Skip to main content

Posts

Showing posts from August, 2024

Dark Matter Could Have Driven the Growth of Early Supermassive Black Holes

The James Webb Space Telescope (JWST) keeps finding supermassive black holes (SMBH) in the early Universe. They’re in active galactic nuclei seen only 500,000 years after the Big Bang. This was long before astronomers thought they could exist. What’s going on? Monster black holes like the ones at the hearts of galaxies take a really long time to grow so massive. They could start as smaller ones that gobble up nearby stars and gases, or they can grow by merging with other supermassive black holes. That typically takes billions of years and a lot of material to build up to something as massive as the four-million-solar-mass one in the heart of our Milky Way Galaxy. It’s even longer for the really big ones that contain tens of millions of stellar masses. A James Webb Telescope image shows the J0148 quasar circled in red. Two insets show, on top, the central supermassive black hole, and on bottom, the stellar emission from the host galaxy. JWST has spotted many SMBH that already a

If Gravitons Exist, this Experiment Might Find Them

There are four fundamental forces in the Universe; strong, weak, electromagnetic and gravity. Quantum theory explains three of the four through the interaction of particles but science has yet to discover a corresponding particle for gravity. Known as the ‘graviton’, the hypothetical gravity particle is thought to constitute gravitational waves but it hasn’t been detected in gravity wave detector. A new experiment hopes to change that using an acoustic resonator to identify individual gravitons and confirm their existence.  The four fundamental forces of nature govern the Universe. Gravity is one that many people are familiar with yet we do not fully understand how it works. Its effects are obvious though as the attraction between objects with mass. It keeps the planets in orbit around the Sun, the Moon in orbit around the Earth and us pinned to the surface of planet Earth. One of the earliest attempts to describe it was  from Isaac Newton who stated that gravity was proportional to

How Vegetation Could Impact the Climate of Exoplanets

The term ‘habitable zone’ is a broad definition that serves a purpose in our age of exoplanet discovery. But the more we learn about exoplanets, the more we need a more nuanced definition of habitable. New research shows that vegetation can enlarge the habitable zone on any exoplanets that host plant life. Every object in a solar system has an albedo. It’s a measurement of how much starlight the object reflects back into space. In our Solar System, Saturn’s moon, Enceladus, has the highest albedo because of its smooth, frozen surface. Its albedo is about 0.99, meaning about 99% of the Sun’s energy that reaches it is reflected back into space. There are many dark objects in space with low albedoes. Some say that another of Saturn’s moons, Iapetus, has the lowest albedo. Earth, the only living planet, has an albedo of about 0.30, meaning it reflects 30% of the Sunlight that reaches it back into space. Many factors affect the albedo. Things like the amount of ice cover, clouds in the

A New Test Proves How to Make the Event Horizon Telescope Even Better

Want a clear view of a supermassive black hole’s environment? It’s an incredible observational challenge. The extreme gravity bends light as it passes through and blurs the details of the event horizon, the region closest to the black hole. Astronomers using the Event Horizon Telescope (EHT) just conducted test observations aimed at “deblurring” that view. The EHT team collaborated with scientists at the Atacama Large Millimeter/submillimeter Array (ALMA) and other facilities to do the tests. The antennas detected light from the centers of distant galaxies at a radio frequency of 354 GHz, equivalent to a wavelength of 0.87 mm. A map of the Event Horizon Telescope observatories used in recent test observations at 0.87 mm of distant galaxies, to bump up its resolution. Credit: ESO/M. Kornmesser This pilot experiment achieved observations with detail as fine as 19 microarcseconds. That’s the highest-ever resolution ever achieved from Earth’s surface. Although there are no images f

NASA's New Solar Sail Extends Its Booms and Sets Sail

Solar sails are an exciting way to travel through the Solar System because they get their propulsion from the Sun. NASA has developed several solar sails, and their newest, the Advanced Composite Solar Sail System (or ACS3), launched a few months ago into low-Earth orbit. After testing, NASA reported today that they extended the booms, deploying its 80-square-meter (860 square feet) solar sail. They’ll now use the sail to raise and lower the spacecraft’s orbit, learning more about solar sailing. “The Sun will continue burning for billions of years, so we have a limitless source of propulsion. Instead of launching massive fuel tanks for future missions, we can launch larger sails that use ‘fuel’ already available,” said Alan Rhodes, the mission’s lead systems engineer at NASA’s Ames Research Center, earlier this year. “We will demonstrate a system that uses this abundant resource to take those next giant steps in exploration and science.” And for all you skywatchers out there, NASA

Webb Discovers Six New “Rogue Worlds” that Provide Clues to Star Formation

Rogue Planets, or free-floating planetary-mass objects (FFPMOs), are planet-sized objects that either formed in interstellar space or were part of a planetary system before gravitational perturbations kicked them out. Since they were first observed in 2000, astronomers have detected hundreds of candidates that are untethered to any particular star and float through the interstellar medium (ISM) of our galaxy. In fact, some scientists estimate that there could be as many as 2 trillion rogue planets (or more!) wandering through the Milky Way alone. In recent news, a team of astronomers working with the James Webb Space Telescope (JWST) announced the discovery of six rogue planet candidates in an unlikely spot. The planets, which include the lightest rogue planet ever identified (with a debris disk around it), were spotted during Webb ‘s deepest survey of the young nebula NGC 1333 , a star-forming cluster about a thousand light-years away in the Perseus constellation. These planets co

