Universe Today

November 3, 2024November 3, 2024 by Matt Williams

Plastic Waste on our Beaches Now Visible from Space, Says New Study

Yellow spot indicating plastic on the blue satellite image of an otherwise pristine beach. Credit: RMIT

According to the United Nations, the world produces about 430 million metric tons (267 U.S. tons) of plastic annually, two-thirds of which are only used for a short time and quickly become garbage. What’s more, plastics are the most harmful and persistent fraction of marine litter, accounting for at least 85% of total marine waste. This problem is easily recognizable due to the Great Pacific Garbage Patch and the amount of plastic waste that washes up on beaches and shores every year. Unless measures are taken to address this problem, the annual flow of plastic into the ocean could triple by 2040.

One way to address this problem is to improve the global tracking of plastic waste using Earth observation satellites. In a recent study, a team of Australian researchers developed a new method for spotting plastic rubbish on our beaches, which they successfully field-tested on a remote stretch of coastline. This satellite imagery tool distinguishes between sand, water, and plastics based on how they reflect light differently. It can detect plastics on shorelines from an altitude of more than 600 km (~375 mi) – higher than the International Space Station‘s (ISS) orbit.

November 3, 2024November 3, 2024 by Brian Koberlein

Future Space Telescopes Could be Made From Thin Membranes, Unrolled in Space to Enormous Size

Illustration of an array of membrane mirror telescopes. Credit: Sebastian Rabien, Max Planck Institute for Extraterrestrial Physics

Space-based telescopes are remarkable. Their view isn’t obscured by the weather in our atmosphere, and so they can capture incredibly detailed images of the heavens. Unfortunately, they are quite limited in mirror size. As amazing as the James Webb Space Telescope is, its primary mirror is only 6.5 meters in diameter. Even then, the mirror had to have foldable components to fit into the launch rocket. In contrast, the Extremely Large Telescope currently under construction in northern Chile will have a mirror more than 39 meters across. If only we could launch such a large mirror into space! A new study looks at how that might be done.

November 2, 2024November 2, 2024 by Mark Thompson

Voyager 1 is Forced to Rely on its Low Power Radio

Voyager 1 was launched waaaaaay back in 1977. I would have been 4 years old then! It’s an incredible achievement that technology that was built THAT long ago is still working. Yet here we are in 2024, Voyager 1 and 2 are getting older. Earlier this week, NASA had to turn off one of the radio transmitters on Voyager 1. This forced communication to rely upon the low-power radio. Alas technology around 50 years old does sometimes glitch and this was the result of a command to turn on a heater. The result was that Voyager 1 tripped into fault protection mode and switch communications! Oops.

November 2, 2024November 2, 2024 by Brian Koberlein

Webb Confirms a Longstanding Galaxy Model

JWST image of the grand design spiral galaxy NGC 628. Credit: NASA / ESA / CSA / Judy Schmidt (CC BY 2.0)

Perhaps the greatest tool astronomers have is the ability to look backward in time. Since starlight takes time to reach us, astronomers can observe the history of the cosmos by capturing the light of distant galaxies. This is why observatories such as the James Webb Space Telescope (JWST) are so useful. With it, we can study in detail how galaxies formed and evolved. We are now at the point where our observations allow us to confirm long-standing galactic models, as a recent study shows.

November 2, 2024November 2, 2024 by Evan Gough

The Aftermath of a Neutron Star Collision Resembles the Conditions in the Early Universe

This artist's illustration shows a neutron star collision leaving behind a rapidly expanding cloud of radioactive material. The conditions in the cloud are similar to the conditions in the early Universe, shortly after the Big Bang. Image Credit: NASA GODDARD SPACE FLIGHT CENTER, CI LAB

Neutron stars are extraordinarily dense objects, the densest in the Universe. They pack a lot of matter into a small space and can squeeze several solar masses into a radius of 20 km. When two neutron stars collide, they release an enormous amount of energy as a kilonova.

That energy tears atoms apart into a plasma of detached electrons and atomic nuclei, reminiscent of the early Universe after the Big Bang.

November 2, 2024November 2, 2024 by Mark Thompson

New View of Venus Reveals Previously Hidden Impact Craters

A synthetic aperture radar image of Haastte-baad Tessera, cut by a set of unique concentric rings that record a newly recognized type of impact crater on Venus, previously only identified on the icy moons of Jupiter. Credit: NASA.

