Thursday, November 23, 2017

Behold!! Observing Sun

A broad hole in the corona was the Sun's dominant feature November 7-9, 2017, as shown in this image from NASA's Solar Dynamics Observatory. The hole is easily recognizable as the dark expanse across the top of the Sun and extending down in each side. Coronal holes are magnetically open areas on the Sun that allow high-speed solar wind to gush out into space. They always appear darker in extreme ultraviolet. This one was likely the source of bright aurora that shimmered for numerous observers, with some reaching down even to Nebraska.

Image Credit:NASA/GSFC/Solar Dynamics Observatory

Solar Dynamics Observatory (SDO)

Wednesday, November 22, 2017

Tending Your Garden .. In Space


If you plant it, will it grow (in space)? The answer is yes, at least for certain types of plants. The Vegetable Production System, or Veggie, was first deployed in 2013 and is capable of producing salad-type crops to provide the crew aboard the International Space Station with a palatable, nutritious, and safe source of fresh food. Veggie provides lighting and nutrient delivery, but utilizes the cabin environment for temperature control and as a source of carbon dioxide to promote growth. This image of a red lettuce plant was taken for the VEG-03 experiment in the Columbus Module by the Expedition 53 crew.

The Interstellar Asteroid "Oumuamua"


Nothing like it has ever been seen before. The unusual space rock 'Oumuamua is so intriguing mainly because it is the first asteroid ever detected from outside our Solar System -- although likely many more are to follow given modern computer-driven sky monitoring. Therefore humanity's telescopes -- of nearly every variety -- have put 'Oumuamua into their observing schedule to help better understand this unusual interstellar visitor. Pictured is an artist's illustration of what 'Oumuamua might look like up close. 'Oumuamua is also intriguing, however, because it has unexpected parallels to Rama, a famous fictional interstellar spaceship created by the late science fiction writer Arthur C. Clarke. Like Rama, 'Oumuamua is unusually elongated, should be made of strong material to avoid breaking apart, is only passing through our Solar System, and passed unusually close to the Sun for something gravitationally unbound. Unlike a visiting spaceship, though, 'Oumuamua's trajectory, speed, color, and evenprobability of detection are consistent with it forming naturally around a normal star many millions of years ago, being expelled after gravitationally encountering a normal planet, and subsequently orbiting in our Galaxy alone. Even given 'Oumuamua's likely conventional origin, perhaps humanity can hold hope that one day we will have the technology to engineer 'Oumuamua -- or another Solar System interloper -- into an interstellar Rama of our own.

Tuesday, November 14, 2017

The Pleiades Deep and Dusty

The well-known Pleiades star cluster is slowly destroying part of a passing cloud of gas and dust. The Pleiades is the brightest open cluster of stars on Earth's sky and can be seen from almost any northerly location with the unaided eye. The passing young dust cloud is thought to be part of Gould's Belt, an unusual ring of young star formation surrounding the Sun in the local Milky Way Galaxy. Over the past 100,000 years, part of Gould's Belt is by chance moving right through the older Pleiades and is causing a strong reaction between stars and dust. Pressure from the stars' light significantly repels the dust in the surrounding bluereflection nebula, with smaller dust particles being repelled more strongly. A short-term result is that parts of the dust cloud have become filamentary and stratified. The featured deep image also captured Comet C/2015 ER61(PanSTARRS) on the lower left.

Image Credit & Copyright: Juan Carlos Casado(TWANEarth & Stars), Miquel Serra-Ricart & Daniel Padron, FECYT

Monday, November 13, 2017

Hubble's Messier 5

"Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] ..." begins the description of the 5th entry in 18th century astronomer Charles Messier's famous catalog of nebulae and star clusters. Though itappeared to Messier to be fuzzy and round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter. It lies some 25,000 light-years away. Roaming the halo of our galaxy, globular star clusters are ancient members of the Milky Way. M5 is one of the oldest globulars, its stars estimated to be nearly 13 billion years old. The beautiful star cluster is a popular target for Earthbound telescopes. Of course, deployed in low Earth orbit on April 25, 1990, the Hubble Space Telescope has also captured its own stunning close-up view that spans about 20 light-years across the central region of M5. Even close to its dense core the cluster's aging red and blue giant stars andrejuvenated blue stragglers stand out in yellow and blue hues in the sharp color image.
For image credit and copyright guidance, please visit the image websitehttps://apod.nasa.gov/apod/ap171104.html

NGC 2261: Hubble's Variable Nebula

What causes Hubble's Variable Nebula to vary? The unusual nebula featured here changes its appearance noticeably in just a few weeks. Discovered over 200 years ago and subsequently cataloged as NGC 2661, the remarkable nebula is named for Edwin Hubble, who studied it early last century. Fitting, perhaps, the featured image was taken by another namesake of Hubble: the Space TelescopeHubble's Variable Nebula is areflection nebula made of gas and fine dustfanning out from the star R Monocerotis. The faint nebula is about one light-year across and lies about 2500 light-years away towards theconstellation of the Unicorn (Monocerotis). The leading variability explanation for Hubble's Variable Nebula holds that dense knots of opaque dust pass close to R Mon and castmoving shadows onto the reflecting dust seen in the rest of the nebula.

