At its death, our universe will be unrecognizable and, unfortunately, no Homo sapiens will exist to witness it or capture the event in poetry or film: “Galaxies will have dispersed, black holes will have evaporated, and the expansion of the universe will have pulled all remaining objects so far apart that none will ever see any of the others explode. It won’t even be physically possible for light to travel that far,” says theoretical physicist Matt Caplan, about the far off heat death of the cosmos which will then be mostly black holes and burned out stars.
One of the brightest stars in the night sky, Betelgeuse is now so huge that if it replaced the Sun at the center of our solar system, its outer surface would extend past the orbit of Jupiter–a star so huge it could collapse into a black hole or neurton star, which would mwake it the closest black hole to Earth only 725 light-years away. Betelgeuse may one day join a string of supernovae that went off over the past 10 million years—a blink of an eye in galactic terms–with two of them near enough to hit Earth with radioactive particles.
“Planet Earth Report” provides descriptive links to headline news by leading science journalists about the extraordinary discoveries, technology, people, and events changing our knowledge of Planet Earth and the future of the human species.
It’s difficult to fully appreciate how much our picture of the universe has changed in the span of a single human lifetime. A century ago, the universe was viewed as static and eternal, consisting of one single “island” galaxy, our Milky Way, surrounded by vast, infinite, dark, and empty space. “With increasing distance,” said Edwin Hubble, “our knowledge fades, and fades rapidly. Eventually, we reach the dim boundary—the utmost limits of our telescopes.”
In the fall of 2018, astronomers reported the detection of 39 dwarf galaxies orbiting the Milky Way, with many yet to be discovered that are hiding at large distances from the galactic center, one of which was a strangely large and dim ‘Ghost’ dwarf hiding at the edge of the Milky Way. The object is about the same size as the 7,000 light-year-wide Large Magellanic Cloud (LMC), which is the Milky Way’s largest satellite galaxy, yet 10,000 times fainter. The discovery suggests other nearby “ghost” galaxies could exist undetected.
This June, 2020, NASA announced that intelligent computer systems will be installed on space probes to direct the search for life on distant planets and moons, starting with the 2022/23 ESA ExoMars mission, before moving beyond to moons such as Jupiter’s Europa, and of Saturn’s Enceladus and Titan.
Our solar system’s ice giants are bizarre worlds of extremes… if you were born at one of Uranus’s poles, for example, you would be middle-aged at sunset and a very old, 84-year old before it was time for a second sunrise and by the time of a second dawn on Neptune, a dark, cold world, whipped by supersonic winds that can reach up 1,500 miles per hour, you would be 165. But their real stories going back billions of years, lie locked in their water.
