A new report from the UN was just published. It proposes and discusses ways to cool our planet by restricting sunlight and darkening our skies.

What is this about? Why block sunlight, of all things? Let me explain.

The UN is worried about climate change. As the efforts to reduce CO2 emissions are faltering, the UN is looking for more ways to cool the Earth. The UNEP's report details ideas called "Solar Radiation Modification," the gist of which is to reflect sunlight and prevent it from heating the surface of our planet.

Here are the main ideas that the UN will consider:

• Injecting reflective nanoparticles/sulfur dioxide into the atmosphere (stratospheric aerosol injection)
• Brightening of low clouds over the ocean by seeding ocean clouds with submicron salt particles
• Using space mirrors, that is, many giant mirrors launched into outer space to reflect sunlight.

The UN explains that should the "global stakeholders" decide to proceed, the skies could be darkened within only a few years:

SRM is the only option that could cool the planet within years. To be effective at limiting global warming, SRM would need to be maintained for several decades to centuries, depending on the pace of emissions reductions and carbon removal.

Billions of people around the world face starvation if Net Zero policies ban the production of nitrogen fertiliser derived from fossil fuels. This is the stark warning from two top American scientists who say that eliminating fossil fuel-derived nitrogen fertilisers and pesticides "will result in about half the world's population not having enough food to eat". They add that eliminating Net Zero fertiliser will create "worldwide starvation".

In a wide-ranging paper titled 'Challenging 'Net Zero' with Science', Emeritus Professors William Happer and Richard Lindzen of Princeton and MIT respectively, along with geologist Gregory Wrightstone, state that Net Zero - the global movement to eliminate fossil fuels and its emissions of carbon dioxide and other greenhouse gases - to be "scientifically invalid and a threat to the lives of billions of people".

The battle over nitrogen fertiliser is being hard fought by green activists who argue for massive reductions in its use and more organic methods to be mandated. This can extend to fanaticism, as marked by the Guardian's George Monbiot who argues for an end to dependence on farming. The ground for less choice and food is also being prepared in academia. Recently, three barking academics operating through the University of Leeds suggested World War II rationing could be an effective way to reduce carbon emissions. Also harking back to the days of spam and when spivs controlled parts of the supply chain was the actress Joanna Lumley, who has suggested a return to a points distribution system and a form of wartime rationing.

Take a look at Earth from far off in space, you'd notice it looks uniformly bright. Considering the Southern Hemisphere's disproportionate expanse of dark ocean waters should reflect back less sunlight, this isn't what we might expect down here on the surface.

It's a mystery that's been of interest to scientists since the early 1970s, when we were first able to get satellites into orbit to measure reflected solar radiation, which is technically known as albedo. Now, that mystery may have been solved.

The explanation is that while the oceans of the Southern Hemisphere absorb more sunlight, they also produce a higher number of storms - and the resulting storm clouds act as reflectors that balance out the solar radiation being sent back into space.

A "biocomputer" powered by human brain cells could be developed within our lifetime, according to Johns Hopkins University researchers who expect such technology to exponentially expand the capabilities of modern computing and create novel fields of study.

The team outlines their plan for "organoid intelligence" today in the journal Frontiers in Science.

Thomas Hartung, a professor of environmental health sciences at the Johns Hopkins Bloomberg School of Public Health and Whiting School of Engineering who is spearheading the work, says:

"Computing and artificial intelligence have been driving the technology revolution, but they are reaching a ceiling. Biocomputing is an enormous effort of compacting computational power and increasing its efficiency to push past our current technological limits."

For nearly two decades scientists have used tiny organoids, lab-grown tissue resembling fully grown organs, to experiment on kidneys, lungs, and other organs without resorting to human or animal testing. More recently Hartung and colleagues at Johns Hopkins have been working with brain organoids, orbs the size of a pen dot with neurons and other features that promise to sustain basic functions like learning and remembering.

"This opens up research on how the human brain works. Because you can start manipulating the system, doing things you cannot ethically do with human brains."

The Minor Planet Center (MPC) has given an official name to the comet, which is already being called the main comet of 2024. It received the designation C/2023 A3 ().

C/2023 A3 was first discovered in images taken on January 9 by the Chinese observatory Tsuchinshan (translated as Purple Mountain). On February 22, the ATLAS automated telescope located in South Africa took independent images of the object. The analysis carried out by astronomers showed that it was a comet. C/2023 A3 has a small tail and a very compact coma.

At the moment, C/2023 A3 is located at a distance of 7.3 AU (1090 million km) from the Sun, which exceeds the distance to Jupiter. But it is rapidly approaching the perihelion of its orbit, which will be passed on September 28, 2024. On this day, the comet will fly at a distance of 0.39 AU (58 million km) from the Sun.

