Tag: science

The 1572 Tycho supernova, as seen by Chandra

11:58 am

Remnant of Tycho's supernova

Cool image time! The Chandra science team has released a beautiful X-ray image of the remnant from the 1572 supernova first discovered by astronomer Tycho Brahe.

As with many supernova remnants, the Tycho supernova remnant, as it’s known today (or “Tycho,” for short), glows brightly in X-ray light because shock waves — similar to sonic booms from supersonic aircraft — generated by the stellar explosion heat the stellar debris up to millions of degrees. In its two decades of operation, NASA’s Chandra X-ray Observatory has captured unparalleled X-ray images of many supernova remnants.

Chandra reveals an intriguing pattern of bright clumps and fainter areas in Tycho. What caused this thicket of knots in the aftermath of this explosion? Did the explosion itself cause this clumpiness?

The image to the right, reduced to post here, is a composite of both X-ray (the remnant) and optical light (the background stars).

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Sinkholes on Mars

2:01 pm

Collapse pit on Mars
Click for full image.

Cool image time! In this week’s exploration of Martian geology that is reminiscent of Earth-based lava geology, today’s image is of a collapse pit in Ceraunius Fossae, the vast region of north-south fissures found to the south of the volcano Alba Mons. The photo to the right, cropped to post here, zooms in on that pit.

The picture was part of the most recent image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO). What makes it especially interesting is the sharpness of its rim, in comparison to the collapse channel to the east. This suggests the pit is younger and fresher than the channel, and happened more recently. This also implies that the voids below the ground in which the surface is sinking are either still there, or due to on-going processes might be still be forming (like caves are on Earth).

For example, if there is underground ice, temperature changes or even thermal heat from the nearby giant volcanoes could melt that underground ice periodically, allowing it to flow and erode the surrounding material, forming voids. That this pit is located at 30 degrees north latitude, just inside the northern hemisphere band where glaciers are found, adds weight to this possibility.

The image below, reduced and rotated so that north is to the left, shows the entire sequence of collapse channels, with the more distinct pit from above in the bottom center of the picture.
» Read more

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Hubble snaps photo of Comet Borisov

11:23 am

Comet Borisov by Hubble
Click for full image.

Cool image time! Using the Hubble Space Telescope astronomers have snapped the best image so far of interstellar Comet Borisov. The image to the right, reduced and cropped to post here, is that photograph.

Comet 2I/Borisov is only the second such interstellar object known to have passed through our Solar System. In 2017, the first identified interstellar visitor, an object dubbed ‘Oumuamua, swung within 38 million kilometres of the Sun before racing out of the Solar System. “Whereas ‘Oumuamua looked like a bare rock, Borisov is really active, more like a normal comet. It’s a puzzle why these two are so different,” explained David Jewitt of UCLA, leader of the Hubble team who observed the comet.

The comet was 260 million miles away when Hubble took this picture.

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Europe schedules new parachute tests for ExoMars 2020

8:59 am

Following the failure on all previous tests of the parachutes for its ExoMars 2020 Mars lander, the European Space Agency has now made some design changes and is planning to do additional tests in the first quarter of 2020.

ESA has also requested support from NASA to benefit from their hands-on parachute experience. This cooperation gives access to special test equipment at NASA’s Jet Propulsion Laboratory that will enable ESA to conduct multiple dynamic extraction tests on the ground in order to validate any foreseen design adaptations prior to the upcoming high altitude drop tests.

The next opportunities for high altitude drop tests are at a range in Oregon, US, January–March. ESA is working to complete the tests of both the 15 m and 35 m parachute prior to the ExoMars project’s ‘qualification acceptance review’, which is planned for the end of April in order to meet the mission launch window (26 July–11 Aug 2020).

Their schedule is incredibly tight, since their launch window to Mars is in July 2020, and if they fail to meet it the launch will have to be delayed two years until the next launch window.

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InSight’s mole digs an inch

8:33 am

The InSight science team today tweeted that their attempt to use the lander’s robot arm to help the mole push downward in its effort to insert a heat sensor fifteen feet into the Martian interior has resulted in a gain of about an inch or three centimeters.

This success, small as it seems, is important in that it proves that the reason the drill had been stopped penetrating downward was not because of the presence of a rock, but because the drill hole had become so wide that the drill no longer had side friction to hold it in place. They are now using the arm to give the mole that friction.

