NasaBot's Space

Cocoon Nebula Wide Field [apod.nasa.gov]

When does a nebula look like a comet?

In this crowded starfield, covering over two degrees within the high flying constellation of the Swan (Cygnus), the eye is drawn to the Cocoon Nebula.

A compact star forming region, the cosmic Cocoon punctuates a nebula bright in emission and reflection on the left, with a long trail of interstellar dust clouds to the right, making the entire complex appear a bit like a comet.

Cataloged as IC 5146, the central bright head of the nebula spans about 10 light years, while the dark dusty tail spans nearly 100 light years.

Both are located about 2,500 light years away.

The bright star near the bright nebula's center, likely only a few hundred thousand years old, supplies power to the nebular glow as it helps clear out a cavity in the molecular cloud's star forming dust and gas.

The long dusty filaments of the tail, although dark in this visible light image, are themselves hiding stars in the process of formation, stars that can be seen at infrared wavelengths.

Jupiter Rotates as Moons Orbit [apod.nasa.gov]

Jupiter and its moons move like our Sun and its planets.

Similarly, Jupiter spins while its moons circle around.

Jupiter’s rotation can be observed by tracking circulating dark belts and light zones.

The Great Red Spot, the largest storm known, rotates to become visible after about 15 seconds in the 48-second time lapse video.

The video is a compilation of shorts taken over several nights last month and combined into a digital recreation of how 24-continuous hours would appear.

Jupiter's brightest moons always orbit in the plane of the planet's rotation, even as Earth’s spin makes the whole system appear to tilt.

The moons Europa, Ganymede, and Io are all visible, with Europa's shadow appearing as the icy Galilean moon crosses Jupiter's disk.

Jupiter remains near opposition this month, meaning that it is unusually bright, near to its closest to the Earth, and visible nearly all night long.

Visit Page [apod.nasa.gov]

Clouds Around Galaxy Andromeda [apod.nasa.gov]

What are those red clouds surrounding the Andromeda galaxy?

This galaxy, M31, is often imaged by planet Earth-based astronomers.

As the nearest large spiral galaxy, it is a familiar sight with dark dust lanes, bright yellowish core, and spiral arms traced by clouds of bright blue stars.

A mosaic of well-exposed broad and narrow-band image data, this deep portrait of our neighboring island universe offers strikingly unfamiliar features though, faint reddish clouds of glowing ionized hydrogen gas in the same wide field of view.

Most of the ionized hydrogen clouds surely lie in the foreground of the scene, well within our Milky Way Galaxy.

They are likely associated with the pervasive, dusty interstellar cirrus clouds scattered hundreds of light-years above our own galactic plane.

Some of the clouds, however, occur right in the Andromeda galaxy itself, and some in M110, the small galaxy just below.

Milky Way and Zodiacal Light over Australian Pinnacles [apod.nasa.gov]

What strange world is this?

Earth.

In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia.

Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains a topic of research.

The picturesque panorama was taken in 2017 September.

A ray of zodiacal light, sunlight reflected by dust grains orbiting between the planets in the Solar System, rises from the horizon near the image center.

Arching across the top is the central band of our Milky Way Galaxy.

The planets Jupiter and Saturn, as well as several famous stars are also visible in the background night sky.

NGC 1499: The California Nebula [apod.nasa.gov]

Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States.

Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from the California Nebula.

Also known as NGC 1499, the classic emission nebula is around 100 light-years long.

The California Nebula shines with the telltale reddish glow characteristic of hydrogen atoms recombining with long lost electrons.

The electrons have been stripped away, ionized by energetic starlight.

Most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot star Xi Persei just to the right of the nebula.

A popular target for astrophotographers, this deep image reveals the glowing nebula, obscuring dust, and stars across a 3 degree wide field of view.

The California nebula lies toward the constellation Perseus, not far from the Pleiades.

Andromeda in Southern Skies [apod.nasa.gov]

Looking north from southern New Zealand, the Andromeda Galaxy never gets more than about five degrees above the horizon.

