Tag: science

Despite good first images from Euclid, the orbiting telescope has a problem

10:05 am

Even though the first light images from Euclid have been sharp and exactly what astronomers want, the orbiting telescope designed to make a 3D map of billions of galaxies has an issue that will likely put some limits to that map.

When the telescope started booting up, ESA observers were concerned by the appearance of light markings on the first images relayed to Earth. This, it confirmed, was due to sunlight filtering into the telescope, “probably through a tiny gap”.

A correction to Euclid’s position was able to offset this issue. It means that while the ESA is confident Euclid will be fine to proceed with its mapping mission, particular orientations for the telescope may not be possible.

A limitation like this means that the telescope will not being able to look in some directions and get mapping images. Thus, the overall map will have gaps, though it appears at this moment that the scientists think those gaps will not seriously impact the telescope’s overall work. We shall see.

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The dry and mountainous terrain west of Jezero Crater

12:00 pm

The dry and mountainous terrain west of Jezero Crater
Click for original image.

Since my earlier update today about Perseverance and Ingenuity mentioned the very diverse and strange geology known to exist west of Jezero Crater and where the rover is eventually headed, I thought it worthwhile to post another cool image of that terrain.

The picture to the right, rotated, cropped, reduced and sharpened to post here, was taken on May 22, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled a “terrain sample” image, the location was likely chosen by the camera team in order to fill a gap in the camera’s schedule so that they can maintain its proper temperature. Having a gap that put the spacecraft over this region to the west of Jezero was however a great opportunity to get another look at this rocky, mountainous, and very parched terrain, located in Mars’ very dry equatorial regions.
» Read more

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Perseverance snaps new close-up of Ingenuity

10:28 am

Overview map
Click for interactive map.

Ingenuity as seen by Perseverance on August 2, 2023
Ingenuity as seen by Perseverance on August 2, 2023.
Click for original image.

Cool image time! With Perseverance and Ingenuity in the past week getting close together for the first time in months, the Perseverance team naturally turned its high resolution mast cameras at the helicopter. The picture to the right, cropped, reduced, and sharpened to post here, was taken on August 2, 2023 by the rover’s left mast camera, showing Ingenuity only about two hundred feet away.

The blue dot on the overview map above shows Perseverance’s present location, with the green dot marking Ingenuity’s. The picture to the right is therefore looking almost due south. The red dotted line indicates the rover’s planned route, moving towards Neretva Vallis, the gap in the rim of Jezero Crater from which the delta had flowed, eons ago. The rover’s goal is to eventually enter that gap and explore the very diverse and strange geology known to exist outside the crater to the west.

We should also expect even better images of Ingenuity in the next week. Its 54th flight is scheduled for today, in which the engineering team wants to send the helicopter on a simple straight up and down hop of sixteen feet in order to better “localize” the helicopter. With Perseverance less than two hundred feet away, its cameras should be able to assemble a great movie of that flight.

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New software detects its first potentially dangerous asteroid

9:32 am

New software designed to detect asteroids, developed for use with the Rubin Observatory presently being built in Chile, has successfully discovered its first potentially hazardous asteroid (PHA) using data from another smaller operational ground-based telescope.

The discovered asteroid is 600 feet long, large enough to pose a real threat should it ever hit the Earth. Fortunately, the data says that though its orbit can take it as close as 140,000 miles there is no impact likely in the foreseeable future.

When the Rubin telescope begins its planned ten year survey of the entire night sky in 2025, this software is expected to almost triple the number of known potentially-hazardous-asteroids, from 2,350 to almost 6,000.

Funded primarily by the U.S. National Science Foundation and the U.S. Department of Energy, Rubin’s observations will dramatically increase the discovery rate of PHAs. Rubin will scan the sky unprecedentedly quickly with its 8.4-meter mirror and massive 3,200-megapixel camera, visiting spots on the sky twice per night rather than the four times needed by present telescopes. But with this novel observing “cadence,” researchers need a new type of discovery algorithm to reliably spot space rocks.

Thus, the development of this new software.

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The first glacial evidence found on Mars back in 2007

11:36 am

Glaciers on Mars?
Click for original image.

