Tag: science

As Curiosity retreats from rough country, scientists look at the future geology it will see

3:51 pm

Overview map
Click for interactive map.

Cool image time! For the past two weeks the Curiosity science team has been gingerly and slowing backing the rover off from the very rough terrain of the Greenheugh pediment, as shown on the overview map to the right. The blue dot indicates Curiosity’s present position, with the red dotted line marking its original planned route, now abandoned.

The main question remains: Where to go next? At this point the science team is still debating their exact path forward. As Catherine Weitz of the Planetary Science Institute explained to me in an email today,

The Curiosity team is still working out the details. Maybe in another month or so the new route will be finalized so stay tuned.

No matter what route they eventually choose, the white arrows mark one of the more interesting upcoming geological features that the scientists very much intend Curiosity to reach. In a paper published at the end of March in which Weitz was the lead author, they describe this “marker horizon” as follows:
» Read more

2 comments

Dunes on Jupiter’s volcano moon Io?

9:35 am

Dunes on Io?
Click for full image.

The uncertainty of science: According to a just published paper, scientists now propose that the dune-like ridges long known to exist on Io, Jupiter’s volcano-covered moon, might actually be dunes, even though Io has no real atmosphere.

The photo to the right, cropped, reduced, and annotated to post here, was taken by the Galileo while it orbited Jupiter from 1995 to 2003. It illustrates what the scientists believe is the proposed process:

McDonald and his colleagues used mathematical equations to simulate the force required to move grains on Io and calculated the path those grains would take. The study simulated the movement of a single grain of basalt or frost, revealing that the interaction between flowing lava and sulfur dioxide beneath the moon’s surface creates venting that is dense and fast moving enough to form large dune-like features on the moon’s surface, according to the statement.

In what might be a monumental understatement about the reality of interplanetary geology, McDonald said this in the press release: “This work tells us that the environments in which dunes are found are considerably more varied than the classical, endless desert landscapes on parts of Earth.”

Damn right. The possibility of unexpected geology of all kinds on the millions of planets, moon, and asteroids not yet studied is endless, and guaranteed.

3 comments

Ingenuity photographs Perseverance’s abandoned parachute on 26th flight

10:05 am

Perseverance's parachute, as photographed by Ingenuity
Click for full image.

Overview map
Click for interactive map.

In the past week the Mars helicopter Ingenuity successfully completed its 26th and 27th flights, with the first specifically planned to fly over the parachute that had been used by Perseverance when it landed on Mars on February 18, 2021. The first photo to the right, enhanced, cropped, and reduced to post here, is the color photo of that parachute that Ingenuity took during that flight on April 20th. Near the top of the frame you can also see the equipment used to attach the chute to the rover. The photo looks to the southwest.

The map to the right indicates the flight paths for both hops, both slightly more than 1,000 feet total. The green dot marks Ingenuity’s position yesterday, the red dot Perseverance’s position. The small white dot indicates the parachute’s location.

On April 8th Perseverance had snapped a picture of the parachute, from the position indicated by the black dot. Since that photo was taken from a distance, it could not show much. Ingenuity’s more recent photo from overhead however captures the chute quite clearly, and suggests that in the year since landing the weak Martian wind has shifted its edges slightly while depositing some dust on its surface.

You can see the changes at the edges by comparing Ingenuity’s picture with a photo taken on February 19, 2021 by Mars Reconnaissance Orbiter (MRO). In Ingenuity’s picture the near edge of the parachute especially appears to have become bunched up over time, suggesting the prevailing and strongest winds have come from the south.

4 comments

InSight scientists publish paper describing last year’s big Martian quakes

9:43 am

Figure 5: global map of located Martian quakes

The InSight science team has now published a paper [pdf] describing in detail what they gleaned from the two large earthquakes the lander detected on Mars last year, measuring 4.1 and 4.2 magnitudes.

