Tag: science

A hint at Mars’ past climate cycles

11:16 am

Terraced glaciers in Martian crater
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on October 28, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as a “layered feature” inside a small 4,500-foot-wide crater.

Located at 36 degrees north latitude, we are likely looking at glacial ice layers inside this crater, with each layer probably marking a different Martian climate cycle. The terraces suggest that during each growth cycle the glaciers grew less, meaning that less snow fell with each subsequent cycle. This in turn suggests a total loss of global water over time on Mars.

The overview map below gives us the wider context.
» Read more

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China to build giant ground-based optical telescope

9:45 am

China has announced its plan to build ground-based multi-segmented optical telescope, similar in design to the 10-meter Keck Telescope in Hawaii.

Peking University wants to build the largest optical telescope in Asia and close the gap in astronomy capabilities with the rest of the world.

The project aims to create an initial telescope with an aperture of 19.7 feet (6 meters) by 2024; the mirror will be expanded to 26.2 feet (8 m) by 2030. The project, which in English is called the Expanding Aperture Segmented Telescope (EAST), is being led by Peking University.

Like Keck, the primary mirror would be made of smaller segments, fitted together to create the larger mirror. While not as large as Keck, EAST would be among the largest in the world.

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Royal Astronomical Society ends blacklisting of James Webb

9:30 am

That’s nice of them: The Royal Astronomical Society in Britain last week announced that it has ended its blacklisting of James Webb, the man who headed NASA during the 1960s space race, by once again permitting writers of science papers for its Monthly Notices journal to use the full name of the James Webb Space Telescope.

The Royal Astronomical Society (RAS) previously criticized NASA for not immediately addressing concerns that Webb persecuted queer employees; the NASA-led James Webb Space Telescope (JWST or Webb) that launched in December 2021 is named after him. But with new information to hand suggesting Webb played no direct role in these issues, Webb’s name can now reappear in scientific papers, the RAS stated Dec. 22.

“The RAS will now allow authors submitting scientific papers to its journals to use either ‘James Webb Space Telescope’ or the acronym ‘JWST’ to refer to the observatory,” RAS officials wrote. The major journals of the RAS include the Monthly Notices of the Royal Astronomical Society (MNRAS), one of the top astronomical journals worldwide.

The society backed off from its position after NASA published a long detailed report documenting the utter falsehood of the claim. Too bad this so-called science organization didn’t consider the evidence itself before issuing its blacklist order. One would think scientists above all would consider evidence, not undocumented slanders, as essential before condemning a person.

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A “What the heck?” glacier image on Mars

5:36 pm

Glacial material on Mars
Click for full image.

Sometimes a cool image goes from bafflement to obvious as you zoom into it. The cool image to the right, cropped to post here, does the opposite. It was taken on October 11, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have purposely cropped it at full resolution, so that its eroded glacier nature is most obvious.

The cracks and hollows are likely caused by the sublimation of the near surface underground ice, breaking upward so that the protective surface layer of debris and dust collapses at some points, and cracks at others.

The overview map below further confirms the likelihood that we are looking at glacial features, but when we also zoom out from this close-up we discover things are not so easily explained.
» Read more

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Using reflected light from Jupiter to photograph Ganymede’s night side

12:15 pm

Ganymede as seen in the reflected light of Jupiter
Click for full image.

During Juno’s June 7, 2021 close fly-by of Ganymede, scientists used its instruments to obtain the first good image of a part of this Jupiter moon. What made the achievement especially amazing was that the area photographed was only lit by the reflected light from Jupiter, the equivalent of its “earthshine.” From the paper’s abstract:

On 7 June 2021, the Juno spacecraft flew within about 1,000 km of the surface of Jupiter’s largest moon, Ganymede. The Mission used their sensitive navigation camera to photograph the moon’s dark side where it was lit only by scattered sunlight from Jupiter. This new imaging approach revealed multiple surface features, including a patchwork of different surface textures (such as grooved terrain), several craters, and ejecta deposits. These features had not been visible in images collected by previous spacecraft.

