This serene view from the coast of Sweden looks across the Baltic sea and compresses time, presenting the passage of one night in a single photograph. From sunset to sunrise, moonlight illuminates the creative sea and skyscape. Fleeting clouds, fixed stars, and flowing northern lights leave their traces in planet Earth's sky. To construct the timelapse image, 3296 video frames were recorded on the night of a nearly full moon between 7:04pm and 6:35am local time. As time progresses from left to right, a single column of pixels was taken from the corresponding individual frame and combined in sequence into a single digital image 3296 pixels wide.

Recorded during 2017, timelapse sequences from the International Space Station are compiled in this serene video of planet Earth at Night. Fans of low Earth orbit can start by enjoying the view as green and red aurora borealis slather up the sky. The night scene tracks from northwest to southeast across North America, toward the Gulf of Mexico and the Florida coast. A second sequence follows European city lights, crosses the Mediterranean Sea, and passes over a bright Nile river in northern Africa.

Just two weeks ago, dark skies over the desert in northern Iran held this alluring celestial vista. The dramatic digital mosaic finds the Moon and Mars alongside the Milky Way's dusty rifts, stars, and nebulae. Captured through a series of exposures to cover a range in brightness, that night's otherwise Full Moon is immersed in Earth's shadow. It actually appears fainter and redder than the Red Planet itself during the widely watched total lunar eclipse. For cosmic tourists, the skyscape also includes the Lagoon (M8) and Trifid (M20) nebulae and planet Saturn shining against the Milky Way's pale starlight.

What's that green streak in front of the Andromeda galaxy? A meteor.

On September 26, 2022, NASA’s Double Asteroid Redirection Test (DART) spacecraft crashed into a binary asteroid system. By intentionally ramming a probe into the 160-meter-wide moonlet named Dimorphos, the smaller of the two asteroids, humanity demonstrated that the kinetic impact method of planetary defense actually works. The immediate result was that Dimorphos’ orbital period around Didymos, its larger parent body, was slashed by 33 minutes.

Of course, altering a moonlet’s local orbit doesn’t seem like enough to safeguard Earth from civilization-ending impacts. But now, as long-term observational data has come in, it seems we accomplished more than that. DART actually changed the trajectory of the entire Didymos binary system, altering its orbit around the Sun. //

Because Dimorphos orbits Didymos, some of the ejecta remained trapped in the system, where it altered the mutual orbit between the two rocks. But a crucial fraction of the ejecta achieved escape velocity from the entire binary system. The momentum carried away by the system-escaping debris is what ultimately contributed to shoving the center of mass of the whole Didymos-Dimorphos pair. “In our case, we found that the beta parameter due to DART impact was around two,” Makadia explained.

The debris blasted completely out of the Didymos system gave the asteroids a push roughly equal to the initial impact of the spacecraft itself. //

The goal of DART was primarily to take our planetary defense out of the realm of computer models and get us some hands-on, practical experience, and Makadia thinks we succeeded in doing that. “Our work proves that hitting the secondary asteroid is a viable path for deflecting a binary system away as long as the push is large enough,” he said. “This wasn’t the goal of DART, but we can always design a bigger spacecraft.”

This is the thermal IR (LWIR) of the total lunar eclipse. A 12" Newtonian has been used as fore-optics. Pseudo color to enhance the details. The pictures shows some younger craters are very bright when the sun is temporarily blocked by the Earth.

MST 20260303 03:35 Partial Lunar Eclipse Thermal Vs. Visible (HDR) Fun to see the dramatic difference on the surface in difference wavelength ranges

Cradled in red-glowing hydrogen gas, stars are being born in Orion. These stellar nurseries lie at the edge of the giant Orion molecular cloud complex, some 1,500 light-years away. This detailed view spans about 12 degrees across the center of the well-known constellation, with the Great Orion Nebula, the closest large star-forming region, visible toward the lower right. The deep mosaic also includes, near the top center, the Flame Nebula and the Horsehead Nebula.

What does the universe look like through infrared goggles? Our eyes can only see visible light, but astronomers want to see more. Today’s APOD shows spiral galaxy IC 5332 as seen by two NASA telescopes: Webb in mid-infrared and Hubble in ultraviolet and visible light. To toggle between the two space-based views just slide your cursor over the image (or follow this link). The Hubble image highlights the spiral arms of the galaxy separated by dark regions, whereas the Webb image reveals a finer, more tangled structure. Interstellar dust scatters and absorbs light from the stars in the galaxy, causing the dark dust lanes in the Hubble image, and then emits heat in infrared light, so dust glows in this Webb image. The Mid-InfraRed Instrument on Webb needs to operate at a chilling temperature of -266ºC (or - 447ºF), otherwise it would detect infrared radiation from the telescope itself. Combining these observations, astronomers connect the “small scale” of gas and stars to the truly large scale of galactic structure and evolution.

Analemma image taken between 2021 and 2022, with images taken at 4 p.m. on a weekly basis, clouds permitting. The analemma was calibrated and overlaid with an image taken over Lake Varese in the late afternoon of the winter solstice in 2021, featuring one of the many swans that flock to the shores of Lake Varese in the foreground. Canon 400D + Sigma zoom lens 10 mm. Happy solstice!

Can you tell that today is a solstice by the tilt of the Earth? Yes. At a solstice, the Earth's terminator -- the dividing line between night and day -- is tilted the most. The featured time-lapse video demonstrates this by displaying an entire year on planet Earth in twelve seconds. From geosynchronous orbit, the Meteosat 9 satellite recorded infrared images of the Earth every day at the same local time. The video started at the September 2010 equinox with the terminator line being vertical: an equinox. As the Earth revolved around the Sun, the terminator was seen to tilt in a way that provides less daily sunlight to the northern hemisphere, causing winter in the north. At the most tilt, winter solstice occurred in the north, and summer solstice in the south. As the year progressed, the March 2011 equinox arrived halfway through the video, followed by the terminator tilting the other way, causing winter in the southern hemisphere -- and summer in the north. The captured year ends again with the September equinox, concluding another of the billions of trips the Earth has taken -- and will take -- around the Sun.