The map above, figure 5 of their paper, marks their best estimate of the quakes’ locations, dubbed S0976a and S1000a. From the caption:

Mars surface relief map showing InSight’s location (orange triangle), the location of other located mars-quakes (magenta dots) that cluster around 30° distance, close to Cerberus Fossae, and S0976a, located within Valles Marineris just north of Sollis Planum. Because no back azimuth can be determined for S1000a, its location is predicted to be somewhere within the shaded region between 107° and 147° from InSight. The event’s preferred distance (116°) is marked with the white dashed line. The black dotted lines mark radii around InSight up to 80°.

A review of Mars Reconnaissance Orbiter (MRO) high resolution images of that part of Valles Marineris where S096a occurred will likely uncover a whole bunch taken since last August, all attempting to detect any actual surface changes produced by quake. I think I’ll do that review, and see if I can spot something.

The paper also notes the uniqueness of S1000a, which lasted 94 minutes, the longest so far detected on Mars. The complexity of its signal also makes locating it difficult, though the most likely possible locations — indicated by the white dashed line in the map above — crosses through the Tharsis Bulge where Mars’ biggest volcanoes are found.

Sadly, InSight will likely shut down before the end of this year due to loss of power, so until another seismometer is sent there no further Martian quakes will be detected.

Leave a comment

NASA extends eight planetary missions, including sending OSIRIS-REx to the asteroid Apophis

1:18 pm

Apophis' path past the Earth in 2029
Apophis’ path past the Earth in 2029.

NASA today announced that it is extending the missions of eight different planetary probes.

The missions – Mars Odyssey, Mars Reconnaissance Orbiter, MAVEN, Mars Science Laboratory (Curiosity rover), InSight lander, Lunar Reconnaissance Orbiter, OSIRIS-REx, and New Horizons – have been selected for continuation, assuming their spacecraft remain healthy. Most of the missions will be extended for three years; however, OSIRIS-REx will be continued for nine years in order to reach a new destination, and InSight will be continued until the end of 2022, unless the spacecraft’s electrical power allows for longer operations.

The biggest news is the decision to extend OSIRS-REx so that it can rendezvous with the asteroid Apophis in 2029. The science team…

…will redirect the spacecraft to encounter Apophis, an asteroid roughly 1,200 feet (roughly 370 meters) in diameter that will come within 20,000 miles (32,000 kilometers) of Earth in 2029. OSIRIS-APEX will enter orbit around Apophis soon after the asteroid’s Earth flyby, providing an unprecedented close-up look at this S-type asteroid. It plans to study changes in the asteroid caused by its close flyby of Earth and use the spacecraft’s gas thrusters to attempt to dislodge and study the dust and small rocks on and below Apophis’ surface.

Apophis is a potentially dangerous asteroid, with a 1 in 150,000 chance it will hit the Earth in 2068. Getting as much information about it as soon as possible is crucial so that future generations will be prepared should its path eventually become a collision course.

9 comments

The icy Reull Valley of Mars

12:33 pm

Eroded ice in crater near Reull Valles
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on February 20, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the eroded floor of a 10-mile-wide very obscured unnamed crater that sits above the northern wall of a canyon dubbed Reull Valles.

For reference the interior slope of the crater’s southern rim is labelled. The crater sits at 40 degrees south latitude. Thus, this crater is inside the 30 to 60 degree mid-latitude bands where scientists have found many glaciers on Mars. The eroded floor of this crater appears to confirm this conclusion. In the full photo the erosion is even more pronounced, as well as more chaotic, farther from that rim to the north.

Because Reull Valles sits inside that southern glacial band, it is home to much evidence of ice. The overview map below provides the context.
» Read more

One comment

Ispace secures first insurance deal for private lunar lander

9:25 am

Capitalism in space: The Japanese startup Ispace has now obtained the first insurance plan ever for a private lunar lander.

The startup has signed a Memorandum of Understanding with Mitsui Sumitomo Insurance (MSI), a Tokyo-based firm that started working with Ispace in 2019, to insure its first attempt to send a lander to the moon later this year. The agreement outlines intentions to finalize terms for the insurance in the months leading up to Ispace’s Mission 1 (M1), which is currently slated to fly on a Falcon 9 rocket no earlier than the fourth quarter of 2022.