The picture to the right is from figure 2 of the paper, cropped and reduced to post here. It shows a region on Ganymede that in the earlier images had shown few details because the lighting was poor and thus features were not easily discerned (as can be seen by the inset in the lower right). In the new picture, the only light was reflected from Jupiter, and its low angle brings out the surface topography.

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Today’s blacklisted American: Black scientist blacklisted for doing good research

1:57 pm

Oluseyi Hakeem, blacklisted
Hakeem Oluseyi, Space Science Education Lead
for NASA’s Science Mission Directorate

They’re coming for you next: Today’s blacklist column describes an effort to not only cancel from history the man who led NASA for almost the entire 1960s space race, but to also blackball a scientist for doing good research that proved the campaign was not based on any facts.

Shortly before the launch of the James Webb Space Telescope last year, a petition was instigated to get it renamed because of accusations that Webb had persecuted homosexuals during his term as NASA administrator in the 1960s. As is now typical of our modern bankrupt intellectual class, as soon as this petition was issued more than 1,700 people signed it, all accepting at face value its accusations against Webb without any further research.

One scientist, who happened to be black, took a more detailed look at those accusations however and found them to be spurious. As Hakeem Oluseyi wrote:
» Read more

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Finding Martian glaciers from orbit

11:45 am

Glacier flow on Mars
Click for full image.

Today’s cool image is a great example of the surprises one can find by exploring the archive of the high resolution pictures that Mars Reconnaissance Orbiter (MRO) has produced since it arrived in Mars orbit back in 2006. The picture to the right, rotated, cropped, and reduced to post here, was taken by MRO’s high resolution camera back on May 4, 2017. I only found it because I had picked out a October 24, 2022 high resolution image that covered a different area of this same flow feature just to the north east. In trying to understand that 2022 picture I dug to see other images had been taken around it, and found the earlier 2017 photo that was even more interesting.

Neither however really covered the entire feature, making it difficult to understand its full nature. I therefore searched the archive of MRO’s context camera, which has imaged the entire planet with less resolution but covering a much wider area per picture. The context camera picture below captures the full nature of this feature.
» Read more

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Cones, mounds, and layers of Martian ice?

2:20 pm

Cones, mounds, and layers of Martian ice?
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on September 10, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The location is at 38 degrees north latitude, in the Martian northern lowland plains. At this latitude in these plains the geological features seen in high resolution pictures almost always invoke near surface ice, including processes that disturb that underground ice layer.

This picture is no different. Not only does it appear that a glacier is flowing down from the top of east-west ridge, the middle mound includes a crater with its southeast rim gone and appears filled with material that suggests ice.

The greater geographic context of this location can be seen in the overview map below.
» Read more

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A long-armed galaxy

8:51 am

Galaxy with long and faint tidal streams
Click for full image.

Cool image time! The photo to the right, cropped, enhanced, and reduced to post here, was taken by the Hubble Space Telescope as part of a survey of peculiar looking galaxies.

The peculiar spiral galaxy ESO 415-19, which lies around 450 million light-years away, stretches lazily across this image from the NASA/ESA Hubble Space Telescope. While the centre of this object resembles a regular spiral galaxy, long streams of stars stretch out from the galactic core like bizarrely elongated spiral arms. These are tidal streams caused by some chance interaction in the galaxy’s past, and give ESO 415-19 a distinctly peculiar appearance.

ESO 415-19’s peculiarity made it a great target for Hubble. This observation comes from an ongoing campaign to explore the Arp Atlas of Peculiar Galaxies, a menagerie of some of the weirdest and most wonderful galaxies that the Universe has to offer. These galaxies range from bizarre lonesome galaxies to spectacularly interacting galaxy pairs, triplets, and even quintets. These space oddities are spread throughout the night sky, which means that Hubble can spare a moment to observe them as it moves between other observational targets.

