Tag: science

More evidence found suggesting supernovae occurred near the solar system during its formation

9:22 am

Scientists have now detected more evidence that suggests a supernovae occurred very close to our solar system during its early period of formation.

Astronomers have for decades found such evidence inside meteorites. Small spherical inclusions called chondrules are thought by some to have formed when the heat of a nearby supernova caused melting. The new study finds more evidence in isotopes also found in primitive meteorites dubbed short-lived radionuclides (SLRs).

While SLRs probably existed in the part of the filament where the Sun and Solar System formed, the meteorite samples contained too much of a particular aluminum isotope for the interstellar medium to have been the Solar System’s only SLR source. Cosmic rays, which can convert stable isotopes to radioactive ones, had a better chance of explaining the number of isotopes found in the meteorites. However, it would have taken too long for this process to produce the levels of SLRs found in the early Solar System.

It is most likely that such high SLR levels could have come from either very intense stellar winds, which would have occurred during massive star formation, or from what was left after one of the massive stars went supernova.

You can read the published paper here.

If true, this data adds weight to the possibility that our solar system is somewhat unique, which in turn suggests finding just another like it — with life — might be difficult.

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Parker completes 16th orbit of the Sun

8:53 am

On June 22, 2023 the Parker Solar Probe completed its 16th close approach to the Sun, passing within 5.3 million miles of the solar surface while moving at 364,610 miles per hour.

The mission team at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, noted the close approach was preceded by a small trajectory correction maneuver (TCM) on June 7 —​ the first course correction since March 2022. Mission Design and Navigation Manager​ Yanping Guo of APL said TCMs are performed periodically to ensure that the​ spacecraft remains on course, and the latest maneuver kept Parker on track to hit the “aim point” for the mission’s sixth Venus flyby on Aug. 21. ​

With each perihelion now, Parker sets new records of speed. No human spacecraft has ever flown so fast.

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Sunspot update: June saw the most sunspots in more than two decades

8:47 pm

Time for our monthly sunspot update, based on NOAA’s monthly graph that tracks the number of sunspots on the Sun’s Earth-facing hemisphere. I have posted that graph below, but have added some extra details to provide some context.

June saw the highest sunspot count in a month since September 2002, when the Sun was just beginning its ramp down after its solar maximum that reached its peak in late 2001. From that time until now, the Sun has been in a very prolonged quiet period, with two solar minimums that were overly long and a single solar maximum that was very weak with a extended double peak lasting almost four years.
» Read more

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A Martian volcanic ash field covering an ancient lava flow

12:38 pm

A Martian volcanic ash field covering an ancient lava flow
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 16, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows in the center an ancient tongue of lava flow that is surrounded by thick dust fields on the north and the south.

The arrow indicates the downhill grade. It also shows the direction of the prevailing winds, downhill to sculpt the volcanic ash into long streamers of parallel grooves, with obvious eddies forming around bits of older lava that still stick up through the ash. On the lava flow can also be seen one small volcano cone, on the picture’s right edge, suggesting that either during this flow or after it hardened magma bubbled up from below.

The location is fascinating, and in fact puts this picture into its much more spectacular context.
» Read more

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A spiral galaxy as seen by Hubble

9:40 am

A spiral galaxy as seen by Hubble
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken as part of a research project to use the Hubble Space Telescope to photograph galaxies where supernovae had recently occurred. From the caption:

UGC 11860 lies around 184 million light-years away in the constellation Pegasus, and its untroubled appearance can be deceiving; this galaxy recently played host to an almost unimaginably energetic stellar explosion.

A supernova explosion — the catastrophically violent end of a massive star’s life — was detected in UGC 11860 in 2014 by a robotic telescope dedicated to scouring the skies for transient astronomical phenomena; astronomical objects which are only visible for a short period of time. Two different teams of astronomers used Hubble’s Wide Field Camera 3 to search through the aftermath and unpick the lingering remnants of this vast cosmic explosion.

This Hubble image once again illustrates the vastness of the universe. Note that every single dot surrounding UGC 11860 in this picture is another far more distant galaxy. As much as UGC 11860 is in our local intergalactic neighborhood, it is still so distant that this field of view is small enough that it contains no stars.

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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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