The goal was to insert to heat sensor five meters or about sixteen feet into the ground. They are presently a little over a foot down. If this effort has really succeeded, they can then proceed to drill the remaining distance.

One issue however is whether the unexpected weak and porous nature of the soil, which allowed the hole to become so wide, might affect any data produced by the heat sensor. This is presently unknown, but it is a significant question that the scientists involved must ask. If the sensor ends up inside a very wide shaft that allows the surface environment to reach the sensor then it will not really be measuring the temperature of the Martian interior.

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Astronomers identify likely origin star for interstellar Comet Borisov

3:49 pm

Astronomers have backtracked the path of interstellar Comet Borisov to identify its likely origin.

When you rewind Comet Borisov’s path through space, you’ll find that 1 million years ago, the object passed just 5.7 light-years from the center of Kruger 60, moving just 2.13 miles per second (3.43 kilometers per second), the researchers wrote.

That’s fast in human terms —— about the top speed of an X-43A Scramjet, one of the fastest aircraft ever built. But an X-43A Scramjet can’t overcome the sun’s gravity to escape our solar system. And the researchers found that if the comet were really moving that slowly at a distance of no more than 6 light-years from Kruger 60, it probably wasn’t just passing by. That’s probably the star system it came from, they said. At some point in the distant past, Comet Borisov likely orbited those stars the way comets in our system orbit ours.

The remains some uncertainty about these calculations because astronomers are still gathering data on the comet’s path.

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Ice suspected in both old and young lunar craters

1:46 pm

The uncertainty of science: New research of the craters where ice is suspected to exist on the Moon suggests that the ice is found in both young and old craters, which also suggests both that it comes from multiple sources and that some has been deposited more recently.

The majority of the reported ice deposits are found within large craters formed about 3.1 billion years or longer ago, the study found. Since the ice can’t be any older than the crater, that puts an upper bound on the age of the ice. Just because the crater is old doesn’t mean that the ice within it is also that old too, the researchers say, but in this case there’s reason to believe the ice is indeed old. The deposits have a patchy distribution across crater floors, which suggests that the ice has been battered by micrometeorite impacts and other debris over a long period of time.

If those reported ice deposits are indeed ancient, that could have significant implications in terms of exploration and potential resource utilization, the researchers say. “There have been models of bombardment through time showing that ice starts to concentrate with depth,” Deutsch said. “So if you have a surface layer that’s old, you’d expect more underneath.”

While the majority of ice was in the ancient craters, the researchers also found evidence for ice in smaller craters that, judging by their sharp, well-defined features, appear to be quite fresh. That suggests that some of the deposits on the south pole got there relatively recently. “That was a surprise,” Deutsch said. “There hadn’t really been any observations of ice in younger cold traps before.”

If there are indeed deposits of different ages, the researchers say, that suggests they may also have different sources. Older ice could have been sourced from water-bearing comets and asteroids impacting the surface, or through volcanic activity that drew water from deep within the Moon. But there aren’t many big water-bearing impactors around in recent times, and volcanism is thought to have ceased on the Moon over a billion years ago. So more recent ice deposits would require different sources — perhaps bombardment from pea-sized micrometeorites or implantation by solar wind.

I must emphasize that there is much uncertainty here. Most fundamental is the fact that at this moment we still really do not have a solid confirmation of the presence of ice in these permanently shadowed craters, only orbital data that suggests the presence of hydrogen, which scientists believe can only be there if it is locked in water molecules. This is not yet proven however.

It is intriguing however the evidence suggests ice in both young and old craters. This implies either some on-going process to put water there, or a series of specific but different events over time.

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Ice! Ice! Everywhere on Mars ice!

1:20 pm

Ice scarp in Milankovic Crater
Click for full image.

In January 2018 scientists announced the discovery of exposed ice in a number scarp cliff faces found in the high-mid-latitudes of Mars.

These scarps, which have so far been found in one southern 50-55 degree latitude strip and in one crater, Milankovic, at the same latitude in the north, are important because they are one of the first places on Mars in its lower latitudes where we have found ice actually exposed and visible, not buried like the many buried glaciers very near the surface found in the 30 to 60 degree northern and southern latitude bands.

Since that press announcement, scientists have been monitoring these sites for changes, as well as expanding their survey to see if they can locate more of these scarps.

