Tag: science

Is a recently discovered near Earth asteroid a piece from the Moon?

10:38 am

The uncertainty of science: Researchers now think they have enough information to claim that a recently discovered near Earth asteroid, dubbed Kamo`oalewa, could actually be a piece of the Moon, flung from it during a asteroid impact in the past few million years.

The 2021 study found that Kamo`oalewa’s spectrum was unlike that of other near-Earth asteroids but matched most closely that of the moon. Based on this, the team hypothesized that the asteroid could have been ejected from the lunar surface as a result of a meteoroidal impact.

In the new study, Malhotra and her team wanted to determine the feasibility for a knocked-off piece of the moon to get into this quasi-satellite orbit – a phenomenon that is quite unlikely, Malhotra said. Moon fragments that have enough kinetic energy to escape the Earth-moon system also have too much energy to land in the Earth-like orbits of quasi-satellites, she said.

With numerical simulations that accurately account for the gravitational forces of all the solar system’s planets, Malhotra’s group found that some lucky lunar fragments could actually find their way to such orbits. Kamo`oalewa could be one of those fragments created during an impact on the moon in the past few million years, according to the study.

The scientists add that the asteroid’s solar orbit, which keeps its flying in relative formation with the Earth for millions of years, strengthens this hypothesis.

It must be noted that this remains an unconfirmed hypothesis. A spacecraft would have to visit Kamo’oalewa and obtain samples to study to confirm it.

3 comments

The icy terrain near one of Starship’s prime candidate landing spots on Mars

1:35 pm

The icy terrain near Starship's prime landing spot on Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on August 22, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The camera team labeled the picture a “terrain sample,” which generally means it was not taken as part of any scientist’s specific research request, but to fill a gap in the schedule so as to maintain the camera’s proper temperature. When the team needs to do this, they try to pick a location in the gap that might have some interesting features. Sometimes such pictures show relatively boring features. Sometimes the results are fascinating.

In this case the location chosen was in the northern lowland plains of Mars, in a region called Amazonis Planitia. At 38 degrees north latitude it is not surprising that the photo shows ice features. All the depressions here appear to have an eroding glacier, while the surrounding plateau resembles an untouched snow field in the very early spring, the snow beginning to sublimate away to leave the top rough and stuccoed. Note too that these depressions are likely not impact craters (they have no upraised rims and many are distorted in shape), but were likely formed by that same sublimation process.
» Read more

0 comments

New data better maps the supernova remnant SN1006

10:50 am

SN1006, as seen in X-rays
Click for original image.

Using data from both the Chandra X-ray Observatory and the Imaging X-ray Polarimetry Explorer (IXPE), scientists have now better mapped the magnetic field and the remnant from the supernova that occurred in 1006 AD.

The false color image to the right shows this data. From the caption:

The red, green, and blue elements reflect low, medium, and high energy X-rays, respectively, as detected by Chandra. The IXPE data, which measure the polarization of the X-ray light, is show in purple in the upper left corner, with the addition of lines representing the outward movement of the remnant’s magnetic field.

From the press release:

Researchers say the results demonstrate a connection between the magnetic fields and the remnant’s high-energy particle outflow. The magnetic fields in SN 1006’s shell are somewhat disorganized, per IXPE’s findings, yet still have a preferred orientation. As the shock wave from the original explosion passes through the surrounding gas, the magnetic fields become aligned with the shock wave’s motion. Charged particles are trapped by the magnetic fields around the original point of the blast, where they quickly receive bursts of acceleration. Those speeding high-energy particles, in turn, transfer energy to keep the magnetic fields strong and turbulent.

At present scientists really do not understand the behavior of stellar-sized magnetic fields. It is very complex, involving three dimensional movements that are hard to measure, as well as electromagnetic processes that are not well understood. While this new data doesn’t provide an explanation, it does tell us better what is actually happening. The theories will follow.

1 comment

Swirling galactic-sized streams surrounding a pair of supermassive black holes

1:25 pm

Swirling galactic arms surrounding two supermassive black holes

Time for another galactic cool image! The picture to the right, reduced and sharpened to post here, was released today by the Gemini South ground-based telescope in Chile. It shows the streams of gas and stars that swirl around a pair of supermassive black holes at the center of this galaxy, located only 90 million light years away.

The image reveals vast swirling bands of interstellar dust and gas resembling freshly-spun cotton candy as they wrap around the merging cores of the progenitor galaxies. From the aftermath has emerged a scattered mix of active starburst regions and sedentary dust lanes encircling the system.