According to Ispace, the insurance would cover any damage the lander takes between separating from the rocket in a trans-lunar orbit (TLO) and touching down on the moon. As well as covering a failed landing, the insurance would guard against issues stemming from radiation exposure as the lander travels through the Van Allen belts to its destination.

The insurance does not cover the payloads Ispace’s lander will carry, including a rover from the United Arab Emirates.

3 comments

Colliding galaxies

1:11 pm

Merging galaxies

The string of amazing galaxy images coming from the Hubble Space Telescope continues. The photo to the right, cropped and reduced to post here, was released today and shows an object dubbed VV-689 that is believed to be two galaxies in the process of colliding and merging.

The angelic image comes from a set of Hubble observations that took a closer look at “Zoo Gems,” interesting galaxies from the Galaxy Zoo citizen science project. This crowdsourced program relies on hundreds of thousands of volunteers to classify galaxies and help astronomers wade through a deluge of data from robotic telescopes. In the process, volunteers discovered a gallery of weird and wonderful galaxy types, some not previously studied.

This image will lay the groundwork for more detailed research. Right now it appears no one has even estimated its distance.

4 comments

The gigantic lava flows off of the solar system’s biggest known volcano

12:50 pm

Olympus Mons' gigantic lava flow
Click for full image.

Cool image time! The photo to the right, cropped, reduced, and annotated to post here, was taken on October 30, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The picture covers a very tiny section of the southeast flank of Olympus Mons, the largest known volcano in the solar system. The arrow indicates the direction of the downward slope.

Olympus Mons itself is about 400 miles wide with an actual height relative to Mars’ “sea level” of just under 70,000 feet, more than twice as high as Mount Everest on Earth. The mountain’s flanks, almost 200 miles long from caldera edge to base, drop about 54,000 feet. That average drop of about 270 feet every mile is not particular steep, but its continuous nature over such a very very long distance makes its quite daunting.

You can see evidence of that slope in the photo. The downward pointing lobes each indicate the volcano’s last separate lava flows that ceased moving when each froze in place, probably several tens of millions of years ago. These lobes were also placed on top of many earlier flows from the volcano’s past eruptions that probably continued for several billion years, beginning 3.5 billion years ago.

The overview map helps provide a sense of scale by placing this image on that mountain flank.
» Read more

2 comments

Lucy team schedules attempt to complete solar panel deployment

3:21 pm

Lucy solar panel graphic
Artist’s impression of solar panel

After months of discussions, the engineering team of the Lucy asteroid probe have now scheduled the week of May 9th as when they will begin their attempt to complete the deployment of the spacecraft’ partly opened solar panel.

The team is now preparing to complete the solar array deployment in two steps. The first step, tentatively scheduled for the week of May 9, is intended to pull in most of the remaining lanyard and verify that flight results are consistent with ground testing. This step will also strengthen the array by bringing it closer to a fully tensioned state. Because this step is designed to be limited in duration, the array is not likely to latch at that point.

If this step goes as planned, the second step will continue the array deployment with the intent to fully latch. Information gleaned from the first part will help fine-tune the second. The second step is currently planned for a month after the initial one, giving engineers enough time to analyze the data seen in the first attempt.

When launched in October 2021 one of Lucy’s two large solar panels did not completely open and latch, as shown above. Though the spacecraft is presently getting 90% of its expected power, the scientists want to get the panel fully open and latched to insure it will function as planned once the spacecraft gets out to the asteroid belt, where sunlight is dimmer.

One comment

Astronomers discover new type of stellar explosion

11:31 am

Using data from the orbiting TESS observatory and the ground-based Very Large Telescope (VLT) in Chile, astronomers have detected evidence of a new type of stellar explosion they have dubbed a “micronova.”

The micronova appears to be a smaller version of a nova, which brightens the entire star for a month or so.

A white dwarf in a two-star system can steal material, mostly hydrogen, from its companion star if they are close enough together. As this gas falls onto the very hot surface of the white dwarf star, it triggers the hydrogen atoms to fuse into helium explosively. In novae, these thermonuclear explosions occur over the entire stellar surface. “Such detonations make the entire surface of the white dwarf burn and shine brightly for several weeks,” explains co-author Nathalie Degenaar, an astronomer at the University of Amsterdam, the Netherlands.

