves beneath the visible cloud deck, making Saturn a natural laboratory for studying fluid dynamics under extreme conditions.

…In Webb’s infrared image, the rings are extremely bright because they are made of highly reflective water ice. In both images, we’re seeing the sunlit face of the rings, a little less so in the Hubble image, hence the shadows visible underneath on the planet.

There are also subtle ring features such as spokes and structure in the B ring (the thick central region of the rings) that appear differently between the two observatories. The F ring, the outermost ring, looks thin and crisp in the Webb image, while it only slightly glows in the Hubble image.

The press release says little about the Hubble image, mostly because it shows little new by itself. It however is part of an on-going decade-long survey using Hubble to track Saturn’s changing weather patterns.

While both images are valuable, they also highlight our present limits in observing Saturn. Views from Earth can only see so much. It is like trying to watch a football game from ten miles away, with binoculars. And sadly, no mission is presently planned to return to Saturn.

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Triton: Neptune’s largest moon

The southern mid-latitudes of Neptune's moon Trident
Click for original image.

Triton

Today’s cool image begins a new tour I plan on doing over the next week or so of the few close-up photographs we have of Neptune and its moons, sent back by Voyager-2 when it did its close fly-by of this distant planet on August 25, 1989. That fly-by was almost 37 years ago, and it remains our only close look. While at the time it shined a quick flashlight of new knowledge on Neptune, its moons, and its ring system, we remain generally in the dark about what’s there, despite some good imagery produced in subsequent years by Hubble and some ground-based telescopes.

The image above, cropped and enhanced to post here, shows a portion of the southern mid-latitudes of Triton, Neptune’s largest moon, as Voyager-2 made its closest pass at a distance of about 25,000 miles. The photo to the right, cropped and reduced, shows a more global view to provide some context, with the box indicating the approximate area covered by the upper image. It was taken when Voyager-2 was on approach, at a distance of about 330,000 miles. The top picture captures several dozen black plumes that appear to vent material from below. From the caption:

The plumes originate at very dark spots generally a few miles in diameter and some are more than 100 miles long. The spots which clearly mark the source of the dark material may be vents where gas has erupted from beneath the surface and carried dark particles into Triton’s nitrogen atmosphere. Southwesterly winds then transported the erupted particles, which formed gradually thinning deposits to the northeast of most vents.

It is possible that the eruptions have been driven by seasonal heating of very shallow subsurface deposits of volatiles, and the winds transporting particles similarly may be seasonal winds. The polar terrain, upon which the dark streaks have been deposited, is a region of bright materials mottled with irregular, somewhat dark patches. The pattern of irregular patches suggests that they may correspond to lag deposits of moderately dark material that cap the bright ice over the polar terrain.

As we only have a few images of this planet, and those provided views of only about 40% of its surface, any theory that tries to explain the weird geology here is certain to be wrong to some degree.

More to come in the next few days. As much as we think we know, these pictures are going instead highlight how sparse that knowledge really is.

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Changes to the Crab Nebula after a quarter century

The Crab Nebula, changes after a quarter century
For original images go here and here.

Using the Hubble Space Telescope, astronomers have obtained a new high resolution image of the Crab Nebula, and by comparing it with earlier Hubble images taken in 1999/2000 have been able to track the continuing expansion and evolution of this supernova remnant over a period now covering almost a quarter century.

The supernova itself became visible on Earth in 1054, though it actually erupted about 6,500 years earlier, as the Crab Nebula is 6,500 light years away. In the 25 years Hubble has been tracking the remnant’s expansion astronomers estimate it is expanding at about 3.4 million miles per hour.

[William Blair of Johns Hopkins University] noted that filaments around the periphery of the nebula appear to have moved more compared to those in the center, and that rather than stretching out over time, they appear to have simply moved outward. This is due to the nature of the Crab as a pulsar wind nebula powered by synchrotron radiation, which is created by the interaction between the pulsar’s magnetic field and the nebula’s material. In other well-known supernova remnants, the expansion is instead driven by shockwaves from the initial explosion, eroding surrounding shells of gas that the dying star previously cast off.

The new, higher-resolution Hubble observations are also providing additional insights into the 3D structure of the Crab Nebula, which can be difficult to determine from a 2D image, Blair said. Shadows of some of the filaments can be seen cast onto the haze of synchrotron radiation in the nebula’s interior. Counterintuitively, some of the brighter filaments in the latest Hubble images show no shadows, indicating they must be located on the far side of the nebula.

A movie showing the changes between these two images can be seen here. It is worth your while to take a look. These optical images will be further enhanced as the Webb Space Telescope gathers infrared data.