What is most noteworthy about NGC 7727 is undoubtedly its twin galactic nuclei, each of which houses a supermassive black hole, as confirmed by astronomers using the European Southern Observatory’s Very Large Telescope (VLT). Astronomers now surmise the galaxy originated as a pair of spiral galaxies that became embroiled in a celestial dance about one billion years ago. Stars and nebulae spilled out and were pulled back together at the mercy of the black holes’ gravitational tug-of-war until the irregular tangled knots we see here were created.

The black holes themselves are 154 and 6.3 million solar masses respectively, and are presently about 1,600 light years apart. Scientists calculate that they will merge in about 250 million years. Each once formed the center of its own galaxy. Now both galaxies have merged, creating this three-dimensional whirlpool of arms.

6 comments

A dance of three galaxies

10:40 am

Three galaxies merging
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. Though it appears to show two galaxies interacting with each other, other spectroscopic data proves there are actually three large galaxies in the picture. From the caption:

The two clearly defined galaxies are NGC 7733 (smaller, lower right) and NGC 7734 (larger, upper left). The third galaxy is currently referred to as NGC 7733N, and can actually be spotted in this picture if you look carefully at the upper arm of NGC 7733, where there is a visually notable knot-like structure, glowing with a different colour to the arm and obscured by dark dust. This could easily pass as part of NGC 7733, but analysis of the velocities (speed, but also considering direction) involved in the galaxy shows that this knot has a considerable additional redshift, meaning that it is very likely its own entity and not part of NGC 7733.

All three galaxies are quite close to each other, which means they are in the long process of merging together into one larger galaxy.

1 comment

More Io images by Juno, enhanced by citizen scientists

1:27 pm

Io in natural and enhance colors
Click here for original of top image,
here for bottom.

Since Juno completed its 55th close swing past Jupiter on October 15, 2023, including the closest fly by of its volcano-covered moon Io since the 1990s, citizen scientists have been grabbing the spacecraft’s raw images of the moon and enhancing them to bring out the details.

Immediately after the fly-by I posted on October 17, 2023 the top image to the right, processed by Ted Stryk. This version attempted to capture the view of Juno is natural color. As I noted then, “The dark patches are lava flows, with the dimensions of mountains along the terminator line between night and day clearly distinguishable.”

The bottom picture to the right was first processed by citizen scientist Gerald Eichstädt, who like Stryk attempted to capture Io’s natural colors. Thomas Thomopoulos then took Eichstädt’s image and enhanced the colors as well as reduced the brightness, in order to bring out the details as much as possible.

I have rotated, cropped, and reduced this bottom image further to post it here.

In comparing this image with earlier pictures of Io, taken by both Juno and Galileo in the 1990s, there is evidence that some of the lava flows visible now have changed significantly in the intevening time. This is not a surprise, as volcanic eruptions take place on Io so frequently that it has not unusual to capture one in the rare times close up images are possible, going back to the discovery of volcanic activity by Voyager-1 in 1979.

It will take a bit of time for scientists, both professional and amateur, to pick out the specific changes. That work will be further aided by Juno’s next fly-by on December 30, 2023, where it will dip to less than 1,000 miles of the surface.

3 comments

Scientists: The solar cycle was only 8 years long during the Maunder Minimum in the 1600s

9:58 am

Using archival records gathered in Korea during the 1600s when the Sun was undergoing a long period of almost no sunspots — called the Maunder Minimum — scientists have discovered evidence that the solar cycle during that time was only 8 years long.

You can read their paper here. Since almost no sunspots were visible at that time, the scientists used reports of aurora in Korea to determine periods when the Sun was more active. From their abstract:

By analyzing the variations in solar activity-related equatorial auroras recorded in Korean historical books in the vicinity of a low-intensity paleo-West Pacific geomagnetic anomaly, we find clear evidence of an 8-year solar cycle rather than the normal 11-year cycle during the Maunder Minimum.

This 8-year cycle is shorter than the 9-year cycle that other researchers had estimated based on the few sunspots that did appear during this grand minimum. Both conclusions however challenge what is known of the Sun. Since the 11-year cycle resumed in the 1700s, short cycles have generally been associated with very active periods, the opposite of what has been found during Maunder.

In other words, we know better what happened, but have no understanding of why. Since the Maunder Minimum appears associated with the Little Ice Age of the 1600s, and fits other data that says the climate cools when the Sun produces few sunspots, gaining some understanding of this process is important for understanding past and future changes to the global climate.

