Tag: science

Was the Chicxulub bolide 65 million years ago an asteroid from beyond Jupiter?

9:21 am

According to a new study, the Chicxulub bolide that impacted the Yucatan 65 million years ago and is thought to have been a major cause of the extinction of the dinosaurs was likely a carbonaceous-type asteroid from beyond Jupiter.

The researchers attempted to pinpoint the nature of that bolide by analyzing the isotope samples from the thin layer of materials found worldwide that corresponds to the impact (dubbed the K-Pg boundary) as well number of different impact samples from different layers.

To address these questions, Mario Fischer-Gödde and colleagues evaluated ruthenium (Ru) isotopes in samples taken from the K-Pg boundary. For comparison, they also analyzed samples from five other asteroid impacts from the last 541 million years, samples from ancient Archaean-age (3.5 – 3.2 billion-years-old) impact-related spherule layers, and samples from two carbonaceous meteorites.

Ficher-Gödde et al. found that the Ru isotope signatures in samples from the K-Pg boundary were uniform and closely matched those of carbonaceous chondrites (CCs), not Earth or other meteorite types, suggesting that the Chicxulub impactor likely came from a C-type asteroid that formed in the outer Solar System. They also rule out a comet as the impactor. Ancient Archean samples also suggest impactors with a CC-like composition, indicating a similar outer Solar System origin and perhaps representing material that impacted during Earth’s final stages of accretion. In contrast, other impact sites from different periods showed Ru isotope compositions consistent with S-type (salicaceous) asteroids from the inner Solar System.

My headline poses this result as a question because these results are unconfirmed, and based on a very small sample of data. Nonetheless, this research not only gives us a better idea of the nature of the Chicxulub impactor, it does the same for a number of other important past impacts. That data in turn will help theorists refine their theories describing the early formation history of the solar system.

Sidebar: As always, there are numerous stories today in the mainstream press going ga-ga over this paper and declaring with certainty the utter truth of its conclusions. This of course is junk reporting, as there is no utter truth here, only some educated speculation based on some new data.

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Astronomers discover a nearby star moving so fast it could even escape the Milky Way

10:20 am

Astronomers, both professional and amateur, have discovered a nearby star only 400 light years away that is moving so fast, 1.3 million miles per hour (almost three times faster than the Sun), it might very well escape the Milky Way and fly into intergalactic space in the far future.

The star, named CWISE J124909+362116.0 (or “J1249+36” for short), was first spotted by some of the over 80,000 citizen science volunteers participating in the Backyard Worlds: Planet 9 project, who comb through enormous reams of data collected over the past 14 years by NASA’s Wide-field Infrared Survey Explorer (WISE) mission. This project capitalizes on the keen ability of humans, who are evolutionarily programmed to look for patterns and spot anomalies in a way that is unmatched by computer technology. Volunteers tag moving objects in data files and when enough volunteers tag the same object, astronomers investigate.

J1249+36 immediately stood out because it was moving at about .1 percent the speed of light.

The star itself is either a very low mass red dwarf, or possibly a brown dwarf that never quite had enough mass to ignite as a star.

You can read the research paper here [pdf]. The researchers posit two possible explanations for the star’s speed. Either it was once part of a binary and thrown out when its white dwarf companion exploded as a supernova, or was once located in a densely packed globular cluster, where the interaction with other stars or even black holes could have flung it away.

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The future route of Perseverance out of Jezero Crater

10:01 am

Perseverance's future route
Click for original image.

The science team for the Mars rover Perseverance today outlined the planned route they intend to follow to bring the rover out of Jezero Crater.

The map to the right shows that route in red, with the rover presently at the upper right. Though Perseverance presently sits inside Neretva Vallis, which is the channel that cuts through the rim of the crater through which poured the delta material the rover has been sampling since landing, the route out of the crater will instead head south and west, crossing over the rim.

NASA’s Perseverance Mars rover will soon begin a monthslong ascent up the western rim of Jezero Crater that is likely to include some of the steepest and most challenging terrain the rover has encountered to date. Scheduled to start the week of Aug. 19, the climb will mark the kickoff of the mission’s new science campaign — its fifth since the rover landed in the crater on Feb. 18, 2021.

…Two of the priority regions the science team wants to study at the top of the crater are nicknamed “Pico Turquino” and “Witch Hazel Hill.” Imagery from NASA’s Mars orbiters indicates that Pico Turquino contains ancient fractures that may have been caused by hydrothermal activity in the distant past.
Rover looking back at the “Bright Angel” area

Orbital views of Witch Hazel show layered materials that likely date from a time when Mars had a very different climate than today. Those views have revealed light-toned bedrock similar to what was found at “Bright Angel,” the area where Perseverance recently discovered and sampled the “Cheyava Falls” rock, which exhibits chemical signatures and structures that could possibly have been formed by life billions of years ago when the area contained running water.

For Perseverance’s recent travels, go here.

