Tag: science

Ingenuity responds after 63 days of silence

12:02 pm

Overview map
Click for interactive map.

For the past two months the science and engineering teams for the Perseverance rover and the Ingenuity helicopter in Jezero Crater have been very silent as to the status of Ingenuity. On April 25, 2023 the Ingenuity team had posted their flight plan for the helicopter’s 52nd flight, with an expected flight date the next day.

Until today, however, no information about the results of that flight had been released. Except for one update in late May describing earlier issues with communications after flight 49, the science and engineering teams maintained radio silence about that 52nd flight in April.

Today’s update finally explained that silence:

The flight took place back on April 26, but mission controllers at NASA’s Jet Propulsion Laboratory in Southern California lost contact with the helicopter as it descended toward the surface for landing.

The Ingenuity team expected the communications dropout because a hill stood between the helicopter’s landing location and the Perseverance rover’s position, blocking communication between the two. The rover acts as a radio relay between the helicopter and mission controllers at JPL. In anticipation of this loss of communications, the Ingenuity team had already developed re-contact plans for when the rover would drive back within range. Contact was re-established June 28 when Perseverance crested the hill and could see Ingenuity again.

The flight plan for the 52nd flight in April had been to fly 1,191 feet to the west. Though the Ingenuity team has not yet released the actual flight details, I have indicated with the green line on the overview map above the estimated distance and direction planned. The green dot marks Ingenuity’s position before the flight, with the blue dot marking Perseverance’s present location. The red dotted line indicates the planned route for Perseverance.

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Galaxies at the dawn of time

10:40 am

Link here. The article takes a quick look at six galaxies found by Webb’s infrared view that all less than 650 million years after the Big Bang is thought to have occurred.

None disprove the Big Bang. All however raise serious questions about the cosmological theories that posit that event and the subsequent evolution of the universe. Take a look. It is worthwhile reading.

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Another layered mesa in the Cydonia region of Mars

12:16 pm

Another layered mesa in the Cydonia region of Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on March 22, 2023, and shows a 100-foot-high many-layered mesa in the Cydonia region of Mars.

The shadows in this picture are deceptive. The mesa’s high point is not the narrow ridge-line, but at the green dot just beyond that ridge’s northern terminus. In fact, if you were walking south from that dot and then along the crest of that ridge you would be walking downhill the entire length.

Cydonia is in the Martian northern lowland plains, in the mid-latitudes. Thus, there are many features in this picture suggesting near surface ice, such as the mounds with craters at their peak. All could be mud volcanoes as seen in many places in the northern lowland plains.
» Read more

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Curiosity tops a ridge to see its rough path forward

10:12 am

Curiosity's view ahead on June 29, 2023
Click for original image.

Overview map
Click for interactive map

After more than a month of struggle to get Curiosity to maneuver uphill through a very rocky and steep terrain, the science team today finally announced that the rover had topped the ridge and could once again see its way forward into Gediz Vallis, the slot canyon it plans to use as its route up Mount Sharp.

The panorama above, cropped, reduced, sharpened, and annotated to post here, was taken on June 29, 2023 following Curiosity’s last move forward. The yellow lines on the overview map to the right indicate the approximate area covered by this panorama. The red dotted line on both images indicates Curiosity’s planned route, with the white dotted line its actual course.

The white ridge to either side of the central peak dubbed Kukenan is actually the higher flanks of Mount Sharp. The peak of Kukenan is about a half mile away and about 400 feet higher, with those white flanks about 2.5 miles beyond. The actual peak of Mount Sharp is about 25 miles farther south and about 17,000 feet higher.

The panorama makes clear that the path forward is not going to be any less rough for Curiosity and its damaged wheels. Expect progress to be slow for many months to come.

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Webb takes infrared (heat) image of Saturn

8:41 am

Saturn in infrared
Click for original image.

Using the Webb Space Telescope, scientists on June 25, 2023 took the wonderful false color infrared (heat) image of Saturn above, cropped to post here, as part of a research project [pdf] to take a number of long exposures of the ringed planet in order to test Webb’s ability to see its small moons. From the press release:

Saturn itself appears extremely dark at this infrared wavelength observed by the telescope, as methane gas absorbs almost all of the sunlight falling on the atmosphere. However, the icy rings stay relatively bright, leading to the unusual appearance of Saturn in the Webb image.

…This new image of Saturn clearly shows details within the planet’s ring system, along with several of the planet’s moons – Dione, Enceladus, and Tethys. Additional deeper exposures (not shown here) will allow the team to probe some of the planet’s fainter rings, not visible in this image, including the thin G ring and the diffuse E ring. Saturn’s rings are made up of an array of rocky and icy fragments – the particles range in size from smaller than a grain of sand to a few as large as mountains on Earth.

