Astronomy Archives

December 12, 2022December 12, 2022 by Evan Gough

A Black Hole has been Burping for 100 Million Years

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

Black holes are gluttonous behemoths that lurk in the center of galaxies. Almost everybody knows that nothing can escape them, not even light. So when anything made of simple matter gets too close, whether a planet, a star or a gas cloud, it’s doomed.

But the black hole doesn’t eat it at once. It plays with its food like a fussy kid. Sometimes, it spews out light.

When the black hole is not only at the center of a galaxy but the center of a cluster of galaxies, these burps and jets carve massive cavities out of the hot gas at the center of the cluster called radio bubbles.

December 10, 2022December 10, 2022 by Scott Alan Johnston

To Fight Climate Change, We Could Block the Sun. A Lightweight Solar Sail Could Make it Feasible

Could a solar-sail-like structure (or structures) tethered to an asteroid provide a sunshade for Earth to block sunlight and mitigate climate change? A recent study looks into it. Courtesy NASA.

Can we build an enormous umbrella to dim the Sun? Such a feat would be a megaproject on a scale like no other. It would take at least 400 dedicated rocket launches a year, for ten years (There have been 172 rocket launches by all nations so far in 2022). The project would weigh in at 550,000 tons: at its lightest. And it would be an ecological experiment that puts us all – the entire planet – in the petri dish, with high risk and high reward. But could such a project actually reverse climate change and bring us back from the brink of global disaster?

The answer seems to be yes, it could work. But there are consequences, and with the planet at stake, it seems wise to examine them before committing to such a thing.

December 10, 2022December 10, 2022 by Anton Pozdnyakov

Iconic Earthrise By Artemis 1, Rule-Breaking GRB, SpaceX Launches Starshield

Construction Begins on the Square Kilometer Array. Artemis I’s iconic crescent Earthrise picture. A gamma-ray burst that breaks all the rules. SpaceX launches a new service.

December 9, 2022December 9, 2022 by Evan Gough

This Hellish Planet Orbits its Star Every 18 Hours. How Did it Get There?

An artist’s impression of the planet 55 Cnc e (smaller, dark orange circle) blocking the light from its rotating host star. Image Credit: Maggie Chiang/Simons Foundation

Astronomers discovered 55 Cancri e in 2004. That was five years before NASA’s Kepler planet-hunting spacecraft was launched, and exoplanet science has come a long way in the intervening years. Astronomers discovered the planet with the radial velocity method rather than Kepler’s transit method. 55 Cancri e was the first super-Earth found around a main-sequence star. The 55 Cancri system was also the first star discovered with four, and then five, planets.

The discovery was big news then; over the years, follow-up work has revealed more details, including that 55 Cancri e is extremely close to its star and has a molten surface.

But one question remained unanswered: How did it get there?

December 9, 2022December 12, 2022 by Matt Williams

A new 3D map of the Milky Way Uses close to 66,000 Stars and Reveals New Details About the Shape of our Galaxy

The warping of the Milky Way disk. Credit: University of Warsaw

In the 17th century, Galileo Galilee aimed his telescope at the stars and demonstrated (for the first time) that the Milky Way was not a nebulous band but a collection of distant stars. This led to the discovery that our Sun was merely one of the countless stars in a much larger structure: the Milky Way Galaxy. By the 18th century, William Herschel became the first astronomer to create a map that attempted to capture the shape of the Milky Way. Even after all that time and discovery, astronomers are still plagued by the problem of perspective.

While we have been able to characterize galaxies we see across the cosmos with relative ease, it is difficult for astronomers to study the size, shape, and population of the Milky Way because of how our Solar System is embedded in its disk. Luckily, there are methods to circumvent this problem of perspective, which have provided astronomers with clues to these questions. In a recent paper, a team from the Astronomical Observatory at the University of Warsaw (AstroUW) used a large collection of Mira variable stars to trace the shape of the Milky Way, which yielded some interesting results!

December 8, 2022December 9, 2022 by Alan Boyle

Japanese Billionaire Reveals His Round-the-Moon Crew

DearMoon crew — Japanese spaceflier-entrepreneur Yusaku Maezawa (center) has selected his crew for a Starship flight around the moon. From left: Kaitlyn Farrington, Brendan Hall, Tim Dodd, Yemi A.D., TOP, Maezawa, Steve Aoki, Rhiannon Adam, Karim Iliya, Dev D. Joshi and Miyu. (DearMoon Photo)

Four years after announcing that he’d lead an around-the-moon mission aboard SpaceX’s Starship spacecraft, Japanese billionaire Yusaku Maezawa has named the eight people he wants to fly with him.

