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NASA Astronomy Picture of the Day:

Comet C/2023 A3 (Tsuchinshan–ATLAS) is growing brighter in planet Earth's sky. Fondly known as comet A3, this new visitor to the inner Solar System is traveling from the distant Oort cloud. The comet reached perihelion, its closest approach to the Sun, on September 27 and will reach perigee, its closest to our fair planet, on October 12, by then becoming an evening sky apparition. But comet A3 was an early morning riser on September 30 when this image was made. Its bright coma and already long tail share a pre-dawn skyscape from Praia Grande, Santa Catarina in southern Brazil with the waning crescent Moon just peeking above the eastern horizon. While the behaviour of comets is notoriously unpredictable, Tsuchinshan–ATLAS could become a comet visually rivaling C/2020 F3 (NEOWISE). Comet NEOWISE wowed skygazers in the summer of 2020. Growing Gallery: Comet Tsuchinsan-ATLAS in 2024

Photo by Gabriel Zaparolli

NASA Astronomy Picture of the Day:

The second solar eclipse of 2024 began in the Pacific. On October 2nd the Moon's shadow swept from west to east, with an annular eclipse visible along a narrow antumbral shadow path tracking mostly over ocean, crossing land near the southern tip of South America, and ending in the southern Atlantic. The dramatic total annular eclipse phase is known to some as a ring of fire. Still, a partial eclipse of the Sun was experienced over a wide region. Captured at one of its earliest moments, October's eclipsed Sun is seen just above the clouds near sunrise in this snapshot. The partially eclipsed solar disk is close to the maximum eclipse as seen from Mauna Kea Observatory Visitor Center, Island of Hawaii, planet Earth.

Photo by Wang Letian

NASA Astronomy Picture of the Day:

It is the largest satellite galaxy of our home Milky Way Galaxy. If you live in the south, the Large Magellanic Cloud (LMC) is quite noticeable, spanning about 10 degrees across the night sky, which is 20 times larger than the full moon towards the southern constellation of the dolphinfish (Dorado). Being only about 160,000 light years away, many details of the LMC's structure can be seen, such as its central bar and its single spiral arm. The LMC harbors numerous stellar nurseries where new stars are being born, which appear in pink in the featured image. It is home to the Tarantula Nebula, the currently most active star forming region in the entire Local Group, a small collection of nearby galaxies dominated by the massive Andromeda and Milky Way galaxies. Studies of the LMC and the Small Magellanic Cloud (SMC) by Henrietta Swan Leavitt led to the discovery of the period-luminosity relationship of Cepheid variable stars that are used to measure distances across the nearby universe. Survey: Color Blindness and Astronomical Images

Photo by Ireneusz Nowak; Text: Natalia Lewandowska (SUNY Oswego)

NASA Astronomy Picture of the Day:

How far can black hole jets extend? A new record was found just recently with the discovery of a 23-million light-year long jet pair from a black hole active billions of years ago. Dubbed Porphyrion for a mythological Greek giant, the impressive jets were created by a type of black hole that does not usually create long jets -- one that is busy creating radiation from infalling gas. The featured animated video depicts what it might look like to circle around this powerful black hole system. Porphyrion is shown as a fast stream of energetic particles, and the bright areas are where these particles are impacting surrounding gas. The discovery was made using data from the Keck and Mayall (DESI) optical observatories as well as LOFAR and the Giant Metrewave Radio Telescope. The existence of these jets demonstrates that black holes can affect not only their home galaxies but far out into the surrounding universe. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

NASA Astronomy Picture of the Day:

The new comet has passed its closest to the Sun and is now moving closer to the Earth. C/2023 A3 (Tsuchinshan–ATLAS) is currently moving out from inside the orbit of Venus and on track to pass its nearest to the Earth in about two weeks. Comet Tsuchinshan-ATLAS, pronounced "Choo-cheen-shahn At-less,", is near naked-eye visibility and easily picked up by long-exposure cameras. The comet can also now be found by observers in Earth's northern hemisphere as well as the south. The featured image was captured just a few days ago above Zacatecas, Mexico. Because clouds were obscuring much of the pre-dawn sky, the astrophotographer released a drone to take pictures from higher up, several of which were later merged to enhance the comet's visibility. Although the future brightness of comets is hard to predict, there is increasing hope that Comet Tsuchinshan-ATLAS will further brighten as it enters the early evening sky. Growing Gallery: Comet Tsuchinsan-ATLAS in 2024

Photo by Daniel Korona

NASA Astronomy Picture of the Day:

Is this really the famous Pleiades star cluster? Known for its iconic blue stars, the Pleiades is shown here in infrared light where the surrounding dust outshines the stars. Here, three infrared colors have been mapped into visual colors (R=24, G=12, B=4.6 microns). The base images were taken by NASA's orbiting Wide Field Infrared Survey Explorer (WISE) spacecraft. Cataloged as M45 and nicknamed the Seven Sisters, the Pleiades star cluster is by chance situated in a passing dust cloud. The light and winds from the massive Pleiades stars preferentially repel smaller dust particles, causing the dust to become stratified into filaments, as seen. The featured image spans about 20 light years at the distance of the Pleiades, which lies about 450 light years distant toward the constellation of the Bull (Taurus).