Micronovae are similar explosions that are smaller in scale and faster, lasting just several hours. They occur on some white dwarfs with strong magnetic fields, which funnel material towards the star’s magnetic poles. “For the first time, we have now seen that hydrogen fusion can also happen in a localised way. The hydrogen fuel can be contained at the base of the magnetic poles of some white dwarfs, so that fusion only happens at these magnetic poles,” says Paul Groot, an astronomer at Radboud University in the Netherlands and co-author of the study.

What this discover really reveals is that as our astronomical observing technology improves, we can observe a greater variety of stellar phenomenon. Expect astronomers in future years to detect an even wider variety of stellar explosions, most of which have not be detectable up until now because we simply couldn’t see them.

One comment

Astrobotics unveils nearly complete Peregrine lunar lander

10:04 am

Capitalism in space: Astrobotics yesterday unveiled its nearly complete Peregrine lunar lander, scheduled for launch later this year on the first launch of ULA’s new Vulcan rocket.

The lander is still being assembled, said John Thornton, chief executive of Astrobotic. Remaining work includes installation of its solar panels, two fuel tanks and decks holding payloads. The engines are “just about done,” he said, and will soon be installed.

He was optimistic that remaining work will be done quickly. “In just a couple months’ time, this will be heading out to environmental testing,” he said, followed by shipment to the launch site late this year.

This announcement now strongly suggests that Peregrine would not have been ready for Vulcan’s original launch date in late 2021. Since then the delays by Blue Origin in developing Vulcan’s first stage BE-4 engine has pushed the rocket’s first launch back by more than a year, time that apparently Astrobotics needed to finish Peregrine.

Leave a comment

Perseverance captures solar eclipse by Phobos

1:40 pm

Phobos eclipse the Sun
Click for full image.

Cool movie time! The photo to the right, cropped to post here, shows the Sun partly blocked by the Mars’ moon Phobos, taken by the high resolution camera on Perseverance on the surface of Mars. Below I have embedded the full movie compiled from the images taken as Phobos moved across the Sun’s face. From the caption:

It’s long been known that Phobos is drifting toward the Martian surface year by year; tens of millions of years from now, it is expected to crash into the planet or fragment into chunks that will impact the planet. Studying Phobos’ orbit also allows scientists to refine predictions of when the doomed moon will crash into Mars.

Unfortunately, the website does not say when this solar eclipse occurred. The spots on the lower left of the Sun’s face are sunspots.
» Read more

7 comments

Planetary scientists propose next NASA boondoggle

11:28 am

The decadal survey's fantasy about future budget allocations
Figure 22.2 from the decadal survey, outlining its fantasy about future
budget allocations.

Let me admit right off the bat that my headline above is a bit too cynical as well as a bit unfair. In releasing yesterday their decadal survey, outlining what they hope planetary missions NASA will do in the next decade, the planetary science community was mostly interested in recommending the planetary missions in the coming decade it thought would provide the best actual science.

The problem is that in recent decades, these decadal surveys, from both the astronomers and the planetary scientists, have evolved into documents designed to encourage a few big expensive missions, rather than a suite of many smaller probes to many different places. For examples, consider this quote from the article in Science describing yesterday’s announcement:
» Read more

12 comments

Hubble looks at a tight cluster of five galaxies

1:33 pm

Hickson Compact Group 40
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope to celebrate the telescope’s 32nd year in orbit. This cluster of five galaxies is dubbed Hickson Compact Group 40.

This menagerie includes three spiral-shaped galaxies, an elliptical galaxy, and a lenticular (lens-like) galaxy. Somehow, these different galaxies crossed paths in their evolution to create an exceptionally crowded and eclectic galaxy sampler.

Caught in a leisurely gravitational dance, the whole group is so crowded that it could fit within a region of space that is less than twice the diameter of our Milky Way’s stellar disk.

Though such cozy galaxy groupings can be found in the heart of huge galaxy clusters, these galaxies are notably isolated in their own small patch of the universe, in the direction of the constellation Hydra.