Think of the Moon and most people will imagine a barren world pockmarked with craters. The same is likely true of Mars albeit more red in colour than grey! The Earth too has had its fair share of craters, some of them large but most of the evidence has been eroded by centuries of weathering. Surprisingly perhaps, Venus, the second planet from the Sun does not have the same weathering processes as we have on Earth yet there are signs of impact craters, but no large impact basins! A team of astronomers now think they have secured a new view on the hottest planet in the Solar System and revealed the missing impact sites.

November 1, 2024November 1, 2024 by Matt Williams

Multimode Propulsion Could Revolutionize How We Launch Things to Space

An illustration of the Gateway’s Power and Propulsion Element and Habitation and Logistics Outpost in orbit around the Moon. Credits: NASA

In a few years, as part of the Artemis Program, NASA will send the “first woman and first person of color” to the lunar surface. This will be the first time astronauts have set foot on the Moon since the Apollo 17 mission in 1972. This will be followed by the creation of permanent infrastructure that will allow for regular missions to the surface (once a year) and a “sustained program of lunar exploration and development.” This will require spacecraft making regular trips between the Earth and Moon to deliver crews, vehicles, and payloads.

In a recent NASA-supported study, a team of researchers at the University of Illinois Urbana-Champaign investigated a new method of sending spacecraft to the Moon. It is known as “multimode propulsion,” a method that integrates a high-thrust chemical mode and a low-thrust electric mode – while using the same propellant. This system has several advantages over other forms of propulsion, not the least of which include being lighter and more cost-effective. With a little luck, NASA could rely on multimode propulsion-equipped spacecraft to achieve many of its Artemis objectives.

November 1, 2024November 1, 2024 by Mark Thompson

China Trains Next Batch of Taikonauts

The Shenzhou-16 taikonauts undertake training programs. Credit CFP

China has a fabulously rich history when it comes to space travel and was among the first to experiment in rocket technology. The invention of the rocket is often attributed to the Sung Dynasty (AD 960-1279.) Since then, China has been keen to develop and build its own space industry. The Chinese National Space Administration has already successfully landed probes on the Moon but is preparing for their first human landers. Chinese astronauts are sometimes known as taikonauts and CNSA has just confirmed their fourth batch of taikonauts are set for a lunar landing.

November 1, 2024November 1, 2024 by Mark Thompson

NASA Focusses in on Artemis III Landing Sites.

This image shows nine candidate landing regions for NASA’s Artemis III mission, with each region containing multiple potential sites for the first crewed landing on the Moon in more than 50 years. The background image of the lunar South Pole terrain within the nine regions is a mosaic of LRO (Lunar Reconnaissance Orbiter) WAC (Wide Angle Camera) images. Credit: NASA

It was 1969 that humans first set foot on the Moon. Back then, the Apollo mission was the focus of the attempts to land on the Moon but now, over 50 years on, it looks like we are set to head back. The Artemis project is the program that hopes to take us back to the Moon again and it’s going from strength to strength. The plan is to get humans back on the Moon by 2025 as part of Artemis III. As a prelude to this, NASA is now turning its attention to the possible landing sites.

November 1, 2024November 1, 2024 by Mark Thompson

The Connection Between Black Holes and Dark Energy is Getting Stronger

JWST NIRCam imaging of star-forming protocluster PHz G191.24+62.04, 11 billion years ago as the universe was approaching the peak of star formation. These early galaxies are among the most active star-forming galaxies observed between 10.5 and 11.5 billion years ago. Each galaxy seen in this image is therefore producing many black holes, which are converting matter into dark energy according to the cosmologically coupled black hole hypothesis. This image shows the two "modules" of JWST NIRCam: The leftmost module contains the protocluster, and the rightmost module is an adjacent blank field. Each module sees thousands of galaxies.

The discovery of the accelerated expansion of the Universe has often been attributed to the force known as dark energy. An intriguing new theory was put forward last year to explain this mysterious force; black holes could be the cause of dark energy! The theory goes on to suggest as more black holes form in the Universe, the stronger the pressure from dark energy. A survey from the Dark Energy Spectroscopic Instrument (DESI) seems to support the theory. The data from the first year of operation shows the density of dark energy increases over time and seems to correlate with the number and mass of black holes!