Overview map

My previous posts on this subject were mostly focused on that southern strip near Hellas Basin, as shown on the map on the right. In reviewing the most recent image download from the high resolution camera on Mars Reconnaissance Orbiter (MRO), I noticed that the only new images of ice scarps were taken in the northern location, in Milankovic Crater, as indicated by the white dot north of Olympus Mons. The first image above shows the north-facing scarp of one of these images, cropped to focus in on the color section where, if you look close, you will see a strip of blue across the base of the scarp. That’s the ice layer, exposed as the scarp sublimates away over time from the north to the south.

over view of all MRO images taken so far in Milankovic Crater

This scarp, labeled #2 on the overview map of Milankovic Crater on the right, is located inside the crater’s eastern rim. The second image, posted below and labeled #1 on the overview map, shows a wider area of several ice scarps located on the inside of the crater’s southwestern rim.

The red boxes in the overview map indicate all the images taken by MRO inside this crater. If you go to the camera’s archive and focus in on Milankovic Crater at 54.5 degrees north latitude and 213.3 degrees longitude, you can then click on each red box to see the high resolution image. In practically every image along the crater’s inside rim can be found numerous scarps.
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World’s largest camera lens arrives safely for assembly into LSST

1:05 pm

Link here. The lens will be part of the camera used in the Large Synoptic Survey Telescope (LSST), planned for first light in Chile in 2021, and the video at the link showed the moment they removed the shipping container to inspect the lens to make sure it wasn’t damaged during transport.

The lens will next be installed inside the 3.2 gigapixel camera that will be used by LSST, which will do the following:

The LSST will live on a mountain in Chile, where it will use a 3.2-gigapixel camera and some massive optics to capture a 15-second exposure of the night sky every 20 seconds. At this rate, the LSST will be able to image the entire visible southern sky every few nights.

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I have embedded the video below the fold. This five foot diameter lens is quite astonishing, though the technology that produced it is merely a variation of the same engineering that now routinely produces telescope mirrors 26 feet across.

Hat tip Mike Nelson.
» Read more

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Swirls and layers in Martian depression

12:42 pm

Close-up on swirls and layers

Context of depressions in Columbus Crater
Click for full resolution image.

Cool image time! The southern highlands of Mars is littered with numerous craters, making it look from a distance not unlike the Moon. A closer inspection of each crater and feature, however has consistently revealed a much more complex history than seen on the Moon, with the origins of many features often difficult to explain.

The two images on the right, rotated, cropped, and reduced to post here, shows one such feature in the floor of one southern highlands crater, dubbed Columbus Crater. The top image is a close-up of the area shown by the box in the bottom image.

The uncaptioned full photograph was taken on May 20, 2019 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and was simply titled “Depression in Columbus Crater.” Since the photo included two large depressions, as shown in the wider view in the bottom image, I’m not sure which depression this title refers. In both cases the features do not appear to be impact craters. The top depression is far too irregular, while both do not have the upraised rims that are found on most impact craters.

I have zoomed into the top depression because of its many swirls and layers. On Earth such terrain is usually caused by either water or wind erosion, slowly carving a smooth path across multiple geological layers. Here, there is no obvious evidence of any flows in any direction. Something ate out the material in this depression, exposing the many layers, but what is not clear.

The lower depression reminds me of sinkholes on Earth, where the ground is subsiding into a void below ground The same process could have also formed the top depression.

The surrounding terrain is equally baffling, resembling the eroded surface of an ice block that has been sprayed with warm water. In fact, the entire floor of Columbus Crater appears to have intrigued planetary scientists, as they have requested a lot of images of it from MRO. So far they do not have enough of these images to produce a full map. Since the terrain appears to change drastically over short distances, it is therefore hard to fit the geology of each image together. The overall context is missing.

When I first saw this image I tried to reach the scientist who requested it in the hope he might provide me a more nuanced explanation of what we see here, but despite repeated requests he never responded. Therefore let me propose one theory, based on my limited knowledge of Martian geology.
» Read more

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Sunspot update Sept 2019:
The blankest Sun in decades

1:28 pm

With the release yesterday by NOAA of its September update of its graph showing the long term sunspot activity of the Sun, we find ourselves in what might be the longest stretch of sunspot inactivity in decades, part of what might become the most inactive solar minimum in centuries.

In the last four months the Sun has produced practically no sunspots. There were two in June, two in July, and one in August. The September graph, posted below with additional annotations by me to give it context, shows that the past month was as weak as August, with only one sunspot again.