NASA Astronomy Picture of the Day:

Shockwaves ripple across the glare as a launch eclipses the setting Sun in this exciting close-up. Captured on September 17, the roaring Falcon 9 rocket carried European Galileo L13 navigation satellites to medium Earth orbit after a lift-off from Cape Canaveral on Florida's space coast. The Falcon 9 booster returned safely to Earth about 8.5 minutes later, notching the 22nd launch and landing for the reusable workhorse launch vehicle. But where did it land? Just Read the Instructions.

Photo by Ben Cooper

NASA Astronomy Picture of the Day:

The twenty galaxies arrayed in these panels are part of an ambitious astronomical survey of tidal stellar streams. Each panel presents a composite view; a deep, inverted image taken from publicly available imaging surveys of a field that surrounds a nearby massive galaxy image. The inverted images reveal faint cosmic structures, star streams hundreds of thousands of light-years across, that result from the gravitational disruption and eventual merger of satellite galaxies in the local universe. Such surveys of mergers and gravitational tidal interactions between massive galaxies and their dwarf satellites are crucial guides for current models of galaxy formation and cosmology. Of course, the detection of stellar streams in the neighboring Andromeda Galaxy and our own Milky Way also offers spectacular evidence for ongoing satellite galaxy disruption within our more local galaxy group.

NASA Astronomy Picture of the Day:

In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shows itself to the naked Eye, when the Sky is serene and the Moon absent." Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster's hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core, upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. The deep, wide-field image also reveals distant background galaxies including NGC 6207 at the upper left, and faint, foreground Milky Way dust clouds known to some as integrated flux nebulae.

Photo by Jan Beckmann, Julian Zoller, Lukas Eisert, Wolfgang Hummel

NASA Astronomy Picture of the Day:

Comet Tsuchinshan-ATLAS is now visible in the early morning sky. Diving into the inner Solar System at an odd angle, this large dirty iceberg will pass its closest to the Sun -- between the orbits of Mercury and Venus -- in just two days. Long camera exposures are now capturing C/2023 A3 (Tsuchinshan–ATLAS), sometimes abbreviated as just A3, and its dust tail before and during sunrise. The featured image composite was taken four days ago and captured the comet as it rose above Lake George, NSW, Australia. Vertical bands further left are images of the comet as the rising Sun made the predawn sky increasingly bright and colorful. Just how bright the comet will become over the next month is currently unknown as it involves how much gas and dust the comet's nucleus will expel. Optimistic skywatchers are hoping for a great show where Tsuchinshan–ATLAS creates dust and ion tails visible across Earth's sky and becomes known as the Great Comet of 2024. Survey: Color Blindness and Astronomical Images Growing Gallery: Comet Tsuchinsan-ATLAS in 2024

Photo by Lucy Yunxi Hu

NASA Astronomy Picture of the Day:

This dusty region is forming stars. Part of a sprawling molecular cloud complex that resembles, to some, a rampaging baboon, the region is a relatively close by 500 light-years away toward the constellation Corona Australis. That's about one third the distance of the more famous stellar nursery known as the Orion Nebula. Mixed with bright nebulosities, the brown dust clouds effectively block light from more distant background stars in the Milky Way and obscure from view embedded stars still in the process of formation. The eyes of the dust creature in the featured image are actually blue reflection nebulas cataloged as NGC 6726, 6727, 6729, and IC 4812, while the red mouth glows with light emitted by hydrogen gas. Just to the upper left of the baboon's head is NGC 6723, a whole globular cluster of stars nearly 30,000 light years in the distance. Explore Your Universe: Random APOD Generator

Photo by Alpha Zhang & Ting Yu

NASA Astronomy Picture of the Day:

What will happen as this already bright comet approaches? Optimistic predictions have Comet C/2023 A3 (Tsuchinshan–ATLAS) briefly becoming easily visible to the unaided eye -- although the future brightness of comets are notoriously hard to predict, and this comet may even break up in warming sunlight. What is certain is that the comet is now unexpectedly bright and is on track to pass its closest to the Sun (0.39 AU) later this week and closest to the Earth (0.47 AU) early next month. The featured image was taken in late May as Comet Tsuchinshan–ATLAS, discovered only last year, passed nearly in front of two distant galaxies. The comet can now be found with binoculars in the early morning sky rising just before the Sun, while over the next few weeks it will brighten as it moves to the early evening sky. Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Photo by Brian Valente & Greg Stein