The Tarantula Nebula, also known as 30 Doradus, is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud. About 180 thousand light-years away, it’s the largest, most violent star forming region known in the whole Local Group of galaxies. The cosmic arachnid sprawls across this spectacular view, composed with narrowband filter data centered on emission from ionized hydrogen atoms. Within the Tarantula (NGC 2070), intense radiation, stellar winds and supernova shocks from the central young cluster of massive stars, cataloged as R136, energize the nebular glow and shape the spidery filaments. Around the Tarantula are other star forming regions with young star clusters, filaments, and blown-out bubble-shaped clouds. In fact, the frame includes the site of the closest supernova in modern times, SN 1987A, left of center. The rich field of view spans about 1 degree or 2 full moons, in the southern constellation Dorado. But were the Tarantula Nebula closer, say 1,500 light-years distant like the local star forming Orion Nebula, it would take up half the sky. via NASA https://ift.tt/2K8NcnP
Archives mensuelles : novembre 2018
The Hill, The Moon, and Saturn
Last Sunday when the Moon was young its sunlit crescent hung low near the western horizon at sunset. With strong earthshine it was joined by Saturn shining in the early evening sky for a beautiful conjunction visible to skygazers around our fair planet. On that clear evening on a hill near Veszprem, Hungary mother, daughter, bright planet, and young Moon are framed in this quiet night skyscape taken with a telephoto lens. Of course the Moon ages too quickly for some, and by tonight the sunlit part has reached its first quarter phase. This weekend skygazers spending quality time under Moon and stars might expect to see the annual rain of comet dust otherwise known as the Leonid meteor shower. via NASA https://ift.tt/2FqWSes
The Cave Nebula in Hydrogen, Oxygen, and Sulfur
What’s inside this cosmic cave? A stellar nursery 10 light-years deep. The featured skyscape is dominated by dusty Sh2-155, the Cave Nebula. In the telescopic image, data taken through a narrowband filters tracks the nebular glow of hydrogen, oxygen, and sulfur, colors that together form the Hubble Palette. About 2,400 light-years away, the scene lies along the plane of our Milky Way Galaxy toward the royal northern constellation of Cepheus. Astronomical explorations of the region reveal that it has formed at the boundary of the massive Cepheus B molecular cloud and the hot, young stars of the Cepheus OB 3 association. The bright rim of ionized hydrogen gas is energized by radiation from the hot stars, dominated by the bright star just to the left of the cave entrance. Radiation driven ionization fronts are likely triggering collapsing cores and new star formation within. via NASA https://ift.tt/2QFg9Kl
Rotating Asteroid Bennu from OSIRIS REx
Could this close-by asteroid ever hit the Earth? Eventually yes — but probably not for a very long time, even though the asteroid is expected to pass inside the orbit of the Moon next century. However, to better understand the nature and orbit of all near-Earth asteroids, NASA sent the robotic Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) to investigate this one: the 500-meter across asteroid 101955 Bennu. Launched in 2016, OSIRIS-REx is now approaching Bennu, and is first scheduled to map the minor planet’s rough surface. The featured time-lapse video taken earlier this month compacts Bennu’s 4.25-hour rotation period into about 7 seconds. Bennu’s diamond-like appearance is similar to asteroid Ryugu currently being visited by the Japanese spacecraft Hayabusa2. The exact future orbit of Bennu is a bit uncertain due to close passes near the Earth and the Yarkovsky effect: a slight force created by an object’s rotationally-induced, asymmetric infrared glow. If all goes according to plan, ORISIS-Rx will actually touch the asteroid in 2020, collect soil samples, and return them to Earth in 2023 for detailed analyses. via NASA https://ift.tt/2Qysr7g
The Lagoon Nebula is Stars, Gas, and Dust
The majestic Lagoon Nebula is filled with hot gas and the home for many young stars. Spanning 100 light years across while lying only about 5000 light years distant, the Lagoon Nebula is so big and bright that it can be seen without a telescope toward the constellation of the Archer (Sagittarius). Many bright stars are visible from NGC 6530, an open cluster that formed in the nebula only several million years ago. The greater nebula, also known as M8 and NGC 6523, is named « Lagoon » for the band of dust seen to the left of the open cluster’s center. The featured image was taken in three colors with details are brought out by light emitted by Hydrogen Star formation continues in the Lagoon Nebula as witnessed by the many dark dust-laden globules that exist there. via NASA https://ift.tt/2FkNYz9
The Old Moon in the Young Moon s Arms
Tonight the Moon is young again, but this stunning image of a young Moon near the western horizon was taken just after sunset on October 10. On the lunar disk Earthshine, earthlight reflected from the Moon’s night side, is embraced by the slim, sunlit crescent just over 2 days old. Along the horizon fading colors of twilight silhouette the radio telescope dish antennas of the Very Large Array, New Mexico, planet Earth. The view from the Moon would be stunning, too. When the Moon appears in Earth’s sky as a slender crescent, a dazzlingly bright, nearly full Earth would be seen from the lunar surface. A description of earthshine, in terms of sunlight reflected by Earth’s oceans in turn illuminating the Moon’s dark surface, was written 500 years ago by Leonardo da Vinci. via NASA https://ift.tt/2qEORID
Little Planet Lookout
Don’t panic. This little planet projection looks confusing, but it’s actually just a digitally warped and stitched, nadir centered mosaic of images that covers nearly 360×180 degrees. The images were taken on the night of October 31 from a 30 meter tall hill-top lookout tower near Tatabanya, Hungary, planet Earth. The laticed lookout tower construction was converted from a local mine elevator. Since planet Earth is rotating, the 126 frames of 75 second long exposures also show warped, concentric star trails with the north celestial pole at the left. Of course at this location the south celestial pole is just right of center but below the the little planet’s horizon. via NASA https://ift.tt/2yZ3I5g
Mars in the Loop
This composite of images spaced some 5 to 9 days apart, from late April (bottom right) through November 5 (top left), traces the retrograde motion of ruddy-colored Mars through planet Earth’s night sky. To connect the dots and dates in this 2018 Mars retrograde loop, just slide your cursor over the picture (and check out this animation). But Mars didn’t actually reverse the direction of its orbit. Instead, the apparent backwards motion with respect to the background stars is a reflection of the motion of the Earth itself. Retrograde motion can be seen each time Earth overtakes and laps planets orbiting farther from the Sun, the Earth moving more rapidly through its own relatively close-in orbit. On July 27, Mars was near its favorable 2018 parihelic opposition, when Mars was closest to the Sun in its orbit while also opposite the Sun in Earth’s sky. For that date, the frame used in this composite was taken during the total lunar eclipse. via NASA https://ift.tt/2zzb9zN
NGC 6188: The Dragons of Ara
Dark shapes with bright edges winging their way through dusty NGC 6188 are tens of light-years long. The emission nebula is found near the edge of an otherwise dark large molecular cloud in the southern constellation Ara, about 4,000 light-years away. Born in that region only a few million years ago, the massive young stars of the embedded Ara OB1 association sculpt the fantastic shapes and power the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions, from previous generations of massive stars, that swept up and compressed the molecular gas. With image data from the Chilescope Observatory, a false-color Hubble palette was used to create this gorgeous wide-field image and shows emission from sulfur, hydrogen, and oxygen atoms in red, green, and blue hues. The field of view spans about four full Moons, corresponding to about 150 light years at the estimated distance of NGC 6188. via NASA https://ift.tt/2yXJ6ui
NGC 1499: The California Nebula
There’s even a California in space. 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. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei just to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades. via NASA https://ift.tt/2yUmn2i