Magazine Posts

NASA Astronomy Picture of the Day:

Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232, captured in detail by one of the Very Large Telescopes, is a good example. The visible is dominated by millions of bright stars and dark dust, caught up in a gravitational swirl of spiral arms revolving about the center. Open clusters containing bright blue stars can be seen sprinkled along these spiral arms, while dark lanes of dense interstellar dust can be seen sprinkled between them. Less visible, but detectable, are billions of dim normal stars and vast tracts of interstellar gas, together wielding such high mass that they dominate the dynamics of the inner galaxy. Leading theories indicate that even greater amounts of matter are invisible, in a form we don't yet know. This pervasive dark matter is postulated, in part, to explain the motions of the visible matter in the outer regions of galaxies. Free APOD Lecture: January 9, 2024 to the Amateur Astronomers of Association of New York

January opens the year with moments that altered the course of history. Julius Caesar crosses the Rubicon in defiance of the Roman Senate. The Continental Congress ratifies the Treaty of Paris, securing American independence. In Philadelphia, the first successful balloon flight in the United States lifts into the sky. The month also brings global cooperation and ambition, from the League of Nations convening its first Council meeting to the United States entering the space age with the launch of its first satellite.

January also reflects history’s sharper edges. “Bloody Sunday” echoes through the civil rights movement. The Space Shuttle Challenger disaster shocks the world. In a quieter but symbolic shift, the first McDonald’s opens in Moscow’s Pushkin Square, signaling cultural change at the end of the Cold War. Exploration continues beyond Earth as NASA’s Opportunity rover lands on Mars, extending human reach across the solar system.

Explore historical events throughout January by browsing the full month timeline, or jump to a specific date to see what happened on this day in history—from January 1 through January 31. Use the timeline to research individual years or trace the events that shaped January’s place in history.

NASA Astronomy Picture of the Day:

How did we get here? Click play, sit back, and watch. A computer simulation of the evolution of the universe provides insight into how galaxies formed and perspectives into humanity's place in the universe. The Illustris project exhausted 20 million CPU hours in 2014 following 12 billion resolution elements spanning a cube 35 million light years on a side as it evolved over 13 billion years. The simulation tracks matter into the formation of a wide variety of galaxy types. As the virtual universe evolves, some of the matter expanding with the universe soon gravitationally condenses to form filaments, galaxies, and clusters of galaxies. The featured video takes the perspective of a virtual camera circling part of this changing universe, first showing the evolution of dark matter, then hydrogen gas coded by temperature (0:45), then heavy elements such as helium and carbon (1:30), and then back to dark matter (2:07). On the lower left the time since the Big Bang is listed, while on the lower right the type of matter being shown is listed. Explosions (0:50) depict galaxy-center supermassive black holes expelling bubbles of hot gas. Interesting discrepancies between Illustris and the real universe have been studied, including why the simulation produced an overabundance of old stars.

NASA Astronomy Picture of the Day:

Known to some in the northern hemisphere as December's Cold Moon or the Long Night Moon, the last full moon of 2023 is rising in this surreal mountain and skyscape. The Daliesque scene was captured in a single exposure with a camera and long telephoto lens near Monte Grappa, Italy. The full moon is not melting, though. Its stretched and distorted appearance near the horizon is caused as refraction along the line of sight changes and creates shifting images or mirages of the bright lunar disk. The changes in atmospheric refraction correspond to atmospheric layers with sharply different temperatures and densities. Other effects of atmospheric refraction produced by the long sight-line to this full moon rising include the thin red rim seen faintly on the distorted lower edge of the Moon and a thin green rim along the top.

Photo by Giacomo Venturin

NASA Astronomy Picture of the Day:

In 1986, Voyager 2 became the only spacecraft to explore ice giant planet Uranus close up. Still, this newly released image from the NIRCam (Near-Infrared Camera) on the James Webb Space Telescope offers a detailed look at the distant world. The tilted outer planet rotates on its axis once in about 17 hours. Its north pole is presently pointed near our line of sight, offering direct views of its northern hemisphere and a faint but extensive system of rings. Of the giant planet's 27 known moons, 14 are annotated in the image. Mixed with fuzzy background galaxies, the brighter moons show hints of Webb's characteristic diffraction spikes. And though these worlds of the outer Solar System were unknown in Shakespearean times, all but two of the 27 Uranian moons are named for characters in the English bard's plays.

