China targets 2028 for its own Mars sample return mission

According to a report today in China’s state-run press, it now hopes to launch its own Mars sample return mission in 2028, dubbed Tianwen-3.

The report is very vague about the missions design. It notes that it will involve two launches, including “key technologies such as collecting samples on the Martian surface, taking off from the Red Planet, [and] rendezvous on the orbit around Mars.”

Based on China’s overall track record for its planetary program, it is likely that the launch will likely take place somewhat close to this schedule, though a delay of one or two years would not be unreasonable. If so, we are looking at either two or three different projects to bring Mars samples back to Earth at almost the same time.

The first is the NASA/ESA joint Mars sample return mission, which is presently far behind schedule with large cost overruns, all because the mission design has been haphazard and confusing. At the moment it involves an American lander, a European orbiter and return capsule, a Mars launch rocket to be built by Lockheed Martin, and at least one Mars helicopter. None of this however is certain, as NASA is right now asking industry for suggestions for redesigning the mission. It is presently hoping to bring its samples back sometime in the 2030s.

The second is this China mission, which appears to have some of the same planned components, which is not surprising considering China’s habit of copying or stealing other people’s ideas.

A third sample return mission might also be flown, by SpaceX using its Starship spaceship and Superheavy rocket. Both are built with Mars missions specifically in mind. SpaceX has also ready done work locating a preliminary landing zone. If so, it could possible attempt this mission at about the same time, independent of both China or NASA.

Or it might simply offer Starship as part of the redesigned NASA sample return mission. There is also the chance SpaceX would do both.

If I had to bet, I would say SpaceX (on its own) is the most likely to do this first, with China second. If SpaceX teams up with NASA then it will be a close race between NASA and China.

NASA confirms Europa Clipper launch on October 10, 2024 with questionable transistors

NASA yesterday confirmed that it has decided to go ahead with the October 10, 2024 launch of its $5+ billion Europa Clipper mission to Jupiter, despite the installation of transistors on the spacecraft that the agency knows are not properly hardened for that harsh environment.

Those transistors were built by a German company as part of equipment used by the spacecraft’s electrical system. Apparently that company hired a subcontractor to furnish the transistors, which failed to make them to the right specifications. Subsequent testing found that it is quite likely that at least some of the transistors will fail when Europa Clipper reaches Jupiter orbit.

It appears that NASA decided that the issue risk was small enough for the mission to achieve its minimal expected results, and decided the cost of delay and bad publicity replacing the transistors before launch would be worse than the limited science payoff and bad publicity that would take place years hence, when those transistors fail.

Remember this story in in 2030 when Europa Clipper enters Jupiter orbit and begins to experience problems.

A channel of ice, water, or lava?

A channel of ice, water, or lava?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows one small section of a Martian canyon approximate 750 miles long and dubbed Elysium Fossae.

The canyon walls at this spot rise about 3,300 to 3,800 feet from the canyon floor. The canyon itself is thought to be what geologists call a graben, initially formed when the ground was pulled apart to form a large fissure.

That’s what happened at this location, at least to start. This canyon is on the lower western flank of the giant shield volcano Elysium Mons. The cracks, which radiate out outward from the volcano’s caldera, likely formed when pressure from magma below pushed upward, splitting the surface.

That formation process however does not fully explain everything.
» Read more

NASA asks space industry for proposals on using the shelved Janus probes on mission to Apophis

NASA has now put out a request for proposals from the space industry for refitting the two Janus planetary probes, whose asteroid mission was shelved when its launch as a secondary payload was delayed due to problems with the Psyche primary payload, as a mission to the asteroid Apophis in connection with its April 13, 2029 close approach to the Earth.

NASA has been studying this new mission goal since early 2023, but apparently had failed to come up with a plan. It is now asking the private sector for suggestions on getting it done, including finding the funding for any plans.

Russia claims its next unmanned Moon mission, Luna-26, is on schedule

Phase I of China/Russian Lunar base roadmap
The original phase I plan of Chinese-Russian lunar
base plan, from June 2021.

According to Russia’s state-run press, its next unmanned Moon mission, Luna-26, is on schedule for a planned launch in 2027, though that press also claims the launch may happen in 2026 instead.

