Tag: science

Yutu-2 completes 20th lunar day on Moon

10:28 am

The new colonial movement: The Chinese lunar rover Yutu-2 has completed its 20th lunar day on the farside of the Moon, and has now been put in sleep mode for the long lunar night.

Yutu 2 continued on its planned journey to the northwest of the lander, according to the China Lunar Exploration Program (CLEP). The rover covered 90 feet (27.64 meters) during the lunar day to make a total of 1,610 feet (490.9 m) of roving since setting down on the far side of the moon in January 2019.

The article at the link includes some images, including visual data from the ground-piercing radar that suggests at least four layers in the lunar subsurface.

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Midnight repost: A scientist’s ten commandments

11:59 pm

The tenth anniversary retrospective of Behind the Black continues: The post below, from September 27, 2010, reports on one of the simplest but most profound scientific papers I have ever read. Its advice is doubly needed today, especially commandment #3.

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A scientist’s ten commandments

Published today on the astro-ph website, this preprint by Ignacio Ferrín of the Center for Fundamental Physics at the University of the Andes, Merida, Venezuala, is probably the shortest paper I have ever seen. I think that Dr. Ferrin will forgive me if I reprint it here in its entirety:

1. Go to your laboratory or your instrument without any pre-conceived ideas. Just register what you saw faithfully.

2. Report promptly and scientifically. Check your numbers twice before submitting.

3. Forget about predictions. They are maybe wrong.

4. Do not try to conform or find agreement with others. You may be the first to be observing a new phenomenon and you may risk missing credit for the discovery.

5. Criticism must be scientific, respectful, constructive, positive, and unbiased. Otherwise it must be done privately.

6. If you want to be respected, respect others first. Do not use insulting or humiliating words when referring to others. It is not in accord with scientific ethics.

7. Do not cheat. Cheating in science is silly. When others repeat your experiment or observation, they will find that you were wrong.

8. If you do not know or have made a mistake, admit it immediately. You may say, “I do not know but I will find out.” or “I will correct it immediately.” No scientist knows the answer to everything. By admitting it you are being honest about your knowledge and your abilities.

9. Do not appropriate or ignore other people’s work or results. Always give credit to others, however small their contribution may have been. Do not do unto others what you would not like to be done unto you.

10. Do not stray from scientific ethics.

It seems that some scientists in the climate field (Phil Jones of East Anglia University and Michael Mann of Pennsylvania State University are two that come to mind immediately) would benefit by reading and following these rules.

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Perseverance’s planned journey in Jezero Crater

1:34 pm

Jezero Crater delta
Jezero Crater delta

If all goes right, on February 18, 2021 the rover Perseverance will gently settle down onto the floor of Jezero Crater on Mars. The image to the right is probably the most reproduced of this site, as it shows the spectacular delta that some scientists believe might be hardened mud that had once flowed like liquid or lava from the break in the rim to the west.

They hope to put Perseverance down to the southeast of that delta, as shown in the overview map below.
» Read more

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Astronomers find freshly fallen meteorites based on tracking their fall

11:36 am

Australian astronomers have found two meteorites on the ground after spotting them in the sky before they fell, with one found only

The first had been spotted in the sky only a few weeks earlier, while the second had been spotted back in November 2019. They had had to postpone the search for the second until the restrictions for the Wuhan flu were lifted.

The discovery of the first was amusing:

Astronomer Dr Hadrien Devillepoix and planetary geologist Dr Anthony Lagain originally went on a reconnaissance mission to assess the latest fall site near Madura, taking drone imagery of the area. Dr Devillepoix said that as they were walking back to their car along the old telegraph track near Madura Cave, they spotted what appeared to be a real meteorite on the ground just in front of them.

“I thought Anthony was playing a prank on me, that he planted one of the fake meteorites we were using for the drone training session. But after a closer inspection, it was evident that the fist-sized, 1.1 kilogram rock we just found was indeed the meteorite we were after,” Dr Devillepoix said. Dr Devillepoix explained that although the rock was very close to the predicted fall position, the team was not expecting to find it that quickly in this bushy terrain.

Based on its track as it fell, the astronomers think it might be from the Aten family of asteroids, which orbit the Sun between Venus and Earth. Such asteroids are hard to find because of the glare of the Sun, and are thus not as well studied. This makes this find even more significant.

