Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 11

Andromeda over the Sahara Desert

Credit & Copyright: Jordi Coy

Explanation: What is the oldest thing you can see? At 2.5 million light years distant, the answer for the unaided eye is the Andromeda galaxy, because its photons are 2.5 million years old when they reach you. Most other apparent denizens of the night sky — stars, clusters, and nebulae — appear as they were only a few hundred to a few thousand years ago, as they lie well within our own Milky Way Galaxy. Given its distance, light from Andromeda is likely also the farthest object that you can see. Also known as M31, the Andromeda Galaxy dominates the center of the featured zoomed image, taken from the Sahara Desert in Morocco last month. The featured image is a combination of three background and one foreground exposure — all taken with the same camera and from the same location and on the same calendar day — with the foreground image taken during the evening blue hour. M110, a satellite galaxy of Andromenda is visible just above and to the left of M31’s core. As cool as it may be to see this neighboring galaxy to our Milky Way with your own eyes, long duration camera exposures can pick up many faint and breathtaking details. Recent data indicates that our Milky Way Galaxy will collide and combine with the similarly-sized Andromeda galaxy in a few billion years.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 10

In the Center of the Cat’s Eye Nebula

Credit: NASA, ESA, Hubble, HLA; Reprocessing & Copyright: Raul Villaverde

Explanation: Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat’s Eye Nebula (NGC 6543), to be one of the most complex planetary nebulae known. Spanning half a light-year, the features seen in the Cat’s Eye are so complex that astronomers suspect the bright central object may actually be a binary star system. The term planetary nebula, used to describe this general class of objects, is misleading. Although these objects may appear round and planet-like in small telescopes, high resolution images with large telescopes reveal them to be stars surrounded by cocoons of gas blown off in the late stages of stellar evolution. Gazing into this Cat’s Eye, astronomers may well be seeing more than detailed structure, they may be seeing the fate of our Sun, destined to enter its own planetary nebula phase of evolution … in about 5 billion years.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 9

Saturn and the ISS

Image Credit & Copyright: Tom Glenn

Explanation: Soaring high in skies around planet Earth, bright planet Saturn was a star of June’s morning planet parade. But very briefly on June 24 it posed with a bright object in low Earth orbit, the International Space Station. On that date from a school parking lot in Temecula, California the ringed-planet and International Space Station were both caught in this single high-speed video frame. Though Saturn was shining at +0.5 stellar magnitude the space station was an even brighter -3 on the magnitude scale. That difference in brightness is faithfully represented in the video capture frame. In the challenging image, the orbiting ISS was at a range of 602 kilometers. Saturn was about 1.4 billion kilometers from the school parking lot.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 8

Roots on a Rotating Planet

Image Credit & Copyright: Marcella Giulia Pace

Explanation: With roots on a rotating planet, an old tree is centered in this sequence of 137 exposures each 20 seconds long, recorded one night from northern Sicily. Digital camera and fisheye lens were fixed to a tripod to capture the dramatic timelapse, so the stars trailed through the region’s dark sky. Of course that makes it easy to spot the planet’s north celestial pole. The extension of Earth’s axis of rotation into space is toward the upper left, at the center of the concentric star trail arcs. The Milky Way is there too. The plane of our galaxy stretches across the wide field of view from north to east (left to right) creating a broader luminous band of diffuse starlight.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 7

The NGC 6914 Complex

Image Credit & Copyright: Giorgio Ferrari

Explanation: A study in contrasts, this colorful skyscape features stars, dust, and glowing gas in the vicinity of NGC 6914. The interstellar complex of nebulae lies some 6,000 light-years away, toward the high-flying northern constellation Cygnus and the plane of our Milky Way Galaxy. Obscuring interstellar dust clouds appear in silhouette while reddish hydrogen emission nebulae, along with the dusty blue reflection nebulae, fill the cosmic canvas. Ultraviolet radiation from the massive, hot, young stars of the extensive Cygnus OB2 association ionize the region’s atomic hydrogen gas, producing the characteristic red glow as protons and electrons recombine. Embedded Cygnus OB2 stars also provide the blue starlight strongly reflected by the dust clouds. The over 1 degree wide telescopic field of view spans about 100 light-years at the estimated distance of NGC 6914.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 5

A Molten Galaxy Einstein Ring

Image Credit: ESA/Hubble & NASA, S. Jha; Processing: Jonathan Lodge

Explanation: It is difficult to hide a galaxy behind a cluster of galaxies. The closer cluster’s gravity will act like a huge lens, pulling images of the distant galaxy around the sides and greatly distorting them. This is just the case observed in the featured image recently re-processed image from the Hubble Space Telescope. The cluster GAL-CLUS-022058c is composed of many galaxies and is lensing the image of a yellow-red background galaxy into arcs seen around the image center. Dubbed a molten Einstein ring for its unusual shape, four images of the same background galaxy have been identified. Typically, a foreground galaxy cluster can only create such smooth arcs if most of its mass is smoothly distributed — and therefore not concentrated in the cluster galaxies visible. Analyzing the positions of these gravitational arcs gives astronomers a method to estimate the dark matter distribution in galaxy clusters, as well as infer when the stars in these early galaxies began to form.

New APOD Social Mirrors in Arabic: On Facebook, Instagram, and Twitter

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 4

Strawberry Supermoon Over Devil’s Saddle

Image Credit & Copyright: Lorenzo Busilacchi

Explanation: Near the horizon the full moon often seems to loom large, swollen in appearance by the famous Moon illusion. But time-lapse image sequences demonstrate that the Moon’s angular size doesn’t really change as it rises or sets. Its color does, though. Recording a frame about every 60 seconds, this image also shows how red the Sun can look while low on the horizon. The featured montage was taken from Cagliari, Sardinia, Italy, the day after June’s Strawberry Moon, a full moon dubbed a supermoon due to its slightly larger-than-usual angular size. This Strawberry Supermoon is seen rising behind the Devil’s Saddle, a mountain named for the unusual moon-sized dip seen just to the right of the rising moon. A shrinking line-of-sight through planet Earth’s dense and dusty atmosphere shifted the moonlight from strawberry red through honey-colored and paler yellowish hues. That change seems appropriate for a northern June Full Moon also known as the Strawberry or Honey Moon. A Thunder Supermoon — the third of four supermoons in 2022 — will occur later this month.

Today’s Adventure Link: Click on “Cagliari”