adplus-dvertising
Connect with us

Science

On Mars, massive ice sheets — not rivers — may have carved ancient valleys – Space.com

Published

 on


Early Mars may not have been quite the warm, wet paradise scientists have hoped for — not if the valleys scarring its surface work the same way as their counterparts here on Earth do.

That’s the conclusion of new research that tried to suss out what the Red Planet really looked like during its first billion years by analyzing more than 10,000 segments of valleys on Mars. In particular, the scientists were inspired by the look of Devon Island in the Canadian Arctic, which is dry and frigid. According to the new analysis, some Martian valleys may have been formed by a similar process to those lurking below Devon Island’s ice.

“If you look at Earth from a satellite, you see a lot of valleys: some of them made by rivers, some made by glaciers, some made by other processes, and each type has a distinctive shape,” Anna Grau Galofre, lead author of the new research and a geophysicist at Arizona State University, said in a statement released by the University of British Columbia, where she did the research. “Mars is similar, in that valleys look very different from each other, suggesting that many processes were at play to carve them.”

300x250x1

Related: The search for water on Mars in photos

And one of those processes, the researchers say, could be meltwater flowing between an ice sheet and the ground below it. That sort of erosion produces a different valley pattern than one generated by a free-flowing river, according to the scientists, and many of the Martian valleys they studied seem to be a better match for that ice sheet formation model.

Grau Galofre and her colleagues started with detailed maps produced by the Mars Orbiter Laser Altimeter, which flew on NASA’s Mars Global Surveyor spacecraft and studied the Red Planet between 1997 and 2001. The scientists developed a program that incorporated six different characteristics about each of more than 10,000 valley segments, then compared each cluster with attributes based on four different formation scenarios.

According to that analysis, 22 of the 66 networks evaluated best match the patterns formed by meltwater running under a glacier, the researchers concluded. Another nine best match patterns formed by glaciers themselves, whereas 14 best match patterns formed by rivers. Most of the rest weren’t distinct enough matches for a specific formation scenario.

The researchers also found that the valleys that looked like they were formed by meltwater running beneath glaciers were spread across Mars, while those that looked to have been formed by rivers were concentrated around Arabia Terra, a particularly old region of Mars, according to NASA.

Rivers and the melted water slipping below a glacier imply one key difference about their surroundings: temperature. The scientists argue that their new research matches well with recent theories that Mars may have been cooler in its distant past than other hypotheses have suggested.

“For the last 40 years, since Mars’s valleys were first discovered, the assumption was that rivers once flowed on Mars, eroding and originating all of these valleys,” Grau Galofre said. “We tried to put everything together and bring up a hypothesis that hadn’t really been considered.”

The research is described in an article published on Monday (Aug. 3) in the journal Nature Geoscience.

Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

Let’s block ads! (Why?)

728x90x4

Source link

Continue Reading

Science

Solar eclipse April 8 – South Grey News

Published

 on


March 28, 2024

Graphic: Appalachian Mtn Club

300x250x1

Grey Bruce Public Health is urging residents to resist the temptation to look directly at the sun during the upcoming solar eclipse and take steps to safeguard their visual health during this relatively rare celestial event.

On April 8, 2024, parts of southern and eastern Ontario will experience a total solar eclipse for the first time since 1925. Grey-Bruce will be outside of the so-called Path of Totality — a narrow area where the moon will completely block out the sun — but will still experience a partial eclipse.

The eclipse is expected to begin at about 2 pm and continue until 4:30 pm The eclipse will peak around 3:20 pm.

It is never safe to stare directly at the sun, but it may be tempting to do so during a solar eclipse.

Looking directly at the sun during an eclipse can cause retinal burns, blurred vision, and/or temporary or permanent loss of visual function, according to the Ontario Association of Optometrists. Damage to the eyes can occur without any sensation of pain.

Grey Bruce Public Health advises the following:

  • Do not look directly at the sun without proper eye protection during the solar eclipse. Looking at even a small sliver of the sun before or after the eclipse without proper eye protection can harm vision.
  • Keep a close eye on children and other vulnerable family members during the eclipse to ensure they do not inadvertently look up at the sun without proper eye protection.
  • To safely view the eclipse, ISO-certified eclipse glasses that meet the ISO 12312-2 international safety standard must be worn. Ensure these glasses are in good condition, without any wrinkles or scratches, and that they fully cover the entire field of vision. Put on the glasses when looking away from the sun, then look at the eclipse. Look away from the sun before taking the glasses off.
  • Regular sunglasses or homemade filters will not protect the eyes.
  • It is not safe to view the eclipse through a camera/phone lens, telescope, binoculars, or any other optical device.