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CrabNebula2000-2024reduced

This newly processed image comes from data originally captured by the NASA/ESA Hubble Space Telescope in 1999 and 2000. Updated image-processing technology allows for this archival image to be best compared with more recent data, including those captured by Hubble itself. Hubble received a new imaging instrument in 2009, the Wide Field Camera 3.

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Uranus: one glimpse and that was forty years ago

Uranus as seen by Voyager-2, natural colors on left, false color on right
Uranus as seen by Voyager-2, natural colors on left, false color on right. Click for original.

I close today our week-long tour of Voyager-2’s fly-by of Uranus in January 1986 with three cool images, the two images of the planet itself above and a close-up of its rings. All three illustrate that though Voyager-2 gave us our first very good first close-up view of this distant world, it also gave us only a tiny glimpse, very superficial and lacking in any larger context.

The two images above were taken on January 17, 1986 when Voyager 2 was till 5.7 million miles away, on approach.

The picture at left has been processed to show Uranus as human eyes would see it from the vantage point of the spacecraft. The picture is a composite of images taken through blue, green and orange filters. The darker shadings at the upper right of the disk correspond to the day-night boundary on the planet. Beyond this boundary lies the hidden northern hemisphere of Uranus, which currently remains in total darkness as the planet rotates. The blue-green color results from the absorption of red light by methane gas in Uranus’ deep, cold and remarkably clear atmosphere.

The picture at right uses false color and extreme contrast enhancement to bring out subtle details in the polar region of Uranus. Images obtained through ultraviolet, violet and orange filters were respectively converted to the same blue, green and red colors used to produce the picture at left. The very slight contrasts visible in true color are greatly exaggerated here. In this false-color picture, Uranus reveals a dark polar hood surrounded by a series of progressively lighter concentric bands. One possible explanation is that a brownish haze or smog, concentrated over the pole, is arranged into bands by zonal motions of the upper atmosphere. The bright orange and yellow strip at the lower edge of the planet’s limb is an artifact of the image enhancement. In fact, the limb is dark and uniform in color around the planet.

The third cool image below of Uranus’s rings was taken just after the closest approach, when Voyager-2 was in Uranus’s shadow and looking back at its rings from a distance of 142,000 miles.
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Uranus’s moon Oberon, of which we know little

Uranus' five biggest moonsThe historically known moons of Uranus. Click for original NASA press release.

Oberon, as seen by Voyager-2
Click for original image.

Today we finish our week-long tour of the five largest moons of Uranus, all discovered by astronomers before the start of the space age, and imaged successfully if not very completely by Voyager-2 when it did its fly-by of the planet on January 24, 1986. The gallery of these moons above was taken by the spacecraft when it was on approach, still about three million miles from Uranus, and shows them in order from the innermost on the left to the outermost on the right. They are also scaled to show their relative sizes. To see Voyager-2’s close-up images of the four inner moons, posted earlier this week, go here, here, here, and here.

The picture to the right, cropped slightly to post here, is Voyager-2’s only high resolution image of Oberon, the outermost moon of this group. From NASA’s press release:

This Voyager 2 picture of Oberon is the best the spacecraft acquired of Uranus’ outermost moon. The picture was taken shortly after 3:30 a.m. PST on Jan. 24, 1986, from a distance of 410,000 miles. The color was reconstructed from images taken through the narrow-angle camera’s violet, clear and green filters.

The picture shows features as small as 7 miles on the moon’s surface. Clearly visible are several large impact craters in Oberon’s icy surface surrounded by bright rays similar to those seen on Jupiter’s moon Callisto. Quite prominent near the center of Oberon’s disk is a large crater with a bright central peak and a floor partially covered with very dark material. This may be icy, carbon-rich material erupted onto the crater floor sometime after the crater formed. Another striking topographic feature is a large mountain, about 6 km (4 mi) high, peeking out on the lower left limb.

Oberon is about 946 miles in diameter, making it the tenth-largest moon in the solar system. Because of the quickness of Voyager-2’s fly-by, it could get no closer images, and none of the planet’s nightside. Thus, only 40% of the surface has been photographed, and at not very high resolution.

Later spectroscopy from Hubble and other telescopes suggests there is water ice on the surface. Other data suggests Oberon may have a liquid underground ocean, but that conclusion is highly uncertain. Other than these vague facts and the image to the right, we essentially know almost nothing about this moon. Like Titiania, Uranus’s largest moon, Voyager-2’s data merely gave us a tantalizing glimpse, and that glimpse is now forty years old. No other mission has been there since, and none is planned in the near future.