The picture also shows differences between Saturn’s northern and southern hemispheres, caused by the seasonal differences between the two.

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A new theory for making liquid water once possible on Mars

1:14 pm

In order to explain the many gullies on Mars, scientists at Brown University have now proposed a new model that says liquid water could exist periodically on the surface of Mars, caused by the cyclical changes in the planet’s rotational tilt, ranging from 11 to 60 degrees.

From editor’s summary of the paper:

Some steep slopes on Mars have gullies with morphologies suggesting that they were formed by a fluid. However, the planet’s current climate is not conducive to the melting of water ice at those locations, and mechanisms involving carbon dioxide ice do not explain the distribution of the gullies. [This paper] simulated how the climate of Mars differed when its axis tilted by different amounts over the past few million years. At a tilt of 35 degrees, the ice caps partially melted, raising the atmospheric pressure, and there were higher summer temperatures. Under these conditions, the atmospheric pressure at the gullies would be above the triple point of water, so it could melt to form a liquid.

The paper estimates these conditions last existed on Mars about 630,000 years ago, though the process repeated itself many times over the past several million years, each time causing some water ice to melt and flow down to form gullies. As the planet’s inclination then changed, conditions changed as well, producing colder temperatures at these latitudes so the water froze once again.

Though this is only a model with many uncertainties, it suggests a more reasonable explanation for the past existence of liquid surface water on Mars, temporary, periodic, and rare, than most other models. Combined with the possibility that ice glaciers themselves could have contributed to the formation of many of Mars’ riverlike channels, it seems that scientists are beginning to form a rough concept explaining how Mars evolved to what it is today.

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The icy floor of one of Mars’ most ancient craters

12:44 pm

Overview map

The icy floor of one of Mars' most ancient craters
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 3, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It focuses on a small crater in the center of 265-mile-wide Greeley Crater, named in 2015 after the late Ron Greeley, who had been involved in almost every planetary mission from the 1960s until his passing in 2011.

Greeley Crater is intriguing because of its age, estimated to be about four billion years old, as indicated by crater counts and the crater’s heavily eroded condition.

This ancient crater, which has already been heavily eroded and filled with sediment, is difficult to make out against the Martian landscape due to its relatively shallow depth of only 1.5 kilometres – indeed, the crater rim has disappeared altogether in places.

Greeley is also intriguing by its location in the southern mid-latitudes. On the overview map above the red dot inside Greeley marks the location of today’s picture. This is a region with lots of evidence of ice and glacial features inside craters. The picture shows a small two-mile-wide crater about 500 feet deep inside Greeley. Both inside and outside the crater the surface suggests ice, either in glacial formations on the crater floor or as a soft flat plain that allows impacts to sink in without producing a rim or much ejecta.

While research has suggested a large number of glaciers in the outlined region on the western edge of the overview map, the evidence continues to build that near-surface ice exists everywhere throughout the mid-latitudes of Mars.

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Using pulsars scientists detect background signal of the universe’s gravitational waves

10:07 am

The uncertainty of science: Using the variations in the precise radio pulses sent out by many pulsars over a fifteen year year astronomers think they have detected the background signal produced by many gravitational waves over time throughout the universe.

Astrophysicists using large radio telescopes to observe a collection of cosmic clocks in our Galaxy have found evidence for gravitational waves that oscillate with periods of years to decades, according to a set of papers published today in The Astrophysical Journal Letters. The gravitational-wave signal was observed in 15 years of data acquired by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) Physics Frontiers Center (PFC), a collaboration of more than 190 scientists from the US and Canada who use pulsars to search for gravitational waves. International collaborations using telescopes in Europe, India, Australia and China have independently reported similar results.

Imagine that each wave is a single wave on the ocean. This detection is the rough equivalent of looking at the ocean’s overall surface and measuring the general roughness of all the waves.

The press is making a big deal about this discovery. It is good science, and will over time provide valuable insights into evolution and merger of black holes, but it is not that big a deal, especially because this research carries with it many assumptions and uncertainties that good scientists recognize. They thus remain somewhat skeptical about the data. Mainstream journalists however consider gravitational waves cool, and so they hype any press release about them, sometimes to the point of absurdity.

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Perseverance spots a doughnut-shaped rock

1:03 pm

Doughnut-shaped rock in Jezero Crater
Click for original image.

The Mars rover has spent the last few months exploring just beyond the western rim of half-mile-wide Belva crater, which sits on top of the delta that eons ago flowed into 30-mile-wide Jezero Crater. During that time the science team has been using its various cameras to study the surrounding terrain.