September 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.

The 2008-2009 solar minimum was one of the deepest and longest ever recorded. Yet, it never produced a stretch of four months with so few sunspots, as shown in the graph above. Moreover, during that minimum the Sun was blank 71% of the time in 2008 and 73% of the time in 2009 (a record). Right now, with almost three months to go in 2019, the Sun has already been blank 73% of time, with every indication that it will top that number before the year is out.

Furthermore, the trend continues to suggest we are heading for a period of very few sunspots. Though one of the six sunspots seen since June 1 had a polarity that belonged to the next solar cycle, we have seen no further such next-cycle sunspots since July. There was one active region on October 6 with a next solar cycle polarity, but it was never able to gather enough magnetic energy to mature into a sunspot.

As I noted in my July 8 sunspot update,
» Read more

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Astronomers find 20 more moons orbiting Saturn

10:21 am

Astronomers have discovered an additional twenty moons orbiting Saturn, bringing the total known to 82, three more than the 79 moons known to circle Jupiter.

Each of the newly discovered moons is about five kilometers, or three miles, in diameter. Seventeen of them orbit the planet backwards, or in a retrograde direction, meaning their movement is opposite of the planet’s rotation around its axis. The other three moons orbit in the prograde—the same direction as Saturn rotates.

Two of the prograde moons are closer to the planet and take about two years to travel once around Saturn. The more-distant retrograde moons and one of the prograde moons each take more than three years to complete an orbit.

The astronomers have also created a contest allowing the public to help name these new moons.

I will make one prediction: They are going to find many more.

In fact, Saturn’s rings and its numerous moons raise the question of what defines a moon. At present, a moon is defined as any object orbiting a planet, regardless of size. With Saturn’s rings however we have millions of objects orbiting that planet, many very tiny. It seems we have never put a size limit on the definition of a moon, and really need to.

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Astronomers photograph baby binary system

9:23 am

Baby binary stars dance in joint accretion disk
Click for full image.

Using the Atacama Large Millimetre/submillimetre Array (ALMA), astronomers have obtained the first high resolution image of a baby binary system, its two young stars dancing within a joint accretion disk.

Most stars in the universe come in the form of pairs – binaries – or even multiple star systems. Now, the formation of such a binary star system has been observed for the first time with high-resolution ALMA (Atacama Large Millimetre/submillimetre Array) images. An international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics targeted the system [BHB2007] 11, the youngest member of a small cluster of young stellar objects in the Barnard 59 core in the Pipe nebula molecular cloud. While previous observations showed an accretion envelope surrounding a circum-binary disk, the new observations now also reveal its inner structure.

“We see two compact sources, that we interpret as circum-stellar disks around the two young stars,” explains Felipe Alves from MPE, who led the study. “The size of each of these disks is similar to the asteroid belt in our Solar System and their separation is 28 times the distance between the Sun and the Earth.” Both proto-stars are surrounded by a circum-binary disk with a total mass of about 80 Jupiter masses, which contains a complex network of dust structures distributed in spiral shapes. The shape of the filaments suggests streamers of in-falling material, which is confirmed by the observation of molecular emission lines.

Why most stars form as binary systems is as yet not understood. This data is a major first step towards figuring this out.

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Weird glacial features in Martian crater

1:47 pm

weird glacial feature in crater on Mars
Click for full image.

Cool image time! In reviewing today’s October release of new images from the high resolution camera of Mars Reconnaissance Orbiter (MRO), I came across the strange geology shown in the image to the right, rotated, cropped, and reduced to post here.

The uncaptioned image calls these “glacial features within crater.” The crater is located at 35 degrees north latitude in Arabia Terra, one of the more extensive regions of the transition zone between the northern lowlands and the southern highlands. It is also located within the northern band from 30 to 60 degrees latitude where most of the buried Martian glaciers are found.

The most abundant type of buried glaciers are called concentric crater fill (CCF) because they are found inside craters, and often show decay in a concentric manner. This weird feature likely falls into that category, though I would hardly call these glacier features concentric.

I’m not even sure if this is an impact crater. If it is, its rim has been heavily obscured, making it look instead like an irregular depression with one outlet to the south. In fact, I suspect it is possibly one of the lakes that scientists believe pepper this part of Arabia Terra and might have contained liquid water two to three billion years ago. That water would have later frozen, and possibly become covered by dust and debris to protect it.