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Webb data suggests the possibility of ice and hydrated minerals on surface of Psyche

9:33 am

Using the Webb Space Telescope, astronomers have detected evidence of hydrated minerals and even possibly a very tiny amount of water ice on the surface of the metal asteroid Psyche.

The Webb data point to hydroxyl and perhaps water on Psyche’s surface. The hydrated minerals could result from external sources, including impactors. If the hydration is native or endogenous, then Psyche may have a different evolutionary history than current models suggest. “Asteroids are leftovers from the planetary formation process, so their compositions vary depending on where they formed in the solar nebula,” said SwRI’s Dr. Anicia Arredondo, another co-author. “Hydration that is endogenous could suggest that Psyche is not the remnant core of a protoplanet. Instead, it could suggest that Psyche originated beyond the ‘snow line,’ the minimum distance from the Sun where protoplanetary disc temperatures are low enough for volatile compounds to condense into solids, before migrating to the outer main belt.”

However, the paper found the variability in the strength of the hydration features across the observations implies a heterogeneous distribution of hydrated minerals. This variability suggests a complex surface history that could be explained by impacts from carbonaceous chondrite asteroids thought to be very hydrated.

You can read the research paper here [pdf]. The actual amount of water possible is at most 39 parts per million and is also an order of magnitude lower than that found on the Moon, which strongly suggests that it comes from outside sources, such as impacts from other asteroids, not from the inherent geological history of Psyche itself.

The uncertainties of this research, which are large, which should be resolved when the probe Psyche, launched last year, reaches the asteroid Psyche in August 2029.

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Intuitive Machines wants to land VIPER rover on Moon

9:04 am

VIPER's planned route on the Moon
VIPER’s now canceled planned route at the Moon’s south pole

The lunar lander startup Intuitive Machines has now revealed it is putting together an industry partnership to bid on flying NASA’s VIPER lunar rover on its own largest lander, still under development.

In an Aug. 13 earnings call about its second quarter financial results, Intuitive Machines executives said they were planning to respond to a request for information (RFI) that NASA issued Aug. 9 seeking input from companies and organizations interested in taking over the Volatiles Investigating Polar Exploration Rover (VIPER) mission that the agency said in July it would cancel.

Steve Altemus, chief executive of Intuitive Machines, said on the call that his company, which also responded to an earlier call for “expressions of interest” from NASA regarding VIPER, is working with other companies, universities and international partners on responding to NASA’s RFI. He did not identify any of those prospective partners.

…NASA, in its RFI, said that prospective partners would be responsible for the costs of any final testing and other work on the rover itself, as well as delivering it to the lunar surface and operating it once there. NASA, in its July 17 announcement that it would cancel VIPER, said the agency would save at least $84 million by halting work now on the rover, now complete and undergoing environmental testing.

Whether this company can raise the capital to finish this mission, now that NASA has said it cannot, remains unclear. That it is trying, and NASA is not, illustrates however why NASA should get out of the business of building anything and just buy it from the private sector. NASA’s attempt to build VIPER went 3Xs over budget and is considerably behind schedule. Now the private sector see profits in finishing the job, which will in turn save the agency considerable money. Imagine if NASA had done this from the beginning. The savings would have been even greater, and VIPER might right now be even closer to launch.

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Buried peaks in a sea of Martian sand

12:46 pm

Buried peaks in a sea of sand
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 13, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the MRO science team labels as “streamlined features”, though that doesn’t seem to me to be the best description.

Granted, the prevailing winds, from the northeast to the southwest, appear to pushing the sand dune fields to the southwest. The dark line — created recently by a dust devil — indicates the wind direction. The mesas, from 100 to 200 feet high, do not however appear very streamlined. Instead, they simply look like they are poking up through this sea of sand and dunes, with the wind able over time to successfully push that sand uphill a hundred-plus feet into the saddle between the mesas.

The overview map below provides some context and possibly an explanation, though not a very conclusive one.
» Read more

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More bad journalism, this time about a hypothesized “underground ocean” on Mars

10:14 am

How today's journalists analyze potential stories
How today’s journalists analyze potential stories

Today’s example of modern bad journalism from our dismal mainstream press concerns a paper published yesterday in the journal of the National Academy of Sciences describing the possibility of liquid water in the Martian “mid-crust,” based on InSight seismological data and computer modeling.

I read the paper yesterday and decided that there really wasn’t much there. While the data suggests a lot of liquid water might be saturated within the fractured rocks of this deep underground crustal layer six to twelve miles down, the paper was based on many assumptions and had many uncertainties. It is also not confirmed by other researchers, and remains nothing more than educated speculation at this point.

