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How do galaxies get their shape? The science of key Webb Telescope targets, explained – Inverse

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Galaxies are collections of stars, gas, dust, and dark matter throughout the universe. Their size and scale can vary considerably. The Milky Way in which we live has 200 billion stars, which puts it about midway on the scale between the very largest galaxies and smaller types, like dwarf galaxies.

Like humans, these galaxies are shaped by their environment, which explains the different shapes we see, Karen Masters says. She is a Haverford College astrophysicist and the project scientist at Galaxy Zoo, a citizen science project that classifies different galaxy types.

“There’s a lot of variety out there in the universe,” Masters tells Inverse. Spiral galaxies have a circular shape like a Blu-Ray, while elliptical galaxies look something like an American pigskin football. Dwarf galaxies, which are far less massive than spirals or ellipticals, tend to be a lot more irregular, she says.

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A pivotal step to thinking about galaxy shapes is understanding how they fit into the environment around them. To Masters, these galaxies are kind of like building blocks. “I sometimes think of them as like the fairy lights lighting up the branches of the tree, where the branches are kind of the underlying infrastructure that we have,” she says.

The infrastructure she refers to is dark matter, which is concentrations of mass that are invisible to the telescopes we use.

We can, however, infer the presence of dark matter due to the gravitational effects it produces on the matter that we can see. One common effect dark matter produces is light distortion, as NASA’s Jet Propulsion Laboratory explained on a web page.

“As the light from distant galaxies travels to us, it must pass through the gravitational fields of other galaxies. Hence, we see distorted images of the distant galaxies,” JPL stated. “Ordinary matter does not account for the amount of distortion that astronomers observe.”

The three main types of galaxies — with many dwarf galaxies belonging to irregular. A. Feild (STScI)

Galaxies have vast concentrations of dark matter that also causes them to be gravitationally attracted to each other, Masters says. “There will be galaxies gobbling up small galaxies,” she says, citing the Milky Way’s long history as an example. The Milky Way is also on an eventual collision course with a large neighbor, the Andromeda Galaxy.

Another important element to a galaxy’s shape is when they were formed. When the universe was smaller, and at an earlier stage of expansion following the Big Bang, mergers were much more common since galaxies were brought into interaction more frequently, Masters says. Gas was also quite abundant in these younger galaxies, leading to more possible materials that galaxies could use during these mergers.

These days, some 13.8 billion years after the universe was formed, most galaxies are changing more slowly. Internal changes lead to structures such as bar shapes occurring. Mergers still happen, however, albeit less frequently than before.

The orbits of stars can also influence the shape of a galaxy through various “density waves,” which occur as material gets compacted in galaxies in something equivalent to a traffic jam, Masters says. That’s because the orbits do not happen regularly, and stars might jam up together due to their mutual gravities influencing each other.

Conversely, supermassive black holes embedded in many galaxies’ centers don’t appear to have a significant effect on how a galaxy is shaped, since the black holes are so small relative to a galaxy’s mass, Masters adds.

Since galaxies have so many different varieties of shape within the big three (elliptical, spiral, and dwarf), Masters says Galaxy Zoo continues to be important in assisting with the classification of these various types. While machine learning is making computers more adept in picking out galaxy types, human intervention is good for putting the findings in the big picture.

As observatories like the James Webb Space Telescope accrue observations, Masters says, the numbers and types of galaxies we see will only increase. The community, she added, is very excited about the high-resolution views of early galaxies that Webb will provide when it completes commissioning this summer.

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New England College of Optometry Issues Safety Advisory for Solar Eclipse – New England College of Optometry

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NECO Issues Safety Advisory for Solar Eclipse – New England College of Optometry


Watching the celestial event safely is possible with the right equipment and some preparation.

With the upcoming total solar eclipse on April 8, 2024, the New England College of Optometry (NECO) urges the general public to observe this celestial phenomenon safely. Solar eclipses are rare events that spark widespread interest and excitement. To ensure everyone can enjoy the eclipse without risking their vision, NECO is sharing crucial guidelines for proper viewing.  

“Solar eclipses present a wonderful opportunity for communities to engage with astronomy, but it’s vital that safety is a  priority,” says George Asimellis, PhD, Msc, MBA, Professor of Vision Science at NECO. “Viewing a solar eclipse without appropriate protection can result in solar retinopathy, which can cause lasting damage to the eyes. You must take proper precautions to view the eclipse.” PLEASE NOTE: NECO recommends that individuals who have recently undergone eye surgery or who have chronic eye conditions should refrain from viewing the eclipse. 

Student helps patient pick glasses frame

To prevent eye injuries and ensure a memorable experience, NECO advises the following: 

  • Always use solar viewing glasses. “When gearing up to watch the magical solar eclipse, it’s important to use specialized solar filters known as ‘eclipse glasses,’” says Alina Reznik, OD ’16, NECO Alumni Liaison. “These viewers adhere to the international safety standard ISO 12312-2 for safe viewing.” The ISO certification should be visible somewhere on the product. Ordinary sunglasses, even those with UV protection, are NOT safe for looking directly at the sun. They transmit thousands of times too much sunlight to be used for solar viewing.
  • If you wish to capture the event, do not look at the sun through camera viewfinders or phone cameras, as this can also lead to serious eye damage and can even destroy a phone. 
  • The safest way to view the eclipse is to create a camera obscura by finding a piece of cardboard and piercing a small hole in the center. With your back to the sun, hold the cardboard at shoulder height. In your other hand, hold a sheet of paper and align it with the cardboard until you see a tiny image of the sun projected onto the surface of the paper. You can even put cardboard around the “screen” to block out ambient light and see the eclipse image more clearly.

