Tag: science

Voyager-1 back on line after software patch works

9:09 am

For the first time since November, Voyager-1 is sending data back to Earth coherently, after engineers figured out a way to isolate a corrupted computer chip.

The team discovered that a single chip responsible for storing a portion of the FDS memory — including some of the FDS computer’s software code — isn’t working. The loss of that code rendered the science and engineering data unusable. Unable to repair the chip, the team decided to place the affected code elsewhere in the FDS memory. But no single location is large enough to hold the section of code in its entirety.

So they devised a plan to divide the affected code into sections and store those sections in different places in the FDS. To make this plan work, they also needed to adjust those code sections to ensure, for example, that they all still function as a whole. Any references to the location of that code in other parts of the FDS memory needed to be updated as well.

The software patch was sent to the spacecraft on April 18, 2024, taking 22.5 hours to get there. It then took 22.5 hours for a response. On April 20th they received a confirmation that the patch had worked. Over the next few weeks more patches will be sent to Voyager-1 to allow it to resume sending science data back to Earth.

Both Voyager-1 and Voyager-2 were launched almost a half century ago, in 1977, and both are now more than more than 15 billion miles from Earth, traveling in interstellar space. Their computers are also the longest continuously running operating systems. Both only have a little more than two years left in their nuclear power supply, which was always expected to run out of power about a half century after launch. That both have continued to function for that entire time is a magnificent testament to the engineers who designed them.

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Patchy arms in a nearby spiral galaxy

9:16 am

Patchy arms in spiral galaxy
Click for original image.

Cool image time! The photo to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope to study this southern hemisphere galaxy in detail. The galaxy, dubbed ESO 422-41, is located about 34 million light years away, and thus is a relatively close neighbor. From the caption:

A spiral galaxy, with a brightly shining core and two large arms. The arms are broad, faint overall and quite patchy, and feature several small bright spots where stars are forming. A few foreground stars with small diffraction spikes can be seen in front of the galaxy.

The patchy nature of the two arms makes each somewhat indistinct, so that at first glance this galaxy looks more like a elliptical blob, until you look close and notice those arms winding around that bright core. And as patchy as those arms are, the patches of blue are regions where new stars are forming.

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Computer models suggest there is no life in Europa’s underground ocean

11:22 am

The uncertainty of science: Several different computer simulations now suggest that the underground ocean inside the Jupiter moon Europa is inert and likely harbors no existing lifeforms.

He and his colleagues constructed computer simulations of Europa’s seafloor, accounting for its gravity, the weight of the overlying ocean and the pressure of water within the seafloor itself. From the simulations, the team computed the strength of the rocks about 1 kilometer below the seafloor, or the stress required to force faults in the seafloor to slide and expose fresh rock to seawater.

Compared with the stress applied to the seafloor by Jupiter’s gravity and by the convection of material in Europa’s underlying mantle, the rocks comprising Europa’s seafloor are at least 10 times as strong, Byrne said. “The take home message is that the seafloor is likely geologically inert.”

A second computer model also suggested that the moon’s deep magna is not capable to pushing upward into that sea, further reinforcing the first model that the sea is geological inert, lacking the heat or energy required for life.

Though unconfirmed and uncertain, these results when looked at honestly make sense. Europa is a very cold world. An underground ocean might exist due to tidal forces imposed by Jupiter, but that dark and sunless ocean is also likely to be very hostile to life. Not enough energy to sustain it.

Like the water imagined to exist at poles of the Moon, we go to Europa on the hope of finding life, even if that hope is very ephermal.

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Analysis of Io’s atmosphere suggests it has been volcanically active for its entire 4+ billion year history

9:34 am

By analysizing the isotobes in Io’s atmosphere, scientists now believe that it has been volcanically active since its initial formation at the birth of the solar system 4.5 billion years ago.

de Kleer et al. found that both elements [ sulfer- and chlorine-bearing molecules] are highly enriched in heavy isotopes compared to average Solar System values due to the loss of lighter isotopes from the upper atmosphere as material is continuously recycled between Io’s interior and atmosphere. The findings indicate that Io has lost 94% to 99% of the sulfur that undergoes this outgassing and recycling process. According to the authors, this would require Io to have had its current level of volcanic activity for its entire lifetime.

