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.Continue reading “The Solar System Might Not Exist if There Wasn’t a Huge Galactic Collision with the Milky Way Billions of Years Ago”
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.Continue reading “Decaying Dark Matter Should be Visible Here in the Milky Way as a Halo Around the Galaxy”
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.Continue reading “Dark Matter Could Be A Source of Gamma Rays Coming from the Center of the Milky Way”
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.Continue reading “This Astrophotographer Makes the World Turn and the Sky Stand Still”
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.Continue reading “Milky Way’s Black Hole Just Flared, Growing 75 Times as Bright for a Few Hours”
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.Continue reading “What Did the Early Milky Way Look Like?”
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.Continue reading “This is What It’ll Look Like When the Milky Way and Andromeda Galaxies Collide Billions of Years from Now”
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.Continue reading “Thanks to Gaia, We Now Know Exactly When We’ll be Colliding with Andromeda”
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”
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.