Connect with us


Astronomers May Have Solved One Of Webb’s First Puzzles



Almost immediately after scientists pointed the James Webb Space Telescope at the earliest galaxies in the universe, they were seeing things that didn’t jibe with the rules of the cosmos.

These galaxies, viewed as they were only 500 to 700 million years after the Big Bang, seemed too massive and mature for their young age. It was like finding parents and children alongside their grandparents, who were themselves still children, two physicists said in a piece written for The New York Times.

“It’s bananas,” said Erica Nelson, an astrophysicist at the University of Colorado in Boulder, earlier this year in a statement. “You just don’t expect the early universe to be able to organize itself that quickly. These galaxies should not have had time to form.”

But new space research using advanced computer simulations suggests that the reason they appear mature through the infrared eyes of Webb, run by NASA and the European and Canadian space agencies, is not because they are uncharacteristically massive. Though a galaxy’s brightness usually corresponds to its mass, small, less-developed galaxies could burn just as bright from irregular bursts of star formation, scientists say.

A group of astrophysicists led by Northwestern University was able to demonstrate this without contradicting existing and widely accepted cosmology theories. The computer experiment was also able to reproduce the same number of bright galaxies at the cosmic dawn that astronomers observed with Webb. The research was published this week in Astrophysical Journal Letters.

“The key is to reproduce a sufficient amount of light in a system within a short amount of time,” said Guochao Sun, lead author on the study, in a statement. “A system doesn’t need to be that massive. If star formation happens in bursts, it will emit flashes of light. That is why we see several very bright galaxies.”

The James Webb Space Telescope spotted ancient galaxies initially considered extremely massive for their age because of their brightness.

Want more science and tech news delivered straight to your inbox? Sign up for Mashable’s Light Speed newsletter today.

One of Webb’s primary missions is to watch the universe “turn the lights on” for the first time by observing the ancient galaxies from the cosmic dawn — a period between 100 million years to 1 billion years after the Big Bang. In astronomy, looking farther translates into observing the past because light and other forms of radiation take longer to reach us.

Space is filled with gas and dust, which obscures the view to extremely distant and inherently dim light sources, but infrared light waves can penetrate the clouds. A NASA scientist once compared the infrared telescope’s sensitivity to being able to detect the heat of a bumblebee on the moon.

The Northwestern simulations revealed that the early galaxies could have undergone something the intellectuals refer to as — we kid you not — “bursty star formation.” Rather than making stars at a steady clip like the Milky Way does, for instance, these galaxies churn out stars inconsistently, with a proliferation all at once, followed by stagnant periods sometimes stretching millions of years before another so-called burst.

Bursty star formation is common in low-mass galaxies, said Claude-André Faucher-Giguère, a professor of physics and astronomy at Northwestern, though it’s unclear why.

NASA released the first deep field image by the James Webb Space Telescope on July 11, 2022, at the White House.

“What we think happens is that a burst of stars form, then a few million years later, those stars explode as supernovae,” he said in a statement. “The gas gets kicked out and then falls back in to form new stars, driving the cycle of star formation.”

That might not happen in more massive galaxies because they have stronger gravity.

In that case, “When supernovae explode, they are not strong enough to eject gas from the system,” Faucher-Giguère continued. “The gravity holds the galaxy together and brings it into a steady state.”

Source link

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *


Greenhouse Gases Are Alerting Oceans ‘Before Our Eyes,’ Says NASA




NASA has shared a stunning yet concerning visualisation of sea surface currents and how they are being altered due to global warming. The visualisation depicts the average temperatures of ocean currents and how they differ at different locations.

The warmer hues such as red, orange, and yellow indicate higher temperatures, and cooler shades like green and blue represent lower temperatures.

“With 70% of the planet covered by water, the seas are important drivers of Earth’s global climate. Yet, increasing greenhouse gases from human activities are altering the ocean before our eyes,” the agency captioned the post.

According to NASA, 90 percent of the planet’s warming occurs within the ocean. Since modern recordkeeping began in 1955, the internal heat of the ocean has steadily increased, contributing significantly to climate change.

ALSO SEE: World’s Oceans Are Losing Their “Memory” As A Result Of Global Warming, Experts Claim

The heat stored in the ocean leads to thermal expansion, a process where water expands as it warms. This phenomenon is a major contributor to global sea level rise, accounting for one-third to one-half of the increase.