The problem with this claim is that Russia had for years said that this lunar orbiter would launch by 2025. As expected, the mission has not launched on time, as have all of Russia’s 21st century lunar exploration plans. For example, the previous lunar mission, the Luna-25 lunar lander, was originally supposed to land on the Moon in 2021, was not launched until 2023, and ended up crashing on the Moon when the spacecraft did not function properly during a engine burn in lunar orbit.

In the first phase of the so-called China-Russian partnership to explore the Moon, is shown by the 2021 graph to the right, China continues to do all the heavy lifting, and do so pretty much on the schedule predicted. Russian meanwhile continues to do what I predicted back in 2021, get nothing done on time and when launched have problems.

A frozen Martian splash

A frozen Martian splash
Click for original image.

Cool image time! The picture to the right, rotated, cropped, and enhanced to post here, was taken on July 11, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the southeast quadrant of a three-mile-wide unnamed crater that is surrounded on all sides by a dramatic but frozen splash apron of material, created when this impact occurred.

The rim rises between 200 to 400 feet from the surrounding plains, while the crater floor drops 700 feet to sit below those plains by 300 to 500 feet. In other words, that splash apron contains the material that was thrown up when the bolide drilled into the plain at impact, leaving behind this deep hole.

Why such a dramatic splash apron? Its existence suggests that the ground here was muddy, with a lot of water ice likely present. The location and wider context helps confirm this guess.
» Read more

Two-lobed asteroid imaged by radar

Two-lobed asteroid
Click for original image.

During the August 18, 2024 first close fly-by of a potentially-dangerous asteroid only discovered back in May, astronomers used the Goldstone dish in California to produce the high resolution radar images shown in the picture to the right, reduced and sharpened to post here.

The images were captured when the asteroid was at a distance of 2.8 million miles (4.6 million kilometers), about 12 times the distance between the Moon and Earth.

Discovered by the NASA-funded Catalina Sky Survey in Tucson, Arizona, on May 4, the near-Earth asteroid’s shape resembles that of a peanut – with two rounded lobes, one lobe larger than the other. Scientists used the radar images to determine that it is about 980 feet (300 meters) long and that its length is about double its width. Asteroid 2024 JV33 rotates once every seven hours.

Asteroids formed as contact binaries, once considered the stuff of science fiction, have now been found to be relatively common, comprising about 14% of the near Earth asteroids larger than 700 feet across that have been radar-imaged. The refined orbital data suggests this asteroid might be a dead comet, though that conclusion is unconfirmed. That orbital data also tells us that though this object has the potential of hitting the Earth, it will not do so “for the foreseeable future.”

Scientists find oldest known reference to a solar eclipse dated approximately 6,000 years ago

In studying an ancient Hindu text called the Rig Veda that was compiled around 1,500 BC, scientists have found what they think is the oldest known reference to a solar eclipse, dated approximately 6,000 years ago.

You can read the peer-reviewed paper here [pdf]. From the paper’s conclusion:

We propose that the eclipse recorded in the Rig Veda refers to observations made of an eclipse around 4000 BC. By analyzing the description, we propose that the eclipse was the one that occurred in 4202 BC or else in 3811 BC. We propose that it was observed in Central Asia. To our knowledge, this is one of the oldest known references to a specific total solar eclipse mentioned in the historical literature.

The scientists came to this conclusion based on information contained and not contained in the Hindu text. The text noted the event occurred three days before the autmnal equinox, and that it occurred when that equinox occurred in the constellation Orion, when today the equinox occurs in the constellation Pisces. This reduced the number of possible eclipses to a small number during the time period around 4,000 BC. The text also lacked any mention of various Hindo myths explaining eclipses that appeared more recently, thus confirming this ancient date and telling the researchers that the nomadic people who compiled the Rig Veda were likely living in central Asia at that time.

The only two eclipses that fit the bill occurred on either October 22, 4202 BC or October 9, 3811 BC. This makes it the earliest known reference to an eclipse, far earlier than the possible eclipses that occurred in around 3340 BC and around 1300 BC.

Sunspot update: The Sun continues to boom!

It is time for my monthly sunspot update, taking NOAA’s most recent update of its monthly graph tracking the number of sunspots on the Sun’s Earth-facing hemisphere and adding my own analysis as well as some additional details to provide the larger context.

During August the Sun continued to confound the experts, with the number of sunspots not only greater than July’s high count. the August count exceeded the numbers from December 2001 (215.5 vs 213.4), the last time the Sun was this active.