The red streaks in three galaxies is thought to be dust, suggesting that stars are still forming in these galaxies. The vertical galaxy on the right is seen edge on. Note too the tilted ring that appears to surround the galaxy on the left.

As for Hubble’s anniversary, the press release notes that since launch in 1990 the space telescope has made 1.5 million observations covering 50,000 heavenly objects, an archive of data available to anyone to access.

13 comments

Perseverance spots its parachute

11:50 am

Perseverance spots its parachute
Click for full resolution. Original images found here and here.

Overview map
Click for interactive map.

Cool image time! Today the Perseverance science team released two photos taken on April 6th that captured the parachute that the rover had used to land on Mars on February 18, 2021. The enhanced panorama above is from those images. The white feature near the center is the parachute. The mountains in the distance are the southern rim of Jezero Crater, about 40 miles away.

The overview map to the right gives the context. The red dot is Perserverance’s location as of yesterday, on sol 413. The black dot marks its location on April 6th, when it took the pictures. The green dot marks Ingenuity’s present position. The yellow lines indicate the approximate area covered by the panorama.

Ingenuity had not completed its 25th flight until April 8th, two days after these photos were taken, so it isn’t actually just off the edge of these photos, it is beyond the near ridgeline out of sight.

One comment

Dawn on the Moon

5:34 pm

Dawn on the Moon's far side
Click for full image.

Cool image time! The photo to the right, reduced to post here, was taken on August 25, 2019 by Lunar Reconnaissance Orbiter (LRO). It shows an oblique view looking west just after lunar dawn of an unnamed 13-mile-wide crater in Mare Moscoviense on the far side of the Moon. From the caption:

Mare Moscoviense is one of the few volcanic plains on the farside, which is largely comprised of ancient cratered highland terrain. The fact that the farside was strikingly different from the familiar nearside was a surprise when the Soviet Luna 3 spacecraft returned the first farside images in 1959. The highland crust is thicker on the farside than on the nearside, which is thought to have inhibited magmas from reaching the surface as frequently as they once did on the nearside.

As seen in the image above, Mare Moscoviense lies within a large impact basin, the formation of which thinned the local crust, perhaps making it easier for lavas to erupt that would have otherwise stalled below the surface. But why does this global asymmetry in crustal thickness exist? This is still a mystery, like the origins of the large-scale asymmetries observed on Mars and Mercury, though ideas like a giant impact event that stripped off a portion of the crust or asymmetric overturn of the mantle have been proposed.

Note the dark shadow obscuring the foreground on the left. It appears from the topography in the overhead map at the link that the ridgeline that marks the eastern border of Mare Moscoviense is just high enough at dawn to keep the mare in shadow while allowing the sun’s dawn light to peek over and illuminate the crater’s rim. That ridgeline however only extends so far to the north, thus allowing sunlight to hit the plains on the right sooner.

3 comments

White sediment in Martian slot canyon

9:43 am

White sediment in Martian slot canyon
Click for full image.

Yesterday’s Picture of the Day from the high resolution camera on Mars Reconnaissance Orbiter (MRO) revisited a captioned image first posted in February 2014 by the science team. That picture, cropped and enhanced, is to the right. From the 2014 caption:

There is a large channel system that flows into the basin, called Ladon Valles, and scientists think that the basin may have once filled with water before another channel to the north formed and drained it. These exposures of light-toned layered sediments provide clues about the environment that existed within Ladon Basin when water may have ponded and deposited these sediments.

Later research has generally concluded that these white sediments are iron and magnesium smectites, often appearing as white tuff material whose deposition is generally associated with precipitation of water or snow and its subsequent evaporation or sublimation.
» Read more

Leave a comment

Astronauts return from Chinese station; China launches satellite

9:06 am

Late yesterday China’s Shenzhou descent capsule successfully brought home three astronauts from its Tiangong-3 space station after spending six months in space.return from Chinese station.

During their stay they completed two spacewalks and prepared the station for the arrival of two more large modules in the next six months.

China yesterday also used its Long March 4C rocket to launch a new radar satellite designed to observe the Earth’s atmosphere.