Image Copyright: Image Credit: HubbleNASA,ESAData: Mark Clampin (NASA s GSFC);Processing & LicenseJudy Schmidt

Hubble Space Telescope

Sunday, November 12, 2017

NGC 1055 a Close up

Big, beautiful spiral galaxy NGC 1055 is a dominant member of a small galaxy group a mere 60 million light-years away toward the aquatically intimidating constellation Cetus. Seen edge-on, the island universe spans over 100,000 light-years, a little larger than our own Milky Way. The colorful stars in this cosmicclose-up of NGC 1055 are in the foreground, well within the Milky Way. But the telltale pinkish star forming regions are scattered through winding dust lanes along the distant galaxy's thin disk. With a smattering of even more distant background galaxies, the deep image also reveals a boxy halo that extends far above and below the central bluge and disk of NGC 1055. The halo itself is laced with faint, narrow structures, and could represent the mixed and spread out debris from a satellite galaxy disrupted by the larger spiral some 10 billion years ago.

Image Credit & Copyright: Processing - Robert GendlerRoberto Colombari
Data - European Southern ObservatorySubaru Telescope (NAOJ), et al.

Tuesday, November 7, 2017

A year of full Moons


Do all full moons look the same? No. To see the slight differences, consider this grid of twelve full moons. From upper left to lower right, the images represent every lunation from 2016 November through 2017 October, as imaged from Pakistan. The consecutive full moons are all shown at the same scale, so unlike the famous Moon Illusion, the change in apparent size seen here is real. The change is caused bythe variation in lunar distance due to the Moon's significantly non-circular orbit. The dark notch at the bottom of the full moon of 2017 August is the shadow of the Earth -- making this a partial lunar eclipse. Besides the sometimes exaggerated coloring, a subtler change in appearance can also be noticed on close examination, as the Moon seems to wobble slightly from one full moon to the next. This effect, known as libration, is more dramatic and easier to see in this lunation video highlighting all of the ways that the Moon appears to change over a month (moon-th).
Image Credit & CopyrightTalha Zia

Sunday, October 8, 2017

Dark Molecular Cloud Barnard

Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gasabsorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors ofmolecular clouds some of the coldest and mostisolated places in the universe. One of the most notable of these dark absorption nebulae is a cloud toward the constellation Ophiuchusknown as Barnard 68pictured here. That no stars are visible in the center indicates thatBarnard 68 is relatively nearby, with measurements placing it about 500 light-years away and half a light-year across. It is not known exactly how molecular clouds likeBarnard 68 form, but it is known that these clouds are themselves likely places for new stars to form. In fact, Barnard 68 itself has been found likely to collapse and form a new star system. It is possible to look right through the cloud in infrared light.
Image Credit: FORS Team8.2-meter VLT Antu,ESO

Thursday, October 5, 2017

Pluto's Bladed Terrain

Imaged during the New Horizons spacecraft flyby in July 2015, Pluto's bladed terrain is captured in this close-up of the distant world.The bizarre texture belongs to fields of skyscraper-sized, jagged landforms made almost entirely of methane ice, found at extreme altitudes near Pluto's equator. Casting dramatic shadows, the tall, knife-like ridges seem to have been formed by sublimation. By that process, condensed methane ice turns directly to methane gas without passing through a liquid phase during Pluto's warmer geological periods. On planet Earth, sublimation can also produce standing fields of knife-like ice sheets, found along the high plateau of the Andes mountain range. Known as penitentes, those bladed structures are made of water ice and at most a few meters tall.

New Horizons

Wednesday, October 4, 2017

95 Minutes Over Jupiter

This sequence of color-enhanced images shows how quickly the viewing geometry changes for NASA’s Juno spacecraft as it swoops by Jupiter. The images were obtained by JunoCam.

Once every 53 days, Juno swings close to Jupiter, speeding over its clouds. In just two hours, the spacecraft travels from a perch over Jupiter’s north pole through its closest approach (perijove), then passes over the south pole on its way back out. This sequence shows 11 color-enhanced images from Perijove 8 (Sept. 1, 2017) with the south pole on the left (11th image in the sequence) and the north pole on the right (first image in the sequence).

The first image on the right shows a half-lit globe of Jupiter, with the north pole approximately at the upper center of the image close to the terminator -- the dividing line between night and day. As the spacecraft gets closer to Jupiter, the horizon moves in and the range of visible latitudes shrinks. The second and third images in this sequence show the north polar region rotating away from the spacecraft's field of view while the first of Jupiter's lighter-colored bands comes into view. The fourth through the eighth images display a blue-colored vortex in the mid-southern latitudes near Points of Interest "Collision of Colours," "Sharp Edge," "Caltech, by Halka," and "Structure01." The Points of Interest are locations in Jupiter’s atmosphere that were identified and named by members of the general public. Additionally, a darker, dynamic band can be seen just south of the vortex. In the ninth and tenth images, the south polar region rotates into view. The final image on the left displays Jupiter's south pole in the center.

From the start of this sequence of images to the end, roughly 1 hour and 35 minutes elapsed.

JunoCam's raw images are available for the public to peruse and process into image products at:

www.missionjuno.swri.edu/junocam      

Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill

Larger view

Juno