Other ways to safely experience the solar eclipse include watching a livestream of the event or creating and using an eclipse box or pinhole projector.

Anyone experiencing temporary vision loss or blurred vision during or after the eclipse should speak with their eye care professional or healthcare provider as soon as possible.

Anyone experiencing blindness (immediate or delayed) after viewing the eclipse must seek emergency care immediately.

More information on the upcoming eclipse is available on the GBPH website.


At South Grey News, we endeavour to bring you truthful and factual, up-to-date local community news in a quick and easy-to-digest format that’s free of political bias. We believe this service is more important today than ever before, as social media has given rise to misinformation, largely unchecked by big corporations who put profits ahead of their responsibilities.

South Grey News does not have the resources of a big corporation. We are a small, locally owned-and-operated organization. Research, analysis and physical attendance at public meetings and community events requires considerable effort. But contributions from readers and advertisers, however big or small, go a long way to helping us deliver positive, open and honest journalism for this community.

Please consider supporting South Grey News with a donation in lieu of a subscription fee and let us know that our efforts are appreciated. Thank you.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

NASA to launch sounding rockets into moon's shadow during solar eclipse – Phys.org

Published

 on


This photo shows the three APEP sounding rockets and the support team after successful assembly. The team lead, Aroh Barjatya, is at the top center, standing next to the guardrails on the second floor. Credit: NASA/Berit Bland

NASA will launch three sounding rockets during the total solar eclipse on April 8, 2024, to study how Earth’s upper atmosphere is affected when sunlight momentarily dims over a portion of the planet.

The Atmospheric Perturbations around Eclipse Path (APEP) sounding rockets will launch from NASA’s Wallops Flight Facility in Virginia to study the disturbances in the created when the moon eclipses the sun. The sounding rockets had been previously launched and successfully recovered from White Sands Test Facility in New Mexico, during the October 2023 .

300x250x1

They have been refurbished with new instrumentation and will be relaunched in April 2024. The mission is led by Aroh Barjatya, a professor of engineering physics at Embry-Riddle Aeronautical University in Florida, where he directs the Space and Atmospheric Instrumentation Lab.

The sounding rockets will launch at three different times: 45 minutes before, during, and 45 minutes after the peak local eclipse. These intervals are important to collect data on how the sun’s sudden disappearance affects the ionosphere, creating disturbances that have the potential to interfere with our communications.

The ionosphere is a region of Earth’s atmosphere that is between 55 to 310 miles (90 to 500 kilometers) above the ground. “It’s an electrified region that reflects and refracts and also impacts as the signals pass through,” said Barjatya. “Understanding the ionosphere and developing models to help us predict disturbances is crucial to making sure our increasingly communication-dependent world operates smoothly.”

A sounding rocket is able to carry science instruments between 30 and 300 miles above Earth’s surface. These altitudes are typically too high for science balloons and too low for satellites to access safely, making sounding rockets the only platforms that can carry out direct measurements in these regions. Credit: NASA’s Goddard Space Flight Center

The ionosphere forms the boundary between Earth’s lower atmosphere—where we live and breathe—and the vacuum of space. It is made up of a sea of particles that become ionized, or electrically charged, from the sun’s energy or .

When night falls, the ionosphere thins out as previously ionized particles relax and recombine back into neutral particles. However, Earth’s terrestrial weather and space weather can impact these particles, making it a dynamic region and difficult to know what the ionosphere will be like at a given time.

It’s often difficult to study short-term changes in the ionosphere during an eclipse with satellites because they may not be at the right place or time to cross the eclipse path. Since the exact date and times of the are known, NASA can launch targeted sounding rockets to study the effects of the eclipse at the right time and at all altitudes of the ionosphere.

As the eclipse shadow races through the atmosphere, it creates a rapid, localized sunset that triggers large-scale atmospheric waves and small-scale disturbances or perturbations. These perturbations affect different radio communication frequencies. Gathering the data on these perturbations will help scientists validate and improve current models that help predict potential disturbances to our communications, especially high-frequency communication.

