Tag: science

InSight has buried its Mole

9:58 am

The Mole buried

Using the scoop on InSight’s robot arm, engineers have now successfully filled the large hole that had formed around the spacecraft’s mole, the drill that has been trying but failing to dig down about fifteen feet so that a heat sensor could measure the internal temperature of Mars.

The image to the right shows the filled hole with the mole’s communications tether snaking away. Earlier this month they used InSight’s scoop to scrape surface material into the hole, as planned in June. According to the mole’s principle investigate, Tilman Spohn,

I had estimated that the first scrape of 12 centimetres swath length would raise the bottom of the pit but leave the Mole sticking out of the sand. By the way, this was the condition for some to agree to the quite controversial ‘scratch test’. As one can see in the image from Sol 600 shown below, that estimate was not quite right. The scraping was a complete success! The scrape was much more effective than expected and the sand filled the pit almost completely. The Mole is now covered, but there is only a thin layer of sand on the back cap.

Their next step will be to use the scoop to press down on the dirt of the filled hole, with the hope this added pressure will keep the dirt pressed against the mole as it hammers downward, thus holding it place with each downward stroke.

4 comments

Newly upgraded solar telescope sees first light

9:39 am

Early image from upgraded solar telescope.

Astronomers have finished a major instrument upgrade of the GREGOR solar telescope in the Canary Islands, making it possible for them to observe features on the Sun’s surface as small as thirty miles in diameter.

The image to the right is an example of the telescope’s new capability, showing the Sun’s granular surface features. From the introduction of the paper describing the upgrade:

GREGOR is Europe’s largest solar telescope. … Its 1.5 m diameter with an optical footprint of 1.44 m allows us to resolve structures on the Sun as small as 50 km at 400 nm.

…A past drawback of GREGOR was that its image quality did not reach the theoretical limit, partly because a risk was taken with untested technologies, such as silicon carbide mirrors, which could not be polished well enough, and partly because of design problems. These difficulties have recently been solved by replacing all silicon carbide mirrors with mirrors made of Zerodur, which can be polished to the required quality, and by redesigning the AO relay optics. GREGOR now operates at its diffraction limit. [emphasis mine]

In other words, the initial mirrors did not work as promised, requiring them to replace them to get the telescope to function as initially designed. By the image above, it looks like their upgrade has worked admirably.

8 comments

A star with giant misaligned rings

8:52 am

Star with misaligned rings

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have detected a nearby star, dubbed GW Ori, with multiple rings of dust with several tilted in relation to the others.

The rings, with dust equaling 75, 170, and 245 Earth masses each, are 46, 188, and 336 astronomical units (au) each from their star. (An au is the distance of the Earth to the Sun.) If you look closely at the image to the right, you can see that the inner rings are circular, while the outer rings appear oval, suggesting that we are looking directly down at the inner rings, but the outer rings are tilted to our line of sight. Moreover, another team of astronomers

…observed GW Ori with ALMA and the European Southern Observatory’s Very Large Telescope (VLT). Near infrared observation with VLT showed for the first time that the innermost ring casts a shadow on the outer rings, which is clear evidence of disk misalignment. Kraus and his colleagues also performed a computer simulation and suggest that the triple star system can create misaligned rings, without gravitational assistance from planets. The two teams have different theories for the origin of the misaligned rings, but no conclusions have been reached so far. Nevertheless, GW Ori is a precious example to understand planet formation in the complex gravitational environment around multiple stars. [emphasis mine]

As noted, there is no agreement on the cause of the misalignment, only that it does exist.

0 comments

Bright-tipped perplexing terrain on Mars

1:29 pm

Perplexing terrain on Mars
Click for full image.

The photo to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on June 24, 2020, and shows a bit of inexplicable country in Arabia Terra, the widest and largest transition zone region on Mars between the northern lowland plains and southern cratered highlands.

The stuff visible in this image falls into what I call “What the heck?” geology. It is very clear we are looking at a collection of straight and curved ridges and mesas, all of which for some reason are bright at their tips and edges. Some of the curved ridges might be the rims of craters, but only some. Other ridge lines look more like leftovers following a strange erosion process. The problem is that to my uneducated eye I can find little rhyme or reason to these shapes. The mesas and canyon on the image’s right edge might be explained by the erosion processes that create chaos terrain on Mars, but that process does not do a good job of explaining anything else in the photo.

That this uncaptioned image is merely labeled “Arabia Terra” suggests that the scientists involved in getting this image were equally perplexed by it, and could not give it a better description.