None of the predictions by anyone in the solar science community had predicted this level of activity.
» Read more

A galaxy with a halo and a stupendous central black hole

A galaxy with a halo and a stupendous black hole
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a survey of galaxies that have what astronomers call active galactic nuclei (AGNs). This galaxy, dubbed IC 4709, is about 240 million light years away.

If IC 4709’s core were just filled with stars, it would not be nearly so bright. Instead it hosts a gargantuan black hole, 65 million times the mass of our Sun. A disc of gas spirals around and eventually into this black hole, with the gas crashing together and heating up as it spins. It reaches such high temperatures that it emits vast quantities of electromagnetic radiation, from infrared to visible to ultraviolet light and beyond — in this case including X-rays. The AGN in IC 4709 is obscured by a lane of dark dust, just visible at the centre of the galaxy in this image, which blocks any optical emission from the nucleus itself.

To get a very vague sense of scale, this supermassive black hole is more than sixteen times more massive than the relatively inactive supermassive black hole in the center of the Milky Way. This imagery and data from Hubble will help astronomers better understand the interaction between the black hole and its surrounding galaxy.

Due to thruster problem, the Mercury orbiter BepiColombo will arrive at Mercury almost one year late

The joint ESA and JAXA Mercury mission BepiColombo will now reach its destination eleven months late because its ion electric thrusters are producing less thrust than expected.

The spacecraft is actually made up of two orbiters, one built by the European Space Agency (ESA) and the second built by Japan’s space agency JAXA. During launch and the journey to Mercury each is attached to a third spacecraft called the Mercury Transfer Module (MTM), which has the large electric ion thrusters used for making the mid-course corrections prior to and after each fly-by of the Earth (once), Venus (twice), and Mercury (six) before finally entering orbit around Mercury. It has already completed the Earth, Venus and three Mercury fly-bys.

In April 2024 engineers discovered that during a mid-course correction on April 26st the MTM’s thrusters failed to produce the desired thrust.

Engineers identified unexpected electric currents between MTM’s solar array and the unit responsible for extracting power and distributing it to the rest of the spacecraft. Onboard data imply that this is resulting in less power available for electric propulsion. ESA’s BepiColombo Mission Manager, Santa Martinez explains: “Following months of investigations, we have concluded that MTM’s electric thrusters will remain operating below the minimum thrust required for an insertion into orbit around Mercury in December 2025.”

In order not to lose the mission entirely, the science team has come up with a new trajectory that will have it fly past Mercury on its fourth fly-by on September 4, 2024 only 103 miles above the surface, 22 miles closer than originally planned. This will give it a larger slingshot speed boost to help make up for the under-powered thrusters. It will then make its planned fifth and sixth Mercury fly-bys in December ’24 and January ’25, the adjusted route having it arrive in Mercury orbit eleven months later than planned, in November 2026.

This new plan however means that the pictures taken this week during the Mercury fly-by will provide some nice high resolution details, far better than those produced by the earlier fly-bys.

A cliff of ice on Mars

A cliff of ice on Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on April 10, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the southern nose of a large plateau located in the deep south of Mars, at 63 degrees south latitude. This cliff is only about 20-25 feet high, but within that small distance orbital imagery as revealed what appears to be an underground layer of ice. When this photo was released in late June, it came with a short caption, which noted:

On these steep scarps, ice can still be seen on the south facing walls of the scarp towards the end of the Southern Hemisphere’s winter.

Note the white sections on that cliff wall, both inside and outside the color strip. The surrounding orange suggests dust and sand. This photo suggests that during the dark winter underground ice leaches out on these slopes, and is then sublimated away when the Sun returns in the spring. Since the south-facing walls remain in shadow the longest, the ice there lasts the longest, leaving behind these patches we see now.

It is also possible that this is not water ice and there is no underground ice layer. Instead, this might be the last leftover of the dry ice mantle that falls as snow and covers all of the Martian high latitudes during the winter, and then sublimates away come spring.
» Read more

First New Glenn launch, set for October 13, 2024, only has an 8-day launch window

According to an article from Aviation Week today, in order for Blue Origin’s New Glenn rocket to get its payload of two Mars orbiters on their way to Mars it must launch within a very short window lasting only eight days, beginning on the present launch date of October 13, 2024.