According to present theories, Mars is presently in a period where its mid-latitude glaciers are shrinking, the water sublimating away and being transported back to its poles. The weird formations here suggest this process. Imagine what happens when you spray warm water on a big block of ice. It dissolves, but randomly to form weird shapes.

In this case the glacier is shrinking randomly where the ice has gotten exposed. In the thin Martian atmosphere, it transitions directly from a solid to a gas, sublimating into the atmosphere to leave these inexplicable shapes.

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Astronomers roughly map out Andromeda’s history

10:40 am

The uncertainty of science: Astronomers have now roughly mapped out the history of the Andromeda galaxy, identifying two major events whereby it had absorbed nearby dwarf galaxies.

“It’s been known for 10 to 15 years that Andromeda has a vigorous history of accumulating and destroying its neighbours,” Mackey says. In fact, he says, “It seems to have a much more intense history of that than the Milky Way.”

…[New data] “tells us there were two main events that formed the halo of Andromeda,” Mackey says. “One occurred very long ago. The other must have happened relatively recently.”

Not that Andromeda couldn’t also have eaten innumerable smaller galaxies. ”We can’t trace them with galactic clusters, because they didn’t have any to begin with,” Mackey says.

Most of the news reports about this new research have been very overwrought (Andromeda is “violent” and is going to “eat us!”) and very unaware that the assimilation of nearby small galaxies by Andromeda is not really news. Astronomers have known for years that big galaxies like Andromeda and the Milky Way absorb the dwarf galaxies around them. All this story does is postulate a more detailed though very rough timeline.

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InSight robot arm to help mole dig

10:20 am

Mole in hole, with robot arm and scoop above
Click for full image.

In their effort to solve the issues that have prevented InSight’s mole from penetrating more than fourteen inches into the ground on Mars, engineers now plan to use the scoop on the robot arm to “pin” the mole up against one wall of the hole so that it will have the friction necessary to drill downward.

The image to the right, cropped and reduced to post here, illustrates what they have been doing and what they will do. Previously the hole was much larger, which prevented the mole from moving downward because it needed the friction from the material around it to hold it in place after each hammer action. (Think of pounding a nail into a wooden board: The nail is gripped tightly by the wood around it as it goes down, so that after each hit it goes further in.)

Since June they have been using the arm and scoop to fill in the hole around the mole. Now I think they intend to bring the scoop around to the mole’s left side, as shown in the image, and pin it upright against the right wall of the hole. When it resumes hammer-drilling they hope both the wall and the scoop will provide enough friction for the mole to drill downward.

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The slowly changing dunes of Mars

1:15 pm

Map of Mars

In order to better understand the climate and geology of Mars, scientists need to study how the thin Martian atmosphere causes changes to the planet’s numerous sand dunes. To do this, they have been using the high resolution camera on Mars Reconnaissance Orbiter (MRO) to periodically snap photos of the same places repeatedly over time, to track any changes that might occur.

Recently the monthly download dump of images from MRO included one such location in the northwest quadrant of Hellas Basin, what I call the basement of Mars because it the planet’s lowest point. The uncaptioned image was taken on May 20, 2019 and was titled “Hellas Region Sand Dune Changes.” A review of past images shows that MRO has taken pictures of this location several times in the past, in 2011 and in 2017. All these images were taken during the Martian autumn season, and were taken to see if over time there were any significant changes to the dunes due to winds.

My superficial comparison of the 2011 and 2017 images does not show much obvious change. There could be small changes that my quick review did not spot, and there is also the strong possibility that the entire dune field could have shifted as a unit over those three Martian years, a change that would require a more detailed analysis beyond my technical capabilities. Click on both links, put the photographs in separate tabs, and switch quickly between them to see if you can spot any differences.

Comparing the 2011 and 2019 images however shows some significant changes, most of which I think are due to the 2018 global dust storm. Below is that comparison.
» Read more

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More organics detected in Enceladus’ plumes

10:23 am

Using Cassini archived data scientists have detected evidence of new organic molecules in the water-ice plumes coming from the tiger stripe fissures on Saturn’s moon Enceladus.

Powerful hydrothermal vents eject material from Enceladus’ core, which mixes with water from the moon’s massive subsurface ocean before it is released into space as water vapor and ice grains. The newly discovered molecules, condensed onto the ice grains, were determined to be nitrogen- and oxygen-bearing compounds.