One of those cameras is the SuperCam Remote Micro Imager. This camera is a variation of Curiosity’s ChemCam, designed initially to look very closely at nearby objects. The Curiosity team however discovered they could also use ChemCam to look at distant objects, and in this case the Perseverance team was doing the same with SuperCam, gazing outward at more remote features.

The result was the picture to the right, cropped, reduced, brightened, and sharpened to post here. It was taken on June 23, 2023, and shows what appears to be a several-foot-wide rock with a hole in its center. According to the SETI Institute’s tweet that publicized the picture, the rock might be “a large meteorite alongside smaller pieces.”

If this was Curiosity I would be certain the science team would take the rover close to the rock. The Perseverance team however seems to have different goals, mostly centered on finding drill spots for obtaining its core samples for later return to Earth. It has not therefore been as exploratory as Curiosity. It seems to have rarely diverged from its planned route, and when it has it has not done so to look at singular features like this. We shall see what they finally decide.

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Another tourist site for future Starship passengers on Mars

12:16 pm

Another tourist site for future Starship passengers 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 April 11, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the northwest quadrant of a 7-mile-wide crater whose western rim was smashed by the later impact that created a smaller 2.8-mile-wide crater.

What makes this location interesting is what fills both craters, and how that material appears to flow through a gap in the smaller crater. The color strip suggests the peaks of the rim and small knobs are dust-covered, while the flat materials below are either “coarser-grained materials” that might also have elements of frost or ice within them. The science team thinks ice is involved, having labeled this picture “Ice Flow Features between Craters.”
» Read more

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Host galaxies for two quasars in early universe detected for the first time

10:06 am

Quasar and host galaxy
One of the quasars, with its light subtracted on the right,
revealing the host galaxy. Click for original image.

The uncertainty of science: Using data from both the infrared Webb Space Telescope and the Subaru optical telescope in Hawaii, astronomers have observed for the first time the host galaxies of two quasars that formed less than a billion years after the Big Bang.

Just a few months after JWST started regular operations, the team observed two quasars, HSC J2236+0032 and HSC J2255+0251, at redshifts 6.40 and 6.34 when the universe was approximately 860 million years old, both of which were discovered using Subaru Telescope’s deep survey program. The relatively low luminosities of these quasars made them prime targets for measuring the properties of their host galaxies.

The images of the two quasars were taken at infrared wavelengths of 3.56 and 1.50 microns with JWST’s NIRCam instrument, and the host galaxies became apparent after carefully modeling and subtracting glare from the accreting black holes. The stellar signature of the host galaxy was also seen in a spectrum taken by JWST’s NIRSPEC for J2236+0032, further supporting the detection of the host galaxy.

Photometric analyses found that these two quasar host galaxies are massive, measuring 130 and 34 billion times the mass of the Sun, respectively. Measuring the speed of the turbulent gas in the vicinity of the quasars from the NIRSPEC spectra suggests the black holes that power them are also massive, measuring 1.4 and 0.2 billion times the mass of the Sun. The ratio of the black hole to host galaxy mass is similar to those of galaxies in the more recent past, suggesting that the relationship between black holes and their hosts was already in place 860 million years after the Big Bang. [emphasis mine]

Normally, quasars are so bright the host galaxy is obscured. Computer modeling that subtracted the quasar’s light produced the host galaxy image on the right.

The highlighted sentence raises intriguing questions again about the Big Bang. Webb is once again finding evidence that the early universe quickly became like today’s universe, much faster than expected by cosmologists.

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Spring near the Martian north pole

12:28 pm

Spring near the Martian north pole
Click for original image.

Overview map

Cool image time! The picture above, rotated, reduced, and brightened slightly to post here, was taken on April 13, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It cuts a swath across an eleven-mile-wide crater only about 500 miles from the edge of Mars’ north pole ice cap.

The overview map to the right marks its location, as indicated by the white dot on the right edge of the map. The inset shows the soft and likely icy nature of the surface in which this impact occurred. The crater resulted in a secondary outside ripple, that quickly hardened after impact.

The image was taken during spring, shortly after the sun’s light hit this crater. The cracks in the ice indicate long term sublimation that is slowly reducing the amount of water ice inside the crater. Like mud cracks in the desert after a puddle has evaporated, the ice here is cracking to produce polygon fractures.

It is also very likely that everything here is coated with a thin mantle of clear dry ice, deposited as snow from the atmosphere in the winter and then sublimating away with the coming of spring. That spring dry ice sublimation is likely ongoing, and this picture is probably an attempt by scientists to detect that process.

Why the surface colors shift from aquablue to orange might have to do with that sublimation process, or it might be revealing areas covered with dust (orange). That the northern parts of the strip is blue and the southern parts orange suggests the former. Or not. I don’t have enough information to answer this question with any confidence.

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