The Oct. 13-21 launch window is an ambitious goal. The aft and mid modules of New Glenn’s reusable first stage were recently attached, clearing the path for installation of the vehicle’s seven methane-fueled BE-4 engines, CEO Dave Limp noted in an Aug. 23 update on the X social media site.

A static hot-fire at New Glenn’s Florida launch complex is planned prior to launch. The company did not release the status of the New Glenn upper stage, which is to be powered by a pair of BE-3U engines fueled by liquid oxygen and liquid hydrogen. A hot-fire of the second stage is also pending.

This launch will be the first ever for New Glenn. To get ready for that tight launch window it appears a great deal of work must be done in the next six weeks, some of which Blue Origin engineers will be doing for the very first time.

If there are any issues and that launch window is missed, the two NASA Escapade orbiters, built by Rocket Lab, will face a two-year delay until the next window to get to Mars re-opens. At that point New Glenn will likely do this launch with a dummy payload, since it needs to get off the ground in order to fulfill other launch contracts, including a 27-launch contract with Amazon for its Kuiper satellite constellation.

Changing Martian slope streaks

Changing slope streaks on Mars
Click here, here, and here for original images.

Overview map

Time for some cool images from Mars taken over a dozen years! The three pictures above were taken, from left to right, in 2012, 2020, and 2024 and show the same exact Martian terrain. The first two pictures were photographed by the lower resolution context camera on Mars Reconnaissance Orbiter (MRO). The rightmost picture was taken on May 20, 2024 by MRO’s high resolution camera.

The white dot on the overview map to the right marks the location, in the middle of the vast lava flood plains found between Mars’ giant volcanos and north of the Medusae Fossae Formation, the largest volcanic ash deposit on Mars. The 1,200-foot-high mesa pictured above, its peak indicated by the red dot, is part of a group of such mesas that either represent the peaks of a mountain range now mostly buried by lava, or volcanic vents pushed up when those eruptions were occurring more than a billion years ago.

The focus of these pictures however is not volcanism, but the numerous slope streaks seen on the mesa slopes. Note how the 2012 earliest streaks are still visible in 2024, but have faded. Note also how there appears to have been no new streaks since 2020.

Slope streaks are a geological feature unique to Mars that at the moment remain unexplained. At first glance they appear to be a landslide of some kind, but years of orbital study has shown they do not change the topography at all, they never have debris piles at their base, and the streaks even sometimes actually flow up and over small rises in the slopes. They occur randomly throughout the year, and as seen above, over time fade.

Recent research has suggested their formation is related to dust avalanches triggered by dust storms, conclusions that are strengthened by the fact that slope streaks are generally found on dusty slopes, which in this case makes sense as the location is in the dry Martian tropics. That these dust avalanches do not change the topography at all, merely staining it, while sometimes actually flowing up and over rises, illustrates how Mars’ one-third gravity and thin, cold atmosphere makes things happen that are impossible on Earth.

NASA leans toward launching Europa Clipper as scheduled, despite transistor issue

Though the final decision will be made in early September, NASA revealed today in a short post that management is leaning towards launching the multi-billion Europa Clipper mission as scheduled on October 10, 2024, despite a very recently discovered transistor issue where the transistors were not properly hardened in construction for the harsh radiation environment surrounding Jupiter.

The next major milestone for Clipper is Key Decision Point E on Monday, Sept. 9, in which the agency will decide whether the project is ready to proceed to launch and mission operations. NASA will provide more information at a mission overview and media briefing targeted for that same week.

The Europa Clipper mission team recently conducted extensive testing and analysis of transistors that help control the flow of electricity on the spacecraft. Analysis of the results suggests the transistors can support the baseline mission. [emphasis mine]

The highlighted sentence suggests NASA officials have weighed the option between launching on time with a limited ability to do science once at Jupiter versus delaying the launch years to fix the transistors, and are now favoring the former option. The cost of delay would be high and long, and NASA officials might believe the bad press for that option would be much greater than a mission that only achieves its bare minimum results. For example, to admit publicly that NASA installed transistors that were not space-hardened when that necessity has been known about since the 1960s would be as embarrassing to the agency as it was for Boeing when it discovered it had installed flammable tape in its Starliner capsule. NASA management might be leaning to letting a flawed multi-billion dollar project launch, knowing its capabilities are quite limited, in order to avoid that embarrassment.