Finds like this, which are beginning to happen more and more, are important because, first, the meteorite doesn’t spend much time in the Earth environment, and second, they can precisely identify where the asteroid came from. Both facts allow scientists a much better understanding of the asteroids themselves.

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Neutron star left over from Supernova 1987A?

8:24 am

The uncertainty of science: Two different teams of astronomers are now suggesting that, based on evidence recently obtained by the Atacama Large Millimeter/submillimeter Array (ALMA), a neutron star is what is left over from the star that caused Supernova 1987A, the only naked eye supernova in the past four hundred years.

Recently, observations from the ALMA radio telescope provided the first indication of the missing neutron star after the explosion. Extremely high-resolution images revealed a hot “blob” in the dusty core of SN 1987A, which is brighter than its surroundings and matches the suspected location of the neutron star.

..The theoretical study by Page and his team, published today in The Astrophysical Journal, strongly supports the suggestion made by the ALMA team that a neutron star is powering the dust blob. “In spite of the supreme complexity of a supernova explosion and the extreme conditions reigning in the interior of a neutron star, the detection of a warm blob of dust is a confirmation of several predictions,” Page explained.

These predictions were the location and the temperature of the neutron star. According to supernova computer models, the explosion has “kicked away” the neutron star from its birthplace with a speed of hundreds of kilometers per second (tens of times faster than the fastest rocket). The blob is exactly at the place where astronomers think the neutron star would be today. And the temperature of the neutron star, which was predicted to be around 5 million degrees Celsius, provides enough energy to explain the brightness of the blob.

They haven’t actually gotten any direct evidence of this stellar remnant, so some healthy skepticism is required. At the same time, the data favors this solution, which means the star did not collapse into a black hole when it exploded.

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Live stream of Perseverance launch tomorrow

8:13 pm

I have embedded below the fold NASA’s live stream channel for tomorrow’s 7:50 am (Eastern) launch of the Perseverance rover to Mars on a ULA Atlas-5 rocket.

At present the channel is carrying NASA’s programming leading up to the launch. The actual live stream for the launch begins at 7 am (Eastern).

The weather looks good, and there appear to be no issues, as of 11 pm (Eastern).

» Read more

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Glacier country on Mars

12:47 pm

Glacial flow in Protonilus Mensae
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on May 24, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and provides a wonderful example of the kind of evidence of buried glaciers found extensively in the mid-latitudes of Mars.

This particular region, called Protonilus Mensae, is a region of chaos terrain at the transition zone between the southern cratered highlands and the northern lowland plains. I have featured a number of cool images in Protonilus, all of which show some form of buried glacial flow, now inactive.

The last cool image above was one that the MRO science team had picked to illustrate how to spot a glacier on Mars.

In this particular image are several obvious glacier features. First, we can see a series of moraines at the foot of each glacier in the photo, each moraine indicating the farthest extent of the glacier when it was active and growing. It also appears that there are two major layers of buried ice, the younger-smaller layer near the image’s bottom and sitting on top of a larger more extensive glacier flow sheet. This suggests that there was more ice in the past here, and with each succeeding ice age the glaciers grew less extensive.

Second, at the edges of the flows can be seen parallel ridges, suggestive also of repeated flows, each pushing to the side a new layer of debris.

Third, the interior of the glacier has parallel fractures in many places, similar to what is seen on Earth glaciers.

Protonilus Mensae, as well as the neighboring chaos regions Deuteronilus to the west and Nilosyrtis to the east, could very well be called Mars’ glacier country. Do a search on Behind the Black for all three regions and you will come up with numerous images showing glacial features.

Below is an overview of Protonilus, the red box showing the location of this image. Also highlighted by number are the locations of the three features previously posted and listed above.
» Read more

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Martian eroding ridges amid brain terrain

12:09 pm

Brain terrain and bisected ridges on Mars
Click for full image.

Today’s very cool image is cool because of how inexplicable it is. To the right, cropped to post here, is a photo taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) of an area of what they call “Ribbed Terrain and Brain Terrain”.

I call it baffling.

Nor am I alone. At the moment the processes that create brain terrain (the undulations between the ridges) remain a complete mystery. There are theories, all relating to ice sublimating into gas, but none really explains the overall look of this terrain.

Making this geology even more baffling are the larger ridges surrounding the brain terrain, all of which appear to have depressions along their crests. Here too some form of sublimation process appears involved, but the details remain somewhat mysterious.
» Read more

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Another university researcher arrested for spying for China

2:18 pm

The FBI yesterday arrested a researcher who had been working at the University of California-Davis and had lied about here contacts with the Chinese communist party and its military.