Eclipse tables in the Dresden Codex were based on lunar tables and adjusted for slippage over time. //

The Maya used three primary calendars: a count of days, known as the Long Count; a 260-day astrological calendar called the Tzolk’in; and a 365-day year called the Haab’. Previous scholars have speculated on how awe-inspiring solar or lunar eclipses must have seemed to the Maya, but our understanding of their astronomical knowledge is limited. Most Maya books were burned by Spanish conquistadors and Catholic priests. Only four hieroglyphic codices survive: the Dresden Codex, the Madrid Codex, the Paris Codex, and the Grolier Codex. //

They concluded that the codex’s eclipse tables evolved from a more general table of successive lunar months. The length of a 405-month lunar cycle (11,960 days) aligned much better with a 260-day calendar (46 x 260 =11,960) than with solar or lunar eclipse cycles. This suggests that the Maya daykeepers figured out that 405 new moons almost always came out equivalent to 46 260-day periods, knowledge the Maya used to accurately predict the dates of full and new moons over 405 successive lunar dates.

The daykeepers also realized that solar eclipses seemed to recur on or near the same day in their 260-day calendar and, over time, figured out how to predict days on which a solar eclipse might occur locally. “An eclipse happens only on a new moon,” said Lowry. “The fact that it has to be a new moon means that if you can accurately predict a new moon, you can accurately predict a one-in-seven chance of an eclipse. That’s why it makes sense that the Maya are revising lunar predicting models to have an accurate eclipse, because they don’t have to predict where the moon is relative to the ecliptic.” //

“The traditional interpretation was that you run through the table, eclipse by eclipse, and then you rebuilt the table every iteration,” said Lowry. “We figured out that if you do that, you’re going to miss the eclipses, and we know they didn’t. They made internal adjustments. We think they’d restart the table midway. When you do that, you go from having missed eclipses to having none. You would never miss an eclipse. So it’s not a calculated predictive table, it’s a calculated predictive table plus adjustments based on empirical observations over time.”

“This is the basis of true science, empirically collected, constant revision of expectations, built into a system of understanding planetary bodies, so that you can predict when something happens,” said Lowry.

On June 30, 1973, a supersonic jet screamed across the African sky at 58,000 feet, chasing darkness at 1,450 miles per hour. Inside Concorde 001, seven scientists peer through holes cut in the roof, watching the longest solar eclipse in human history unfold. //

Over Africa, the Moon’s shadow raced across Earth at over 1,300 miles per hour. Ground observers got seven minutes before the shadow moved on. But Concorde at Mach 2.2 could actually outrun the shadow, staying locked in totality for as long as fuel lasted. //

Height mattered as much as speed. At 58,000 feet, the aircraft flew above weather, water vapor, and atmospheric turbulence that would blur ground observations. The combination of speed, altitude, and precise navigation created a stable observatory hurtling through space faster than a rifle bullet.

Perseid Meteors from Durdle Door

The limestone arch in the foreground in Dorset, England is known as Durdle Door, a name thought to survive from a thousand years ago.

While most people witness only the familiar crack of thunder and flash of lightning from storms on Earth, brilliantly-colorful electric fireworks detonate much higher, in the thin air up to 55 miles overhead, easily seen from the ISS.

These brief spectacles – blue jets, red sprites, violet halos, ultraviolet rings – are collectively known as transient luminous events, or TLEs.

For decades, they eluded systematic study, appearing only in pilots’ anecdotes and the occasional lucky photograph.

The International Space Station (ISS) has changed that by offering an unobstructed seat above the storms, where specialized cameras and sensors capture every fleeting spark.

Sunrise, sunset, moon phase

Earth is expected to spin more quickly in the coming weeks, making some of our days unusually short. On July 9, July 22 and Aug. 5, the position of the moon is expected to affect Earth's rotation so that each day is between 1.3 and 1.51 milliseconds shorter than normal.

A powerful new observatory has unveiled its first images to the public, showing off what it can do as it gets ready to start its main mission: making a vivid time-lapse video of the night sky that will let astronomers study all the cosmic events that occur over ten years. //

Named after an astronomer famous for her research related to dark matter, the Vera C. Rubin Observatory is perched on a mountaintop in Chile. It's equipped with a specially-designed large telescope, as well as a car-sized digital camera that's the biggest such camera in the world.

The camera is controlled by an automated system that moves and points the telescope, snapping pictures again and again, to cover the entire sky every few days. Each image is so detailed, displaying it would take 400 ultra high-definition television screens.

By constantly comparing new images to ones taken before, the facility's computer systems will be able to spot anything in the sky that changes or moves or goes boom.

"It will be capable of really detecting things that actually change very rapidly," says Sandrine Thomas, deputy director of Rubin Observatory and the observatory's telescope and site project scientist. "That, in itself, will be unique to the world. No other telescope would be able to do that."

"It has such a wide field of view and such a rapid cadence that we do have that movie-like aspect to the night sky," she says.

The space agency’s astronomical models suggest that a lunar eclipse turned the moon red over Jerusalem on Friday, April 3, 33 AD — a date many scholars tie to Jesus’ death. //

The eclipse theory, originally floated by Oxford University researchers Colin Humphreys and W. Graeme Waddington, https://www.asa3.org/ASA/PSCF/1985/JASA3-85Humphreys.html