Evidence of Martian near-surface ice in an unusual location

Evidence of Martian near-surface ice in an unusual location
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 27, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a terrain sample, it was likely taken not as part of any specific research request, but to fill a gap in the camera’s picture-taking schedule so as to maintain its proper temperature.

The picture however shows features that help confirm earlier research into the near-surface ice believed to permeate Mars’ middle latitudes. The knobby flat terrain both inside and outside of the crater resembles what scientists have labeled “brain terrain”, an as-yet unexplained geological feature unique to Mars and usually associated with near-surface ice and the glacial features found above 30 degrees latitude.

This 1.4-mile-wide unnamed crater is located at 40 degrees north latitude, so expecting near-surface ice or glacial features here is not unreasonable. The location however is different for other reasons, that make this data more intriguing.
» Read more

Webb finds six exoplanets, all flying in interstellar space without a star

Astronomers using the Webb Space Telescope have discovered six different planets ranging in mass 5 to 10 times that of Jupiter, all unattached to any star or solar system.

The most intriguing of the starless objects is also the lightest, having an estimated mass of five Jupiters (about 1,600 Earths). The presence of a dusty disk means the object almost certainly formed like a star, as space dust generally spins around a central object in the early stages of star formation, said Langeveld, a postdoctoral researcher in Jayawardhana’s group.

All of these starless planets likely formed like this one, coalescing like a star does but unlike a star never having enough mass to ignite.

The astronomers are next going to attempt to detect the atmosphere’s of these rogue exoplanets, though it is not clear exactly how they will do this unless one of the exoplanets just happened to transit across a more distant star, something that simply does not happen very often.

A real whirlpool in space

A real whirlpool in space
Click for original image.
Cool image time! The picture above, cropped to post here, was taken by the Hubble Space Telescope as part of a survey of nearby galaxies that have what astronomers call an Active Galactic Nuclei (AGN), because the supermassive black hole at the center is devouring nearby material at a great rate and thus producing high energy emissions as it does so.

Many active galaxies are known to astronomers at vast distances from Earth, thanks to the great brightness of their nuclei highlighting them next to other, dimmer galaxies. At 128 million light-years from Earth, UGC 3478 is positively neighbourly to us. The data used to make this image comes from a Hubble survey of nearby powerful AGNs found in relatively high-energy X-rays, like this one, which it is hoped can help astronomers to understand how the galaxies interact with the supermassive black holes at their hearts.

The bottom line is that this spiral galaxy literally is a whirlpool, the entire galaxy spiralling down into that massive black hole in its center. One cannot help wondering why such galaxies don’t end up eventually getting completely swallowed by that black hole.

Or maybe they do, and we don’t see such things because all that is left is a supermassive black hole that emits no light or energy at all, a dark silent ghost traveling between the galaxies unseen and undetectable.

First high resolution images released from Juice’s fly-by of the Earth & Moon

Juice's high resolution view of the Moon
Click for original image.

The Italian science team that runs the high resolution camera on the asteroid probe Juice have now released that camera’s first images, taken to test its operation during the spacecraft’s close fly-by of both the Moon and then the Earth a week ago.

The picture to the right, cropped, reduced, and sharpened to post here, shows the Moon’s surface during that close fly-by, which got within 435 miles. The camera is dubbed Janus, and was developed by Italy and operated by the Italian National Institute for Astrophysics.

JANUS will study global, regional and local features and processes on the moons, as well as map the clouds of Jupiter. It will have a resolution up to 2.4 m per pixel on Ganymede and about 10 km per pixel at Jupiter.

The main aim of JANUS’s observations during the lunar-Earth flyby was to evaluate how well the instrument is performing, not to make scientific measurements. For this reason, JANUS took images with various camera settings and time intervals – a bit like if you’re going out to test a DSLR camera for the first time. In some cases, researchers intentionally ‘blurred’ the images so that they can test out resolution recovery algorithms. In other cases, they partially saturated the image to study the effects induced on the unsaturated areas.

As can be seen by the sample image above, the test images appear to have demonstrated that Janus will function as planned when Juice arrives in orbit around Jupiter in 2031 in order to study that gas giant’s upper atmosphere as well as its larger icy moons, Ganymede, Calisto, and Europa.