This conceptual animation is an example of what observers might expect to see during a total solar eclipse, like the one happening over the United States on April 8, 2024. Credit: NASA’s Scientific Visualization Studio

The APEP rockets are expected to reach a maximum altitude of 260 miles (420 kilometers). Each rocket will measure charged and neutral particle density and surrounding electric and magnetic fields. “Each rocket will eject four secondary instruments the size of a two-liter soda bottle that also measure the same data points, so it’s similar to results from fifteen rockets while only launching three,” explained Barjatya. Embry-Riddle built three secondary instruments on each rocket, and the fourth one was built at Dartmouth College in New Hampshire.

In addition to the rockets, several teams across the U.S. will also be taking measurements of the ionosphere by various means. A team of students from Embry-Riddle will deploy a series of high-altitude balloons. Co-investigators from the Massachusetts Institute of Technology’s Haystack Observatory in Massachusetts and the Air Force Research Laboratory in New Mexico will operate a variety of ground-based radars taking measurements.

Using this data, a team of scientists from Embry-Riddle and Johns Hopkins University Applied Physics Laboratory are refining existing models. Together, these various investigations will help provide the puzzle pieces needed to see the bigger picture of ionospheric dynamics.

The animation depicts the waves created by ionized particles during the 2017 total solar eclipse. Credit: MIT Haystack Observatory/Shun-rong Zhang. Zhang, S.-R., Erickson, P. J., Goncharenko, L. P., Coster, A. J., Rideout, W. & Vierinen, J. (2017). Ionospheric Bow Waves and Perturbations Induced by the 21 August 2017 Solar Eclipse. Geophysical Research Letters, 44(24), 12,067-12,073. https://doi.org/10.1002/2017GL076054

When the APEP- launched during the 2023 annular solar eclipse, scientists saw a sharp reduction in the density of charged particles as the annular eclipse shadow passed over the atmosphere.

“We saw the perturbations capable of affecting radio communications in the second and third rockets, but not during the first rocket that was before peak local eclipse,” said Barjatya. “We are super excited to relaunch them during the total eclipse to see if the perturbations start at the same altitude and if their magnitude and scale remain the same.”

The next total solar eclipse over the contiguous U.S. is not until 2044, so these experiments are a rare opportunity for scientists to collect crucial data.

Provided by
NASA

Citation:
NASA to launch sounding rockets into moon’s shadow during solar eclipse (2024, March 27)
retrieved 28 March 2024
from https://phys.org/news/2024-03-nasa-rockets-moon-shadow-solar.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Royal Sask. Museum research finds insect changes may have set stage for dinosaurs' extinction – CTV News Regina

Published

 on


Research by the Royal Saskatchewan Museum (RSM) shows that ecological changes were occurring in insects at least a million years before dinosaur extinction.

Papers published in the scientific journal, Current Biology, describe the first insect fossils found in amber from Saskatchewan and the unearthing of three new ant species from an amber deposit in North Carolina, according to a release from the province.

The amber deposit from in the Big Muddy Badlands of Saskatchewan, which was formed about 67 million years ago, preserved insects that lived in a swampy redwood forest about one million years before the extinction of dinosaurs.

300x250x1

“Fossils in the amber deposit seem to show that common Cretaceous insects may have been replaced on the landscape by their more modern relatives, particularly in groups such as ants, before the extinction event,” Elyssa Loewen, curatorial assistant, said.

The research team was led by Loewen and Dr. Ryan McKellar, the RSM’s curator of paleontology.

“These new fossil records are closer than anyone has gotten to sampling a diverse set of insects near the extinction event, and they help researchers fill in a 17-million-year gap in the fossil record of insects around that time,” Dr. McKellar said.

The three ant species discovered in North Carolina also belonged to extinct groups that didn’t survive past the Cretaceous period.

“When combined with the work in Saskatchewan, the two recent papers show that there was a dramatic change in ant diversity sometime between 77 and 67 million years ago,” Dr. McKellar said in the release.

“Our analyses of body shapes in the fossils suggests that the turnover was not related to major differences in ecology, but it may have been related to something like the size and complexity of ant colonies. More work is needed to confirm this.”

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Trending