I often drag out the amazing fact that the Andromeda Galaxy, that faint fuzzy blob just off the corner of the Square of Pegasus, is heading straight for us! Of course I continue to tell people it won’t happen for a few billion years yet but a recent study suggests that we are already seeing hypervelocity stars that have been ejected from Andromeda already. It is just possible that the two galaxies have already started to exchange stars long before they are expected to merge.
Continue reading “Are Andromeda and the Milky Way Already Exchanging Stars?”Astronomers Build a 3D Map of Dust Within Thousands of Light-Years
If you explore the night sky it won’t be long before you realise there is a lot of dust and gas up there. The interstellar dust between the stars accounts for 1% of the mass of the interstellar medium but reflects 30% of the starlight in infrared wavelengths. The dust plays a key role in the formation of stars and the evolution of the Galaxy. A team of astronomers have attempted to map the dust out to a distance of 3000 light years and have just released the first 3D map of the dust in our Galaxy.
Continue reading “Astronomers Build a 3D Map of Dust Within Thousands of Light-Years”JWST Sees a Milky Way-Like Galaxy Coming Together in the Early Universe
The gigantic galaxies we see in the Universe today, including our own Milky Way galaxy, started out far smaller. Mergers throughout the Universe’s 13.7 billion years gradually assembled today’s massive galaxies. But they may have begun as mere star clusters.
In an effort to understand the earliest galaxies, the JWST has examined their ancient light for clues as to how they became so massive.
Continue reading “JWST Sees a Milky Way-Like Galaxy Coming Together in the Early Universe”There’s Less Dark Matter at the Core of the Milky Way
Science really does keep you on your toes. First there was matter and then there were galaxies. Then those galaxies had more stuff in the middle so stars further out were expected to move slowly, then there was dark matter as they actually seemed to move faster but now they seem to be moving slower in our Galaxy so perhaps there is less dark matter than we thought after all!
Continue reading “There’s Less Dark Matter at the Core of the Milky Way”Why Don't We See Robotic Civilizations Rapidly Expanding Across the Universe?
In 1950, while sitting down to lunch with colleagues at the Los Alamos Laboratory, famed physicist and nuclear scientist Enrico Fermi asked his famous question: “Where is Everybody?” In short, Fermi was addressing the all-important question that has plagued human minds since they first realized planet Earth was merely a speck in an infinite Universe. Given the size and age of the Universe and the way the ingredients for life are seemingly everywhere in abundance, why haven’t we found any evidence of intelligent life beyond Earth?
This question has spawned countless proposed resolutions since Fermi’s time, including the infamous Hart-Tipler Conjecture (i.e., they don’t exist). Other interpretations emphasize how space travel is hard and extremely time and energy-consuming, which is why species are likely to settle in clusters (rather than a galactic empire) and how we are more likely to find examples of their technology (probes and AI) rather than a species itself. In a recent study, mathematician Daniel Vallstrom examined how artificial intelligence might be similarly motivated to avoid spreading across the galaxy, thus explaining why we haven’t seen them either!
Continue reading “Why Don't We See Robotic Civilizations Rapidly Expanding Across the Universe?”What Would Happen to Earth if a Rogue Star Came Too Close?
Stars are gravitationally fastened to their galaxies and move in concert with their surroundings. But sometimes, something breaks the bond. If a star gets too close to a supermassive black hole, for example, the black hole can expel it out into space as a rogue star.
What would happen to Earth if one of these stellar interlopers got too close?
Continue reading “What Would Happen to Earth if a Rogue Star Came Too Close?”There Aren’t Many Galaxies Like The Milky Way Nearby. Now We Know Why
The Milky Way is a barred spiral galaxy, maybe even a grand design spiral galaxy. We can’t be sure from our vantage point. But one thing is certain: there aren’t many disk galaxies like it in our part of the Universe called the supergalactic plane.
Continue reading “There Aren’t Many Galaxies Like The Milky Way Nearby. Now We Know Why”Gaze Into the Heart of the Milky Way in This Latest JWST Image
Thanks to its infrared capabilities, the James Webb Space Telescope (JWST) allows astronomers to peer through the gas and dust clogging the Milky Way’s center, revealing never-before-seen features. One of the biggest mysteries is the star forming region called Sagittarius C, located about 300 light-years from the Milky Way’s supermassive black hole. An estimated 500,000 stars are forming in this region that’s being blasted by radiation from the densely packed stars. How can they form in such an intense environment?
Right now, astronomers can’t explain it.
Continue reading “Gaze Into the Heart of the Milky Way in This Latest JWST Image”Astronomers Find Dozens of Massive Stars Fleeing the Milky Way
The Milky Way can’t hold onto all of its stars. Some of them get ejected into intergalactic space and spend their lives on an uncertain journey. A team of astronomers took a closer look at the most massive of these runaway stars to see what they could find out how they get ejected.
Continue reading “Astronomers Find Dozens of Massive Stars Fleeing the Milky Way”A Huge New Gaia Data Release: More Stars, Gravitational Lenses and Asteroids
The ESA’s Gaia mission is releasing a new tranche of astronomical data. The mission has released three regular, massive hauls of data since it launched in 2013, named Gaia DR1, DR2, and DR3. The ESA is calling this one a ‘focused product release,’ and while it’s smaller than the previous three releases, it’s still impactful.
Continue reading “A Huge New Gaia Data Release: More Stars, Gravitational Lenses and Asteroids”