On Earth, similar compounds are part of chemical reactions that produce amino acids, the building blocks of life. Hydrothermal vents on the ocean floor provide the energy that fuels the reactions. Scientists believe Enceladus’ hydrothermal vents may operate in the same way, supplying energy that leads to the production of amino acids.

For clarity I should point out that I am using the term “organics” as chemists do. It refers not to life, but to any molecule that is formed using carbon.

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Juno completes long engine burn to avoid Jupiter’s shadow

10:14 am

In order to avoid a twelve-hour plunge through Jupiter’s shadow that would have likely sucked all power from Juno’s solar powered systems and killed the spacecraft, mission engineers have successfully used its attitude thrusters to complete a 10.5 long engine burn.

Juno began the maneuver yesterday, on Sept. 30, at 7:46 p.m. EDT (4:46 p.m. PDT) and completed it early on Oct. 1. Using the spacecraft’s reaction-control thrusters, the propulsive maneuver lasted five times longer than any previous use of that system. It changed Juno’s orbital velocity by 126 mph (203 kph) and consumed about 160 pounds (73 kilograms) of fuel. Without this maneuver, Juno would have spent 12 hours in transit across Jupiter’s shadow – more than enough time to drain the spacecraft’s batteries. Without power, and with spacecraft temperatures plummeting, Juno would likely succumb to the cold and be unable to awaken upon exit.

“With the success of this burn, we are on track to jump the shadow on Nov. 3,” said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio.

This burn did not use the spacecraft’s main engine, which they fear has a problem that would produce a catastrophic failure if fired. Instead, they used Juno’s small attitude thrusters, which explains the length of the maneuver. In fact, this 10.5 hour burn might actually be the longest chemical engine burn in space ever. While ion engines routinely fire for this long or longer, as far as I can remember no chemical engine in space has ever fired even close to this length of time.

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The sounds of Mars

10:56 am

The InSight seismometer team today issued an update of their results since the instrument began recording quakes on Mars in February.

But after the seismometer was set down by InSight’s robotic arm, Mars seemed shy. It didn’t produce its first rumbling until this past April, and this first quake turned out to be an odd duck. It had a surprisingly high-frequency seismic signal compared to what the science team has heard since then. Out of more than 100 events detected to date, about 21 are strongly considered to be quakes. The remainder could be quakes as well, but the science team hasn’t ruled out other causes.

The press release provides audio for many of these detections, including two 3.3+ earthquakes as well as a strange sequence of what they call “dinks and donks” that appear to occur each evening as the seismometer adjusts to night-time temperatures.

So far the data suggests that Mars’ interior is a relatively quiet place, compared to Earth.

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China to open FAST radio telescope to world

8:48 am

China has decided to allow astronomers worldwide to apply for time on its new FAST radio telescope, the largest such telescope in the world.

Since testing began in 2016, only Chinese scientists have been able to lead projects studying the telescope’s preliminary data. But now, observation time will be accessible to researchers from around the world, says Zhiqiang Shen, director of the Shanghai Astronomical Observatory and co-chair of the Chinese Academy of Sciences’ FAST supervisory committee.

Obviously U.S. astronomers are going to want to use this telescope. I wonder if there will be security issues. I suspect that if they only request time and then make observations, there will be no problems. However, if they need to do anything that will require the use of U.S. technology, in China, then they may find themselves violating the U.S. law that forbids any technology transfer to China.

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Martian impact into lava crust?

1:13 pm

Impact crater north of Pavonis Mons
Click for full image.

Cool image time! The photo on the right, cropped to post here, was taken by the high resolution camera on April 23, 2019. It shows a quite intriguing impact crater on the northern lava slopes of Pavonis Mons, the middle volcano in the chain of three gigantic volcanoes to the west of Valles Marineris.

What makes this image cool is what the impact did when it hit. Note the circular depression just outside the crater’s rim. In the southeast quadrant that ring also includes a number of additional parallel and concentric depressions. Beyond the depression ground appears mottled, almost like splashed mud.

What could have caused this circular depression? Our first clue comes from the crater’s location, as shown in the overview map below and to the right.
» Read more

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First data suggests Comet Borisov resembles solar comets

8:46 am

The first spectrum obtained from Comet Borisov suggests that it is quite similar to comets in our solar system.

