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!
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?
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.
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?
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.
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.
When you launch humanity’s most powerful telescope, you expect results. The JWST has delivered excellent results by detecting ancient galaxies, identifying chemicals in exoplanet atmospheres, and peering into star-forming regions with more detail and clarity than any other telescope.
But every time a new telescope is about to enter service, astronomers tell us they’re excited not only about the expected results but also about the surprising results. And like other telescopes, the JWST has also delivered some surprises. While going about its business, the JWST has discovered 21 brown dwarfs.
There’s an unusual object near the Milky Way’s heart that astronomers call “The Brick.” It’s a massive cloud of gas called an infrared dark cloud (IDC). The Brick is dense and turbulent like others of its type, but for some reason, it shows few signs of star formation.
Until recently, there were only ten known stars on trajectories that will allow them to escape the Milky Way Galaxy, thrown astray by powerful supernova explosions. A new study using data from ESA’s Gaia survey this June has revealed an additional six runaways, two of which break the record for the fastest radial velocity of any runaway star ever seen: 1694 km/s and 2285 km/s.
How do you weigh a galaxy? It’s an astronomical challenge, particularly if it’s the galaxy you call home. It turns out there are several ways to get a handle on the mass of the Milky Way, and a recent study summarizes these methods to present the best value.