The overview map below provides some location context, including how this geology relates to the landing site of Europe’s Rosalind Franklin rover, now scheduled for a 2022 launch.
» Read more

2 comments

Biggest black hole merger yet detected by gravitational waves

3:30 pm

The uncertainty of science: In May 2020 scientists using the LIGO and VIGO gravitational waves telescopes detected evidence of a merger from two giant black holes, one of which was of a size that according to all theories had been considered “impossible.”

The short gravitational wave signal, GW190521, captured by the LIGO and Virgo gravitational wave observatories in the United States and Europe on 21 May last year, came from two highly spinning, mammoth black holes weighing in at a massive 85 times and 66 times the mass of the Sun, respectively.

But that is not the only reason this system is very special. The larger of the two black holes is considered `impossible’. Astronomers predict that stars between 65 – 130 times the mass of the Sun undergo a process called pair instability, resulting in the star being blown apart, leaving nothing behind.

With a mass of 85 solar masses, the larger black hole falls squarely in that forbidden range, referred to as the upper black hole mass gap, and should be `impossible’.

The explanation the scientists propose is that this black hole initially formed with a mass smaller than 65 solar masses, and then sucked in matter, including a possible additional black hole merger, that raised its weight to 85 solar masses.

3 comments

The longest lava tube in the solar system?

9:19 am

A lava tube on Mars
Click for full image.

Before I delve into today’s cool image, I think it important to explain to my readers why I seem to post so many cool images from Mars. The simple explanation is that Mars right now is where almost all the cutting edge planetary research is taking place, and as a science journalist focused on space exploration I must go to that cutting edge. My dear readers know that I love variety (just consider the evening pauses on Behind the Black), but you can’t ignore the reporting of real discoveries simply to increase the diversity of one’s posts. This is too often what modern news outlets do, which is also why they often miss the real story.

Anyway, today’s cool image to the right, rotated, cropped, and reduced to post here, shows only a small section of what might be the longest lava tube in the entire solar system. Taken on May 5, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), it shows a string of pits along a meandering depression coming down the northwest flank of the giant volcano Arsia Mons. The image was a follow-up to a July 2014 photo of the same location, and was taken to produce a stereo pair.

The feature strongly suggests a lava tube, with the pits being skylights into the meandering underground void. From top to bottom this section of the tube is a little over three miles long. Since there are lava tubes on Earth far longer, this one image hardly makes this the longest tube in the solar system.

The tube, however, extends off the image both at the bottom and at the top. Not many high resolution images have been taken in this area, so it is therefore hard to say how far the tube extends. Other nearby high resolution images in this area however have found similar lava tubes, which conceivably could be part of the same tube. The overview map below shows the relationship.
» Read more

3 comments

A collapsed Martian crater in a glacier?

12:43 pm

Collapsed crater in glacier?
Click for full image.

Today’s cool image to the right, cropped and reduced to post here, is another example of evidence that the mid-latitudes of Mars are covered with glaciers and ice. The photo, taken on April 25, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), shows many of the squashed and blobby features found in these mid-latitudes.

What makes the image even more interesting is the small crater in the center of the larger crater. The floor of that larger crater seems filled with glacial fill, and it appears that when that smaller impact occurred it caused the nearby surrounding fill to collapse downward, producing the oblong off-center depression. At least that’s my uneducated guess, which I admit could easily be wrong.

Even if my hypothesis is wrong, the visual evidence here supports the theory that this region, dubbed Deuteronilus Mensae, has lots of buried ice glaciers. Consider for example the distorted crater to the southwest of the big crater. It sure looks like at some point it was heated suddenly, maybe by the impact of the main crater, so that its rim was warped and reshaped, in the manner that ice would be warped and reshaped by sudden heat. Moreover, all the craters in full image appear to have glacial fill.

The overview map below adds weight to this conclusion.
» Read more

1 comment

Revisiting Mars’ glacier country

1:16 pm

Glacial cracks or pits on Mars
Click for full image.

With today’s cool image we return to what I have labeled glacier country on Mars, though this time the image shows a Martian glacial feature that while resembling vaguely such features seen on Earth, has an alienness to it that requires some explanation.

The photo to the right, cropped to post here, was taken on March 24, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The section I have focused on is the floor of a depression with a number of parallel pits, more or less aligned with the packed north-south ridges that cover the entire floor.

