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Explanation: Solar System bodies make deep space exploration more fuel efficient! Today’s video shows the Psyche spacecraft gaining speed and changing its trajectory with minimal fuel spent due to a gravity assist from Mars in May 2026. Mars has an average orbital speed of almost 87,000 km/h (54,000 mph) around the Sun. Its orbital motion and its gravity allowed Mars to pull Psyche along with it, increasing the spacecraft’s speed. Gravity assists have been used since 1959’s Luna 3 mission to allow for spacecraft (the Voyagers, Cassini) to reach farther than they could with fuel alone. This assist helped the...

Explanation: What's connecting these two volcanoes? In ancient folklore, the two volcanoes, Parinacota (left) and Pomerape (right), are connected by representing a mythical prince and princess who engaged in a forbidden romance. Beneath the ground, the two peaks are not known to be connected by a common pool of hot magma, and neither volcano has erupted in the past 1000 years. Above the ground, there is usually nothing in the sky that connects them -- except if you use careful timing and look from a specific location. The featured well-planned image was captured from Bolivia in mid-April with a series...

Explanation: What created this huge space bubble? Blown by the wind from a star, this tantalizing, head-like apparition is cataloged as NGC 7635, but known simply as the Bubble Nebula. Taken from Krakow, Poland, the featured view utilizes a long exposure to reveal the intricate details of this cosmic bubble and its environment. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Seen here right of the Bubble's center, a bright hot star is embedded in the nebula's reflecting dust. A fierce stellar wind and intense radiation from the star, which likely has...

Explanation: How do clusters of galaxies form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. One famous effort is TNG50 from IllustrisTNG, an upgrade of the famous Illustris Simulation. The first part of the featured video tracks cosmic gas (mostly hydrogen) as it evolves into galaxies and galaxy clusters from the early universe to today, with brighter colors marking faster moving gas. As the universe matures, gas falls into gravitational wells, galaxies forms, galaxies spin, galaxies collide and merge, all while black holes form in galaxy centers and expel surrounding gas...

Explanation: The Seas of Tranquility and Serenity are calm today. They're calm most every day though, since they are actually lunar maria, ancient lava flows filling in large impact basins on the Moon. Also known by Latin names Mare Tranquillitatis (right) and Mare Serenitatis, the smooth dark lunar "seas" are in stark contrast to the bright cratered lunar highlands surrounding them in this telescopic view. Of course their names are based on the historical, pre-telescopic designations of lunar maria. Easily visible to the unaided eye, the broad features on the Moon's near side were imagined to be like the expansive...

Explanation: In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism. That part of the sky is identified with part of the southern constellation Centaurus on modern star charts. In fact, the new star was reported to be visible to the naked eye for months before it faded from view, and is now thought to be the earliest recorded supernova. In this 21st century telescopic image, the wispy outlines of a faint emission nebula recognized as the remnant of that historical stellar explosion can be traced against a starry background. The ragged but roughly...

Explanation: Have you ever seen another galaxy with your own eyes? The featured image shows the Large Magellanic Cloud (LMC), one of the closest neighbors of our Milky Way. If you are anywhere south of latitude 20° N (but the further south, the better), you can see it with the unaided eye if you go to a dark sky location, away from big cities and light polution. It is a dwarf irregular galaxy about 163,000 light-years away, and a member of our Local Group of galaxies. Despite being small, with a total mass approximately equivalent to 10% - 20% of...

Explanation: The Southern Crown (Corona Australis) dazzles with young and ancient celestial jewels. The Corona Australis Cloud is a collage of reflection and emission nebulae on the left of today’s image. At 430 light years away, this cloud is one of the closest star-forming regions to Earth. It contains gas cool enough (-260 Celsius or -440 Fahrenheit) to collapse into protostars. Recently formed stars paint blue hues across the cloud as their light reflects off surrounding material. The waltz of the R Coronae Australis binary system stirs up the nebula NGC 6729. The younger of the pair ionizes nearby gas...

Explanation: Is this a fossilized turtle on Mars? No. Although resembling a large Earth tortoise, this is a layered rock outcrop on Mars that is estimated to span about 15 meters, making it much larger than turtles on Earth. NASA’s robotic Curiosity rover came across this unusual mound, dubbed Miraflores, last month during its 4922nd Martian day exploring Mars. The small butte may survive because it was somehow more resistant to erosion than surrounding rock. More recent wind has now covered its top with orange Martian sand. Below the top shell, many layers of stratified rock are visible, possibly indicating...

Explanation: What's happening in the Statue of Liberty nebula? Bright stars and interesting molecules are forming and being liberated. The complex nebula resides in the star forming region called RCW 57, and besides the iconic monument, to some looks like a flying superhero or a weeping angel. This re-assigned color image showcases dense knots of dark interstellar dust, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A detailed study of NGC 3576, also known as NGC 3582 and NGC 3584, uncovered at least 33 massive stars in the end stages...