Juan Tang, 37, who had been a visiting cancer researcher at UC Davis for several months, left her Davis apartment in June after FBI agents questioned her about evidence that she lied concerning whether she was a member of the Chinese military or Communist Party when she applied for a visa, according to federal court papers.

…U.S. authorities have no authority to enter the consulate without permission, and it was not immediately clear Friday whether she had voluntarily surrendered. Jail records show the FBI arrested her overnight and booking was still in progress Friday morning.

She is one of four Chinese researchers charged by the Justice Department this week for spying. The other three have already been arrested.

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Slip-sliding away – on Mars

1:00 pm

Faults on Mars
Click for full image.

Today’s cool Martian image, rotated, cropped, and reduced to post here, comes from the camera on Mars Odyssey and was taken on May 18, 2020. It shows an area on Mars where faults and cracks in the ground have caused criss-crossing depressions. In this particular case we can see that the north-south trending fissure at some point got cut in half by east-west trending fault, its northern and southern halves thus getting shifted sideways from each other. For scale the straight section of the northern canyon is about five miles long, with the sideways shift about a mile in length.

As the caption notes, “With time and erosion this region of fault blocks will become chaos terrain,” regions of canyons often cutting at right angles to each other with flat-topped mesas and buttes in between.

Now for the mystery.
» Read more

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A July 4th Hubble image of Saturn

10:27 am

Saturn as seen by Hubble on July 4, 2020
Click for full image, annotated.

Cool image time! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope on July 4, 2020, and shows Saturn, its rings, plus several moons, in all their glory.

The dot near the bottom center is Enceladus. The dot at center right is Mimas. If you click on the annotated full image it will show the locations of several other smaller moons much harder to see.

This new Saturn image was taken during summer in the planet’s northern hemisphere.

Hubble found a number of small atmospheric storms. These are transient features that appear to come and go with each yearly Hubble observation. The banding in the northern hemisphere remains pronounced as seen in Hubble’s 2019 observations, with several bands slightly changing color from year to year. The ringed planet’s atmosphere is mostly hydrogen and helium with traces of ammonia, methane, water vapor, and hydrocarbons that give it a yellowish-brown color.

Hubble photographed a slight reddish haze over the northern hemisphere in this color composite. This may be due to heating from increased sunlight, which could either change the atmospheric circulation or perhaps remove ices from aerosols in the atmosphere. Another theory is that the increased sunlight in the summer months is changing the amounts of photochemical haze produced.

The distance across from one end of the rings to the other is about 150,000 miles, about two thirds the distance from the Earth to the Moon.

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First image of multi-exoplanets around young sunlike star

10:00 am

Two exoplanets in one image

Worlds without end: Using the Very Large Telescope (VLT) in Chile, astronomers have taken the first image that captures two different exoplanets circling a young sunlike star.

The star’s light is partly blocked in the upper left of the photo to the right, cropped slightly to post here.

You can read the paper here [pdf]. The star itself, though similar in mass to the Sun, is thought to be only seventeen million years old.

But the system, dubbed TYC 8998-760-1, is nothing like our solar system. One of the star’s companions straddles the line that defines planets, with a mass 14 times Jupiter’s; the other has a mass of six Jupiters. Both orbit far from the star, about 160 and 320 times the average distance between Earth and the Sun. That puts them more than four times farther out than Pluto is from the Sun.

The size and distance of these giant planets were why they could be imaged from the ground.

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Moving ripples on Mars

9:37 am

Using Mars Reconnaissance Orbiter (MRO) high resolution images, scientists have now determined that the giant ripples seen from space are actually moving, albeit very slowly.

Megaripples are found in deserts on Earth, often between dunes. Waves in the sand spaced up to tens of meters apart, they’re a larger version of ripples that undulate every 10 centimeters or so on many sand dunes. But unlike dunes, megaripples are made up of two sizes of sand grains. Coarser, heavier grains cap the crests of megaripples, making it harder for wind to move these features around, says Simone Silvestro, a planetary scientist at Italy’s National Institute of Astrophysics in Naples.

Since the early 2000s, Mars rovers and orbiters have repeatedly spotted megaripples on the Red Planet. But they didn’t seem to change in any measurable way, which led some scientists to think they were relics from Mars’s past, when its thicker atmosphere permitted stronger winds.