In 2018, Maezawa said he’d fund a mission aimed at letting creative artists on the level of the late Pablo Picasso or Michael Jackson experience a trip beyond Earth orbit. Some of the people he’s picked are making use of creative channels that didn’t exist when Picasso was in his prime.

The eight crew members — and two alternates — were chosen out of more than a million people from 249 countries and regions who registered their interest via Maezawa’s DearMoon website.

“I’m very thrilled to have these amazing people join me on my journey to the moon and excited to see what inspiring creations they come up with in space,” Maezawa said as he announced his selections.

December 8, 2022December 8, 2022 by Anton Pozdnyakov

SpaceX Launches ‘Starshield’. A Quiet Announcement With A Huge Potential

SpaceX revealed their new service called Starshield. It is a “secured satellite network for government entities” and is aimed at “supporting national security.” The project looks similar to Starlink, but instead of providing service to end users and businesses, Starshield is aimed at government entities. Here’s what we know so far.

December 7, 2022December 7, 2022 by Evan Gough

Colliding Neutron Stars can Generate Long Gamma-ray Bursts

Artist's illustration of a bright gamma-ray burst occurring in a star-forming region and beaming out energy into two narrow, oppositely directed jets. Image Credit: By NASA/Swift/Mary Pat Hrybyk-Keith and John Jones - http://imagine.gsfc.nasa.gov/docs/features/news/10sep08.html [1]Transferred from en.wikipedia to Commons by TheDJ using CommonsHelper., Public Domain, https://commons.wikimedia.org/w/index.php?curid=8807284

Gamma-Ray Bursts (GRBs) are the most energetic recurring events in the Universe. Only the Big Bang was more energetic, and it was a singularity. Astronomers see GRBs in distant Universes, and a lot of research has gone into understanding them and what causes them.

A new paper is upending some of what scientists thought they knew about these extraordinary explosions.

December 7, 2022December 7, 2022 by Matt Williams

“Early Dark Energy” Could Explain the Crisis in Cosmology

A diagram of the evolution of the observable universe. The Dark Ages are the object of study in this new research, and were preceded by the CMB, or Afterglow Light Pattern. By NASA/WMAP Science Team - Original version: NASA; modified by Cherkash, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11885244 — A diagram of the evolution of the observable universe. Credit: NASA/WMAP/Wikimedia

In 1916, Einstein finished his Theory of General Relativity, which describes how gravitational forces alter the curvature of spacetime. Among other things, this theory predicted that the Universe is expanding, which was confirmed by the observations of Edwin Hubble in 1929. Since then, astronomers have looked farther into space (and hence, back in time) to measure how fast the Universe is expanding – aka. the Hubble Constant. These measurements have become increasingly accurate thanks to the discovery of the Cosmic Microwave Background (CMB) and observatories like the Hubble Space Telescope.

Astronomers have traditionally done this in two ways: directly measuring it locally (using variable stars and supernovae) and indirectly based on redshift measurements of the CMB and cosmological models. Unfortunately, these two methods have produced different values over the past decade. As a result, astronomers have been looking for a possible solution to this problem, known as the “Hubble Tension.” According to a new paper by a team of astrophysicists, the existence of “Early Dark Energy” may be the solution cosmologists have been looking for.

December 7, 2022December 7, 2022 by Evan Gough

A Star was Blocking a Galaxy, but Now it’s Moved Enough That Astronomers can Finally Examine What it Was Hiding

NASA's Hubble Space Telescope captured a detailed image of the tiny galaxy HIPASS J1131–31, nicknamed the "Peekaboo Galaxy." It's more like an ancient galaxy from the Universe's early days than a modern galaxy. Image Credit: NASA, ESA, and Igor Karachentsev (SAO RAS); Image Processing: Alyssa Pagan (STScI)

One of the biggest puzzles in astronomy, and one of the hardest ones to solve, concerns the formation and evolution of galaxies. What did the first ones look like? How have they grown so massive?

A tiny galaxy only 20 million light-years away might be a piece of the puzzle.