The tattered shell of the first-ever historically recorded supernova was captured by the US Department of Energy-fabricated Dark Energy Camera, which is mounted on the National Science Foundation's (NSF) Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF's NOIRLab. RCW 86's ring of debris is all that remains of a white-dwarf star that exploded more than 1800 years ago, when it was recorded by Chinese stargazers as a 'guest star.'

Draped around the outer edges of this star-filled image are wispy tendrils that appear to be flying away from a central point, like the tattered remains of a burst balloon. These cloud-like features are thought to be the glowing remains of a supernova that was witnessed by Chinese astronomers in the year 185 C.E. When it appeared, this baffling addition to the night sky was referred to as a 'guest star' by ancient astronomers. It remained visible to the naked eye for about eight months before fading from view.

This historical supernova, which astronomers now refer to as SN 185, occurred more than 8000 light-years away in the approximate direction of Alpha Centauri, between the constellations of Circinus and Centaurus. The resulting structure, RCW 86 — as imaged by the Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF's NOIRLab — helps shed light on how the remains of the supernova evolved over the past 1800 years. DECam's amazing wide-field vision enabled astronomers to create this rare view of the entire supernova remnant as it is seen today.

Though the link between RCW 86 and SN 185 is now well established, that wasn't always the case. For decades, astronomers thought it would take about 10,000 years for a traditional core-collapse supernova — one in which a massive star blows material away from itself by exploding — to form the structure as we see it today. This would make the structure far older than the supernova observed in the year 185.

Our solar system is home to millions of renegade space rocks, and this week three particularly large ones will blaze past Earth. But don't worry - the closest one will still miss our planet by a comfy 2.2 million miles (3.5 million kilometers), or about 10 times the average distance between Earth and the moon, according to NASA.

On Monday (Feb. 27), an asteroid named 2012 DK31 will sail past our planet at a distance of about 3 million miles (4.8 million km). The asteroid measures an estimated 450 feet (137 meters) across, or about as wide as a 40-story skyscraper is tall, and its orbit around the sun crosses Earth's orbit every few years.

Although the space rock poses no imminent threat to Earth, NASA classifies it as a potentially hazardous asteroid (PHA) - meaning the rock is large enough and orbits close enough to Earth that it could cause serious damage if its trajectory changed and a collision occurred. Generally, any asteroid measuring greater than 450 feet wide and orbiting within 4.6 million miles (7.5 million km) of Earth is considered a PHA. (NASA has mapped this asteroid's trajectory for the next 200 years, and no collisions are predicted to occur).

But first, let's take a walk down memory land, from nearly two decades ago: "Brain" In A Dish Acts As Autopilot Living Computer:

A University of Florida scientist has grown a living "brain" that can fly a simulated plane, giving scientists a novel way to observe how brain cells function as a network.

The "brain" — a collection of 25,000 living neurons, or nerve cells, taken from a rat's brain and cultured inside a glass dish — gives scientists a unique real-time window into the brain at the cellular level. By watching the brain cells interact, scientists hope to understand what causes neural disorders such as epilepsy and to determine noninvasive ways to intervene.

As living computers, they may someday be used to fly small unmanned airplanes or handle tasks that are dangerous for humans, such as search-and-rescue missions or bomb damage assessments.

A new study from a University of Chicago scientist suggests there may be a layer of surprisingly fluid rock ringing the Earth, at the very bottom of the upper mantle.

The finding was made by measuring the lingering movement registered by GPS sensors on islands in the wake of a deep earthquake in the Pacific Ocean near Fiji. Published Feb. 22 in Nature, the study demonstrates a new method to measure the fluidity of the Earth's mantle.

"Even though the mantle makes up the largest part of Earth, there's still a lot we don't know about it," said Sunyoung Park, a geophysicist with the University of Chicago and the lead author on the study. "We think there's a lot more we can learn by using these deep earthquakes as a way to probe these questions."

Cruise liner guests encountered giant phantom jellyfish off the coast of Antarctica while diving in submersibles, a new study finds.
Rare sightings of giant phantom jellyfish — deep-sea creatures that look like UFO spaceships with thick ribbons streaming from their undersides — have been reported by cruise liner passengers who spotted the otherworldly animals off the coast of Antarctica, a new study finds.

The giant phantom jellyfish (Stygiomedusa gigantea), one of the deep sea's largest invertebrate predators, met the guests while they were riding in a submersible deployed by cruise line operator Viking in early 2022. Researchers estimated that the jellyfish were longer than 16 feet (5 meters), with one stretching to at least 33 feet (10 m) in length, according to a study published Jan. 30 in the journal Polar Research.

Study first author Daniel Moore first realized guests had encountered the giant phantom when he saw a picture of one on a guest's camera. "I instantly recognised it for what it was and, given the rarity of sightings, was flooded with excitement," Moore, one of Viking's chief scientists, told Live Science in an email.