Cool image time! The picture to the right, cropped, reduced, sharpened, and annotated to post here, was taken on January 3, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the eastern wall of what the scientists call a graben, a large depression caused when the ground inside the depression suddenly shifted downward.

The elevation difference between the high and low points is about 3,500 feet. The streaks on the lower half of the cliff wall are slope streaks, a phenomenon unique to Mars that remains at this moment unexplained. Though the streaks resemble avalanches, they do not change the topography in any way, have no debris pile at their base, and appear instead to be a stain that appears at random times of the year that fades with time.

What is intriguing about this picture however is the wavelike floor on its western half. At first glance these waves suggest some form of dust dunes or lava flows, but neither conclusion appears correct. Instead, we are looking at what was one of the first discoveries on Mars of what scientists have determined to be glacial features.
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Bones of the biggest ever whale species possibly found?

8:49 am

A big whale?

The uncertainty of science: Paleontologists have discovered a portion of the skeleton of what they claim might be the biggest and heaviest animal ever found, a whale that potentially grew to be as much as twice as big as a blue whale, the largest living species previously known.

A newly described fossilized whale named Perucetus colossus, dating to roughly 38 million years ago, might have been heavier than a blue whale, even if it was not as long. Blue whales, which are endangered, weigh about 100 to 150 tonnes, although some might be as heavy as 200 tonnes. Perucetus colossus was between 85 and 340 tonnes, according to the scientists who found and described the remains: 13 vertebrae, 4 ribs and a bit of pelvis. Their best-guess estimate is that the whale was around 180 tonnes. This mind-boggling mass is the result of its bones, which were big and dense — an evolutionary adaptation that helped it to dive.

The graphic to the right shows the discovered bones in red, with the rest of the theorized skeleton indicated in grey. Only in the article’s next-to-last paragraph does Nature recognize this very very very large uncertainty:

The team chose to create a visual reconstruction of what the whale might have looked like, basing the head on skulls of related basilosaurid species, but they caution that some of the details are speculative. It could have been skinnier. But it also could have been quite a bit longer or fatter, [co-author Eli] Amson says.

In other words, they presently have no idea what the species actually looked like, or how big it actually was. It very well could have been much shorter and thinner than proposed. It appears therefore they chose to highlight the largest possible size to garner the biggest press coverage — which of course they are getting.

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NASA detects weak signal from Voyager 2

8:22 am

Though communications with Voyager 2 have not been re-established, JPL engineers using NASA’s Deep Space Network of antennas have detected a weak signal from Voyager 2 that indicates the spacecraft is still functioning.

Using multiple antennas, NASA’s Deep Space Network (DSN) was able to detect a carrier signal from Voyager 2. A carrier signal is what the spacecraft uses to send data back to Earth. The signal is too faint for data to be extracted, but the detection confirms that the spacecraft is still operating. The spacecraft also continues on its expected trajectory. Although the mission expects the spacecraft to point its antenna at Earth in mid-October, the team will attempt to command Voyager sooner, while its antenna is still pointed away from Earth. To do this, a DSN antenna will be used to “shout” the command to Voyager to turn its antenna. This intermediary attempt may not work, in which case the team will wait for the spacecraft to automatically reset its orientation in October.

The hope is that new commands to re-orient, sent by the strongest signal possible, might be heard by the spacecraft, causing it to obey now. If not, this weak signal from Voyager 2 still suggests that the October reset will occur as normal and engineers will be able to recover communications then.

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Sunspot update: In July the Sun continued its high sunspot activity

5:05 pm

Today NOAA released its monthly update of its graph that tracks the number of sunspots on the Sun’s Earth-facing hemisphere. As I have done every month for the entire thirteen years I have been doing this website, I have posted that updated graph below, adding to it some extra details to provide some context.

Though the sunspot count in July was slightly less than the very high numbers in June (the highest seen in more than two decades), the decline was almost inconsequential. Except for June’s activity, the activity in July was still 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 the last two months, the Sun had 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.
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The wind-scoured dusty and cratered dry tropics of Mars

1:16 pm

The wind-scoured dusty and cratered dry tropics of Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on June 2, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows one small area in Martian equatorial regions where the main features are a dusty plain interspersed with craters, not entirely dissimilar to the Moon .