Scientists say the majority of this heat is concentrated at the surface, within the top 700 meters of the ocean. According to existing records, the past decade has been the warmest for the ocean since at least the 1800s, with 2023 marking the highest recorded ocean temperatures to date.

ALSO SEE: Arctic Ocean Warming Started Decades Earlier Than Previously Thought

The warming of the ocean has far-reaching effects. One of the most visible impacts is the rise in sea levels, primarily due to thermal expansion. Warmer waters have also led to widespread coral bleaching, which affects marine ecosystems and the increased temperatures also accelerate the melting of Earth’s major ice sheets.

NASA says that the warming ocean intensifies hurricanes affect ocean health and biochemistry, altering marine life habitats and disrupting food chains.

Source link

Continue Reading


NASA Shares Incredible Picture Of ‘Space Potato’ Phobos; It Will Soon Crash Into Mars




Ever seen a space potato? NASA is here to treat you with one. The agency has shared a fascinating image of Phobos, the larger of two moons of Mars, explaining what makes this object so intriguing.

Meauring just 27 by 22 by 18 kilometres in diameter, Phobos orbits Mars about 6,000 km above the red planet’s surface and it is on a collision course with Earth.

This is the closest any Moon orbits a planet and Phobos might crash into Mars in the future. Scientists estimate that this is likely to happen within 50 million years. Another likely scenario of Phobos’ end will be its potential obliteration into pieces, eventually forming a ring around Mars.

According to NASA, Phobos is nearing Mars at the rate of six feet each year.

ALSO SEE: We May Have Been Wrong About Martian Moon Phobos’ Origin, It Could Be A Comet

Phobos (left) and Deimos (right). Image: NASA

Describing the image, the agency said that it was taken by the High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter, which has been studying Mars since 2006.

Phobos was discovered along with its twin just six days apart by astronomer Asaph Hall in 1877.

ALSO SEE: ISRO’s Mangalyaan Presents Breathtaking Video Of Martian Moon ‘Phobos’

The Moon also has several craters but the most dominant one is the 10-km-wide Stickeny crater which Hall named after his wife Angelina.

The second moon is Deimos which measures 15 by 12 by 11 kilometres and orbits the red planet every 30 hours. Both the moons are named after the mythological sons of Ares, the Greek counterpart of the Roman god. Phobos means fear and Deimos means dread, says NASA. As for their origin, astronomers believe they could be asteroids or debris caught by Mars in the early solar system.

(Image: NASA)

Source link

Continue Reading


Rare ‘Gigantic Jets’ Spotted Above The Himalayas, NASA Shares Viral Picture




NASA recently shared a captivating image of gigantic jets soaring from a thunderstorm toward the Himalayan Mountains in China and Bhutan. This composite image, featured in NASA’s Astronomy Picture of the Day segment on June 18, reveals four immense jets captured within minutes of each other.

Gigantic jets are a rare and fascinating type of lightning discharge that have only been documented since the early 2000s. Unlike conventional lightning that occurs between clouds or strikes the ground, gigantic jets bridge the gap between thunderstorms and the Earth’s ionosphere, the layer of the atmosphere that is ionised by solar and cosmic radiation, NASA said.

Jets of lightning spotted over the Himalayas. Image: NASA/Li Xuanhua

These jets are unique in their appearance and behavior, differing significantly from traditional lightning phenomena.

ALSO SEE: Webb Telescope Photographs Baby Stars Burping Out Gases For The First Time

Despite their visual grandeur, the precise mechanisms and triggers behind gigantic jets are still under investigation. What is known is that these jets help to balance electrical charges between different layers of the Earth’s atmosphere, playing a crucial role in maintaining the atmospheric electrical circuit.

For those interested in observing this phenomenon, a powerful but distant thunderstorm viewed from a clear vantage point offers the best chance.

As these jets typically shoot upwards from the storm tops into the ionosphere, they can often be seen from hundreds of kilometers away under the right conditions.

ALSO SEE: NASA Shares First Cosmic Image Of 2024 And It’s Exploding With Stars

Source link

Continue Reading


Copyright © 2023 Dailycrunch. & Managed by Shade Marketing & PR Agency