The leaders in the 2022 launch race:

13 SpaceX
11 China
5 Russia
2 ULA
2 Rocket Lab

The U.S. still leads China 20 to 11 in the national rankings. Note that at this moment the U.S. total is more than all other nations combined (19).

One comment

The spiral galaxy M91

3:38 pm

spiral galaxy M91
Click for full release image.

Cool image time! The image to the right, reduced to post here, was released today by the Space Telescope Science Institute as part of a regular program using the Hubble Space Telescope to photograph galaxies.

This observation is part of an effort to build a treasure trove of astronomical data exploring the connections between young stars and the clouds of cold gas in which they form. To do this, astronomers used Hubble to obtain ultraviolet and visible observations of galaxies already seen at radio wavelengths by the ground-based Atacama Large Millimeter/submillimeter Array.

The galaxy is estimated to be about 55 million light years away, and is thought to have a supermassive black hole at its center with a mass somewhere between 9 and 38 million times the mass of the Sun.

9 comments

Ingenuity completes 25th flight, the longest yet

10:51 am

Overview map
Click for interactive map.

On April 8th the Mars helicopter Ingenuity successfully completed its 25th flight on Mars, traveling 2,310 feet at 18 feet per second while flying for 161.3 seconds.

The long distance was designed to take it out from the rough region dubbed Seitah and near the delta that is the prime geological target of the rover Perseverance.

The overview map shows the location of both rover and helicopter as of today. The red dot is Perseverance, the green dot is Ingenuity. The rover has now completed its entire planned travels, as announced in June 2021. Where it goes next has not as yet not been announced. According to the team, they plan to use Ingenuity to scout out possibly routes up onto the delta. This likely means the rover will likely spend some time at the base of the delta, getting as much data as it can, while Ingenuity does this scouting work.

One comment

The spread of the oceans’ sea floors appears to be slowing

9:33 am

The uncertainty of science: Based on data covering the last 19 million years, scientists now believe that the rate in which the Earth’s ocean sea floors are spreading has been slowing steadily.

Today, spreading rates top out around 140 millimeters per year, but peaked around 200 millimeters per year just 15 million years ago in some places, according to the new study. The study was published in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.

The slowdown is a global average, the result of varying spreading rates from ridge to ridge. The study examined 18 ridges, but took a particularly close look at the eastern Pacific, home to some of the globe’s fastest spreading ridges. Because these slowed greatly, some by nearly 100 millimeters per year slower compared to 19 million years ago, they dragged down the world’s average spreading rates.

You can read the actual paper here.

To put it mildly, the conclusion here is uncertain. The difference between 140 and 200 millimeters is less than two and a half inches. A hundred millimeters is less than four inches. Such small differences over millions of years could simple be caused by random fluctuations over time. Furthermore, the scientists did not actually detect the spreading rates from millions of years ago. They instead inferred it based on the data we do have of the changes in the Earth’s magnetic field over time.

Still, this result is very intriguing indeed. More than anything, it should help geologists develop better theories to explain plate tectonics, and what drives it. At the moment no theory adequate explains it.

7 comments

Frozen lava in Mars’ volcano country

5:31 pm

The frozen lava of the Athabasca flood plain
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on January 28, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what appears to be at first glance a relatively featureless plain with a lighter material covered by a patchwork of darker material.

Note however the lack of craters. Except for several faint depressions near the image’s center, there are none. And those depressions look like the expression of craters that have been covered by material. Is the two-toned surface here an expression of past lava flows? Or are we seeing an ice-sheeted plain, with the patches representing higher terrain above that plain?

The overview map below answers the question somewhat clearly.
» Read more

Leave a comment

Astronomers confirm comet with largest nucleus ever found

9:29 am

Using the Hubble Space Telescope astronomers determined that the nucleus of Comet Bernardinelli-Bernstein (C/2014 UN271) is about 80 miles wide, making it the largest comet on record.

The estimated diameter is approximately 80 miles across, making it larger than the state of Rhode Island. The nucleus is about 50 times larger than found at the heart of most known comets. Its mass is estimated to be a staggering 500 trillion tons, a hundred thousand times greater than the mass of a typical comet found much closer to the Sun.