Explanation: A flying saucer from outer space crash-landed in the Utah desert after being tracked by radar and chased by helicopters. The year was 2004, and no space aliens were involved. The saucer, pictured here, was the Genesis sample return capsule, part of a human-made robot Genesis spaceship launched in 2001 by NASA itself to study the Sun. The unexpectedly hard landing at over 300 kilometers per hour occurred because the parachutes did not open as planned. The Genesis mission had been orbiting the Sun collecting solar wind particles that are usually deflected away by Earth's magnetic field. Despite the...

Explanation: At sunset, an alignment of rainbow and mountain shadow was captured in this remarkable snapshot. The stunning view was recorded from a fire lookout on Smith Peak in the Plumas National Forest near Portola, California on July 13. Still, near sunset it's no accident that the majestic mountain shadow seems to point to the center of the graceful rainbow arc. Due to perspective and the long line of sight the mountain shadow naturally forms a tapering triangular shape, its apex positioned at the point opposite the Sun on the horizon. Following thunderstorms in the region, the rainbow arched across...

Explanation: Comet 10P/Tempel 2 orbits the Sun once every 5.4 years. Currently visible in binoculars or small telescopes toward the constellation Capricornus, the periodic comet is captured in this sharp telescopic image from July 11 sporting a bright nuclear region and pretty greenish coma. Remarkably, a thin dust trail, not a typical dust tail, is also seen extending both east and west of the Tempel 2 nucleus. Unlike a comet dust tail, which tends to temporarily fan out in a direction away from the Sun, this dust trail is due to the residual dust shed during many past orbits along...

Explanation: This sparkling, colorful gemstone is a spiral galaxy, NGC 300. It is one of the closest spiral galaxies to Earth, only about 6 million light-years away. But does it really look like this? Here is a more standard portrait of it. This unusual image combines the light from the stars and dust within the galaxy with the light from ionized clouds of interstellar gas shown in red (Sulphur), green (Hydrogen) and blue (Oxygen). Combining red and green light in different proportions makes yellow or orange light, most visible in the image. Light from other ionized gases is also at...

Explanation: Is there an angry Sith using force lightning in the Tatacoa Desert? This is not science fiction, but a red sprite with multiple streamers! Ordinary lightning occurs when thundercloud particles collide, lose their electrons, and build up negative charge at the cloud bottom. The cloud’s negative charge repels negative charge deeper into the Earth, leaving Earth’s surface positively charged. The opposite charges attract, reaching towards each other and superheating the air into a white strike of plasma. Red sprites are millisecond events triggered by positive cloud-to-ground lightning. They extend up into the mesosphere where the air is too thin...

Explanation: Why is this asteroid a double? Earlier this month the Japanese robotic spacecraft Hayabusa2 shot past asteroid 98943 Torifune and captured pictures. Although previous observations from distant Earth indicated that Torifune was oblong, Hayabusa2 found that Torifune actually has two joined lobes. With a length of about four soccer fields, this space rock frequently comes near the Earth as it orbits the Sun, although it is not a threat. Besides the two lobes, Torifune shows many large boulders, but, surprisingly, no obvious craters, likely because its surface is a pile of rubble. Like asteroid Arrokoth, it appears that each...

Explanation: What do auroras look like from above? Behold! From the ground, auroras dance high above clouds, frequently causing spectacular displays. From space, they look a bit different. As the International Space Station (ISS) circles the Earth every 90 minutes, it sometimes sees auroras below that are active on the night side. A one-hour time-lapse video showing auroras from above was captured about two weeks ago from the orbiting ISS. The ISS -- and all objects in low Earth orbit -- will pass well above green auroras but just a bit above red glowing auroras. The auroras' electron and proton...

Explanation: What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause of the shells is a topic of research, but they are possibly tidal tails related to debris left over from absorbing numerous small galaxies in the past billion years. Alternatively, the shells may be like ripples in a pond, where the ongoing collision with the spiral galaxy just to the right of NGC 474 is causing density waves to ripple through the galactic giant. Regardless of the actual cause, the...

Explanation: Unlike most entries in Charles Messier's famous catalog of deep sky objects, M24 is not a bright galaxy, star cluster, or nebula. It's a gap in nearby, obscuring interstellar dust clouds that allows a view of the distant stars in the Sagittarius spiral arm of our Milky Way galaxy. Direct your gaze through this gap with binoculars or a small telescope and you are looking through a window over 300 light-years wide at stars some 10,000 light-years or more from Earth. Sometimes called the Small Sagittarius Star Cloud, M24's luminous stars stretch across this gorgeous interstellar scene. Spanning over...

Explanation: The Mare Orientale, Latin for Eastern Sea, is one of the most striking large scale lunar features. The youngest of the large lunar impact basins it's very difficult to see from an earthbound perspective. Still, captured on July 7 during a period of favorable tilt, or libration of the lunar nearside, the Eastern Sea can be found at the upper right in this sharp telescopic view. In the image, the large lunar mare is extremely foreshortened and stretches along the Moon's western edge. Formed by the impact of an asteroid over 3 billion years ago and nearly 1000 kilometers...