1 comment

Lucy’s first asteroid fly-by coming on November 1st

9:25 am

Lucy's route through the solar system
Lucy’s route through the solar system

The asteroid probe Lucy is about to do its first asteroid fly-by on November 1, 2023, the first of a planned ten asteroids it will see close-up during its twelve year mission.

The half-mile-wide asteroid, Dinkinesh, is indicated on the graphic to the right by the white dot in the lower left of the main asteroid belt. It was a late addition to the spacecraft’s plan in order to provide a perfect testbed for doing a dress rehearsal of the many later fly-bys.

As this encounter is intended as a test of Lucy’s systems, scientific observations will be simpler than for the mission’s main targets. The spacecraft and the platform that holds the instruments will move into position two hours before the closest approach to Dinkinesh. Once in place, the spacecraft will begin collecting data with its high-resolution camera (L’LORRI) and its thermal-infrared camera (L’TES). One hour before closest approach, the spacecraft will begin tracking the asteroid with the terminal-tracking system. Only in the last eight minutes will Lucy be able to collect data with MVIC and LEISA, the color imager and infrared spectrometer that comprise the L’Ralph instrument. Lucy’s closest approach is expected to occur at 12:54 p.m. EDT, when the spacecraft will be within 270 miles (430 kilometers) of the asteroid. Lucy will perform continuous imaging and tracking of Dinkinesh for almost another hour. After that time, the spacecraft will reorient itself to resume communications with Earth but will continue to periodically image Dinkinesh with L’LORRI for the next four days.

After this close encounter the spacecraft will return to do a flyby of Earth in 2025 to slingshot it to the orbit of Jupiter, where it will do its main work exploring the Trojan asteroids there. On the way it will fly past a second main belt asteroid, dubbed Donaldjohanson.

0 comments

A low mid-latitude crater on Mars apparently filled to overflowing with ice

12:04 pm

ice filling a Martian crater to overflowing
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on June 18, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a steep 1,000-foot-high cliff with what appears to be extensive glacial material at its base.

The many layers all suggest past climate cycles, where snow was deposited and the glacier grew, followed by a period when no snow fell and the glacier either shrank or remained unchanged. The terraced nature of the layers near the base of the cliff suggest that with each active cycle less snow was deposited and the glacier grew less.

The latitude is 33 degrees south, which puts it just outside the dry equatorial regions of Mars and inside the mid-latitude region where many such glacial features are found. Its closeness to the tropics however is significant, because by this point we should be seeing a diminishment of such features. Instead, the wider view shows us that the near surface ice in this region is extensive and in fact appears to cover everything.
» Read more

0 comments

Ingenuity completes 63rd flight on Mars

10:07 am

Overview map
Click for interactive map.

On October 19, 2023 the Mars helicopter Ingenuity successfully completed its 63rd flight on Mars, traveling 1,901 feet (its third longest flight) for 142.6 seconds.

On the overview map above the two dots and the green line mark the flight path, to the southwest and landing about 2,000 feet to the west of where the rover Perseverance presently sits (indicated by the blue dot).

Both the flight time and distance were slightly longer than the flight plan, likely caused by the helicopter making sure it had a safe landing spot before lowering itself to the ground.

Ingenuity is no longer simply an engineering test of whether flight is possible on Mars. It is now serving wholly as a scout for Perseverance, either moving ahead of its planned route (the red dotted line) in order to provide pictures of the ground so that the rover’s science team can better plan their future travels, or going into territory that the rover is not intended to travel in order to gather data that would previously been unavailable.

3 comments

First Bennu asteroid samples recovered from OSIRIS-REx return capsule

10:26 am

Scientists have successfully removed the asteroid samples from the OSIRIS-REx return capsule that the spacecraft obtained from the asteroid Bennu in 2020.

What is more exciting is that though they now have slightly more material than the mission hoped to bring back, they haven’t even opened the capsule’s sample compartment.

The curation team processing NASA’s asteroid Bennu sample has removed and collected 2.48 ounces (70.3 grams) of rocks and dust from the sampler hardware – surpassing the agency’s goal of bringing at least 60 grams to Earth.

And the good news is, there’s still more of NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) sample to collect.

The sample processed so far includes the rocks and dust found on the outside of the sampler head, as well as a portion of the bulk sample from inside the head, which was accessed through the head’s mylar flap. Additional material remaining inside the sampler head, called the Touch-and-Go Sample Acquisition Mechanism, or TAGSAM, is set for removal later, adding to the mass total.

The large amount of material means there will be plenty to distribute to many scientists for study.