The behemoth comet, C/2014 UN271 (Bernardinelli-Bernstein) is barreling this way at 22,000 miles per hour from the edge of the solar system. But not to worry. It will never get closer than 1 billion miles away from the Sun, which is slightly farther than the distance of the planet Saturn. And that won’t be until the year 2031.

The previous record holder is comet C/2002 VQ94, with a nucleus estimated to be 60 miles across. It was discovered in 2002 by the Lincoln Near-Earth Asteroid Research (LINEAR) project.

This measurement does have a great deal of uncertainty, as Hubble cannot yet resolve the nucleus, and thus its diameter was determined by computer models based on the size of the comet’s coma, or surrounding atmosphere.

The comet itself has an orbit 3 million years long, which means it has zipped into the inner solar system many many times. The reason its nucleus remains so large is because its orbit never gets that close to the Sun, so its material does not get burned off so much with each perihelion. That it exists suggests there could be many such large comets which never dip close to the Sun.

4 comments

MAVEN and Al-Amal scientists sign agreement to collaborate

1:20 pm

Scientists running the Mars orbiters MAVEN (from NASA) and Al-Amal (from the United Arab Emirates [UAE]) have signed an agreement to share data and — more importantly — coordinate their observations of the Martian atmosphere.

A new partnership that encourages the sharing of data between NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) project and the Emirates Mars Mission’s (EMM) Hope Probe (Al-Amal in Arabic) will enhance scientific returns from both spacecraft, which are currently orbiting Mars and collecting data on the Red Planet’s atmosphere. The arrangement is expected to add value to both MAVEN and EMM, as well as the scientific communities involved in analyzing the data the missions collect.

MAVEN went into orbit around Mars in 2014. Its mission is to investigate the upper atmosphere and ionosphere of Mars, offering an insight into how the planet’s climate has changed over time. “MAVEN and EMM are each exploring different aspects of the Martian atmosphere and upper-atmosphere system,” said Shannon Curry, MAVEN principal investigator from the University of California, Berkeley. “Combined, we will have a much better understanding of the coupling between the two, and the influence of the lower atmosphere on the escape to space of gas from the upper atmosphere.”

The EMM Hope Probe, which went into Mars orbit in 2021, is studying the relationship between the upper layer and lower regions of the Martian atmosphere, giving insight into the planet’s atmosphere at different times of the day and seasons.

What this agreement means is that the two science teams can more quickly match up the data from both orbiters, and figure out the relationships between both.

4 comments

Interstellar meteor impacted Earth in 2014

10:28 am

According to classified military data just released, it appears that an asteroid from interstellar space impacted the Earth in 2014, with some of its pieces possibly hitting the ocean in the south Pacific.

The meteor ignited in a fireball in the skies near Papua New Guinea, the memo states, and scientists believe it possibly sprinkled interstellar debris into the South Pacific Ocean. The confirmation backs up the breakthrough discovery of the first interstellar meteor—and, retroactively, the first known interstellar object of any kind to reach our solar system—which was initially flagged by a pair of Harvard University researchers in a study posted on the preprint server arXiv in 2019.

Amir Siraj, a student pursuing astrophysics at Harvard who led the research, said the study has been awaiting peer review and publication for years, but has been hamstrung by the odd circumstances that arose from the sheer novelty of the find and roadblocks put up by the involvement of information classified by the U.S. government.

The speed and angle in which the object hit the atmosphere are why the scientists believe it comes from outside the solar system.

Siraj is actually hoping to mount a mission to recover parts of this asteroid, something that is extremely unlikely. First, the meteor itself was small, so it likely all burned up in re-entry. Second, even if pieces survived, finding them on the bottom of the Pacific is likely impossible.

5 comments

Curiosity retreating from Greenheugh Pediment

10:05 am

Overview map
Click for interactive map.

Because of the incredible roughness of the ground on the Greenheugh Pediment, the science team for the rover Curiosity has decided to make a major change in their route. Rather than continue their traverse across this terrain, as planned for years, they have decided to back off in order to protect Curiosity’s dinged wheels, and find a more friendly route up Mount Sharp.

