Space and astronomy news
Although they are very different today, Venus, Earth, and Mars were very similar in their youth. All three were warm, with thick, water-rich atmospheres. But over time, Mars became a cold, dry planet with a thin atmosphere, and Venus became superheated, with a crushing, toxic sky. Only Earth became a warm ocean world teeming with life. But why?
Continue reading “Maybe Venus Was Never Habitable”
In a few billion years, our Sun will die. It will first enter a red giant stage, swelling in size to perhaps the orbit of Earth. Its outer layers will be cast off into space, while its core settles to become a white dwarf. Life on Earth will boil away, and our planet itself might be consumed by the Sun. White dwarfs are the fate of all midsize stars, and given the path of their demise, it seems reasonable to assume that any planets die with their sun. But the fate of white dwarf planets may not be lifeless after all.
Continue reading “White Dwarfs Could Have Habitable Planets, Detectable by JWST”
In our search for exoplanets, we’ve found that many of them fall into certain types or categories, such as Hot Jupiters, Super-Earths, and Ice Giants. While we don’t have any examples of the first two in our solar system, we do have two Ice Giants: Uranus and Neptune. They are mid-size gas planets formed in the cold outer regions of the solar system. Because of this, they are rich in water and other volatile compounds, and they are very different from large gas giants such as Jupiter. We still have a great deal to learn about these worlds, but what we’ve discovered so far has been surprising, such as the nature of their magnetic fields.
Continue reading “What's Inside Uranus and Neptune? A New Way to Find Out”
We have studied the skies for centuries, but we have only found two objects known to come from another star system. The first interstellar object to be confirmed was 1I/2017 U1, more commonly known as ?Oumuamua. It was discovered with the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) and stood out because of its large proper motion. Because ?Oumuamua swept through the inner solar system, it was relatively easy to distinguish. The second interstellar object, 2I/Borisov, stood out because it entered the inner solar system from well above the orbital plane. But while we have only discovered two alien visitors so far, astronomers think interstellar objects are common. It’s estimated that several of them visit our solar system each year, and there may be thousands within the orbit of Neptune on any given day. They just don’t stand out, so we don’t notice them. But that could soon change.
Continue reading “Interstellar Objects Can't Hide From Vera Rubin”
We’ve known for a while that complex chemistry occurs in space. Organic molecules have been detected in cold molecular clouds, and we have even found sugars and amino acids, the so-called “building blocks of life,” within several asteroids. The raw ingredients of terrestrial life are common in the Universe, and meteorites and comets may have even seeded Earth with those ingredients. This idea isn’t controversial. But there is a more radical idea that Earth was seeded not just with the building blocks of life but life itself. It’s known as panspermia, and a recent study has brought the idea back to popular science headlines. But the study is more subtle and interesting than some headlines suggest.
Continue reading “Asteroid Samples Returned to Earth Were Immediately Colonized by Bacteria”
NGC 4594 is an unusual galaxy. It was discovered in 1781 by Pierre Méchain, and is striking because of a symmetrical ring of dust that encircles the visible halo of the galaxy. Images taken of the galaxy in 2003 show this dusty ring in detail, where it almost resembles the brim of a large hat. So it’s understandable that NGC 4594 is more commonly known as the Sombrero Galaxy. Now the James Webb Space Telescope has captured an amazingly sharp image of the galaxy, and it’s revealing some interesting surprises.
Continue reading “Fantastic New Image of the Sombrero Galaxy From Webb”
When Albert Einstein introduced his theory of general relativity in 1915, it changed the way we viewed the Universe. His gravitational model showed how Newtonian gravity, which had dominated astronomy and physics for more than three centuries, was merely an approximation of a more subtle and elegant model. Einstein showed us that gravity is not a mere force but is rather the foundation of cosmic structure. Gravity, Einstein said, defined the structure of space and time itself.
Continue reading “Einstein Predicted How Gravity Should Work at the Largest Scales. And He Was Right”
Earth and Mars were very similar in their youth. Four billion years ago, both planets had vast, warm seas. But while Earth retained its oceans, the waters of Mars evaporated away or froze beneath its dusty surface. Exactly why these two worlds took such divergent paths is unclear, though it may lie in the origins of their water.
Continue reading “There was Hot Water on Mars 4.45 Billion Years Ago”
Earth and Mars are the only two rocky planets in the solar system to have moons. Based on lunar rock samples and computer simulations, we are fairly certain that our Moon is the result of an early collision between Earth and a Mars-sized protoplanet called Theia. Since we don’t have rock samples from either Martian moon, the origins of Deimos and Phobos are less clear. There are two popular models, but new computer simulations point to a compromise solution.
Continue reading “New Supercomputer Simulation Explains How Mars Got Its Moons”
Every now and then, astronomers will detect an odd kind of radio signal. So powerful it can outshine a galaxy, but lasting only milliseconds. They are known as fast radio bursts (FRBs). When they were first discovered a couple of decades ago, we had no idea what might cause them. We weren’t even sure if they were astronomical in origin. FRB’s were so localized and so short-lived, it was difficult to gather data on them. But with wide-field radio telescopes such as CHIME we can now observe FRBs regularly and have a pretty good idea of their source: magnetars.
Continue reading “Are Fast Radio Bursts Caused by Interstellar Objects Crashing Into Neutron Stars?”