I have intentionally brightened the galaxy to make the two faint two tidal streams more obvious. That they are so faint compared to the galaxy itself is in itself a mystery.

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Crater at the edge of the Martian south pole ice cap

11:20 am

Oblique view of south pole crater
Click for full image.

Overview map

Cool image time! The oblique panorama above, reduced and sharpened to post here, was created from an image taken on May 19, 2022 by the European orbiter Mars Express. Its location on edge of the layered deposits of ice and dust that form most of the Martian southern ice cap is indicated by the white rectangle on the overview map to the right. From the press release:

While it may look like a winter wonderland, it was southern hemisphere spring at the time and ice was starting to retreat. Dark dunes are peeking through the frost and elevated terrain appears ice-free.

Two large impact craters draw the eye, their interiors striped with alternating layers of water-ice and fine sediments. These ‘polar layered deposits’ are also exposed in exquisite detail in the rusty red ridge that connects the two craters.

The scattered white patches are either water frost, or the winter mantle of dry ice, both now sublimating away with the coming of spring.

The black line on the overview map indicates the extent of the layered deposits, and suggest that the ridgeline is not considered part of that ice cap layer, in contradiction to the press release language above.

Which is it? I would guess the answer is simply the uncertainty of science. Some scientists took a look here and decided the ridge was actually a base layer sticking up through the layered deposits. The European scientists who took this picture have instead concluded, based on the image, that the ridge is part of the layer deposits.

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NASA requesting proposals for raising Hubble’s orbit

9:23 am

NASA has published a request for proposals from the private commercial space industry for a possible future mission to raise Hubble’s orbit.

NASA published a request for information (RFI) Dec. 22 asking industry how they would demonstrate commercial satellite servicing capabilities by raising the orbit of Hubble. The agency said it is looking for technical information about how a company would carry out the mission, the risks involved and the likelihood of success.

NASA emphasized in the RFI that it had no plans to procure a mission to reboost Hubble. “Partner(s) would be expected to participate and undertake this mission on a no-exchange-of-funds basis,” the document stated, with companies responsible for the cost for the mission.

Apparently, this RFI was issued as a direct result of the agreement between NASA and SpaceX to study a Dragon mission to do exactly this, which in turn was prompted by Jared Isaacman, as part of his private Polaris program of manned Dragon/Starship space flights. I suspect that NASA officials realized that not only were their engineering advantages to getting more proposals, there were probably legal and political reasons for opening the discussion up to the entire commercial space community.

Ideally, a Hubble reboost mission should occur by 2025, though the telescope’s orbit will remain stable into the mid-2030s.

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Juno experienced data download issue during most recent Jupiter close flyby

9:07 am

Right after Juno made its 47th close fly-by of Jupiter on December 14, 2022, the download of the obtained data was suddenly disrupted, forcing engineers to put Juno into safe mode.

The issue – an inability to directly access the spacecraft memory storing the science data collected during the flyby – was most likely caused by a radiation spike as Juno flew through a radiation-intensive portion of Jupiter’s magnetosphere. Mission controllers at NASA’s Jet Propulsion Laboratory and its mission partners successfully rebooted the computer and, on Dec. 17, put the spacecraft into safe mode, a precautionary status in which only essential systems operate.

As of Dec. 22, steps to recover the flyby data yielded positive results, and the team is now downlinking the science data. There is no indication that the science data through the time of closest approach to Jupiter, or from the spacecraft’s flyby of Jupiter’s moon Io, was adversely affected. The remainder of the science data collected during the flyby is expected to be sent down to Earth over the next week, and the health of the data will be verified at that time. The spacecraft is expected to exit safe mode in about a week’s time. Juno’s next flyby of Jupiter will be on Jan. 22, 2023.

That such disruptions have actually not occurred very often on Juno is somewhat remarkable, considering the hostile nature of the environment around Jupiter.

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