Nobody realized that something was missing until 1932.

That was the year that Jan Hendrik Oort made a startling discovery. The Dutch astronomer was measuring the speed of stars in our galaxy, and something was wrong with his calculations. Just as it keeps humans tethered to the Earth, and the Earth looping around the Sun, gravity keeps all the stars in a galaxy clustered together. Oort knew that any stars he observed in the galaxy were held in by gravity. But gravity depends on mass, and a lot of gravitational pull requires a lot of material. Yet when Oort measured the speed of the stars and added up all the mass he could see in our galaxy, he found there was too little mass to keep the stars from hurtling right out of the galaxy. In fact, he could only see only one-third of the mass that was necessary. Oort thought he must have failed to account for some dim or hidden stars.   Full Article »

In the 1920s, a group of young women began showing symptoms of a horrific, but unknown, disease. Many developed mouth sores and lost weight. Some found their jaws extending into a cancerous mimicry of a pharaoh’s beard, tumors sprouting from their bones. Their blood cells and body tissues died, causing anemia and necrosis. Full Article »

If you think back to elementary school, you probably remember learning about the states of matter—solids, liquids, and gases. To get from one state to the next, you need to add or remove heat. Cool down water to make ice. Heat it up to make steam. But nature has a funny way of taking the apparently simple—in this case, the states of matter—and doing profoundly weird stuff. Full Article »

When hunting down the origins of the solar system, it’s all in the Belt

In 1930, a 23-year-old self-taught astronomer named Clyde Tombaugh saw something move in the sky. Working for Lowell Observatory in Arizona, Tombaugh had spent the last ten months photographing tiny patches of the night sky, taking one picture of each individual location then another of the same location several days later. Using a device called a blink comparator, which could rapidly flip from one photo to the next, Tombaugh spotted an object that seemed to jump between the pictures. On March 13, 1930, Lowell Observatory announced the discovery of the dwarf plant that would later be called Pluto. Full Article »

Do you ever look around your apartment and think, where did all this stuff come from? Maybe some of your clothes or books or tchotchkes are unnecessary, and you could stand to de-clutter. Or, to take the very long view—the universe’s view—not only are your books not necessary, but neither are most of the elements that make up your books, your other possessions, or indeed you yourself. There was a time in the universe’s infancy when these elements didn’t exist, and yet somehow the universe managed to create them all, along with you and everything else you can see. Full Article »

Between 3.5 and 4 billion years ago, water carved valleys into the Red Planet’s surface. But as planetary scientists try to understand the ancient Martian climate that caused this erosion, the answers from different scientific approaches don’t add up. Read the full story on NOVA Next.

By tracking galaxies like water drops in a river system, an international team of astronomers has mapped and named the enormous network of galaxies, in which the Milky Way resides. The structure—100 times more massive than previously believed—has been christened Laniakea, Hawaiian for “immeasurable heaven.” Full Article »

Our Milky Way galaxy is vast—100,000 light-years across—but even the Milky Way is part of something larger. As astronomers zoom out to larger and larger scales, they see galaxies bunching up into clusters and these clusters into superclusters.

Astronomers have recently mapped our home supercluster and found that it is five times larger than previously thought. The Milky Way is just one peripheral blip out of 100,000 galaxies. A team led by Brent Tully at the University of Hawaii in Honolulu used a new method to define this supercluster, which they named Laniakea, meaning “immeasurable heaven” in Hawaiian. Laniakea is 500 million light-years across. If the supercluster were as tall as a three-story house, the entire Milky Way would fit inside the head of a pin. Full Article »

Brown dwarf W0855 was already special. A few times the size of Jupiter and super-cold, it’s halfway between a star and free-floating planet. Now ice clouds have been tentatively found in its atmosphere—which would mark the first time they’ve ever been seen on an extrasolar world…

This story appears in full on NOVA Next.