Tomorrow, to summarize this tour, I will outline further what little we know of Uranus and its moons

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Modeling says the Small Magellanic Cloud passed through the Large Magellanic Cloud 200 million years ago

Illustration of collision of Magellanic clouds
Click for original graphic.

According to new computer modeling, some astronomers now believe that a collision between the Small Magellanic Cloud (SMC) and the Large Magellanic Cloud (LMC) 200 million years ago best explains the chaotic movement of the stars in the former.

The SMC contains more mass in gas than in stars. Gas cools, contracts under gravity and settles into a rotating disk, the same process that shaped the spinning plane of our solar system. But when researchers, including those at University of Arizona, previously measured the motion of the SMC’s stars using the Hubble Space Telescope and the Gaia satellite of the European Space Agency, the SMC’s stars were not orbiting around the galaxy’s center the way stars in most galaxies do.

The possible reason, Rathore said, is a collision. A few hundred million years ago, the SMC crashed directly through the LMC’s disk. The LMC’s gravity disrupted the SMC’s internal structure and sent its stars into random, disordered motion. Also, the LMC’s gas applied a tremendous amount of pressure to the SMC’s gas and destroyed its gas rotation.

The graphic to the right illustrates that collision, based on the computer modeling. It appears the Small Magellanic Cloud’s passage through the Large Magellanic Cloud acted to shake the smaller cloud apart, spreading its stars and gas across a wider space.

You can read the paper here [pdf]. There is of course a great deal of uncertainty in these results, but they add weight to the general theory that galaxy formation is strongly impacted by such collisions. As the scientists note in the conclusion of their paper, “The SMC gives a front row view of group processes driving dramatic morphological and kinematic transformations.”

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Continuing our tour of Uranus’ five biggest moons: Ariel

In preparing my cool image last week focused on the best Voyager-2 image of Uranus’ moon Miranda, I came to a realization that was somewhat startling. Voyager-2 is the only time a human spacecraft has gotten close to Uranus, and it was only close for a few days. Thus, the data and images it obtained of the gas giant and its moons is remarkable more sparse than I had ever realized.

You see, when these images were first released in 1986 they were exciting because they gave us that first look. Suddenly, a light was shined on something that had always been shrouded in darkness. It was a flood of data that needed processing.

It is now forty years later. No spacecraft has been there since, and thus we have gotten no more close-up information about Uranus or its moons. Data from Hubble and Webb has helped increase our knowledge of the planet itself, but of the moons nothing really new has been gleaned from this distance.

Uranus' five biggest moons

And so, to highlight how little we know, for the rest of this week I am going give my readers a tour of the few images Voyager-2 gave us of Uranus’ five biggest moons, the five that early astronomers had discovered prior to the space age and shown in the five pictures above, taken by Voyager-2 as it was approaching Uranus from a distance of about three million miles. They are, in order going from closest to farthest from Uranus, Miranda, Ariel, Umbriel, Titania and Oberon, with the images above designed to show their approximate relative sizes.

I already highlighted the strange, patchwork surface of Miranda last week, the smallest of these moons. Below is a mosaic made from the four highest resolution images of 720-mile-wide Ariel, the next out from Uranus, taken from a distance of about 80,000 miles.
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Interstellar comet 3I/Atlas is unusually enriched with windshield wiper fluid

New Hubble image of 3I/Atlas
Comet 3I/Atlas as seen by Hubble
in November 2025. Click for original.

While interstellar comet 3I/Atlas is remarkably like most comets from our own solar system, scientists have now found new evidence that it spalled off unusual amounts of methanol (CH3OH) — material normally used as windshield washer fluid, carburetor fluid, and cooking fuel — when it made its close fly-by of the Sun in the fall of 2025.

You can read the paper here [pdf] . The research also detected large amounts of prussic acid (HCN). As the comet made its closest pass to the Sun, the numbers increased. From the paper’s abstract:

The CH3OH production rate increased sharply from August through October, including an uptick near the inner edge of the H2 O sublimation zone at r H = 2 au. Compared to comets measured to date at radio wavelengths, the derived CH3 OH/HCN ratios in 3I/ATLAS of 124+30 −34 and 79−14 +11 on September 12 and 15, respectively, are among the most enriched values measured in any comet, surpassed only by anomalous solar system comet C/2016 R2 (PanSTARRS).

Though the numbers are high, they aren’t outside the range of what has been found in comets from our own solar system. Instead, this data suggests — as has all data so far — that Comet 3I/Atlas is a normal comet, but unique in its own way, as are all comets and in fact every object in space.

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A nearby red dwarf star has a solar system of four planets, one in the habitable zone

According to a new analysis of new data, astronomers now think the nearby red dwarf star GJ 887, only about 11 light years away, not only has a solar system of four planets, one of those planets is is a super-Earth orbiting the star in the habitable zone.