A NASA Rocket Has Finally Found Earth’s Global Electric Field

Scientists have discovered that Earth has a third field. We all know about the Earth’s magnetic field. And we all know about Earth’s gravity field, though we usually just call it gravity. Now, a team of international scientists have found Earth’s global electric field. It’s called the ambipolar electric field, and it’s a weak electric field that surrounds the planet. It’s responsible for the polar wind , which was first detected decades ago. The polar wind is an outflow of plasma from the polar regions of Earth’s magnetosphere. Scientists hypothesized the ambipolar field’s existence decades ago, and now they finally have proof. The discovery is in a new article in Nature titled “ Earth’s ambipolar electrostatic field and its role in ion escape to space. ” The lead author is Glyn Collinson from the Heliophysics Science Division at NASA Goddard Space Flight Center. “It’s like this conveyor belt, lifting the atmosphere up into space.” Glyn Collinson, Heliophysics Science Division,

What Type of Excavator Is Most Suitable for Asteroids?

Digging in the ground is so commonplace on Earth that we hardly ever think of it as hard. But doing so in space is an entirely different proposition. On some larger worlds, like the Moon or Mars, it would be broadly similar to how digging is done on Earth. But their “milligravity” would make the digging experience quite different on the millions of asteroids in our solar system. Given the potential economic impact of asteroid mining, there have been plenty of suggested methods on how to dig on an asteroid, and a team from the University of Arizona recently published the latest in a series of papers about using a customized bucket wheel to do so. Bucket wheel designs seem to be gaining popularity in space mining more generally lately. NASA’s ISRU Pilot Excavator (IPEx) uses a similar design and has been advanced to Technology Readiness Level 5, according to its latest yearly report. However, it was designed for use on the Moon, where gravity is significantly larger than that of the as

The Rubin Observatory Will Unleash a Flood of NEO Detections

After about 10 years of construction, the Vera Rubin Observatory (VRO) is scheduled to see its first light in January 2025. Once it’s up and running, it will begin its Legacy Survey of Space and Time (LSST), a decade-long effort to photograph the entire visible sky every few nights. It’ll study dark energy and dark matter, map the Milky Way, and detect transient astronomical events and small Solar System objects like Near Earth Objects (NEOs). New research shows the LSST will detect about 130 NEOs per night in the first year of observations. NEOs are small Solar System bodies, usually asteroids, that orbit the Sun and come within 1.3 astronomical units of the Sun. When a NEO crosses Earth’s orbit at some point, it’s considered a potentially hazardous object (PHO). NASA is currently cataloguing NEOs, and while they’ve made progress, there are many more left to find. According to new research, the upcoming LSST will detect about 130 NEOs per night. The research is “ Expected Impact o

What if you Flew Your Warp Drive Spaceship into a Black Hole?

Warp drives have a long history of not existing, despite their ubiquitous presence in science fiction. Writer John Campbell first introduced the idea in a science fiction novel called Islands of Space. These days, thanks to Star Trek in particular, the term is very familiar. It’s almost a generic reference for superliminal travel through hyperspace. Whether or not warp drive will ever exist is a physics problem that researchers are still trying to solve, but for now, it’s theoretical. Recently, two researchers looked at what would happen if a ship with warp drive tried to get into a black hole. The result is an interesting thought experiment. It might not lead to starship-sized warp drives but might allow scientists to create smaller versions someday. NASA’s Eagleworks attempted to test Alcubierre warp drive concept. Credit: 2012 Remo Garattini and Kirill Zatrimaylov theorized that such a drive could survive inside a so-called Schwarzschild black hole. That’s provided the ship

DART Did More Than Deter Dimorphos; It Sent It Into a Chaotic Tumble

In 2022, NASA’s DART (Double Asteroid Redirection Test) spacecraft collided with an object named Dimorphos. The objective was to test redirecting hazardous asteroids by deflecting them with an impact. The test was a success, and Dimorphos was measurably affected. Follow-up research shows that Dimorphos was more than deflected; it was deformed. In recent decades, we’ve made progress cataloguing the asteroids in the Solar System. Some of them are close enough to Earth to be dangerous. If an object comes within 1.3 astronomical units of the Sun, it’s called a Near Earth Object (NEO.) If it’s more than 140 meters (460 ft) across and crosses Earth’s orbit, it’s called a Potentially Hazardous Object (PHO.) Over 99% of NEOs and PHOs are asteroids, and the remainder are comets. Earth has suffered many impacts from these objects in the past. The most famous impactor was Chicxulub . When it struck Earth about 65 million years ago, it was responsible for the end of the dinosaurs. Now that