Finding beauty on Mars in all the strange places

Overview map

Beauty on Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on May 23, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The white dot in the inset of the overview map above indicates the location on Mars, smack dab in the middle of the 2,000-mile-long mid-latitude strip that I call glacier country, because practically every close-up image of this region shows glacial features.

This picture is no exception. The arrows in the inset show the downhill grade, falling about 1,700 feet across the entire inset. That grade is a reflection of the transition that takes place in this glacier country from the cratered southern highlands to the northern lowland plains.

I decided to crop the image at full resolution — showing only a tiny portion — because to my eye these curving linear grooves, produced naturally as Mars’ climate cycles cause glaciers to shrink and then grow repeatedly so that each cycle lays down a new line while squeezing the previous lines, are almost like a work of art. This might be nothing more than a glacier on an alien planet, but nature has caused it to form a very beautiful picture.

Chinese scientists find method to extract water from Chang’e-5 lunar samples

Proposed concept for extracting water from lunar regoilth
Proposed concept for extracting water from
lunar regoilth

Chinese scientists have found that by heating Chang’e-5 lunar samples to 1,700 degrees Fahrenheit it is possible to extract a significant amount of water. From the paper’s abstract:

FeO and Fe2O3 are lunar minerals containing Fe oxides. Hydrogen (H) retained in lunar minerals from the solar wind can be used to produce water. The results of this study reveal that 51–76 mg of H2O can be generated from 1 g of LR [lunar regolith] after melting at temperatures above 1200 K. This amount is ∼10,000 times the naturally occurring hydroxyl (OH) and H2O on the Moon. … Our findings suggest that the hydrogen retained in LR is a significant resource for obtaining H2O on the Moon, which are helpful for establishing scientific research station on the Moon.

A video in Chinese (hat tip BtB’s stringer Jay) that describes this research can be found here. (If any of my readers understands Chinese and can provide a translation of this video’s narration, I would be very grateful.) It includes an artist’s rendering (screen capture to the right) showing how such a system on the Moon could work to extract water from the soil. Sunlight would be focused by a lensed mirror into a glass-domed container, heating the ground. The water would evaporate, condense on the glass and be sucked into a tube that would transfer it to a water tank.

This design is of course very simple and preliminary. According to Jay, “They need to heat the soil to 1000℃ (1832°F) to get the iron oxide in the lunar soil to split, the oxygen combines with hydrogen to make water and iron (melting point of iron is about 1500℃). You will need a nuclear reactor to produce that much power for an inductive furnace to get that hot. Doing the calculation, it would take about 245kw to heat up a metric ton of dirt in one hour to a 1000℃ degrees. It could be done slower over 24 hours at 10kw.”

Despite the technical difficulties getting such equipment operational on the Moon, that this research suggests water can be produced practically anywhere on the lunar surface is signficant. It suggests that even if no easily accessible water ice is found in the permanently shadowed craters at the poles, lunar bases still have viable options for obtaining water, and they don’t have even be at the poles.

The massive scale of Mars’ biggest canyon

Overview map

The south rim of Valles Marineris
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely a “terrain sample” by the camera team, it was likely taken not as part of any particular research project, but to fill a gap in the picture-taking schedule in order to maintain the camera’s proper temperature.

When the camera team needs to do this, they try to pick interesting targets within the required timeframe. Sometimes they succeed, sometimes not. In today’s example, they succeeded quite well. As shown by the overview map above, this picture captures (as indicated by the rectangle) the top of the southern rim of Valles Marineris, the biggest canyon on Mars and quite possibly the biggest in the entire solar system.

For scale, the drop from the rim to the low point in this picture is about 9,000 feet. That’s a 1,000 feet more than the drop from the north rim of the Grand Canyon to the canyon bottom at the Colorado River. In Valles Marineris however our descent has barely begun. To get to the bottom of the southern canyon here you still need to drop 15,000 more feet, for a total descent of 24,000 feet, an elevation change similar to most of the mountains in the Himalayas.

Nor are you yet at the bottom. If you climb over the ridge of 18,000-foot-high mountains that bisect Valles Marineris at this point, you can drop down even further, to a depth 31,000 feet below the southern rim.

Mount Everest is just over 29,000 feet high, which means if placed inside Valles Marineris is peak would still sit 2,000 feet below the rim.