Now, using images captured by NASA’s Mars Reconnaissance Orbiter, Silvestro and his colleagues have shown that some megaripples do creep along—just very slowly.

They found that the ripples shift position about four inches per year, which astonished them since they had not believed the winds of Mars were strong enough to move them at all.

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Tianwen-1 successfully launched, on its way to Mars

9:27 pm

UPDATE: According to news reports, China tonight successfully launched Tianwen-1 towards Mars, with arrival expected in February 2021.

Below the fold is a live stream of the launch of the Long March 5 rocket. It is not in English, and since it was not linked to China’s mission control, it only covers the first two minutes or so, after which the rocket went out of sight.

The leaders in the 2020 launch race:

17 China
11 SpaceX
7 Russia
3 ULA
3 Japan

The U.S. still leads China 18 to 17 in the national rankings.
» Read more

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Rover update: Curiosity pauses to drill

11:27 am

Curiosity's entire journey so far in Gale Crater

Overview map of Curiosity's recent travels

The artist’s oblique drawing above, as well as the map to the right, provide some context as to Curiosity’s present location and its entire journey in Gale Crater. For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. For all rover updates since then through May 2020, go here.

Since my last update on July 7, 2020, Curiosity has quickly moved a considerable distance to the east, as planned, skirting the large sand field to the south in its journey to the best path upward onto Mt. Sharp. The science team however has detoured away from their planned route, shown in red on the map, heading downhill a bit in order to find one last good location in the clay unit to drill. They are at that location now and are presently scouting for the best drilling spot.

About a week ago, before heading downhill, they had stopped to take a set of new images of Curiosity’s wheels. » Read more

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After releasing its Ryugu samples Hayabusa-2’s mission will continue

8:33 am

Japan’s space agency JAXA has revealed that it is looking at two fast-spinning asteroids as possible destinations for its Hayabusa-2 spacecraft after it has dropped off its samples from the asteroid Ryugu on December 6.

The candidate asteroids on the agency’s list are asteroid 2001AV43 which Hayabusa2 would reach in November 2029 after flying by Venus, and asteroid 1998KY26 which the probe would reach in July 2031 after passing by another asteroid.

JAXA says both asteroids are rotating on their axis once every 10 minutes. The high-speed spinning indicates that the asteroids’ inner structures are likely different from that of asteroid Ryugu on the first mission, which consists of pieces of rocks.

The spacecraft will no longer have the equipment for returning additional samples, but everything else is functioning and it has the fuel.

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Tianwen-1 launch set for July 23rd

3:09 pm

China has rolled out its Long March 5 rocket and is now preparing to launch its Tianwen-1 orbiter/lander/rover to Mars this coming Thursday, July 23rd, some time between 12 am and 3 am (Eastern).

A Long March 5 rocket is set for liftoff with China’s Tianwen 1 mission some time between 12 a.m. and 3 a.m. EDT (0400-0700 GMT) Thursday, according to public notices warning ships to steer clear of downrange drop zones along the launcher’s flight path.

Chinese officials have not officially publicized the launch date. Chinese state media outlets have only reported the launch is scheduled for late July or early August, and officials have not confirmed whether the launch will be broadcast live on state television.

This will be the first operational launch of the Long March 5, which has had three previous test launches, with the first two failing. The success of the December launch, as well as the May success of the related Long March 5B, made this Mars mission possible.

After achieving orbit in February 2021 and spending two months scouting the landing site, the lander will descend to the surface, bringing the rover with it. The prime landing site is Utopia Planitia, in the northern lowland plains.

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Active volcanoes on Venus?

9:25 am

Using computer models and past radar images from orbiters, scientists now believe that Venus could have as many as 37 active volcanoes.

The type of feature on Venus they think might still be active is called a coronae, circular features detected by radar and distinct to this planet that have been thought to be inactive ancient volcanic features.

In the new study, the researchers used numerical models of thermo-mechanic activity beneath the surface of Venus to create high-resolution, 3D simulations of coronae formation. Their simulations provide a more detailed view of the process than ever before.

The results helped Montési and his colleagues identify features that are present only in recently active coronae. The team was then able to match those features to those observed on the surface of Venus, revealing that some of the variation in coronae across the planet represents different stages of geological development. The study provides the first evidence that coronae on Venus are still evolving, indicating that the interior of the planet is still churning.

Lots of uncertainty here, but nonetheless this is good science. It also reinforces other evidence in recent years that has suggested active volcanism on Venus.

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