Posts tagged planet

Posted 1 year ago

Earth at Twilight 
Image Credit: ISS Expedition 2 CrewGateway to Astronaut Photography of EarthNASA

Explanation: No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through the dusty troposphere, the lowest layer of the planet’s nurturing atmosphere. A clear high altitude layer, visible along the dayside’s upper edge,scatters blue sunlight and fades into the blackness of space. This picture actually is a single digital photograph taken in June of 2001 from the International Space Station orbiting at an altitude of 211 nautical miles.

Posted 1 year ago

CME, Comet and Planet Earth 
Image Credit: NRL / SECCHI / STEREO / NASA 
Processing - Karl Battams (NRL and @SungrazerComets)

Explanation: After appearing in a popular photo opportunity with a young crescent Moon near sunset, naked-eye Comet PanSTARRScontinues to rise in northern hemisphere skies. But this remarkable interplanetary perspective from March 13, finds the comet posing with our fair planet itself - as seen from the STEREO Behind spacecraft. Following in Earth’s orbit, the spacecraft is nearly opposite the Sun and looks back toward the comet and Earth, with the Sun just off the left side of the frame. At the left an enormous coronal mass ejection (CME) is erupting from a solar active region. Of course, CME, comet, and planet Earth are all at different distances from the spacecraft. (The comet is closest.) The processed digital image is the difference between two consecutive frames from the spacecraft’s SECCHI Heliospheric Imager, causing the strong shadowing effect for objects that move between frames. Objects that are too bright create the sharp vertical lines. The processing reveals complicated feather-like structures in Comet PanSTARRS’s extensive dust tail.

Posted 1 year ago

Grand Canyon Star Trails 
Image Credit & CopyrightBabak Tafreshi (TWAN)

Explanation: One of the natural wonders of planet Earth, the Grand Canyon in the American southwest stretches across this early evening skyscape. The digitally stacked sequence reveals the canyon’s layers of sedimentary rock in bright moonlight. Exposed sedimentary rock layers range in age from about 200 million to 2 billion years old, a window to history on a geological timescale. A recent study has found evidence that the canyon itself may have been carved by erosion as much as 70 million years ago. With the camera fixed to a tripod while Earth rotates, each star above carves a graceful arc through the night sky. The concentric arcs are centered on the north celestial pole, the extension of Earth’s rotation axis into space, presently near the bright star Polaris.

Posted 1 year ago

Miass River Sunrise 
Image Credit & CopyrightMarat Ahmetvaleev

Explanation: Each day on planet Earth can have a serene beginning at sunrise as the sky gently grows bright over a golden eastern horizon. This sunrise panorama seems to show such a moment on the winter morning of February 15. In the mist, a calm, mirror-like stretch of the Miass River flows through the foreground along a frosty landscape near Chelyabinsk, Russia. But the long cloud wafting through the blue sky above is the evolving persistent train of the Chelyabinsk Meteor. The vapor trail was left by the space rock that exploded over the city only 18 minutes earlier, causing extensive damage and injuring over 1,000 people. A well-documented event, the numerous webcam and dashcam video captures from the region soon contributed to a reconstruction of the meteor’s trajectory and an initial orbit determination.Preliminary findings indicate the parent meteoriod belonged to the Apollo class of Earth crossing asteroids.

Posted 1 year ago

Colors of Mercury 
Image Credit: NASA / JHU Applied Physics Lab / Carnegie Inst. Washington

Explanation: The colors of the solar system’s innermost planet are enhanced in this tantalizing view, based on global image data from the Mercury-orbiting MESSENGER spacecraft. Human eyes would not discern the clear color differences but they are real none the less, indicating distinct chemical, mineralogical, and physical regions across the cratered surface. Notable at the upper right, Mercury’s large, circular, tan colored feature known as the Caloris basin was created by an impacting comet or asteroid during the solar system’s early years. The ancient basin was subsequently flooded with lava from volcanic activity, analogous to the formation of the lunar maria. Color contrasts also make the light blue and white young crater rays, material blasted out by recent impacts, easy to follow as they extend across a darker blue, low reflectance terrain.

