Contributor Posts

NASA Astronomy Picture of the Day:

One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear. The sharp, detailed telescopic view reveals M81's bright yellow nucleus, blue spiral arms, pinkish starforming regions, and sweeping cosmic dust lanes. But some dust lanes actually cut across the galactic disk (left of center), contrary to other prominent spiral features. The errant dust lanes may be the lingering result of a close encounter between M81 and the nearby galaxy M82 lurking outside of this frame. Scrutiny of variable stars in M81 has yielded a well-determined distance for an external galaxy -- 11.8 million light-years.

Photo by Lorand Fenyes

NASA Astronomy Picture of the Day:

You'd think the Pacman Nebula would be eating stars, but actually it is forming them. Within the nebula, a cluster's young, massive stars are powering the pervasive nebular glow. The eye-catching shapes looming in the featured portrait of NGC 281 are sculpted dusty columns and dense Bok globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000 light-years away in the constellation Cassiopeia. This sharp composite image was made through narrow-band filters in Spain in mid 2024. It combines emissions from the nebula's hydrogen and oxygen atoms to synthesize red, green, and blue colors. The scene spans well over 80 light-years at the estimated distance of NGC 281.

Photo by Juan Montilla (AAE)

NASA Astronomy Picture of the Day:

What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however -- taken from Norman, Oklahoma (USA) -- has been digitally processed to exaggerate the colors. The gray color on the upper right of the top lunar image is the Moon's natural color, directly illuminated by sunlight. The lower parts of the Moon on all three images are not directly lit by the Sun since it is being eclipsed -- it is in the Earth's shadow. It is faintly lit, though, by sunlight that has passed deep through Earth's atmosphere. This part of the Moon is red -- and called a blood Moon -- for the same reason that Earth's sunsets are red: because air scatters away more blue light than red. The unusual purple-blue band visible on the upper right of the top and middle images is different -- its color is augmented by sunlight that has passed high through Earth's atmosphere, where red light is better absorbed by ozone than blue. Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)

Photo by Zixiong Jin

Albert Einstein (March 14, 1879, - April 18, 1955)

NASA Astronomy Picture of the Day:

This was once a beach -- on ancient Mars. The featured 360-degree panorama, horizontally compressed, was taken in 2017 by the robotic Curiosity rover that explored the red planet. Named Ogunquit Beach after its terrestrial counterpart, evidence shows that at times long ago the area was underwater, while at other times it was at the edge of an ancient lake. The light peak in the central background is the top of Mount Sharp, the central feature in Gale Crater where Curiosity explored. Portions of the dark sands in the foreground were scooped up for analysis. The light colored bedrock is composed of sediment that likely settled at the bottom of the now-dried lakebed. The featured panorama (interactive version here) was created from over 100 images and seemingly signed by the rover on the lower left.

NASA Astronomy Picture of the Day:

What's the sound of one laser zapping? There's no need to consult a Zen master to find out, just listen to the first acoustic recording of laser shots on Mars. On Mars Rover Perseverance mission sol 12 (March 2, 2021) the SuperCam instrument atop the rover's mast zapped a rock dubbed Ma'az 30 times from a range of about 3.1 meters. Its microphone recorded the soft staccato popping sounds of the rapid series of SuperCam laser zaps. Shockwaves created in the thin Martian atmosphere as bits of rock are vaporized by the laser shots make the popping sounds, sounds that offer clues to the physical structure of the target. This SuperCam close-up of the Ma'az target region is 6 centimeters (2.3 inches) across. Ma'az means Mars in the Navajo language.

"Power in the Middle East shifted in 2025, with Sunni groups gaining influence while Shiite factions linked to Iran weakened. Political turmoil, economic struggles, and escalating conflicts—especially between Israel and Iran—deepened instability, hindering regional diplomacy, development, and prospects for long-term peace." More at The Wilson Center ➜

NASA Astronomy Picture of the Day:

This popular group leaps into the early evening sky around the March equinox and the northern hemisphere spring. Famous as the Leo Triplet, the three magnificent galaxies found in the prominent constellation Leo gather here in one astronomical field of view. Crowd pleasers when imaged with even modest telescopes, they can be introduced individually as NGC 3628 (bottom left), M66 (middle right), and M65 (top center). All three are large spiral galaxies but tend to look dissimilar, because their galactic disks are tilted at different angles to our line of sight. NGC 3628, also known as the Hamburger Galaxy, is temptingly seen edge-on, with obscuring dust lanes cutting across its puffy galactic plane. The disks of M66 and M65 are both inclined enough to show off their spiral structure. Gravitational interactions between galaxies in the group have left telltale signs, including the tidal tails and warped, inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous view of the region spans over 1 degree (two full moons) on the sky. Captured with a telescope from Sawda Natheel, Qatar, planet Earth, the frame covers over half a million light-years at the Leo Trio's estimated 30 million light-year distance.

Photo by Rabeea Alkuwari

NASA Astronomy Picture of the Day:

Recorded from 2024 March 10, to 2025 March 1, this composited series of images reveals a pattern in the seasonal drift of the Sun's daily motion through planet Earth's sky. Known to some as an analemma, the figure-eight curve was captured in exposures taken on the indicated dates only at 18:38 UTC from the exact same location south of Stephenville, Texas. The Sun's position on the 2024 solstice dates of June 20 and December 21 would be at the top and bottom of the curve and correspond to the astronomical beginning of summer and winter in the north. Points that lie along the curve half-way between the solstices would mark the equinoxes. The 2024 equinox on September 22, and in 2025 the equinox on March 20 (today) are the start of northern fall and spring. And since one of the exposures was made on 2024 April 8 from the Stephenville location at 18:38:40 UTC, this analemma project also reveals the solar corona in planet Earth's sky during a total solar eclipse.

Photo by Hunter Wells

There are only two moments each year when the Sun lies directly above Earth’s equator. These moments are the equinoxes, when, at any location, the lengths of day and night are roughly equal. The March equinox happens sometime between March 19 and 21. The September equinox occurs sometime between September 21 and 24.
In the Northern Hemisphere, the March equinox marks the beginning of Spring and the September equinox the beginning of Fall. The reverse takes place in the Southern Hemisphere.

NASA Astronomy Picture of the Day:

On March 14 the Full Moon slid through Earth's dark umbral shadow and denizens of planet Earth were treated to a total lunar eclipse. Of course, from the Moon's near side that same astronomical syzygy was seen as a solar eclipse. Operating in the Mare Crisium on the lunar surface, the Blue Ghost lander captured this video frame of Earth in silhouette around 3:30am CDT, just as the Sun was emerging from behind the terrestrial disk. From Blue Ghost's lunar perspective the beautiful diamond ring effect, familiar to earthbound solar eclipse watchers, is striking. Since Earth appears about four times the apparent size of the Sun from the lunar surface the inner solar corona, the atmosphere of the Sun most easily seen from Earth during a total solar eclipse, is hidden from view. Still, scattering in Earth's dense atmosphere creates the glowing band of sunlight embracing our fair planet.

Carl Edward Sagan (1934 – 1996) ~ American astronomer, planetary scientist and science communicator. He was one of the most well-known scientist of the 1970's and 1980's . He was controversial in scientific, political, and religious circles for his views on extraterrestrial intelligence, nuclear weapons, and religion. His best known scientific contribution is his research on the possibility of extraterrestrial life. He was an advocate for nuclear disarmament and co-wrote and hosted 'Cosmos: A Personal Voyage.'  He was widely regarded as a freethinker and one of his most famous quotations, in Cosmos, was, "Extraordinary claims require extraordinary evidence.