milky way Archives

May 27, 2020May 27, 2020 by Evan Gough

The Solar System Might Not Exist if There Wasn’t a Huge Galactic Collision with the Milky Way Billions of Years Ago

Artist's conception of a solar system in formation. It's likely that exoplanet formation around other stars proceeded similarly. Credit: NASA/FUSE/Lynette Cook

The Milky Way has a number of satellite galaxies; nearly 60 of them, depedending on how we define them. One of them, called the Sagittarius Dwarf Spheroidal Galaxy (Sgr d Sph), may have played a huge role when it comes to humans, our world and our little civilization. A collision between the Milky Way and the Sgr d Sph may have created the Solar System itself.

April 7, 2020April 7, 2020 by Paul M. Sutter

Decaying Dark Matter Should be Visible Here in the Milky Way as a Halo Around the Galaxy

A simulated image of what the X-ray emission from dark matter might be. Image credit: Christopher Dessert, Nicholas L. Rodd, Benjamin R. Safdi, Zosia Rostomian (Berkeley Lab), based on data from the Fermi Large Area Telescope

Astronomers are very sure that dark matter exists, but they’re not sure at all what it’s made of.

The problem is that it isn’t just dark, it’s invisible. As far as we know, dark matter doesn’t emit light, absorb light, reflect light, refract light, scatter light, diffract light, or really have anything to do with light at all. This makes it hard to study. We know that dark matter exists, however, through its gravitational effects. Even though it’s invisible, it still has mass, and so the dark matter in our universe (which, by the way, makes up 85% of all the mass in the cosmos) can affect the motions of normal (or light-interacting) matter, like stars and galaxies.

December 12, 2019December 12, 2019 by Evan Gough

Dark Matter Could Be A Source of Gamma Rays Coming from the Center of the Milky Way

A map of gamma ray emissions throughout the Milky Way galaxy, based on observations from the Fermi Gamma-ray Space Telescope. The inset depicts the Galactic Center Excess – an unexpected, spherical region of gamma ray emissions at the center of our galaxy, of unknown origin. Credit: NASA/T. Linden, U.Chicago

There’s a lot of mysterious goings-on at the center of the Milky Way. The supermassive black hole that resides there is chief among them. But there’s another intriguing puzzle there: an unexpected spherical region of intense gamma ray emissions.

A new study suggests that dark matter could be behind those emissions.

September 18, 2019September 18, 2019 by Evan Gough

This Astrophotographer Makes the World Turn and the Sky Stand Still

Photographer Eric Brummel has created a stunning time-lapse of the Milky Way. Time-lapses of the Milky Way are not rare, but Eric has turned convention on its head. Instead of the Milky Way moving across the night sky, it’s the Earth that’s in motion.

August 13, 2019August 13, 2019 by Evan Gough

Milky Way’s Black Hole Just Flared, Growing 75 Times as Bright for a Few Hours

Illustration of the supermassive black hole at the center of the Milky Way. Credit: NRAO/AUI/NSF — Illustration of the supermassive black hole at the center of the Milky Way. It's huge, with over 4 times the mass of the Sun. But ultramassive black holes are even more massive and can contain billions of solar masses. Image Credit: Credit: NRAO/AUI/NSF

Even though the black hole at the center of the Milky Way is a monster, it’s still rather quiet. Called Sagittarius A*, it’s about 4.6 million times more massive than our Sun. Usually, it’s a brooding behemoth. But scientists observing Sgr. A* with the Keck Telescope just watched as its brightness bloomed to over 75 times normal for a few hours.

July 26, 2019July 26, 2019 by Evan Gough

What Did the Early Milky Way Look Like?

The Milky Way 10 billion years ago and the Milky Way today. Image Credit: Gabriel Pérez Díaz, SMM (IAC)

In the very early days of our Universe, just over 13 billion years ago, there was very little structure. There were stars, and they were forming at a rapid rate, kicking off what’s known as the Stelliferous Era. But the enormous, majestic galaxies that we see today, including our Milky Way galaxy, hadn’t formed yet.

March 13, 2019March 13, 2019 by Evan Gough

This is What It’ll Look Like When the Milky Way and Andromeda Galaxies Collide Billions of Years from Now

Located in the constellation of Hercules, about 230 million light-years away, NGC 6052 is a pair of colliding galaxies. Image Credit: ESA/Hubble & NASA, A. Adamo et al.

What happens when two galaxies collide? The Milky Way and the Andromeda Galaxy are on a collision course, and in about 4.5 billion years, they will meet. Now astronomers using the Hubble have provided some visual insight into what that collision might look like.

February 12, 2019February 12, 2019 by Evan Gough

Thanks to Gaia, We Now Know Exactly When We’ll be Colliding with Andromeda

The trajectories of the Milky Way, Andromeda, and the Triangulam galaxies. Image Credit: E. Patel, G. Besla (University of Arizona), R. van der Marel (STScI)

Astronomers have known for some time that the Milky Way and the Andromeda galaxies will collide on some future date. The best guess for that rendezvous has been about 3.75 billion years from now. But now a new study based on Data Release 2 from the ESA’s Gaia mission is bringing some clarity to this future collision.

November 14, 2018November 14, 2018 by Evan Gough

Gaia Spots an Enormous Ghost Galaxy Right Next Door that’s Being Dismantled by the Milky Way

From left to right: Large Magellanic Cloud, the Milky Way, and Antlia 2, our next door neighbor and so-called ghost galaxy. Credit: V. Belokurov based on the images by Marcus and Gail Davies and Robert Gendler

Astronomers combing through data from the ESA’s Gaia spacecraft have discovered what they’re calling a ghost galaxy. The galaxy, named Antlia 2 (Ant 2) is an extremely low-density dwarf galaxy that was formed in the early days of the universe. And it is being stripped of its mass by the tidal forces of the Milky Way.
Continue reading “Gaia Spots an Enormous Ghost Galaxy Right Next Door that’s Being Dismantled by the Milky Way”

October 29, 2018 by Evan Gough

Whoa. That’s the Milky Way, Bouncing off the Moon in Radio Waves

Radio waves from our galaxy, the Milky Way, reflecting off the surface of the Moon. Image Credit: Dr Ben McKinley, Curtin University/ICRAR/ASTRO 3D. Moon image courtesy of NASA/GSFC/Arizona State University.

The universe wasn’t always such a well-lit place. It had its own Dark Ages, back in the days before stars and galaxies formed. One of the big questions in astronomy concerns how stars and galaxies shaped the very early days of the Universe. The problem is, there’s no visible light travelling through the Universe from this time period.

Now, a team of astronomers led by Dr. Benjamin McKinley of the International Centre for Radio Astronomy Research (ICRAR) and Curtin University are using the Moon to help unlock these secrets.

Continue reading “Whoa. That’s the Milky Way, Bouncing off the Moon in Radio Waves”