NASA Astronomy Picture of the Day:

For a brief moment, this brilliant fireball meteor outshone Jupiter in planet Earth's night. The serendipitous image was captured while hunting meteors under cold Canadian skies with a camera in timelapse mode on December 14, near the peak of the Geminid meteor shower. The Geminid meteor shower, asteroid 3200 Phaethon's annual gift, always arrives in December. Dust shed along the orbit of the mysterious asteroid causes the meteor streaks, as the vaporizing grains plow through our fair planet's upper atmosphere at 22 kilometers per second. Of course Geminid shower meteors appear to radiate from a point in the constellation of the Twins. That's below and left of this frame. With bright Jupiter on the right, also in the December night skyview are the Pleiades and Hyades star clusters.

Photo by Gaurav Singh

NASA Astronomy Picture of the Day:

Yes, but can your aurora do this? First, yes, auroras can look like rainbows even though they are completely different phenomena. Auroras are caused by Sun-created particles being channeled into Earth's atmosphere by Earth's magnetic field, and create colors by exciting atoms at different heights. Conversely, rainbows are created by sunlight backscattering off falling raindrops, and different colors are refracted by slightly different angles. Unfortunately, auroras can’t create waterfalls, but if you plan well and are lucky enough, you can photograph them together. The featured picture is composed of several images taken on the same night last month near the Skógafoss waterfall in Iceland. The planning centered on capturing the central band of our Milky Way galaxy over the picturesque cascade. By luck, a spectacular aurora soon appeared just below the curving arch of the Milky Way. Far in the background, the Pleiades star cluster and the Andromeda galaxy can be found. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Photo by Stefano Pellegrini

A community in India called Banda has been facing severe water scarcity due to climate change and overuse of resources. Now it has found a way to combat drought by implementing a system of water budgeting to minimize overuse of resources and water waste.  The villagers have reported an increase in crop yields and have been able to maintain a steady supply of water for their daily needs. More at Reasons to be Cheerful ➜

NASA Astronomy Picture of the Day:

Why is this jellyfish swimming in a sea of stars? Drifting near bright star Eta Geminorum, seen at the right, the Jellyfish Nebula extends its tentacles from the bright arcing ridge of emission left of center. In fact, the cosmic jellyfish is part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded. Light from the explosion first reached planet Earth over 30,000 years ago. Like its cousin in astronomical waters, the Crab Nebula supernova remnant IC 443 is known to harbor a neutron star -- the remnant of the collapsed stellar core. The Jellyfish Nebula is about 5,000 light-years away. At that distance, the featured image would span about 140 light-years across. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Photo by David Payne

"Christians in Bethlehem have been holding a muted celebration to mark Christmas amid the ongoing Israel - Gaza war. Worshippers lit candles and prayed at the nativity scene, with the figures standing amid an installation of rubble and razor wire, outside the Church of the Nativity in Manger Square in Bethlehem. In previous years, Christmas in Bethlehem has seen decorations of a tree and festive lights". More at The BBC ➜

NASA Astronomy Picture of the Day:

Single shots like this require planning. The first step is to realize that such an amazing triple-alignment actually takes place. The second step is to find the best location to photograph it. But it was the third step: being there at exactly the right time -- and when the sky was clear -- that was the hardest. Five times over six years the photographer tried and found bad weather. Finally, just ten days ago, the weather was perfect, and a photographic dream was realized. Taken in Piemonte, Italy, the cathedral in the foreground is the Basilica of Superga, the mountain in the middle is Monviso, and, well, you know which moon is in the background. Here, even though the setting Moon was captured in a crescent phase, the exposure was long enough for doubly reflected Earthlight, called the da Vinci glow, to illuminate the entire top of the Moon. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Photo by Valerio Minato