In the picture the northwest-to-southeast orientation of ridge-lines, plus the position of divots with their steep and deep end all on the northwest side, all suggest the prevailing winds here blow in the same direction, from the northwest to the southeast.

We are looking at a very ancient terrain. Many of these craters likely date from the early bombardment period of the solar system, just after the planets had formed but there was still a lot of objects around crashing into them.
» Read more

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Eruption on comet results in its tail splitting as it brightens by 100x

9:28 am

On July 20, 2023 the Comet 12P/Pons-Brooks suddenly erupted for the first time in almost seven decades, making it a hundred times brighter than normal while splitting its tail in two.

As of July 26, the comet’s coma had grown to around 143,000 miles (230,000 kilometers) across, or more than 7,000 times wider than its nucleus, which has an estimated diameter of around 18.6 miles (30 km), Richard Miles, an astronomer with the British Astronomical Association who studies cryovolcanic comets, told Live Science in an email.

But interestingly, an irregularity in the shape of the expanded coma makes the comet look as though it has sprouted horns. Other experts have also likened the deformed comet to the Millennium Falcon, one of the iconic spaceships from Star Wars, Spaceweather.com reported.

It is believed the tail’s shape is the result of the shape of the comet’s nucleus, which probably had a solid ridge acting as a barrier to material at that point.

The comet, which orbits the Sun every 71 years, will make its closest approach to Earth in the spring of 2024, when it will likely be visible to the naked eye.

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Monitoring the gullies on Mars for changes

12:54 pm

Monitoring the gullies on Mars
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken on March 24, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) as part of a long term monitoring program of the many Martian gullies scientists have found above 30 degrees north latitude on a variety of slopes.

Martian gullies are small, incised networks of narrow channels and their associated downslope sediment deposits, found on the planet of Mars. They are named for their resemblance to terrestrial gullies. First discovered on images from Mars Global Surveyor, they occur on steep slopes, especially on the walls of craters. Usually, each gully has a dendritic alcove at its head, a fan-shaped apron at its base, and a single thread of incised channel linking the two, giving the whole gully an hourglass shape. They are estimated to be relatively young because they have few, if any craters.

…Most gullies occur 30 degrees poleward in each hemisphere, with greater numbers in the southern hemisphere. Some studies have found that gullies occur on slopes that face all directions; others have found that the greater number of gullies are found on poleward facing slopes, especially from 30° to 44° S. Although thousands have been found, they appear to be restricted to only certain areas of the planet. In the northern hemisphere, they have been found in Arcadia Planitia, Tempe Terra, Acidalia Planitia, and Utopia Planitia. In the south, high concentrations are found on the northern edge of Argyre basin, in northern Noachis Terra, and along the walls of the Hellas outflow channels.

Orbital data has identified almost 5,000 gullies on Mars. Based on their shape and the Martian climate, scientists generally think these gullies were formed by some form of water flow, possibly coming from an underground aquifer at their top.
» Read more

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Scientists increasingly put politics over uncertainty in their research papers

10:35 am

The modern scientific method
The modern scientific method

The death of uncertainty in science: According to a paper published this week in the peer-review journal Science, scientists in recent years are increasingly abandoning uncertainty in their research papers and are instead more willing to make claims of absolute certainty without hesitation or even proof.

If this trend holds across the scientific literature, it suggests a worrisome rise of unreliable, exaggerated claims, some observers say. Hedging and avoiding overconfidence “are vital to communicating what one’s data can actually say and what it merely implies,” says Melissa Wheeler, a social psychologist at the Swinburne University of Technology who was not involved in the study. “If academic writing becomes more about the rhetoric … it will become more difficult for readers to decipher what is groundbreaking and truly novel.”

The new analysis, one of the largest of its kind, examined more than 2600 research articles published from 1997 to 2021 in Science, which the team chose because it publishes articles from multiple disciplines. (Science’s news team is independent from the editorial side.) The team searched the papers for about 50 terms such as “could,” “appear to,” “approximately,” and “seem.” The frequency of these hedging words dropped from 115.8 instances per 10,000 words in 1997 to 67.42 per 10,000 words in 2021.

Those numbers represent a 40% decline, a trend that has been clear for decades, first becoming obvious in the climate field. » Read more

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