This data suggests that Io, as well as Jupter’s other three large Galilean moons (Europa, Calisto, and Ganymeded) have been in their present orbits since their formation 4.5 billion years ago. It also means that, while Io’s geological history keeps getting wiped out by its volcanic activity, the other three contain detailed geological records of the solar system’s entire history. Combine that with the geological data we will eventually get from Mars, it appears that we shall someday be able to document that history far beyond anything expected.

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Ancient flood lava in the Martian cratered highlands

2:13 pm

Ancient flood lava on the cratered highlands of Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 4, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The ridges were the primary reason this photo was taken, as they cover a 50-mile-square region of relatively flat terrain that also appears to be a series of steps downward to the west. The dotted line on the picture indicates one of those steps downward, with the plain to the west of that line about 100 to 200 feet lower that the plain to the east.

My first guess was that these ridges might be inverted channels, but that really didn’t make sense considering their random nature completely divorced from the downward grade. Then I took a wider view, and came up with a better guess.
» Read more

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TESS has resumed science operations

9:15 am

Engineers have successfully returned TESS to full science operations, without providing as yet any explanaton as to why on April 8, 2024 it went into safe mode or what they did to fix the issue.

The Aprill 11 press release announcing the safe mode had only mentioned that the shut down had occurred “during scheduled engineering activities.” The lack of information continues to suggest that someone did an “Oops!” during those activities, and NASA is too embarassed to reveal that fact.

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NASA approves Dragonfly mission to the Saturn moon Titan

9:50 am

NASA yesterday announced that it has given final approval for the Dragonfly helicopter mission to the Saturn moon Titan.

With the release of the president’s fiscal year 2025 budget request, Dragonfly is confirmed with a total lifecycle cost of $3.35 billion and a launch date of July 2028. This reflects a cost increase of about two times the proposed cost and a delay of more than two years from when the mission was originally selected in 2019. Following that selection, NASA had to direct the project to replan multiple times due to funding constraints in fiscal years 2020 through 2022. The project incurred additional costs due to the COVID-19 pandemic, supply chain increases, and the results of an in-depth design iteration. To compensate for the delayed arrival at Titan, NASA also provided additional funding for a heavy-lift launch vehicle to shorten the mission’s cruise phase.

The rotorcraft, targeted to arrive at Titan in 2034, will fly to dozens of promising locations on the moon, looking for prebiotic chemical processes common on both Titan and the early Earth before life developed. Dragonfly marks the first time NASA will fly a vehicle for science on another planetary body. The rotorcraft has eight rotors and flies like a large drone.

Be prepared for the project to go overbudget, as NASA’s biggests projects almost always do.

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Engineers say goodbye to Ingenuity

9:45 am

Ingenuity with missing blade
Ingenuity with its missing blade. Click for original image.

Because Perseverance is about to move out of range of direct communications with the disabled Ingenuity helicopter, engineers have now completed their final transmission from the helicopter yesterday, confirming that a new software update has been successfully installed.

The telemetry confirmed that a software update previously beamed up to Ingenuity was operating as expected. The new software contains commands that direct the helicopter to continue collecting data well after communications with the rover have ceased.

With the software patch in place, Ingenuity will now wake up daily, activate its flight computers, and test the performance of its solar panel, batteries, and electronic equipment. In addition, the helicopter will take a picture of the surface with its color camera and collect temperature data from sensors placed throughout the rotorcraft. Ingenuity’s engineers and Mars scientists believe such long-term data collection could not only benefit future designers of aircraft and other vehicles for the Red Planet, but also provide a long-term perspective on Martian weather patterns and dust movement.

The engineers belief that the helicopter could collect data for as long as twenty years. That data will sit on Ingenuity until such time as a later exploration team arrives, either manned or unmanned. There is also the possibility that later in Perseverance’s mission it could pass nearby again, allowing engineers to grab some of the data then.

According to the press release, those same engineers are now exploring future helicopter missions to Mars. Based on imagery I have seen coming down from Mars Reconnaissance Orbiter (MRO), the as yet unstated target locations could be inside the eastern end of Valles Marineris or on the northern perimeter of Hellas Basin.