The reason the recovery process is going so slowly is to ensure the samples do not get contaminated by the Earth’s atmosphere. The capsule is inside a glovebox filled with nitrogen. The only way any work can be done is by inserting hands inside gloves that extend into the box. This keeps the samples protected but prevents any direct contact, which makes work slow and difficult.

5 comments

The fractured floor of the south Utopia Basin

1:05 pm

The fracture floor of South Utopia Basin

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on August 5, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The central darker strip however comes from a September 27, 2008 image by MRO’s lower resolution context camera, inserted to fill in the blank section where one component on the high resolution camera has failed.

The picture focuses on what the scientists call a “pit interacting with a mound.” The 100-foot-deep pit is one of a very long meandering string of such pits, all of which suggest the existence of an buried river canyon into which debris is sinking. Altogether this particular string runs from several dozen miles, and its interaction with the triangular 300-foot-high mound suggests at first glance that the river that created the canyon did a turn to the left to avoid a large underground mountain, now mostly buried but revealed by its still exposed peak.

As is usual in planetary research, the first glance is often wrong. The overview map below provides a different answer, which says the formation of the aligned pits is related to the formation of the mound itself.
» Read more

5 comments

Astronomers detect what they think is the most distant known fast radio burst yet

9:50 am

The uncertainty of science: Using ground-based radio and optical telescopes, astronomers think they have detected the most distant known fast radio burst yet, coming from a galaxy thought to be eight billion light years away.

On 10 June 2022, CSIRO’s ASKAP radio telescope on Wajarri Yamaji Country was used to detect a fast radio burst, created in a cosmic event that released, in milliseconds, the equivalent of our Sun’s total emission over 30 years.

“Using ASKAP’s array of dishes, we were able to determine precisely where [in the sky] the burst came from,” says Dr Ryder, the first author on the paper. “Then we used the European Southern Observatory (ESO) Very Large Telescope (VLT) in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date, and likely within a small group of merging galaxies.”

Note that the scientists have not actually measured the distance of this burst. They assume it sits at the same distance of the group of merging galaxies that surround it. Only about fifty fast radio bursts have so far been detected. As yet there is no accepted explanation as to what causes them, though knowing their assumed distance helps narrow the possibilities significantly.

The scientists also think they can use the energy from this burst to measure the intervening matter between it and Earth, and thus get a better estimate of the mass of the universe.

0 comments

Webb detects high altitude jet stream above Jupiter’s equatorial band

9:40 am

Jupiter's newly discovered jet stream
Click for original false-color infrared image.

Using the Webb Space Telescope’s infrared capability, scientists have now detected a high altitude jet stream that flows above the equatorial band of Jupiter at speeds estimated to 320 miles per hour.

The false-color infrared image to the right shows evidence of this jetstream in three places by the brightest features seen there. From the caption:

In this image, brightness indicates high altitude. The numerous bright white ‘spots’ and ‘streaks’ are likely very high-altitude cloud tops of condensed convective storms. Auroras, appearing in red in this image, extend to higher altitudes above both the northern and southern poles of the planet. By contrast, dark ribbons north of the equatorial region have little cloud cover. In Webb’s images of Jupiter from July 2022, researchers recently discovered a narrow jet stream traveling 320 miles per hour (515 kilometers per hour) sitting over Jupiter’s equator above the main cloud decks.

These features sit about 25 miles higher than the planet’s previously detected cloudtops.

This discovery only proves what has always been evident, that Jupiter’s atmosphere is very complex with many features earlier optical observations could not see. It also only gives us a hint of that complexity. It will take numerous Jupiter orbiters observing in all wavebands, not just Webb in the infrared millions of miles away, to begin to untangle that complexity. And that untangling will take decades as well, since global weather unfolds over time. You can’t understand it simply by one snapshot. You have to watch the changes from season to season and from year to year. As Jupiter’s year is 12 Earth-years long, this research will take many lifetimes.

1 comment

Erosion revealing ridges on Mars?

12:16 pm

Erosion revealing lava dikes on Mars?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on June 30, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team calls the features here “narrow ridges”, but what makes these criss-crossing ridges interesting is their location within the picture.

They appear only inside the hollows and depressions, as if erosion had stripped out a top layer of softer material to reveal these ridges, made of a harder material. The almost random but straight orientations of the ridges also suggest they formed along faults or cracks, which also suggests we are seeing dikes where lava was pushed up from below.