“It was obvious from Curiosity’s photos that this would not be good for our wheels,” said Curiosity Project Manager Megan Lin of NASA’s Jet Propulsion Laboratory in Southern California, which leads the mission. “It would be slow going, and we wouldn’t have been able to implement rover-driving best practices.”

The gator-back rocks aren’t impassable – they just wouldn’t have been worth crossing, considering how difficult the path would be and how much they would age the rover’s wheels.

So the mission is mapping out a new course for the rover as it continues to explore Mount Sharp, a 3.4-mile-tall (5.5-kilometer-tall) mountain that Curiosity has been ascending since 2014. As it climbs, Curiosity is able to study different sedimentary layers that were shaped by water billions of years ago. These layers help scientists understand whether microscopic life could have survived in the ancient Martian environment.

The plan is to retrace the rover’s path back through Gordon Notch and then head uphill though another gap that will take it directly onto the next sedimentary layer, dubbed the sulfate unit. On the overview map above, the red dotted line shows the long-planned route. The yellow lines indicate the area seen in the panorama I posted on April 6th, when Curiosity was at its farthest into the pediment. The blue dot marks Curiosity’s position two days ago. You can see that it has retreated backwards.

This change means the scientists will likely not get a close look at Gediz Vallis Ridge. However, it also means the rover will likely reach Gediz Vallis much sooner that previously planned.

Leave a comment

Neptune’s cooling when it should be warming

9:45 am

Neptune since 2006

The uncertainty of science: Observations of Neptune during the past seventeen years using the Very Large Telescope have shown the planet mostly cooling during this time period, even though Neptune was moving into its summer season.

Astronomers looked at nearly 100 thermal-infrared images of Neptune, captured over a 17-year period, to piece together overall trends in the planet’s temperature in greater detail than ever before. These data showed that, despite the onset of southern summer, most of the planet had gradually cooled over the last two decades. The globally averaged temperature of Neptune dropped by 8 °C between 2003 and 2018.

The astronomers were then surprised to discover a dramatic warming of Neptune’s south pole during the last two years of their observations, when temperatures rapidly rose 11 °C between 2018 and 2020. Although Neptune’s warm polar vortex has been known for many years, such rapid polar warming has never been previously observed on the planet. “Our data cover less than half of a Neptune season, so no one was expecting to see large and rapid changes,” says co-author Glenn Orton, senior research scientist at Caltech’s Jet Propulsion Laboratory (JPL) in the US.

The sequence of photos above show that change over time. Lower latitudes generally get darker, or cooler, while the south pole suddenly brightens, getting hotter, in 2020.

The scientists have no idea why this has happened, though they have theories, ranging from simple random weather patterns to the influence of the Sun’s sunspot cycle.

8 comments

Perseverance arrives at Three Forks at the base of Jezero Crater’s delta

12:01 pm

Panorama of delta in Jezero Crater
Original images found here, here, here, and here. Click for full resolution.

Overview map
Click for interactive map.

Cool image time! The panorama above was created from four navigation camera images taken by the Mars rover Perseverance on April 10th. Because the lens on Perseverance’s navigation cameras produce slightly curved images which are taken in pairs, the panorama is made of two parts, each a pair perfectly matched images looking from a different angle. I have overlapped the pairs but as you can see, the match at the center is imperfect. While this does not produce a single smooth image, the two paired panoramas show the foot of the entire delta that had flowed into Jezero crater in the past and is the prime geological target of the rover. What is it made of? What caused it to flow into the crater? When did it do it? How was Mars different when it did so? Was the crater wet? Was the delta mud when it flowed, or was it sediment under water, pushed out by that flowing water?

The location map to the right is taken from the “Where is Perseverance?” webpage but annotated to show the planned routes of both Perseverance and Ingenuity, as shown by the tan dashed lines. The red dot marks Perseverance present location, the green dot Ingenuty’s. The yellow lines the approximate area covered by the panorama.

What next? Expect Perseverance to move as close to the base of the delta’s cliff as possible and spend at least several months studying it. Ingenuity meanwhile will be flown to the west to scout the various hollows that are potential routes for Perseverance to climb up onto the delta.

Leave a comment
1 … 62 63 64 65 66 … 279