From the abstract:

With the Bayesian analysis, we confirmed a four-planet model, including the two previously known planets at periods of 9.2619 ± 0.0005 d and 21.784 ± 0.004 d, as well as two newly confirmed exoplanets: an Earth-mass planet, with a 4.42490 ± 0.00014 d period and a sub-meter-per-second amplitude, and a super-Earth with a 50.77 ± 0.05 d period located in the habitable zone (HZ). This super-Earth is the second closest planet in the HZ, after Proxima Cen b.

The super-Earth has a mass estimated to be anywhere from two to ten times that of Earth, so if any life could exist on it that life would have to be adapted for an extremely strong gravitational field. The star itself appears to be relatively benign for an M dwarf, having a “low level of magnetic activity”, though it does exhibit some flaring that could pose a threat to the development of life on the planet.

Unfortunately, this system is not aligned in a way to allow transits of these planets across the face of the star, so these conclusions are based on gravitational wobbles of the star analyzed by computer modeling. Lots of uncertainty. The scientists hope that direct observations of the planet by future space telescopes will reduce these uncertainties. At the moment, the proposed privately-funded Lazuli optical orbiting telescope has the best chance of doing this work, but it isn’t expected to launch before the end of the decade. It will have a 3.1 meter primary mirror, larger than Hubble’s 2.4 meter mirror.

It is a so far very slow news day in space.

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The first orbiting private space telescope releases “first light” image

Mauve's first light image and data
Click for original image.

The first orbiting private space telescope, owned by Blue Skies Space and dubbed Mauve, has successfully taken its first image and data, a 5 second long exposure of a single star.

That image is to the right, with the spectroscopic data shown by the magenta line. The Hubble Space Telescope’s spectroscopic data is shown in blue and while for comparison.

As part of early commissioning, Mauve was pointed at its first calibration target, eta Ursae Majoris (eta UMa), a bright star in the constellation Ursa Major, approximately 104 light-years from Earth, for a 5-second observation. Eta UMa is a hot, blue-white star, much hotter than our Sun. Eta UMa shines brightly in ultraviolet light, making it an ideal calibration target for a UV observatory like Mauve.

The telescope has a 5-inch mirror, so its resolution is far lower than Hubble’s 94-inch mirror, but because it is above the atmosphere its view is far better than larger ground-based telescopes. Mauve is intended as a three-year-long demonstration project, during which it will study flares from nearby stars that are thought to have exoplanets, as well as binary star systems and variable stars. It is also making this data available to scientists, for a subscription fee. It already has almost a dozen universities signed up.

Blue Skies hopes Mauve’s success will help it raise the capital to build Twinkle, a space telescope with an 18-inch primary mirror. If that succeeds, the company plans to scale up to even bigger orbiting telescopes.

This private sector astronomy model is how the U.S. did things routinely prior to World War II. Then, for many reasons, the government took over for the next three-quarters of a century. It now appears the pendulum is shifting back to the private sector.

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Old and new optical space telescopes team up to view the Cat’s Eye

Cat's Eye Nebula as seen by both Hubble and Euclid
Click for original images.

Astronomers using both NASA’s long established Hubble Space Telescope and Europe’s new Euclid space telescope have produced new optical/infrared images of the Cat’s Eye planetary nebula.

Those images are to the right, cropped, reduced, and sharpened to post here. The Hubble image at bottom shows the complex structure of the nebula itself, located about 4,400 light years away and believed created by the inner orbital motions of a binary star system that act almost like the blades in a blender, mixing the material thrown off by one or both of the stars as they erupt in their latter stages of life.

In Euclid’s wide, near-infrared, and visible light view, the arcs and filaments of the nebula’s bright central region are situated within a halo of colorful fragments of gas zooming away from the star. This ring was ejected from the star at an earlier stage, before the main nebula at the center formed. The whole nebula stands out against a backdrop teeming with distant galaxies, demonstrating how local astrophysical beauty and the farthest reaches of the cosmos can be seen together with Euclid.

Euclid has a primary mirror 1.2 meters in diameter, about half that of Hubble. Though it can’t zoom in with the same resolution, its view is as sharp since it is in space above the atmosphere. It thus provides a wider view, which in this case helps provide a larger context to the detailed close-up view provided by Hubble.

In many ways Euclid is Hubble’s replacement, produced by the European Space Agency, as NASA and the American astronomy community has not been able to get together to build their own new optical orbiting telescope.

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March 2, 2026 Quick space links

Courtesy of BtB’s stringer Jay, who is off on a two week vacation, so no quick links for awhile. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

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