Whether the eroded softer material is lava or volcanic ash is unclear, though it certainly resembles the ash layers seen in the giant Medusa Fossae Formation ash field on the opposite side of Mars.

As always, a wider look helps clarify things.
» Read more

0 comments

Location of mud volcanoes in Martian chaos terrain suggest past existence of mud lake

10:18 am

Mud volcanoes in the inland sea

Scientists mapping the location of mud volcanoes in chaos terrain in the dry equatorial regions of Mars have found numerous mud volcanoes, adding weight to the theory that an intermittent shallow lake once existed there.

The inset on the overview map to the right indicates the location of those mud volcanoes (of two types) in white and orange dots. What is significant is that none of the volcanoes are found on the mesas within this chaos terrain, only in the low flats below. From the caption:

Both feature types result from sedimentary volcanism – instead of magma upwells and eruptions, wet sediments, and salts reach and breach the surface, forming mounds and flows. Interestingly, these mounds only occur over the chaotic terrain floor materials and not on the mesas (red-shaded areas) they embay. This suggests a material composition link rather than a genesis by regional extensional forces generated by magmatic rises.

The blue areas are where this same science team think an intermittent inland sea once existed. This new data reinforces that hypothesis.

Features that look like mud volcanoes are common in the icy northern lowland plains. Finding them in the dry equatorial regions strengthens the theory that water was once common there. For this reason the scientists are proposing a mission to this location, especially because the possibility of water might increase the chances of discovering past life.

0 comments

Review of orbital images confirms source of largest Mars quake was not an impact

9:35 am

Location of May quake
The white patches mark the locations on Mars of the largest quakes
detected by InSight. The green dotted patch marks this particular 4.7 quake.

Scientists reviewing images from several different orbiters have confirmed that the source of the largest Mars quake detected by InSight, 4.7 magnitude, was not caused by a meteorite impact and thus proves that movement in the interior of Mars is still occurring.

The quake, which had a magnitude of 4.7 and caused vibrations to reverberate through the planet for at least six hours, was recorded by NASA’s InSight lander on Wednesday 4 May 2022. Because its seismic signal was similar to previous quakes known to be caused by meteoroid impacts, the team believed that this event (dubbed ‘S1222a’) might have been caused by an impact as well, and launched an international search for a fresh crater.

…During its time on Mars, InSight (which was co-designed by the University of Oxford) recorded at least 8 marsquake events caused by meteoroid impacts. The largest two of these formed craters around 150m in diameter. If the S1222a event was formed by an impact, the crater would be expected to be at least 300m in diameter. Each group examined data from their satellites orbiting Mars to look for a new crater, or any other tell-tale signature of an impact (e.g. a dust cloud appearing in the hours after the quake).

After several months of searching, the team announced today that no fresh crater was found.

You can read their paper here. To do the survey, the team used data from the American orbiters Mars Reconnaissance Orbiter and Mars Odyssey, and also enlisted help from scientists controlling the data from Europe’s Mars Express, China’s Tianwen-1, India’s Mangalyaan, and the United Arab Emirates’ Al-Mal.

The results suggest the quake occurred at “a dip-slip fault in the mid-crust, consistent with an origin between 18 and 28 km depth,” as stated in the conclusion of their paper. More analysis is necessary, but this result proves that the Martian interior still active enough to produce relatively large quakes..

0 comments

Ingenuity completes 62nd flight on Mars

8:50 pm

Overview map
Click for interactive map.

On October 12, 2023 the Mars helicopter Ingeniuty successfully completed its 62nd flight on Mars, flying a total of 880 feet for just over two minutes while setting a new ground speed record of 22.4 miles per hour.

The flight was a scouting trip to the northeast about 440 feet, then returning to land back at about its take-off point. The green line on the overview map above shows the route of that flight, with the green dot marking Ingenuity’s landing spot. The blue dot marks Perseverance’s present location.

The distance and time of the flight, as well as the speed record, were almost identical to the flight plan released prior to the flight.

0 comments

More Martian inverted rivers?

12:19 pm

More Martian inverted rivers?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on June 23, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label “branching deposits,” two wiggling ridgelines with other ridges branching off from them.

What caused this? On Mars there are many such meandering ridges, all of which look like rivers that have positive relief, the opposite of what you would expect. The theory is that these weaving ridges were once canyons where either water or ice once flowed, compacting the streambed so that it was more dense than the surrounding terrain. When that terrain eroded away it left that streambed behind, as a raised meandering ridge.

That answer however might not apply here.
» Read more

0 comments
1 … 62 63 64 65 66 … 438