Normally, the north-south ridges would suggest repeated glacial flows moving to either the west or to the east. Such movement could over time, cause the ridges to separate, creating the cracks or pits that we see here. The trouble is that the slope of this depression is very unclear. In fact, the wider view below shows that this depression appears mostly enclosed, or if not it does not seem to be flowing in any particular direction.
» Read more

0 comments

Problem with InSight’s weather station

3:18 pm

Engineers are troubleshooting a problem with the weather sensors on the InSight lander on Mars that has prevented them from collecting data since August 16th.

[The weather system] is in safe mode and unlikely to be reset before the end of the month while mission team members work toward a diagnosis. JPL engineers are optimistic that resetting the control computer may address the issue but need to investigate the situation further before returning the sensors to normal.

Overall InSight has turned out to be of mixed success. The seismometer has worked as planned, but the mole designed to drill the heat thermometer sixteen feet into the ground has so far failed to work, and now the weather station has shut down, though hopefully only temporarily.

4 comments

Cracks and scallops on the lowland plains of Mars

2:37 pm

Utopia Basin cracks and scallops
Click for full image.

Cool image time! To the right is some of the strange terrain seen in the northern lowland plains of Mars. The photo, cropped to post here, was taken on May 4, 2020 by the high resolution camera of Mars Reconnaissance Orbiter (MRO) of an area in the northwest part of Utopia Planitia.

Next year China’s first attempt to soft land a rover on Mars will occur somewhere in Utopia Planitia. Utopia Planitia, also called Utopia Basin, is quite large, however, and in fact is the largest recognizable impact basin on Mars, with a diameter of more than 2,000 miles or about two thirds the width of the United States. If this strange spot was put near Seattle, Tianwen-1 is expected to touch down somewhere near Houston, Texas.

The MRO science team labeled the image “Scalloped terrain in Utopia Planitia.” The curved cliffs in the image illustrate those scallops, found frequently in Utopia. Their formation is believed related to the sublimation of underground ice, changing directly from ice to gas. The theories of this process however are somewhat uncertain at this time.

What stuck me about the image were the north-south oriented cracks. They extend through the full image, all oriented in the same direction. I haven’t the faintest idea what caused them, but they are intriguing, are they not?

This terrain is also different than most Utopia Planitia images I have previously posted. Most look squishy and blobby and distorted, suggesting the presence of soft slush and underground ice. This image instead suggests hard bedrock, even though it is farther north than the previous images and should thus be expected to have more ice underground. Quite mysterious.

I suspect the ice is here, but is simply not made obvious by any surface event. Then again, who knows? The geology of Mars is definitely not obvious, no matter how obvious it sometimes seems.

0 comments

Curiosity captures a dust devil

11:33 am

During its recent and last several-week-long drilling effort in the clay unit in Gale Crater, the rover Curiosity was also able to luckily capture the passing of a nearby dust devil.

It’s almost summer in Gale crater, which puts us in a period of strong surface heating that lasts from early spring through mid-summer. Stronger surface heating tends to produce stronger convection and convective vortices, which consist of fast winds whipping around low pressure cores. If those vortices are strong enough, they can raise dust from the surface and become visible as “dust devils” that we can image with our cameras. The animated GIF shows a dust devil movie we took with Navcam on Sol 2847, covering a period of about five minutes. We often have to process these images, by enhancing what’s changed between them, before dust devils clearly show up. But this dust devil was so impressive that – if you look closely! – you can just see it moving to the right, at the border between the darker and lighter slopes, even in the raw images.

I have embedded the movie below the fold. The dust devil looks like a ghostly white tower moving from the left to the right just above the darkest band of landscape cutting across the middle of the image.
» Read more

1 comment

NASA’s first Orbiting Geophysical Observatory to burn up in atmosphere

11:11 am

The first of six Orbiting Geophysical Observatories, dubbed OGO-1, is set to to burn up in the atmosphere sometime in the next week.

Launched September 5, 1964, OGO-1 operated until 1969. It along with the five later OGO satellites were designed to study the Earth’s magnetic field as well as the Van Allen Belts across a solar minimum and maximum. Together they proved the magnetosphere was homogeneous, somewhat the same wherever data was obtained.

As the first such observatory, the spacecraft was also a technology test. Thus, the failure of its attitude control system, preventing about half its instruments from gathering data, was not really a failure. It laid the groundwork for all such research satellites to follow over the next half century.

2 comments
1 … 263 264 265 266 267 … 729