NECO will host an eclipse viewing party on Monday, April 8, from 2:00-4:00pm at their main campus located at 424 Beacon Street in Boston’s Back Bay. Media are welcome to attend and receive a free pair of eclipse viewing glasses. Faculty will be present to talk about the science behind safely viewing an eclipse.

The map below (courtesy of NASA) shows the eclipse’s path of totality.

For those who reside outside the path of totality: The Boston area is outside the eclipse’s path of totality. However, we will be able to view a partial eclipse starting at about 2:10pm. Our area will experience moderate darkness and a drop in temperature during the partial eclipse, which will last two hours. Eclipse glasses must still be used to protect  your eyes from the harmful rays of the sun, even during a partial eclipse!

Our vision experts are available for comment and additional information on eye care during this astronomical event. Please contact our Marketing Department by calling (617) 587-5609, or email [email protected].

For more information from national experts on the April 8 solar eclipse, visit NASA or the American Optometric Association.

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Changing the way people see the world

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Global wildlife study during COVID-19 shows rural animals are more sensitive to human activity

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Plant-eating animals more active, carnivores more cautious around humans 

One of the largest studies on wildlife activity—involving more than 220 researchers, 163 mammal species and 5,000 camera traps worldwide—reveals that wild animals react differently to humans depending on where the animals live and what they eat.

Bigger herbivores—plant-eating animals like deer or moose—tend to become more active when humans are around, while meat-eaters like wolves or wolverines tend to be less active, preferring to avoid risky encounters.

Urban animals like deer or raccoons may become more active around people, as they get used to human presence and find food like garbage or plants, which they can access at night. But animals living farther from cities and other developed areas are more wary of encountering people.

Wildlife during the pandemic ‘anthropause’

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Dr. Cole Burton

The new study, a collaboration across researchers from 161 institutions, used data from before and during the COVID-19 lockdowns to examine wildlife behaviour amid changing human activity levels.

“COVID-19 mobility restrictions gave researchers a truly unique opportunity to study how animals responded when the number of people sharing their landscape changed drastically over a relatively short period,” said lead author Dr. Cole Burton, an associate professor of forest resources management at UBC and Canada Research Chair in Terrestrial Mammal Conservation.

“And contrary to the popular narratives that emerged around that time, we did not see an overall pattern of ‘wildlife running free’ while humans sheltered in place. Rather, we saw great variation in activity patterns of people and wildlife, with the most striking trends being that animal responses depended on landscape conditions and their position in the food chain.”

In Canada, researchers monitoring areas such as Banff and Pacific Rim national parks, Cathedral, Golden Ears and South Chilcotin Mountains provincial parks, and the Sea-to-Sky corridor in B.C. found that carnivores like wolverines, wolves and cougars were generally less active when human activity was higher.

In several of these parks, and in cities such as Edmonton, large herbivores often increased their activity but became more nocturnal with the presence of more humans. Large carnivores were notably absent from the most human-dominated landscapes.

A coyote warily investigating a camera trap in Malcolm Knapp Research
Forest, British Columbia, Canada. Photo credit: Dr. Cole Burton, UBC WildCo

Preventing conflict through smart conservation measures

These findings highlight the importance of measures to minimize any detrimental effects of human disturbance on wildlife, including reducing overlaps that might lead to conflict.

Dr. Kaitlyn Gaynor

“In remote areas with limited human infrastructure, the effects of our actual presence on wildlife may be particularly strong. To give wild animals the space they need, we may consider setting aside protected areas or movement corridors free of human activity, or consider seasonal restrictions, like temporary closures of campsites or hiking trails during migratory or breeding seasons,” said study co-author and UBC biologist Dr. Kaitlyn Gaynor.

She added that strategies must also fit specific species and locations. In more remote areas, keeping human activity low will be necessary to protect sensitive species. In areas where people and animals overlap more, such as cities, nighttime is an important refuge for wildlife, and keeping it that way can help species survive. Efforts may focus on reducing human-wildlife conflict after dark, such as more secure storage of trash bins to reduce the number of animals getting into human food sources, or use of road mitigation measures to reduce vehicle collisions.

The findings are particularly useful amid the surge in global travel and outdoor recreation post-pandemic, Dr. Burton added.

“Understanding how wildlife respond to human activity in various contexts helps us develop effective conservation plans that have local and global impact. For that reason, we are working to improve wildlife monitoring systems using tools like the camera traps that made it possible to observe animal behaviours during the pandemic.”

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Three Canadian Student CubeSats Set for ISS Launch

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Longueuil, Quebec, – On , three CubeSats designed and built by Canadian students will launch to the International Space Station (ISS).This is the fourth and final launch of miniature satellites under the Canadian CubeSat Project. The teams finalized preparations of their CubeSats in at the Canadian Space Agency (CSA). The teams are:

  • QMSat – Université de Sherbrooke
  • Killick-1 – Memorial University
  • VIOLET – University of New Brunswick

Live coverage of the launch will air on NASA Live.

/Public Release. This material from the originating organization/author(s) might be of the point-in-time nature, and edited for clarity, style and length. Mirage.News does not take institutional positions or sides, and all views, positions, and conclusions expressed herein are solely those of the author(s).View in full here.

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