The photo itself highlights part of the erosion process that formed Valles Marineris. This is the dry tropics, so no water was involved in shaping this terrain for many eons. Instead, what appear to be flows within the hollows is alluvial fill, material that over time breaks off and rolls downhill, filling the slopes below. Erosion will grind this material into smaller particles, so given enough time it flows almost like sand.

Pragyan data confirms theory that the Moon’s surface was once largely covered with molten lava oceans


Vikram as seen by Lunar Reconnaissance Orbiter.
Click for interactive map. To see the original
image, go here.

Data from India’s Pragyan lunar rover that landed in the high southern latitudes of the Moon in August 2023 has now confirmed the theory that the Moon’s surface was once largely covered with molten lava oceans.

Santosh Vadawale, an X-ray astronomer at the Physical Research Laboratory in Ahmedabad, India, and his colleagues analysed radiation data collected by the APXS [one of Pragyan’s instruments], and used this information to identify the elements in the regolith and their relative abundances, which, in turn, revealed the soil’s mineral composition. The team found that all 23 samples comprised mainly ferroan anorthosite, a mineral that is common on the Moon. The results were reported in Nature today.

“It’s sort of what we expected to be there based on orbital data, but the ground truth is always really good to get,” says Lindy Elkins-Tanton, a planetary scientist at Arizona State University in Tempe.

Previous landers obtained similar results. However, the Chandrayaan-3 samples are the first from the subpolar region: previous landers visited equatorial and mid-latitude zones. Together, this suggests that the composition of the regolith is uniform across the Moon’s surface.

These results are no surprise, but they confirm the global nature of the Moon’s early molten history. More important, they demonstrate that India now has the capability to send landers and rovers to other planets that are also capable of doing real research.

The North Star has spots!

The spoted surface of Polaris
Click for original image.

Astronomers using an array of six ground-based telescopes have obtained best new data of Polaris, the North Star, including the first rough image of its surface, and discovered sunspots on its surface.

You can read the paper here [pdf]. The image to the right, taken from figure 4 of the paper, shows the surface as seen by the telescopes over two nights in April 2021. Polaris is what astronomers call a Cepheid variable star, which changes brightness on a very precise schedule as its diameter grows and shrinks. In the case of Polaris, that variation is four days long. The star’s brightness itself varies only slightly, and over the decades has even at times appeared to cease its variations.

As the true brightness of Cepheids is very predictable based on their pulse rate, these stars are one of the main tools astronomers use to determine distances to other galaxies. Knowing more about them thus has great importance to cosmological research.

The orbital motion showed that Polaris has a mass five times larger than that of the Sun. The images of Polaris showed that it has a diameter 46 times the size of the Sun.

The biggest surprise was the appearance of Polaris in close-up images. The CHARA observations provided the first glimpse of what the surface of a Cepheid variable looks like. “The CHARA images revealed large bright and dark spots on the surface of Polaris that changed over time,” said Gail Schaefer, director of the CHARA Array. The presence of spots and the rotation of the star might be linked to a 120-day variation in measured velocity.

The researchers plan to take regular images again of Polaris to better track the changes to its surface.

Juice completes Earth fly-by, heads for Venus fly-by

Earth as seen by Juice
Earth as seen by Juice during fly-by.
Click for original image.

The European probe Juice yesterday successfully completed a close fly-by of the Earth and was thus successfully slingshoted on its way to its next fly-by, of Venus, on its way to Jupiter.

This fly-by was actually a double event. First Juice zipped past the Moon the day before, coming within 435 miles. Then, only one day later it passed the Earth at a distance of 4,230 miles, thus completing the first dual fly-by of the both the Earth and the Moon.

The flyby of the Moon increased Juice’s speed by 0.9 km/s relative to the Sun, guiding Juice towards Earth. The flyby of Earth reduced Juice’s speed by 4.8 km/s relative to the Sun, guiding Juice onto a new trajectory towards Venus. Overall, the lunar-Earth flyby deflected Juice by an angle of 100° compared to its pre-flyby path.

The inherently risky flyby required ultra-precise, real-time navigation, but is saving the mission around 100–150 kg of fuel. In the month before the flyby, spacecraft operators gave Juice slight nudges to put it on exactly the right approach trajectory. Then they tracked Juice 24/7 between 17–22 August.