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Isolated flat-topped mesa inside large Martian crater

1:17 pm

Isolated flat-topped mesa
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken on February 18, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The camera team labels this “layers in butte”, but because we are looking straight down at this 400-foot-high butte, it is difficult to see any layers at all. Based on most Martian geology however it would be shocking if this butte is not made up of multiple horizontal layers, ending with that flat surface layer at the top. Moreover, the base of the mesa to the northeast is clearly made up of a series of terraces that appear obscured at other points due to the presence of dust and dunes.

A side view would help clarify the number of layers and their thickness, but it does appear that this butte contains evidence of the geology that once covered this whole area, but over eons has eroded everything away but this butte.
» Read more

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Scientists: Any ice trapped in Ceres’ permanently shadowed craters has to be very young

10:51 am

The permanently shadowed craters at Ceres' north pole
The permanently shadowed craters (blue) at Ceres’
north pole. Click for original image.

Scientists reviewing the archive data from the Dawn probe that orbited the asteroid Ceres from 2016 to 2018 have found that the permanently shadowed craters at the asteroid’s poles are periodically exposed to sunlight due to long term variations in Ceres’ orbit, meaning that any of the ice in those craters detected by Dawn must be extremely young.

When Ceres reaches its maximum axis tilt, which last occurred about 14,000 years ago, no crater on Ceres remains perennially shadowed and any ice in them must have quickly sublimated into space. “That leaves only one plausible explanation: The ice deposits must have formed more recently than that. The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less. Considering that Ceres is well over 4 billion years old, that is a remarkably young age,” Schorghofer said.

This does not mean that Ceres doesn’t have ice. In fact, it is very ice rich, below the surface. This data instead suggests that the surface remains active, and that there are processes bringing that underground ice to the surface on a regular basis. Except for these craters, which remain permanently shadowed for long time spans, that ice sublimates away relatively quickly. This result fits with earlier data from Dawn, that suggested many active locations on the surface, including its most distinct crater, Occator.

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Using Gaia data scientists discover the heaviest stellar black hole ever found

10:30 am

In digging into the precise motion data from the Gaia space telescope scientists have discovered the Milky Way’s heaviest stellar-sized black hole, with a mass thirty-three times the mass of our Sun.

Stellar black holes are formed from the collapse of massive stars and the ones previously identified in the Milky Way are on average about 10 times as massive as the Sun. Even the next most massive stellar black hole known in our galaxy, Cygnus X-1, only reaches 21 solar masses, making this new 33-solar-mass observation exceptional.

Remarkably, this black hole is also extremely close to us — at a mere 2000 light-years away in the constellation Aquila, it is the second-closest known black hole to Earth.

The only known black hole inside the Milky Way that is larger is Sagittarius A* (pronounced A-star), the supermassive central black hole at the galaxy’s center and weighing over four million solar masses. That creature is a very different thing, as it involves the long term evolution of the galaxy itself. Stellar-sized black holes only involve the death of a single star, with possible additions from a handful of others.

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A Martian rock with holes

10:52 am

A Martian rock with holes
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 13, 2024 by the high resolution camera on the Mars rover Perseverance.

The largest rock in the picture is probably only one or a few feet or so across. It has two holes, one very visible in the center and a second less obvious in the shadow on the right. What makes the obvious hole most intriguing is that it appears it was formerly entirely enclosed by the boulder, and was exposed when a section broke off. That section is the smaller rock in the foreground. I wonder if the Perseverance team will bring the rover around to get a view of that smaller rock, to see if it has its own corresponding part of this hole.

Note the smoothness of the rocks. This smoothness is very similar to what Curiosity saw when it was either on the floor of Gale Crater, or at the base of Mount Sharp. In both cases that smoothness suggests either flowing water or glacial ice erosion, like the smooth cobbles one routinely finds in streambeds or in the moraines of glaciers.

As Curiosity climbed Mount Sharp the smoothness was replaced with a delicate flaky fleecework indicating many layers but little violent erosion capable of smoothing the surface (see for example the images here and here). It appears Perseverance is still low enough in Jezero Crater to be within the ancient active region, formed from flowing water or ice.

As for the holes, my guess is that this rock formed from lava, and the holes are what geologists call “vugs”, bubbles formed within the lava as it solidified.

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