As spring comes to the southern hemisphere, in late September Andromeda is highest in the sky around midnight though.

In a single 30 second exposure this telephoto image tracked the stars to capture the closest large spiral galaxy from Mount John Observatory as it climbed just over the rugged peaks of the south island's Southern Alps.

In the foreground, stars are reflected in the still waters of Lake Alexandrina.

Also known as M31, the Andromeda Galaxy is one of the brightest objects in the Messier catalog, usually visible to the unaided eye as a small, faint, fuzzy patch.

But this clear, dark sky and long exposure reveal the galaxy's greater extent in planet Earth's night, spanning nearly 6 full moons.

A Galaxy Beyond Stars, Gas, Dust [apod.nasa.gov]

Do we dare believe our eyes?

When we look at images of space, we often wonder whether they are "real", and just as often the best answer varies.

In this case, the scene appears much as our eyes would see it, because it was obtained using RGB (Red, Green, Blue) filters like the cone cells in our eyes, except collecting light for 19 hours, not a fraction of a second.

The featured image was captured over six nights, using a 24-inch diameter telescope in the Sierra Nevada Mountains, in California, USA.

The bright spiral galaxy at the center (NGC 7497) looks like it is being grasped by an eerie tendril of a space ghost, and therein lies the trick.

The galaxy is actually 59 million light years away, while the nebulosity is MBM 54, less than one thousand light years away, making it one of the nearest cool clouds of gas and dust — galactic cirrus — within our own Milky Way Galaxy.

Both are in the constellation of Pegasus, which can be seen high overhead from northern latitudes in the autumn.

Milky Way Auroral Flower [apod.nasa.gov]

Could the stem of our Milky Way bloom into an auroral flower?

No, not really, even though it may appear that way in today’s featured all-sky image.

On the left, the central plane of our home galaxy extends from the horizon past the middle of the sky.

On the right, an auroral oval also extends from the sky's center — but is dominated by bright green-glowing oxygen.

The two are not physically connected, because the aurora is relatively nearby, with the higher red parts occurring in Earth's atmosphere only about 1000 kilometers high.

In contrast, an average distance to the stars and nebulas we see in the Milky Way more like 1000 light-years away - 10 trillion times further.

The featured image composite was taken in early October across a small lake in Abisko, northern Sweden.

As our Sun's magnetic field evolves into the active part of its 11-year cycle, auroras near both of Earth's poles are sure to become more frequent.

X-Ray Rings Around a Gamma Ray Burst [apod.nasa.gov]

Why would x-ray rings appear around a gamma-ray burst?

The surprising answer has little to do with the explosion itself but rather with light reflected off areas of dust-laden gas in our own Milky Way Galaxy.

GRB 221009A was a tremendous explosion — a very bright gamma-ray burst (GRB) that occurred far across the universe with radiation just arriving in our Solar System last week.

Since GRBs can also emit copious amounts of x-rays, a bright flash of x-rays arrived nearly simultaneously with the gamma-radiation.

In this case, the X-rays also bounced off regions high in dust right here in our Milky Way Galaxy, creating the unusual reflections.

The greater the angle between reflecting Milky Way dust and the GRB, the greater the radius of the X-ray rings, and, typically, the longer it takes for these light-echoes to arrive.

Barred Spiral Galaxy NGC 1300 [apod.nasa.gov]

Across the center of this spiral galaxy is a bar.

And at the center of this bar is smaller spiral.

And at the center of that spiral is a supermassive black hole.

This all happens in the big, beautiful, barred spiral galaxy cataloged as NGC 1300, a galaxy that lies some 70 million light-years away toward the constellation of the river Eridanus.

This Hubble Space Telescope composite view of the gorgeous island universe is one of the most detailed Hubble images ever made of a complete galaxy.

NGC 1300 spans over 100,000 light-years and the Hubble image reveals striking details of the galaxy's dominant central bar and majestic spiral arms.

How the giant bar formed, how it remains, and how it affects star formation remains an active topic of research.