The gas detected was cyanogen, made of a carbon atom and a nitrogen atom bonded together. It is a toxic gas if inhaled, but it is relatively common in comets.

The team concluded that the most remarkable thing about the comet is that it appears ordinary in terms of the gas and dust it is emitting. It looks like it was born 4.6 billion years ago with the other comets in our Solar system, yet has come from an – as yet – unidentified star system.

It is still very early, so drawing any firm conclusions at this point is risky.

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Movie of Juno’s 22 close fly-by of Jupiter

8:39 am

As he has done previously, citizen scientist Gerald Eichstädt has created a movie using Juno images of the spacecraft’s twenty-second fly-by of Jupiter.

I have embedded the movie below the fold. This fly-by included the images of Io’s shadow posted by other citizen scientists earlier. Because the movie shows this shadow in the context of the fly-by (near its lowest altitude), it illustrates why the shadow appears far larger than it is, relative to the entire planet.

» Read more

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Planet X a small black hole?

8:13 am

In one of the wilder theories attempting to explain the orbits of the outer objects found beyond Neptune, two physicists have proposed that the reason Planet X has not been located is because it might be a small black hole.

Previous studies have suggested Planet Nine, which some astronomers refer to as “Planet X,” has a mass between five and 15 times that of Earth and lies between 45 billion and 150 billion kilometers from the sun. At such a distance, an object would receive very little light from the sun, making it hard to see with telescopes.

To detect objects of that mass, whether planets or black holes, astronomers can look for weird blobs of light formed when light “bends” around the object’s gravitational field on its journey through the galaxy (simulated image above). Those anomalies would come and go as objects move in front of a distant star and continue in their orbit.

But if the object is a planet-mass black hole, the physicists say, it would likely be surrounded by a halo of dark matter that could stretch up to 1 billion kilometers on every side. And interactions between dark matter particles in that halo—especially collisions between dark matter and dark antimatter—could release a flash of gamma rays that would betray the object’s presence, the researchers propose in a forthcoming paper posted on the preprint server arXiv.

Anything is possible, but some things are certainly less likely than others. If these scientists turn out to be right, however, they will have achieved one of the biggest coups in the history of science.

And yes, the undiscovered planet out there should be referred to as “Planet X”, not “Planet Nine.” Not only is Pluto a planet, so are a lot of other objects in the solar system that up to recently were not considered so.

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A big planet circling a small star

10:03 am

The uncertainty of science: In contradiction of every existing stellar and planetary formation model, astronomers have found a half-sized Jupiter exoplanet orbiting a tiny red dwarf star.

The red dwarf GJ 3512 is located 30 light-years from us. Although the star is only about a tenth of the mass of the Sun, it possesses a giant planet – an unexpected observation. “Around such stars there should only be planets the size of the Earth or somewhat more massive Super-Earths,” says Christoph Mordasini, professor at the University of Bern and member of the National Centre of Competence in Research (NCCR) PlanetS: “GJ 3512b, however, is a giant planet with a mass about half as big as the one of Jupiter, and thus at least one order of magnitude more massive than the planets predicted by theoretical models for such small stars.”

It appears the universe does not care what this and other scientists think “should” happen. The universe will do what the universe wants to do.

This discovery only underlines how little we understand of the formation of stars and their solar system. Be prepared for many more like surprises in the coming decades and centuries.

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Astronomer: Look for monolith on co-orbiting asteriods

5:37 pm

According to one astronomer in a paper published this week, the most likely place to find alien artifacts would be on the co-orbital asteroids, objects whose orbit is very similar to the Earth and thus always nearby but mostly unseen.

In this context, a co-orbital is an asteroid that goes around the Sun on the same, or similar, orbital path to Earth. Co-orbital objects approach Earth very closely every year at distance is much shorter than anything except the moon.

Consequently, co-orbitals could be a great place to watch Earth from. Not only would any alien probes on co-orbital objects be concealed, but they would also be anchored and able to access solar energy. They could possibly sustain themselves for many thousands of years.

According to this paper, if aliens have visited the solar system in the past they would place their long-term alien probes on such an asteroid, or even give it a comparable co-orbit. And if we look and don’t find anything, that would strongly imply that we are alone in the universe.

Fun stuff, but need I say that not finding alien artifacts at these locations proves nothing.

Hat tip Jeff Bliss.

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