galaxy

Kepler’s forgotten ideas about symmetry help explain spiral galaxies without the need for dark matter – new research

Kepler’s forgotten ideas about symmetry help explain spiral galaxies without the need for dark matter – new research

The 17th-century astronomer Johannes Kepler was the first to muse about the structure of snowflakes. Why are they so symmetrical? How does one side know how long the opposite side has grown? Kepler thought it was all down to what we would now call a “morphogenic field” – that things want to have the form they have. Science has since discounted this idea. But the question of why snowflakes and similar structures are so symmetrical is nevertheless not entirely understood.

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

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

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.

Gaia Sees Stars Out in Deep Space, Flying Between Galaxies

Gaia Sees Stars Out in Deep Space, Flying Between Galaxies

In December of 2013, the European Space Agency (ESA) launched the Gaia mission. Since that time, this space observatory has been busy observing over 1 billion astronomical objects in our galaxy and beyond – including stars, planets, comets, asteroids, quasars, etc. – all for the sake of creating the largest and most precise 3D space catalog ever made.

The Milky Way is Still Rippling from a Galactic Collision Millions of Years Ago

The Milky Way is Still Rippling from a Galactic Collision Millions of Years Ago

Between 300 million and 900 million years ago, our Milky Way galaxy nearly collided with the Sagittarius dwarf galaxy. Data from the ESA’s Gaia mission shows the ongoing effect of this event, with stars moving like ripples on the surface of a pond. The galactic collision is part of an ongoing cannibalization of the dwarf galaxy by the much-larger Milky Way.

Beaming with the Light of Millions of Suns

Beaming with the Light of Millions of Suns

In the 1980s, scientists started discovering a new class of extremely bright sources of X-rays in galaxies. These sources were a surprise, as they were clearly located away from the supermassive black holes found in the center of galaxies. At first, researchers thought that many of these ultraluminous X-ray sources, or ULXs, were black holes containing masses between about a hundred and a hundred thousand times that of the sun. Later work has shown some of them may be stellar-mass black holes, containing up to a few tens of times the mass of the sun.

Did the milky way steal these stars or kick them out of the galaxy?

Did the milky way steal these stars or kick them out of the galaxy?

Despite thousands of years of research and observation, there is much that astronomers still don’t know about the Milky Way Galaxy. At present, astronomers estimate that it spans 100,000 to 180,000 light-years in diameter and consisting of 100 to 400 billion stars. In addition, for decades, there have been unresolved questions about how the structure of our galaxy evolved over the course of billions of years.

When galaxies collide, size matters if you want to know the fate of our Milky Way

When galaxies collide, size matters if you want to know the fate of our Milky Way

Our Milky Way and the Andromeda galaxy – two giant galaxies in our local patch of the universe – are heading for an immense collision with each other in only a few billion years’ time. So which will dominate in this intergalactic tussle?

A Lonely Beauty

A Lonely Beauty

Beauty, grace, mystery — this magnificent spiral galaxy has all the qualities of a perfect galactic Valentine. Captured by the NASA/ESA Hubble Space Telescope, the galaxy NGC 3344 presents itself face-on, allowing astronomers a detailed look at its intricate and elegant structure. And Hubble’s ability to observe objects over a wide range of different wavelengths reveals features that would otherwise remain invisible.

Astronomers start mapping the structure of the far side of the milky way

Astronomers start mapping the structure of the far side of the milky way

Since the 18th century, astronomers have been aware that our Solar System is embedded in a vast disk of stars and gas known as the Milky Way Galaxy. Since that time, the greatest scientific minds have been attempting to obtain accurate distance measurements in order to determine just how large the Milky Way is. This has been no easy task, since the fact that we are embedded in our galaxy’s disk means that we cannot view it head-on.

Method to weigh galaxy clusters could help us understand mysterious ‘dark matter’ structures

Method to weigh galaxy clusters could help us understand mysterious ‘dark matter’ structures

The furthest galaxy ever observed is so far away that the starlight we now detect was emitted less than 500m years after the Big Bang. It has taken about 13 billion years to reach us. But there’s a lot of things about a galaxy that we can’t see. For example, we think galaxies are immersed within gigantic “halos” of an invisible substance dubbed dark matter. Scientists don’t actually know what dark matter is, but they know it exists because it has a gravitational pull on surrounding matter.

Hubble's Twisted Galaxy

Hubble's Twisted Galaxy

Gravity governs the movements of the cosmos. It draws flocks of galaxies together to form small groups and more massive galaxy clusters, and brings duos so close that they begin to tug at one another. This latter scenario can have extreme consequences, with members of interacting pairs of galaxies often being dramatically distorted, torn apart, or driven to smash into one another, abandoning their former identities and merging to form a single accumulation of gas, dust and stars.

What is the name of our Galaxy?

What is the name of our Galaxy?

Since prehistoric times, human beings have looked up at at the night sky and pondered the mystery of the band of light that stretches across the heavens. And while theories have been advanced since the days of Ancient Greece as to what it could be, it was only with the birth of modern astronomy that scholars have come come to know precisely what it is – i.e. countless stars at considerable distances from Earth.

New insights into the early universe’s galaxy clusters

New insights into the early universe’s galaxy clusters

Molecular gas is the raw material which fuels star formation throughout the universe. Now, using the revolutionary Atacama Large Millimeter Array (ALMA) telescope, an international team of scientists has conducted one of the largest studies of molecular gas in distant galaxy clusters — rare conglomerations containing hundreds of galaxies, trillions of stars, and dark matter.  

NASA’s Cassini, Voyager Missions Suggest New Picture of Sun’s Interaction with Galaxy

NASA’s Cassini, Voyager Missions Suggest New Picture of Sun’s Interaction with Galaxy

New data from NASA’s Cassini mission, combined with measurements from the two Voyager spacecraft and NASA’s Interstellar Boundary Explorer, or IBEX, suggests that our sun and planets are surrounded by a giant, rounded system of magnetic field from the sun — calling into question the alternate view of the solar magnetic fields trailing behind the sun in the shape of a long comet tail.

Ancient Stardust Sheds Light on the First Stars - Most distant object ever observed by ALMA

Ancient Stardust Sheds Light on the First Stars - Most distant object ever observed by ALMA

Astronomers have used ALMA to detect a huge mass of glowing stardust in a galaxy seen when the Universe was only four percent of its present age. This galaxy was observed shortly after its formation and is the most distant galaxy in which dust has been detected. This observation is also the most distant detection of oxygen in the Universe. These new results provide brand-new insights into the birth and explosive deaths of the very first stars.

A Galaxy on the Edge

A Galaxy on the Edge

This colourful stripe of stars, gas, and dust is actually a spiral galaxy named NGC 1055. Captured here by ESO’s Very Large Telescope (VLT), this big galaxy is thought to be up to 15 percent larger in diameter than the Milky Way. NGC 1055 appears to lack the whirling arms characteristic of a spiral, as it is seen edge-on. However, it displays odd twists in its structure that were probably caused by an interaction with a large neighbouring galaxy.