Not surprisingly, our ignorant mainstream press today has immediately declared the discovery of a vast underground ocean on Mars, ready for the taking and possibly harboring life!
» Read more

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The strange carbon dioxide ice cap of Mars’ south pole

12:33 pm

The strange carbon dioxide cap of Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on July 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The image is labeled simply as a “terrain sample,” which usually means it was taken not as part of any specific research project but to fill a gap in the picture-taking schedule in order to maintain the camera’s proper temperate. When the camera team needs to do this, they try to picture interesting features availabe at that time slot. Sometimes the image is boring. Sometimes it is surprisingly interesting.

In this case the picture is the latter, and certainly quite alien. The curly parallel dark lines appear to be grooves, and seem to have ripple dunes within them, as if the only dust here got trapped in those low spots. It is also possible that the dunes are frozen and ancient, and are only being revealed as the top layer in each groove goes away.

What could possibly explain what we are looking at? The overview map below gives only a clue.
» Read more

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A galaxy with a ring

9:34 am

A galaxy with a ring
Click for full image.

Cool image time! The photo to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope, and appears part of a long term survey of nearby ringed galaxies. From the caption:

MCG+07-07-072 has quite an unusual shape, for a spiral galaxy, with thin arms emerging from the ends of its barred core to draw a near-circle around its disc. It is classified, using a common extension of the basic Hubble scheme, as an SBc(r) galaxy: the c denotes that its two spiral arms are loosely wound, each only performing a half-turn around the galaxy, and the (r) is for the ring-like structure they create. Rings in galaxies come in quite a few forms, from merely uncommon, to rare and astrophysically important!

Lenticular galaxies are a type that sit between elliptical and spiral galaxies. They feature a large disc, unlike an elliptical galaxy, but lack any spiral arms. Lenticular means lens-shaped, and these galaxies often feature ring-like shapes in their discs. Meanwhile, the classification of “ring galaxy” is reserved for peculiar galaxies with a round ring of gas and star formation, much like spiral arms look, but completely disconnected from the galactic nucleus – or even without any visible nucleus! They’re thought to be formed in galactic collisions.

This galaxy is about 320 million light years away, and is also known as Abell 426. Though astronomers think that these various shapes of galaxies, from barred to lenticular to ringed, are formed from a variety of galactic collusions and interactions with each galaxy’s nucleus, that remains nothing more than an educated guess. The complexity of galaxy evolution, involving billions of years and millions of stars, is barely in its infancy, and requires a lot of assumptions because our observations only involves a mere nanosecond in that grand history.

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Are these Martian terraced mesas or pits?

2:52 pm

Are these Martian pits or mesas?
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on July 2, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have purposely enhanced the contrast to bring out the strangely shaped and terraced features.

What I cannot figure out from any data available to me is whether these terraced features are mesas rising up, or pits descending down. The resolution in the global mosiac of Mars created both from MRO’s context camera and its elevation data is simply not good enough. It suggests these are pits, but the sunlight is coming from the west, which based on the shadows suggest these could be pits or mesas.

In fact, the dark lines that appear to distinguish the terraces might not be shadows at all, but simply darker material that contrasts with the lighter material on each side.
» Read more

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Crazily eroded rock on Mars

11:15 am

Overview map
Click for interactive map.

A crazily eroded rock in Jezero crater
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken today by the Perseverance Mars rover, using its SHERLOC-WATSON close-up camera at the end of its robot arm.

The size of this rock is tiny, no more than a few inches across. The many holes remind me of surface limestone on Earth. When it rains, the water dissolves the limestone, and so holes will develop and grow over time. You can see this process if you spray very hot water on top of a block of ice.

The problem is that it doesn’t rain on Mars. Lava can sometimes freeze and look this way, but is it lava? The blue dot on the overview map above shows where Perseverance was two days earlier. The rover team has not updated that map so it is not known exactly where the rover was when it snapped this picture today. Nor has the science team posted an update on their activities since June 27th.

These strange features however mirror somewhat the same surface features seen back in June, when the rover was on the north side of Neretva Vallis, so it is likely this rock was produced by the same geological processes. I will however not guess what those processes were.

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WISE/NEOWISE space telescope mission ends after fourteen years

9:11 pm

Comet NEOWISE, photographed by the Hubble Space Telescope
Click for full image.

Launched in 2009, the Wide-field Infrared Survey Explorer (WISE) was shut down today after almost fourteen years of successful observations, with its first years dedicated to creating an infrared survey of the sky. In 2013, after two years of hibernation, it was reactivated and renamed NEOWISE (for reasons that I have always found absurd), with the goal over the next thirteen years of mapping the sky for near Earth objects.

By repeatedly observing the sky from low Earth orbit, NEOWISE created all-sky maps featuring 1.45 million infrared measurements of more than 44,000 solar system objects. Of the 3,000-plus near-Earth objects it detected, 215 were first spotted by NEOWISE. The mission also discovered 25 new comets, including the famed comet C/2020 F3 NEOWISE that streaked across the night sky in the summer of 2020.

A Hubble image of that comet is to the right.

The mission was ended because the telescope’s orbit is now too low to provide good data. It is expected to re-enter the atmosphere and burn up before the end of the year.

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