The Venus fly-by will occur in August 2025, followed by additional Earth flys in September 2026 and January 2029. The spacecraft will finally arrive in Jupiter orbit in July 2031, where it is designed to study the large icy moons (Europa, Gandymede, and Calisto) of that gas giant.

What the heck caused these cones to align on Mars?

Another
Click for original image.

Time for another “What the heck?” cool image! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 23, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels as “longitudinally aligned cones”.

To my eye the cones visibile in this picture seem more aligned latitudinally, to the east-west, instead of longitudinally, north-south, but the larger view in the inset on the overview map below shows that on a larger scale, the cones do appear aligned in a north-south direction.

Either way, this is one of those photos from Mars orbit that leaves me entirely baffled. The cones and the flow feature that cuts across the middle of the image might be either volcanic or glacial, but it is beyond my pay grade to explain what caused this patch of aligned cones.
» Read more

Juice completes fly-by of Moon

Juice's view of the Moon
Click for original image.

Europe’s Juice probe to Jupiter yesterday successfully completed its close fly-by of the Moon, shifting its path as it prepares for a close fly-by of the Earth today.

The picture to the right, cropped, reduced, and sharpened to post here, was taken during yesterday’s flyby. At its closest approach Juice was only 435 miles above the lunar surface. It will pass the Earth today at a distance of 4,230 miles.

If the Earth fly-by today is successful, Juice will then do flybys of Venus in August 2025, Earth in September 2026, and Earth again in January 2029, arriving in Jupiter orbit in July 2031, where it is designed to study the large icy moons (Europa, Gandymede, and Calisto) of that gas giant.

Mining Mars

Mining Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 22, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The picture’s focus of study is the bright strip running diagonally across the center, which the scientists label as a “linear feature exposure of infrared-bright material.”

This bright strip with all the swirls of alternating light and dark terrain is a fissure about 80 feet deep. What is interesting is that the parallel bright features to the north and south are actually ridges, not depressions, even though there appears to be some resemblance between them all. (Note that the patches of very thin parallel lines are likely ripple dunes sitting on top of the topography.)

So, what created this fissure? And why is its inner surface so strange? As is usually the case, a wider look provides some clues.
» Read more

Martian gullies flowing down to a Martian river of ice

Gullies on cliff wall
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists label this as “gullies previously identified in the walls of Harmakhis Vallis.” The gullies are obvious, the series of erosion features on the cliff wall. The cliff itself drops about 2,800 feet from the rim to the floor, and also appears to have internal horizontal layers that the gullies cut through.

What causes the gullies? Planetary scientists have a number of theories, none of which appear to explain the gullies everywhere on the Martian surface. They all appear in the mid-latitudes, where the most glaciers on Mars are found, and appear to be related to ice or frost freeze-thaw processes, with some gullies actually very ancient and formed when the planet’s rotational tilt was significantly different.
» Read more

New data continues to refine the margin of error for the Hubble constant

The uncertainty of science: New data using the Webb Space Telescope’s spectroscopic capabilities has provided a more refined measure of the expansion rate of the universe, dubbed the Hubble constant.

According to previous research, that rate could be anywhere from 67.4 to 73.2 kilometers per second per megaparsecs, depending on whether you rely on data from the Planck orbiter or that of the Hubble Space Telescope. Though this difference appears reasonable considering the uncertainties and assumptions that go into research that determines both numbers, astronomers have been unhappy with the difference. The numbers should match and they don’t.

Now new data from Webb suggests this difference really is nothing more than the margin of error caused by the many uncertainties and assumptions involved. That new Webb data measured the Hubble constant using three different methods, all similar to that used by Hubble, and came up with 67.85, 67.96, and 72.04, all in the middle of the previous two numbers from Hubble and Planck.

In other words, all the data is beginning to fall within this margin of error.

Astronomers are without doubt still going to argue about this, but it does appear that the research is beginning to coalesce around an approximate number. More important, in terms of cosmology these results confirm the theory that the expansion of the universe is accelerating (dubbed “dark energy” simply because it needs a name), since they confirm the method used to measure that expansion rate in the very distant universe.

Keep your minds open however. There remain many questions and uncertainties with all these conclusions. Nothing is settled, nor will it be likely for decades if not centuries.

1 4 5 6 7 8 271