Posted 1 year ago

Snow Moon for a Snowy Planet 
Image Credit & CopyrightGöran Strand

Explanation: The alarmingly tall inhabitants of this small, snowy planet cast long shadows in bright moonlight. Of course, the snowy planet is actually planet Earth and the wide-angle mosaic, shown as a little planet projection, was recorded on February 25 during the long northern night of the Full Snow Moon. The second brightest celestial beacon is Jupiter, on the right above the little planet’s horizon. Lights near Östersund, Sweden glow along the horizon, surrounding the snow covered lake Storsjön. The photographer reports that the journey out onto the frozen lake by sled to capture the evocativeFull Snow Moon scene was accompanied by ice sounds, biting cold, and a moonlit mist.

Posted 1 year ago

Fly Me to the Moons 
Image Credit & Copyright: Greg Gibbs (Capturing the Night

Explanation: Sometimes the Moon is a busy direction. Last week, for example, our very Moon passed in front of the planet Jupiter. While capturing this unusual spectacle from New South WalesAustralia, a quick-thinking astrophotographer realized that a nearby plane might itself pass in front of the Moon, and so quickly reset his camera to take a continuous series of short duration shots. As hoped, for a brief instant, that airplane, the Moon, and Jupiter were all visible in a single exposure, which is shown above. But the project was not complete — a longer exposure was then taken to bring up three of the Jupiter’s own moons: Io, Calisto, and Europa (from left to right). Unfortunately, this triple spectacle soon disappeared. Less than a second later, the plane flew away from the Moon. A few seconds after that, the Moonmoved to cover all of Jupiter. A few minutes after that, Jupiter reappeared on the other side of the Moon, and even a few minutes after that the Moon moved completely away from Jupiter. Although hard to catch, planes cross in front of the Moon quite frequently, but the Moon won’t eclipse Jupiter again for another three years.

Posted 1 year ago

Mercury on the Horizon 
Image Credit & Copyright: Juan Carlos Casado

Explanation: Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth’s sky. If trailing the Sun,Mercury will be visible low on the horizon for only a short while after sunset. If leading the Sun, Mercury will be visible only shortly before sunrise. So at certain times of the year an informed skygazer with a little determination can usually pick Mercury out from a site with an unobscured horizon. Above, a lot of determination has been combined with a little digital manipulation to show Mercury’s successive positions during March of 2000. Each picture was taken from the same location in Spain when the Sun itself was 10 degrees below the horizon and superposed on the single most photogenic sunset. Currently, Mercury is visible in the western sky after sunset, but will disappear in the Sun’s glare after a few days.

Posted 1 year ago

Shadows Across Jupiter 
Image Credit & CopyrightDamian Peach

Explanation: Two dark shadows loom across the banded and mottled cloud tops of Jupiter in this sharp telescopic view. In fact, captured on January 3rd, about a month after the ruling gas giant appeared at opposition in planet Earth’s sky, the scene includes the shadow casters. Visible in remarkable detail at the left are the large Galilean moons Ganymede (top) and Io. With the two moon shadows still in transit, Jupiter’s rapid rotation has almost carried its famous Great Red Spot(GRS) around the planet’s limb from the right. The pale GRS was preceded by the smaller but similar hued Oval BA, dubbed Red Spot Jr., near top center. North is down in the inverted image.

Posted 1 year ago

ISS and the Summer Milky Way 
Image Credit & Copyright: Luis Argerich

Explanation: Clouds on a summer night frame this sea and skyscape, recorded earlier this month near Buenos Aires, Argentina. But planet Earth’s clouds are not the only clouds on the scene. Starry clouds and nebulae along the southern hemisphere’s summer Milky Way arc above the horizon, including the dark Coal Sack near the Southern Cross and the tantalizing pinkish glow of the Carina Nebula. Both the Large (top center) and Small Magellanic Clouds are also in view, small galaxies in their own right and satellites of the Milky Way up to 200,000 light-years distant. Alpha star of the Carina constellation and second brightest star in Earth’s night, Canopus shines above about 300 light-years away. Still glinting in sunlight at an altitude of 400 kilometers, the orbiting International Space Station traces a long streak through the single, 5 minute, star-tracking exposure.